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    Mining Engineering

    Encyclopedia Arctica 2b: Electrical and Mechanical Engineering

    Mining in Northern Climates

    Unpaginated      |      Vol_IIB-0162                                                                                                                  
    EA-I. (Howard G. Wilcox)




    Location of Mines 1
    General Mining Features 2
    Underground Mining 4
    Placer Mining 6
    Stripping 7
    Thawing 8
    Dredging 11
    Other Types of Placer Mining 12
    Bibliography 12

    001      |      Vol_IIB-0163                                                                                                                  
    EA-I. (Howard G. Wilcox)



            Location of Mines .

            Location of Mines . Mining in the Arctic and Subarctic will include practically all of

    the placer-mining operations in Alaska, and these mines account for 75%

    of the gold produced there. Tin, antimony, mercury, asbestos, jade, and

    coal are also produced in the northern part of Alaska.

            The important radium mines at Great Bear Lake, the large Flin Flon

    deposits containing copper, zinc, silver, and gold, the Yellowknife and

    other important gold properties of the western provinces, the Hollinger

    and other gold mines of Ontario and Quebec, the silver and cobalt mines

    of the same provinces, and the gold-lead deposits of northern Labrador are

    in the arctic or subarctic regions. The large iron ore reserves in north–

    eastern Quebec and Labrador will be under subarctic conditions.

            Most of Siberia is included in the A a rctic- S s ubarctic region.

    Industrial enters, metallurgical plants, and mines have been opened on

    a large scale on and near the Trans-Si l berian Railway at Novosibirsk and

    Irkutsk. In northeastern Siberia, gold was being mined in 66 districts

    in 1940. The Kolyma River basin is the most important district. A road

    extends north 400 miles from Magadan to Seimehan in the center of the

    gold fields.

    002      |      Vol_IIB-0164                                                                                                                  
    EA-I. Wilcox: Mining

            Ferrous mines have been opened in the eastern Ural Mountains, and

    coal from the Pechora coal field at Vorkuta is to be used to smelt iron

    ores from the Kola Peninsula.

            The Petsamo nickel deposits in Finland, the Kiruna iron deposits in

    northern Sweden, and iron, nickel, and coal deposits of Norway are all

    mined in arctic or subarctic districts.

            It will be noted from the geographic location of the mines listed

    that all are in the Northern Hemisphere, and that there is a wide difference

    in latitude between the deposits. The southern boundary of the permafrost

    area dips south of 50° N. latitude south of Hudson Bay in Canada, swings

    north of 60° N. latitude in Alaska, then dips south of 50° N. latitude in

    Siberia, and then goes north of 70° N. latitude in Sweden. Probably all

    of the area north of this boundary may be safely classified as A a rctic or

    S s ubarctic and there are additional a reas south of the permafrost boundary

    that may be classified as S s ubarctic.

            General Mining Features .

            General Mining Features . Mines that are developed in arctic or subarctic areas have permafrost

    or substantial seasonal frost to contend with. In some localities this

    may involve mainly constructing, insulating, and heating buildings to

    make them suitable as living quarters, offices, mine entries, or shops.

    i I n other localities the construction of dams, ditches, foundations of

    structures, and many phases of the mining operation may require special

    knowledge and planning.

    003      |      Vol_IIB-0165                                                                                                                  
    EA-I. Wilcox: Mining

            Due to lack of adequate transportation facilities, the first minerals

    mined are those that have high values compared to their weight, such as

    gold and platinum. Also, they are mined by methods that require the mini–

    mum amount of equipment. The adaptation of the airplane to arctic flying

    conditions has greatly facilitated prospecting and mining. Cargo planes

    are used for handling supplies and high-grade ores or concentrates, in

    some instances at lower costs than similar freighting by “cat train”.

    As the cheaper forms of transportation become available, the lower-grade

    deposits are mined, and smelters are built to treat the base-metal ores.

            Mining may be classified as underground and open pit, or surface

    mining. Placer mining is a specialized form of open-pit mining, in which

    the values in gold, platinum, tin, etc., generally occur in loosely or

    unconsolidated sand and gravel that under arctic conditions are usually

    frozen. All muck and gravel that is frozen is not tightly consolidated

    or held together by ice. The voids in the muck or gravel are not ice-filled

    on benches or ridges that were above the ground-water level at the time the

    ground was frozen. The term “dry frost” is often applied to frozen ground

    that is not consolidated by ice. Where this condition exists, the muck can

    be sluiced off practically as readily as unfrozen ground, and the gravels

    can be mined without being thawed. The first seven years the United States

    Smelting Refining and Mining Company operated the Cripple Creek dredge at

    Fairbanks it mined in dry frost ground.

    004      |      Vol_IIB-0166                                                                                                                  
    EA-I. Wilcox: Mining

            Placer deposits can be worked at a lower cost per yard or ton than

    underground mines; and the cost of equipping a placer mine is less than

    for an underground mine of similar size. Consequently, placer mining is

    generally the first type of mining initiated on the fringes of civilization.

    As roads, railroads, and airfields are constructed in the new placer-mining

    districts, development of gold lode mines and base metal mines follows.

    The mining of heavy-tonnage material like iron and coal requires relatively

    low-cost mining and transportation.

            The use of Eskimo labor has proved advantageous in the Seward Peninsula

    and Kobuk River districts in Alaska. The natives have been used as point

    drivers in the thawing operations, and some of them are good semiskilled

    workmen and are used as “cat” drivers, shovel operators, and winchmen on

    the dredges.

            The cost of mining is greater in arctic and subarctic regions, due to

    higher transportation rates, material and labor costs, mining or preparation

    costs, and in many places seasonal operations.

            Underground Mining . Underground mining may be carried on the year

    round if a continuous supply of water and fuel is available, properly

    insulated buildings are constructed, and surface plant and mining methods

    properly planned. Underground mining in a permafrost district does not

    involve unusual mining problems. Shattered frozen ground requires less

    support than thawed ground of similar nature. The supplying of water to

    the working faces may require special precautions, and the ventilation should

    be planned so the main working shaft will not be upcast, as ice will form

    near the collar and interfere with hoisting. Where permafrost is present

    the deeper workings are generally below that area.

    005      |      Vol_IIB-0167                                                                                                                  
    EA-I. Wilcox: Mining

            The disposal of camp sewerage or drain ing age water from the mine may

    require special consideration. Water that flows at a low velocity will

    “glacier.” The water freezes in one channel and then breaks out into a

    new channel. This process is repeated until a large area is covered with

    ice and may reach the camp area if provisions to prevent “glaciering”

    have not been made or the discharge carried to a safe distance.

            Small-scale gold lode mines are operated the year round in perma–

    frost near Fair w b anks, Alaska. Large-scale underground operations in

    arctic ground are conducted in northern Canada, Siberia, Finland, Sweden,

    and Norway. Underground and opencut coal mines are operated on a yearly

    basis in Alaska and other countries within the permafrost regions. Open–

    cut mining can be carried on, as far as mining operations are concerned,

    at any time of the year, but it may be uneconomical to mine when weather

    conditions are too severe during the coldest weather or when thawing

    occurs during the spring breakup. At the Alaskan opencut coal mines,

    stripping of the overburden is accomplished by hydraulic methods in the

    summer season, and stripped ground is mined at any time during the year.

    Coal can be mined more advantageously near high banks in the winter when

    the ground is frozen and no sloughing occurs.

    006      |      Vol_IIB-0168                                                                                                                  
    EA-I. Wilcox: Mining

            Placer Mining . Extensive placer-mining operations are carried on

    in Yukon Territory in northwestern Canada, central and western Alaska,

    and in northern and northeastern Siberia. Gold is the principal mineral

    mined, but minor amounts of platinum, tin, rutile, and jade are also

    recovered. Siberia at one time was the leading producer of platinum

    minerals. In Alaska, limited amounts of cassiterite and jade are being

    recovered from the Seward Peninsula and the Kobuk River areas.

            Most of the placer deposits in the Arctic were laid in the preglacial

    or Pleistocene era, and the principal placer-mining areas are in nonglaciated

    regions. Active glaciers were prevented from forming in the Dawson district

    in Canada, in the Yukon and Kuskokwim River basins in Alaska, and in northern

    and eastern Siberia, not because of warmer temperatures, but because of

    insufficient precipitation. Active glaciers in these regions would have

    scoured out the valleys, and the gold previously concentrated in the stream

    beds would now be disseminated throughout a vast quantity of glacial till

    and outwash. The gold content in streams in glaciated regions is generally

    too limited in extent or low in value to be minable. There are exceptions

    in instances where glacial outwash material has covered undisturbed preglacid

    deposits, as at Nyac in Alaska, and where there have been areas covered by

    ice that did not have enough force to erode all of the preglacial deposits

    as in the Sache Creek district in Alaska.

            The finding of mammoth, mastodon, saber-toothed tiger, and camel

    bones at or near the top of gravel is common. Some of the bones have

    marrow in them, and sinew, hide, flesh, and hair often cling to them.

    Animals lived in the ice-free areas during the early part of the glacial

    period, and their bones remain in the valleys in which they died, because

    there has been no glacial action to carry them away.

    007      |      Vol_IIB-0169                                                                                                                  
    EA-I. Wilcox: Mining

            Stripping . The placer gravel is covered by overburden that varies

    from a few feet to 200 or more feet in depth. This material is very fine

    and often contains considerable vegetable matter. The common term applied

    to it is muck, and it is removed in the preparatory state of a placer

    operation that is called stripping. Most of the muck is frozen and often

    contains ice lenses, and where there are considerable quantities to be

    removed hydraulic methods are employed. First moss and timber are removed

    by bulldozer or nozzle. Bulldozers can be used before the thaw has pene–

    trated too deeply. Nozzles are set up in the area to be stripped and are

    spaced so that the radius of the stream from one nozzle will meet the stream

    spaced so that the radius of the stream from one nozzle will meet the stream

    from the adjacent nozzle. Stripping is done in the summertime. The heat of

    the sun thaws about 4 in. of muck in the first 24 hours , 2 to 3 in. the

    second day, and progressively loss on succeeding days. One nozzlemen will

    take care of about 6 nozzles. He washes off the thawed fine material from

    the area in front of one nozzle, and then goes on to each succeeding nozzle

    to perform the same operation. About 2 in. of thawed much is swept away

    from each station every shift, and the sluicing is carried on 24 hours a

    day. The hydraulic water is generally brought in ditches that reach the

    stripping area 100 ft. or more vertically above the nozzles. The thawed

    material is carried off below the mining area in previously prepared drains

    that require a low gradient due to fine particle size of the suspended


    008      |      Vol_IIB-0170                                                                                                                  
    EA-I. Wilcox: Mining

            The amount of material that can be stripped by a unit of water is

    called the water duty. This is expressed as cubic yards removed per miner’s

    inch. In Alaska a miner’s inch is 1½ cu. ft. of water per minute. This

    amount of water flowing for 24 hours is one miner’s inch daily (MID). Ten

    to fifteen cubic yards of much removed in 24 hours by one miner’s inch

    would be within normal limits. A medium-sized ditch would carry 1,000

    miner’s inches; with a water duty of 15, the water available would strip

    15,000 cubic yards of much in 24 hours. The cost of stripping varies at

    different placer operations in Alaska. The cost, in 1949, is probably

    between 6 and 10 cents a cubic yard.

            Thawing . Most of the gravels in the Arctic or Subarctic are frozen,

    and when frozen must be thawed before they can be mined (Fig. 1). Various

    methods of thawing have been tried, but the cheapest method and the one that

    is used at most properties is cold-water thawing. Steam points are used in

    drift mining and in special cases for small patches of ground that are

    delaying dredging (Fig. 2).

            For ground of average depth, 10 to 30 ft., the thaw points are spaced

    on 16-ft. centers. For deeper ground the points may be spaced on 32-ft.

    centers and in shallower ground they may be on 8- or 12-ft. centers. The

    water is brought to the thaw field in 14- to 18- in. slip - joint hydraulic

    pipe. This is distributed by 8- to 12- in. flanged feeder pipe at 27½-ft.

    intervals; 6-in. slip-joint header pipe is laid across the thaw field.

    On long runs this 6-in. slip-joint header pipe is laid across the thaw field.

    On long runs this 6-in. slip-joint pipe is reduced to 4 in. on the outer

    end. One inch hose connections are tapped into the feeder pipe and a hose

    brings water under 10 to 15 lb. pressure, to a gooseneck at the top of the

    thaw pipe. A chisel bit with water outlets on both sides is attached to

    the bottom of the pipe.

    009      |      Vol_IIB-0171                                                                                                                  
    EA-I. Wilcox: Mining

            The water thaw begins around the pipe and progresses as a cone-shaped

    area, with the apex on bedrock, until the cones coalesce at the surface

    and the thawed area begins to assume the shape of a cylinder. The points

    remain in the ground until all the gravel is thawed (Fig. 3). The ground

    is tested by driving a steel bar to bedrock midway between thaw points.

    t T his is called probing. Then the area is thawed, the points are pulled,

    and a new thaw field is established.

            The thaw points had all been driven manually until the United States

    Smelting Refining and Mining Company developed at Fairbanks an electrically

    operated mechanical driving mechanism in 1946. The mechanical driver will

    eventually replace the manual driving where electricity is available.

            Points are driven mannually by sliding a weight (the hammer) up and

    down the pipe and striking a piece of metal that is clamped to the pipe

    (the anvil). One man may take czre of 50 points by attaching the anvil

    and hammer to each pipe in succession and driving the point to frost.

    It may take a few hours to make the complete circuit, and at each point,

    3 or 4 in. of gravel has thawed below the point before the driver returns.

    The point is driven through the thaw to the frozen ground; it cannot be

    economically driven into frozen material. An individual point is seldom

    driven more than 1 or 2 ft. in a day.

    010      |      Vol_IIB-0172                                                                                                                  
    EA-I. Wilcox: Mining

            The amount of thawing accomplished depends upon the amount and

    temperature of the water used. Each point requires 0.5 minter’s inch

    of water. The available heat in the water is the difference between the

    temperature of the water and 32°F. When thawing water is recirculated

    in the summertime or is taken from long ditches, the temperature may be

    50°F. or more at the time it enters the ground. When the water tempera–

    ture is 38°F. in the spring or fall, the temperature of the water return–

    ing to the surface may be 34°F. Then only 4 degrees of hest have been

    transferred to the gravel and thawing would be very slow. Four months is

    the maximum thawing season in interior Alaska. In 1949, thawing costs

    ar ranged from 6 to 12 cents a cubic yard.

            Under favorable conditions, which is shallow ground that is 10 to

    20 ft. deep and that has fairly open gravel free of sand lenses, natural

    thaw can be used. The overburden is stripped from the gravel three years

    before the ground is dredged, and in that time the gravel and the upper

    foot or two of bedrock will become thawed. Winter frost will penetrate

    5 to 7 ft. into the ground, but this ground will be thawed by about the

    middle of June. The only water thawing necessary where natural thaw has

    taken place is to thaw sufficient ground for dredging before the middle of

    June, at which time the winter frost will have disappeared.

    011      |      Vol_IIB-0173                                                                                                                  
    EA-I. Wilcox: Mining

            Dredging . The bucket-line floating dredge (Fig. 4) is a standardized

    piece of equipment and, where conditions are suitable for dredging, it

    recovers gold at the lowest cost of the same method of placer mining.

    General conditions in the Subarctic are similar, and there are the additional

    features of seasonal frost, insulating and heating the dredge, and

    thawing of ice from ladder, lines, etc. the dredging season for small

    dredges with limited water supply may extend from June 1 to October 15.

    The larger dredges in deeper ground and with sufficient water may operate

    8 months a year. Dredging of frozen ground is not attempted by any well–

    informed operator. The dredging mechanism will not stand the strain, and

    gold in frozen gravel passes through the boat and onto the tailings pile.

            Due to the short season, dredges are put in good operating condition

    before the season begins, and a large stock of parts is carried. A high

    percentage of operating time is essential when seasons are short. The

    financing of relatively large inventories, which must be bought a year

    ahead, and high freight rates substantially increase mining costs. Dredg–

    ing costs in Alaska for the smaller operator are figured at 20 cents a

    cubic yard, stripping costs at 10 cents, and thawing costs at 10 cents,

    a total of 40 cents a cubic yard. The cost for the large well-organized

    and financed operation is substantially below this figure.

    012      |      Vol_IIB-0174                                                                                                                  
    EA-I. Wilcox: Mining

            Other Types of Placer Mining . In the past 10 or 15 years many

    small mechanized placer operations employing 8 to 25 men have started

    mining in Alaska, and this type of operation is being adopted in Canada.

    Mechanized methods are used in small stream deposits, on the benches, or

    where bedrock gradient is too steep to dredge. Elevated sluice boxes

    are mounted on trestles that are built on skids and can be moved by

    tractors. Draglines are used to feed the gravel into a dump box at the

    head of the sluic d e and a bulldozer is used to keep the tailings pushed

    away from the discharge and. A bulldozer is also used to clean bedrock

    and shove the material to the dragline. Sluice boxes are also set in

    bedrock and, where water is limited, a tractor-mounted bulldozer pushes

    the gravel to the mouth of the sluice, and a nozzle, which is often supplied

    with recirculated water, washes it into the box. The tailings that accumu–

    late at the lower end of the box are removed by bulldozer, drag scraper,

    or dragling. These operations, in which modern dirt-moving practices

    are used in placer mining, have made possible the mining of numerous de–

    posits that would otherwise be unworked.


    1. Engineering and mining journal . N.Y. vol.1, 1866-

    2. Western miner . Vancouver, B.C. vol.1, 19 ? -

    3. Mining world , with which is combined Pacific chemical and metallurgical

    industries . Seattle, (etc.) vol.1, July, 1939-

    4. Muller, Siemon. Permafrost or Permanently Frozen Ground and Related

    Engineering Problems . Ann arbor, Mich., Edwards, 19 4 47 .

    5. Peele, Robert, ed. Mining Engineers’ Handbook . 3d ed. N + . Y + . , Wiley,

    1941. 2v.


    Howard G. Wilcox

    Prospecting and Exploration of Minerals in the Arctic and Subarctic Alaska

    Unpaginated      |      Vol_IIB-0175                                                                                                                  
    EA-I. (Robert S. Sanford)





    Introduction 1
    Geophysics 2
    Prospecting Methods 3
    Tracing Float 5
    Trenching 5
    Test Pits and Prospect Shafts 5
    Hydraulic Prospecting 6
    Booming 6
    Drivepipes 6
    Piercing or Probing 7
    Vegetation 7
    Burrowing Animals 7
    Boring 7
    Permafrost 13
    Transportation 15
    Coal Exploration 17
    Outfitting of Personnel 21
    Bibliography 23

    Unpaginated      |      Vol_IIB-0176                                                                                                                  
    EA-I. Sanford: Prospecting and Exploration of Minerals



    Fig. 1 Diagram to show tools and drilling operations of

    Hillman airplane placer drill
    Fig. 5 Construction details for canvas boat 17-a

    Unpaginated      |      Vol_IIB-0177                                                                                                                  
    EA-I. Sanford: Prospecting and Exploration of Minerals



            With the manuscript of this article, the author submitted 7

    photographs, Figures 2 through 4, 6 through 9, for possible use as

    illustrations. Because of the high cost of reproducing them as halftones

    in the printed volume, only a small proportion of the photographs sub–

    mitted by contributors to Volume I, Encyclopedia Arctica , can be used,

    at most one or two with each paper; in some cases none. The number and

    selection must be determined later by the publisher and editors of

    Encyclopedia Arctica . Meantime all photographs are being held at

    The Stefansson Library.

    001      |      Vol_IIB-0178                                                                                                                  
    EA-I. (Robert S. Sanford)






            The necessity for thoroughly prospecting a mineral deposit cannot be

    too strongly emphasized. Many failures in mining are due to a lack of

    careful prospecting or to incorrect interpretation of the results. The

    irregularity of gold distribution in Alaska alluvium makes careful pros–

    pecting necessary in order to trace the limits of the pay streak.

            Contrary to popular belief, the Arctic is not bleak and dangerous.

    True, the early explores, prospectors, and miners did suffer many hard–

    ships, but this was frequently due to inadequate knowledge and preparation.

    The work of Stefansson and others has proved that, with proper knowledge,

    adequate preparation, and suitable, well-chosen equipment, exploration can

    be conducted in the Arctic with a minimum of danger and hardship.

            In the Arctic, some phases of prospecting can be done at all times of

    the year. Winter is often the best season; in fact, many companies do most

    of their exploratory drilling from February to May, inclusive. Heavy drills

    can be readily moved across marshy areas without miring, and it is easy to

    drill a stream bed from ice. Likewise, test pitting can be done best during

    the winter, especially in wet deposits.

    002      |      Vol_IIB-0179                                                                                                                  
    EA-I. Sanford: Prospecting

            All of the tools and supplies of the prospector, the mining engineer,

    and the geologist can be used in the Arctic, and some can be used to better

    advantage in permafrost (permanently frozen ground). The more important

    of these are the pick, shovel, dynamite, gold pan, drivepipe, churn drill,

    core drill, hand drill, compressed-air drill, bulldozer, power shovel with

    trench-hoe attachment, dip needle, and geophysical instruments, including

    the Geiger counter.

            Ordinary prospecting, exploration, and development methods have been

    described in detail in mining literature and are discussed only briefly in

    this article. Arctic conditions have changed or modified certain of the

    methods, and these will be discussed in greater detail.

            Geophysics is the art of applying the physical sciences to the study

    of the structure and composition of that part of the earth that is suffi–

    ciently near the surface to be exploited by man (4,5,11). The earth’s

    surface has been fairly well prospected for outcrops of ore bodies,

    petroleum seepages, and gas bubbles on water. Many of the easily located

    deposits have been found and are being exploited. The increasing demand

    for metals and oil contributed to the development of geophysics. Geo–

    physical methods have been more successful in the exploration for oil than

    for metals (4). According to Jakosky (5), “During the entire life of the

    American petroleum industry an average of about 180.000 barrels of oil have

    been discovered for each dry hole drilled. During the past three years

    (1937-1940), with geophysical exploration as a guide in a large portion

    of the wells drilled, discovery of oil has been at the rate of about

    300,000 barrels for each dry hole.”

    003      |      Vol_IIB-0180                                                                                                                  
    EA-I. Sanford: Prospecting

            The most noteworthy recent advance in geophysical exploration has been

    the development and use of air-borne magnetometers. Four different types

    are either being used or are under construction. Two are modifications of

    the “magnetic air detector” developed by the Navy during the war to assist

    in locating submarines. Both have such sensitive pickup units that the

    pickup must be towed 100 to 200 ft. from the airplane to avoid the dis-turb–

    ing influence of the plane itself. Ground correlation is secured by means

    of terrain photography, using a continuous strip camera, or by radar


            Han e s Lundberg has built a helicop t er-borne magnetometer and is able

    fly close to the ground and secure greater detail than from a conventional


            The U.S. Geological Survey reports that during 1946 more than 50,000 sq.mi.

    was covered by aeromagnetic surveys, including surveys of Naval Petroleum

    Reserve No. 4 in arctic Alaska, the magnetic-iron region in New York State,

    and potential petroleum-producing areas in several states and offshore

    portions of the Gulf Coast.

            Aerial P p hotography is an invaluable aid in mapping, and such maps are

    useful to the prospector and engineer. It is sometimes possible to trace

    poorly exposed outcrops and faults on aerial photographs. (Since 1939, the

    U.S. Air Force and Navy have mapped the larger part of northern Alaska by

    aerial photography.)



            The search for minerals is guided by knowledge of geological associations.

    The presence of mineral outcrops warrants prospecting to determine whether

    shoots of commercial ore exist. The presence of float, (pieces of ore,

    minerals, or metals) also justify prospecting. Favorable geological associa–

    tions and characteristics must be studied carefully and an effort made so

    avoid useless work in unfavorable locations.

    004      |      Vol_IIB-0181                                                                                                                  
    EA-I. Sanford: Prospecting

            Placer deposits may be classified according to origin, as residual,

    sorted, and resorted. Brooks classifies Alaska placers, based on position

    and form, as follows (1):

            Creek placers: Ground deposits in beds and intermediate flood plains of

    small streams.

            Bench placers: Gravel deposits in ancient stream channels and flood plains

    which stand from 50 to several hundred feet above the present streams.

    Hillside placers: A group of gravel deposits intermediate between the

    creek and bench placers. Their bedrock is slightly above the creek bed,

    and the surface topography shows no indication of benching.

            River-bar placers: Placers on gravel flats in or adjacent to the beds

    of large streams.

            Gravel-plain placers: Placers found in the gravels of the coastal or

    other lowland plains.

            Sea-beach placers: Placers reconcentrated from the coastal-plain gravels

    by the waves along the seashore.

            Ancient beach placers: Deposits found on the coastal plain along a line

    of elevated beaches.

            Lake-bed placers: Placers accumulated in the beds of present or ancient

    lakes that were generally formed by landslides or glacial damming.

            Surface methods consist of tracing float ore by panning, trenching,

    and test pitting. Continuing the investigation of ore bodies at depth

    and search for minerals that do not outcrop are done by physical methods,

    such as boring, shaft sinking, or diving adit tunnels.

    005      |      Vol_IIB-0182                                                                                                                  
    EA-I. Sanford: Prospecting

            Tracing Float . Pieces of ore (float) are separated from the vein

    by erosion, work their way downhill into steams, and may be carried long

    distances. The prospector finds the float and tries to follow it back to

    its source. The placer miner’s gold pan is a valuable tool in this work.

            Trenching . After an ore occurrence has been found, its surface limits

    may be determined by trenching. The first trenches should be rather far

    apart; this generally reduces the number, length, and cost of intermediate

    trenches. On the other hand, trenches should be close enough to avoid

    missing ore shoots and to determine average width and value. After the

    direction of the strike of a narrow ore body has been determined by two

    cross trenches, it is often more satisfactory to trench along the strike.

            Trenches may be excavated by hand, but often it is cheaper to use a

    bulldozer or power shovel with a trench-hoe bucket. When permafrost is

    encountered, the Alaska prospector does not try to fight the frozen ground,

    but starts another trench and allows the sun to melt the frost in the first.

    By excavating several trenches in turn, fair progress can be made.

            Test pits and prospect shafts are used where the soil is too deep for

    trenching. For systematic exploration, the pits are located on corners of

    squares, or along lines across the pay streak of a placer deposit. The

    outfit for sinking in permafrost consists, at least, of a 4-hp. boiler,

    steampipe, hose, drive points, and windlass. Some miners thaw only a few

    feet at a time, as the pit is deepened. Other miners drive the pipe slowly,

    steaming the ground 30 to 45 minutes per foot of depth, and adding lengths

    of pipe as needed until the bedrock is reached. During the summer, water

    at natural temperatures can be used for thawing.

    006      |      Vol_IIB-0183                                                                                                                  
    EA-I. Sanford: Prospecting

            Test pits can be sunk in shallow ground by thawing with wood fires.

    As thawing is slow, several pits should be sunk simultaneously. Test

    pits can often be sunk in shallow, wet ground during the winter by

    “freezing down.” The pits are dug to water level and allowed to freeze.

    The frozen material at the bottom of the pit is removed until water is

    again reached, and the process repeated until bedrock is reached. This

    method is slow, but one miner can handle several pits, and it is generally

    cheaper than other methods of sinking through formations saturated with water.

            When thawing mercury-bearing ground, to avoid sal v i t v ation or mercury

    poisoning, adequate ventilation must be provided.

            Hydraulic Prospecting . Where water is available, during summer operations,

    hydraulicking is a great aid in stripping soil for close examination of bedrock.

    Sometimes a small stream can be diverted in a ditch along the hillside above

    the area to be prospected. A small pump and several hundred feet of canvas

    fire hose have been used to advantage in washing the soil off bedrock.

            Booming . In summer, when the water supply is limited, a reservoir can

    be excavated or a dam built. After the reservoir is full, the water, when

    suddenly released, rushes down the hillside and strips the surface soil.

    Booming is also used in placer mining. Automatic gates that open when the

    water reaches a certain depth are useful in booming.

            Drivepipes have limited use in soft soil or fine gravel free from

    large stones or boulders. Pipes are 1 to 3 in. in diameter. The perimeter

    of the bottom end of the pipe is filed to a cutting edge, and a slot of

    about 0.25 in. wide and 4 ft. long is cut in the pipe. The slot aids in

    gripping the soil and facilitates cleaning the pipe. The pipe may be

    churned down by hand or driven with a maul. The upper end of the pipe

    should be protected by a cap while driving. Short lengths of pipe are

    screwed on as the hole deepens. The pipe is pulled every foot or two and

    the contents examined.

    007      |      Vol_IIB-0184                                                                                                                  
    EA-I. Sanford: Prospecting

            Piercing or probing with pointed steel rods with a small slot or recess

    in the point is a method used in searching for minerals lying at shallow

    depths. The mineral or vein sought is either harder or softer than the sur–

    rounding material, or possesses a characteristic color which can be deter–

    mined by the probe.

            Vegetation often grows thickly along outcrops of one geological

    formation and sparsely on another. For example, the soil derived from

    weathered dunite is not fertile, and hence it is easy to trace the outcrop.

    Dunite is often the host rock for chromite ore.

            Burrowing animals often aid the prospector by the debris they throw

    out when digging holes.

            Boring for prospecting, exploration, and development is done with hand

    augers, core drills, and churn drills. The purpose is to locate mineral

    deposits covered by soil, rock, swamp or water; to determine their length

    and depth; and to search for parallel ore bodies. While the size and

    shape of an ore body are being determined, representative samples should be

    obtained so that an estimate of tonnage and grad s e can be calculated.

            Posthole augers have been used for sampling shallow tailing dumps and

    various types of unconsolidated mineral deposits. In 1942-43, Bureau of

    Mines engineers used hand augers , 3 in. in diameter, to sample large deposits

    of high-alumina clay (10). Three hundred and sixty holes were drilled,

    aggregating 14,938 ft; more than 50 of these holes were over 80 ft. deep.

    It is seldom feasible to drill so deep with hand augers, and only under

    exceptional conditions does an auger yield reliably accurate samples.

    It is most useful for preliminary testing of shallow deposits.

    008      |      Vol_IIB-0185                                                                                                                  
    EA-I. Sanford: Prospecting

            A core drill consists of the boring column and the surface power plant.

    Core drills are built in sizes from the small prospect drill with a drilling

    depth capacity of 100 feet, easily carried by two men, to large, diesel–

    powered machines that will drill to a depth of over 10,000 feet. The

    boring column consists of a bit set with diamonds that is rotated under

    pressure; the reaming shell, also set with diamonds, that maintains the

    size of the hole; the core barrel that hol e d s the core while drilling; and

    the drill rods in 5- and 10-ft. lengths. Power may be provided w e ither by

    gasoline, compressed air, steam, or diesel engine. The engine is coupled

    either to a differential-gear screw or to a hydraulic fee t d with bevel gear

    that rotates the boring column and feeds it ahead. A pump is required to

    circulate the drilling water that cools the bit and brings the cuttings or

    sludge to the surface.

            Core drilling has a number of advantages, as follows:

    • (1) In rock a complete cross-sectional sample of the formation pene–

      trated is obtained. The core can be split longitudinally, half sen d t for

      chemical analysis and half retained for a permanent record.
    • (2) Holes can be drilled at any angle: down, horizontal, or up.

            In cold climates the water pipelines must be protected against freezing,

    and it may be necessary to preheat the water. When drilling in permafrost,

    the rods must be kept in motion and the water circulating; otherwise, the

    hole will freeze and the rods, core barrel, and bit will be lost. Low–

    freezing cooling solutions to take the place of water have been used

    successively, but they require special recir c ulating equipment and the loss

    of liquid in porous or fissured ground is costly.

    009      |      Vol_IIB-0186                                                                                                                  
    EA-I. Sanford: Prospecting

            The objective of diamond core drilling is to recover samples to be used for

    chemical analysis, physical tests, or visual inspection (9). Unless the samples

    are reliable and the information systematically recorded, the time and money spent

    in securing them are largely wasted. The diamond-drill sample consists of two

    parts: the core (or cylinder of rock) cut out by the diamond bit, and the sludge

    (or cuttings) group up by the abrasive action of the diamonds. There is often

    excess sludge caused by the rubbing of core against core, or core against the core

    barrel, or by the erosive effect of the core barrel against the side of the hole

    and circulating water, or by caving from the upper part of the hole.

            If it were always possible to obtain complete recovery of core, the sludge

    sample would not be important. In a soft, broken formation, it is impossible to

    save 100 percent of the core. It is obvious that the importance of the sludge

    sample increases as the core recovery drops. A new core barrel has recently been

    developed, in which the inner tube is suspended by a ball-bearing coupling and

    does not rotate with the barrel. It is designed to minimize mechanical friction

    and water erosion of the core inside the bit and the inner tube. Thus, better

    core recovery is obtained.

            The portable churn drill consists of several tools, among which are drill

    bit, drill stem, jars and rope socket, and a gasoline, diesel, steam, or electric

    power plant. Hand-operated churn drills sometimes are used in low-wage areas for

    shallow holes, but seldom in the Arctic. The airplane-type churn drill is light,

    rugged, and extremely portable. It was originally designed for a placer prospecting

    drill, but has been used to explore completely many shallow softer ore deposits.

    009a      |      Vol_IIB-0187                                                                                                                  
    EA-I. Sanford: Prospecting

    (see Fig. 1). The drill is designed with a 4-in. casing, using 5 1/4-in. drive

    shoe, for drilling to a depth of 50 feet., or with a 5-in. casing and a 61/2-in.

    drive shoe to a depth of 35 ft. the weight of the drill, with a 3-hp. gasoline

    engine, is 1,600 lb. the drilling column weighs 300 to 400 lb. the drill can

    be easily disassembled and carried in a small airplane, or on a dogsled.

    009b      |      Vol_IIB-0188                                                                                                                  

    Figure 1.

    010      |      Vol_IIB-0189                                                                                                                  
    EA-I. Sanford: Prospecting

            The airplane drill with a 3-hp. gasoline engine costs $1,340 . ; the same

    drill with a 6-hp. gasoline engine costs $1,560. In addition, drill column,

    tools, tool-dressing outfit, casing, and miscellaneous equipment will cost

    about $700 . (1948 prices).

            Larger churn drills are available, suitable for all types of mounting,

    such as skid, wheel, trailer, truck, or caterpillar. Caterpillar-mounted

    churn dills will move rapidly over almost any ground. Certain caterpillar–

    mounted drills are designed for a ground pressure of only 3.2 pounds per

    square inch of track area. The ground pressure for a man is about 5 pounds

    per square inch, and this unit will travel where a man is unable to walk.

    A churn drill with rotary attachment is also available; it is able to churn

    down a hole through unconsolidated overburden. The rotary attachment can be

    swung into position and a core taken of the solid formation.

            A skid-mounted churn drill with a 30-ft. derrick costs $3,250. Mounted

    on a caterpillar crawler it costs $5,506. In addition, tools, casing and

    placer testing equipment will cost about $1,600 (1948 prices).

            Briefly, the drill is operated as follows. The drill is placed in the

    desired location, leveled, and the derrick raised. Great care must be

    exercised in assembling the tools to see that all joints are b t ight. A

    16-in. hole is dug. A drive shoe is threaded on one end of the casing and

    a drive head on the other. The pipe is placed in the hole and dirt packed

    around it. Tools are lowered, allowing the bit to enter the casing, and

    the drive clamps are bolted on the bit. The engine is started and the

    casing tapped into the ground. Lengths of casing are added as needed and

    driven to gravel or permafrost.

    011      |      Vol_IIB-0190                                                                                                                  
    EA-I. Sanford: Prospecting

            Water is poured into the casing, the drill started, and the rock chopped

    up. In testing placer ground, it is always customary to try to drive the

    casing ahead of drilling. Three or four inches of cuttings are always left

    in the casing to form a plug. When boulders are encountered, it is necessary

    to drill below the drive shoe. A rock bit should be used in place of the

    placer bit. The water level in the casing should be at least as high as the

    water plane in the ground to prevent minerals from being carried into the


            The drill column is washed as it is hoisted out of the hole to remove

    all mineral that may cling to the tools. The sand pump, with a sand line

    attached, is lowered into the hole. The suction-type sand pump must be

    raised rapidly to create a vacuum to suck in the sand, mud, and minerals.

    It is common practice to pump before and after diving. The height of

    cuttings in the casing is checked and recorded. The drive clamp is bolted

    on, and the operations are repeated. After the hole has been completed,

    the casing is pulled. The driv ing e head is removed from the casing. The

    knocking head is slipped over the puling jar, and the rop e socket is attached

    to the pulling jar that is lowered into casing. The knocking head is screwed

    on the top casing and the casing is jarred up.

    012      |      Vol_IIB-0191                                                                                                                  
    EA-I. Sanford: Prospecting

            To evaluate the churn-drill sample, the pump is hoisted out of the casing,

    and the contents are dumped into the mud box. The pump is washed inside and

    out to remove all minerals. Thomas describes the method of evaluation placer–

    tin samples at a Bureau of Mines project as follows (15):

            “The character of materials drilled and depth of each change in

    material were recorded. When practical, 2-foot samples were taken in

    barrel overburden and upper gravels, and 1-foot samples were collected

    in the tin and gold horizons. Each sample was deslimed, measure loose

    in a volume bucket, and panned. Concentrates from the panning of each

    sample were put in separate jars, labeled as to depth, number of hole,

    and line, and brought to a central point at the close of each shift.

            “Each individual sample was then panned, the gold extracted by

    amalgamation and weighed, and the concentrates tested for the presence

    of tin by the zinc method, examined with a hand lens, and weighed. The

    individual samples from one hole were then combined and labeled to form

    one sample of tin concentrates and one sample of gold.

            “All holes were drilled into bedrock for at least 2 feet, and some

    were drilled deeper, depending on the amount of heavy concentrate found.

            “Open holes were drilled in frozen ground. The procedure of

    sampling and recording the formations was that used in thawed ground,

    except that after completing the hole a volumetric water measurement

    was made to determine the size of the hole in the mineral-bearing horizon.

            “Each deslimed sample was measured to the nearest thousandth of

    a cubic foot. The percentage of solids in the mineral-bearing horizon was

    determined by using the sum of the total measured volumes loose and the

    volume of the hole as determined by the water measurement.”

            Later a composite of the tin concentrates was made and assayed for

    metallic tin.

    013      |      Vol_IIB-0192                                                                                                                  
    EA-I. San d ford: Prospecting



            Permanently frozen ground is widespread in the Arctic and Subarctic.

    The expression “permanently frozen ground” is cumbersome, and a shorter

    term, “permafrost,” is in general use as an alternative. Permafrost occurs

    in northern Asia, in most of Alaska, and in northern Canada. Nearly one-fifth

    of the land area of the lead area of the world is underlaid by permanently

    frozen ground. The southern limit of permafrost roughly coincides with the

    30°F. isotherm. Along the southern fringe, most of the ground is unfrozen

    but contains islands of permafrost. To the north, areas of permafrost will

    have islands of unfrozen ground. Continuous permafrost with prevailing

    ground temperature below 28°F. exists still farther north.

            The temperature of permafrost, at depths of 10 ft. or more, remains

    nearly constant summer and winter. Permafrost must not be confused with

    ground frozen by low winter temperatures or “seasonally frozen ground.”

            Stresses developed in permanently frozen ground may exceed 6,000 pounds

    per square inch, and it is not feasible to meet such stresses by structural

    design alone. It has been demonstrated that satisfactory results can be

    achieved if the dynamic stresses of frozen ground are analyzed and structures

    designed accordingly. A systematic and comprehensive study of frozen ground

    should be an integral part of the planning and design of all engineering

    projects in the Arctic.

            Permafrost is a handicap to hand trenching and bulldozer trenching.

    It does not interfere with diamond drilling, except that drill water must be

    kept circulating, and drill rods should never be left in the hole after the

    pump has stopped. Permafrost has made churn-drill exploration for placer gold,

    tin, and platinum very nearly an exact science.

    014      |      Vol_IIB-0193                                                                                                                  
    EA-I. Sanford: Prospecting

            Permafrost interferes, to a certain extent, with opencut mining and

    surface placer mining. Overburden must be thawed and stripped, and the

    gold-bearing gravel thawed before mining operations can begin.

            To balance these disadvantages, permafrost often may aid the miner.

    Livengood Placer, Inc., has constructed an earth dam with a permafrost core.

    Earth was sluiced into place during the summer and frozen solid the next winter.

    This operation was repeated for several years, adding to the height of the dam.

    A minimum of labor was required. Only the last lift of earth was placed with


            The U.S. Smelting, Refining, & Mining Co. has stabilized muck banks at

    a very steep angle by maintaining the permafrost in the muck. Pipes for cir–

    culating the freezing solutions are installed in drill holes. The freezing,

    at depths below the seasonal freeze, usually is done during the winter. The

    solution is pumped through a radiator and chilled by the air in the winter,

    and it is not necessary to use artificial refrigerat or ion except in the summer.

            The same company is dredging a pay streak along one side of wide

    Chatanika Valley. Permafrost has made this possible. Bedrock goes down

    steeper than the valley floor. To dredge bedrock, a very large, deep-digging

    dredge would have to be purchased, or the water level in the dredge pond

    could be lowered below the valley floor by pumping and thus permit digging

    bedrock with an available dredge, provided the inflow was not too great.

    The flow of the two streams that enter the valley was measured and the cost

    of pumping calculated. This was found to be economical because permafrost

    kept out seepage from the wide valley.

            Permafrost does not handicap underground mining operations in hard rock.

    All that is needed is to protect water pipelines against freezing and provide

    other cold-weather protection.

    015      |      Vol_IIB-0194                                                                                                                  
    EA-I. Sanford: Prospecting



            Except for increased costs, there have been few changes in ocean,

    rail, and river transportation during the past few years. In the Arctic

    and Subarctic, the caterpillar tractor and sled have taken the place of the an

    animal-drawn freight wagon and sled, and airplanes have become indispensable.

            Winter freighting with caterpillar tractors to all isolated communi–

    ties is common practice (Fig.2). A train of heavy-duty freight sleds with

    a “wanigan” or caboose to serve as living quarters for the crew is coupled

    to a tractor; and the cross-country trip, often of several hundred miles,

    is begun. Coal has been hauled 75 miles from the Meade River coal mine to

    Barrow, the most northerly village in North America. The trains usually

    operate night and day. In Canada, winter freighting with tractors has

    been used to build and supply sizeable mining towns in advance of railroad

    connections (Figs.3 and 4).

            Cross-country freighting during the summer is possible where the

    ground is not too marshy. Bureau of Mines parties have traveled hundreds

    of miles across virgin country during the summer. A bulldozer blade to

    clear the trail and a power winch to pull the tractor out of mud holes are

    essential for this kind of work. Fuel oil and supplies are hauled on a

    go-devil similar to a stone boat, or on an “Athey wagon,” which has

    crawler-type wheels.

            During the early days, the dogsled trip from Fairbanks to Nome, an

    airline distance of 600 miles, took 28 days and cost about $1,000. Today

    (1949) the same trip can be made by airplane in 4 hours at a cost of $75.

    016      |      Vol_IIB-0195                                                                                                                  
    EA-I. Sanford: Prospecting

            Nearly every village in northern Canada and Alaska has limited landing

    facilities - either a lake or river for float planes or a cleared landing

    strip for wheel planes. In winter, wheels and floats are exchanged for

    skis. Pilots prefer wheels or skis because the extra weight of floats

    cuts down the pay load.

            The speed with which large areas can be covered was illustrated by

    Bureau of Mines engineers in 1943, when an airplane equipped with floats

    was chartered, and all the rumored petroleum seepages on the arctic coast

    of Alaska were visited, sampled, and mapped during a 3-week trip. Five

    new areas containing seepages were found. The plane flew 8,000 miles and

    the charter cost $6,600.

            The prospector or engineer is often flown in by airplane, left to

    conduct the examinations, is subsequently flown out by plane, or must

    walk out. When necessary to return overland, considerable hardship and

    time can be saved by constructing a canvas boat on a spruce or willow frame

    and using it to navigate a river back to civilization. Two men, handy with

    an axe and hunting knife, can construct a boat in 10 hours.

            Norman Ebbley, Jr., formerly a Bureau of Mines engineer in Alaska,

    built several of these boats and is credited with the following directions.

    Material: 1 piece of medium-weight canvas 5 by 15 ft.; 300 feet of strong

    twine; 100 large carpet tacks; 2 dozen 12-penny nails; 18 miner’s candles;

    1 paint brush (2 in.); needle and thread for patching; and one quart of

    kerosene. If kerosene is not available, gasoline, light oil, or animal

    fat can be used.

    017      |      Vol_IIB-0196                                                                                                                  
    EA-I. Sanford: Prospecting

            Time and work will be saved if the poles are selected from a stand of

    small, straight jack-spruce or large willows hewed down until they are

    limber. The boat frame is constructed as shown in Figures 5, 6, 7, 8 and 9.

    The ribs may be single willows bent to shape, or they may be built up as

    shown. The main members are toenailed to the bow piece, and all joints

    are lashed solid with stout twine. After the frame is complete all parts

    that come in contact with the canvas must be rounded and smoothed. A lso,

    pieces of canvas should be tacked over the bow and joints to avoid chafing

    holes in the canvas covering.

            The canvas cover is stretched over the frame, folding at the corners

    and how rather than cutting, then tacked and laced to the top member only.

    The boat is then ready for waterproofing. A hot solution of 1 part can g d le

    grease and 2 parts kerosene or light oil is brushed on the canvas. A fter

    drying for a few minutes the boat is ready for use. A paddle is hewed from

    a dead tree and a long pole complete the job. The boat will weight about

    90 pounds and carry a 1,000-pound load.



            The following is an example of prospecting and mining problems

    encountered in the Arctic (14). There was an acute fuel shortage in

    Barrow during the winter of 1942-43 and again in 1934-44. For many years

    the Barrow Eskimos depended on driftwood, petroleum residue from Cape

    Simpson, and whale blubber for their fuel supply. In recent years the

    supply has not been adequate .

    017a      |      Vol_IIB-0197                                                                                                                  


    018      |      Vol_IIB-0198                                                                                                                  
    EA-I. Sanford: Prospecting

            The presence of coal deposits along the arctic coast has been known

    for many years. At various times a few tons of coal were mined by the

    Eskimos for local use, but no attempt was made to develop and mine the

    deposits systematically.

            Several beds of subbituminous coal outcrop along the banks of the

    Meade, Kuk, and Kugrua Rivers. After a brief preliminary examination,

    it was decided to mine one of the Meade River coal beds by open-cutting.

    The plan e s called for hydraulic stripping of the 25 feet of frozen sand

    overburden with water pumped from the river. Two used caterpillar tractors,

    several freight sleds, a diesel-powered pump, pipe, a hydraulic giant, and

    miscellaneous equipment were purchased and shipped to Barrow on the one

    supply ship that goes North each year. When the p ice pack moved south the

    steamship had to leave before all the equipment was unloaded.

            In the spring of 1944, the hydraulic equipment was set up and the

    overburden thawed and stripped from an opencut adjacent to the Meade River.

    The following difficulties were encountered: Even during the summer the

    river water is 40°F. and hence contains very little heat that can be

    utilized in thawing. The season is so short that the pump and hydraulic

    giant had to be operated continually in a small area to thaw and strip the

    overburden from the required tonnage of coal. Under these conditions

    this method was very inefficient. Nevertheless, stripping was completed

    and opencut mining started.

            In the interior of Alaska the overburden is thawed by the sun and a

    hydraulic giant used only to wash it away.

    019      |      Vol_IIB-0199                                                                                                                  
    EA-I. Sanford: Prospecting

            In the spring of 1944, the Bureau of Mines purchased the only

    available light prospect drill, and airplane-type churndrill, and had

    it flown to Meade River. Clean coal samples were not obtained from the

    churn drilling, as sloughing of loose sand and clay contaminated the

    material pumped from the coal-bearing strata, but it was possible to

    secure a fair idea of the character of the coal and to determine the

    elevation and thickness of the bed. Several trenches and 19 holes,

    ranging in depth up to 46 feet, were completed.

            The steamship that arrived in September 1944, was endanged by the

    ice pack and did not discharge the coal consigned to Barrow. As the open-

    cut mine was flooded, it became imperative to procure fuel immediately.

    The Bureau of Mines sank a 5- by 8-ft. prospect shaft and mined a few tons

    of coal to determine whether or not it was feasible to mine frozen coal

    with the inadequate equipment on hand. The airplane drill was set up over

    the shaft and used as a headframe and hoist.

            Underground coal mining presented the problem of supp o rting the ground,

    as there was no timber available. However, throughout northern Alaska

    shafts have been sunk 20 feet into the frozen ground and large rooms

    excavated for storing mea n t and ice. The underground cellars stand for

    many years with no timber support except at the collar of the shafts,

    where a watertight seal must be made and a door provided. The temperature

    in these cellars with the door closed is about 20°F. throughout the year.

    (See article on “Natural Cold Storage , ”) Thus frozen ground offered a

    possible solution. On August 29, 1944, when the air temperature was 42°F.

    the following drill-hole temperatures were recorded:

    020      |      Vol_IIB-0200                                                                                                                  
    EA-I. Sanford: Prospecting

    ( Ground temperature. °F. )
    Depth. ft. Drill hole 9 Drill hole 11
    5 38 32
    10 30 30
    15 26 25
    20 22 23
    25 20 20
    30 18 19 (in coal bed)
    35 18 30 19 (in coal bed)

            After these preliminary studies the Bureau of Mines recommended that

    experimental underground mining be started.

            Ed Burnell, foreman for the Alaska Native Service, continued to

    mine coal from the enlarged prospect shaft, using the same makeshift

    equipment. During the winter, 640 tons of coal was mined and 490 tons

    hauled to Barrow, a distance of 75 miles, with one tractor and sled.

    The fuel famine was alleviated.

            Hand-operated coal augers were used for drilling, and no difficulty

    was experienced in drilling the frozen coal. Blasting was done at the

    end of the shaft, and the mine was clear of smoke in about one hour. As

    a safety precaution, a second shaft was excavated. That winter all of

    the coal was mined from one large 60- by 65-ft. room. The roof was roof was

    frozen sand, and even though no timber supports were used there was no

    sign of roof failure.

            The advantages of underground mining are as follows: (1) it is

    independent of season and weather; (2) it is independent of summer

    thawing; and, (3) coal can be mined during the winter and loaded directly

    into the sleds.

    021      |      Vol_IIB-0201                                                                                                                  
    EA-I. Sanford: Prospecting



            Clothes used throughout central Alaska can be worn during the summer

    months along the arctic coast with the following additions: Heavy wool

    underwear and a cloth parka to serve as a windbreak, and shoepacks, or

    better yet, Eskimo-made waterproof boots. During the winter months it

    is advisable to wear Eskimo clothing, namely, fur inside against the

    skin and a second fur suit with the fur outside, fur socks, and boots.

    The late Charlie Brower told the author that the only time he suffered

    from frostbitten feet during the 60 years he spent in the Arctic was on

    the trip when he substituted woolen socks for fur socks. Any standard

    cold-weather sleeping bag is sufficient for summer use, but an Eskimo-made

    caribou bag is needed during the winter. A strong, well-built tent is

    needed as protection against rain, snow, and wind.

            Matches must be kept dry, and waterproof containers should, therefore,

    be used. Another excellent method is to dip the heads of ordinary kitchen

    matches, not the so-called safety match, in melted candle grease, or fill

    the match box with melted paraffin. These matches will keep dry indefinitely

    under very wet conditions.

            Many experienced prospectors and trappers in the Arctic carry short

    pieces of candles and call them their “life-savers.” When the wood is

    wet, the wind is blowing, and hands are stiff with cold, a short piece

    of candle placed at the base of the driest kindling available will help

    to start a fire with one match.

    022      |      Vol_IIB-0202                                                                                                                  
    EA-I. Sanford: Prospecting

            A first-aid ki g t should always be carried. During the spring, summer,

    and early fall the outfit should include mosquito repellent, head nets,

    and be t d nets. Fishline and hooks and an adequate gun should be carried

    for protection and to furnish meat in remote regions. Seven feet of the

    kind of wire used for hanging pictures can be used to make si z x rabbit snares.

            A 100- or 200-ft. coil of lightweight wire is often an aid in crossing

    swift streams. One member of the party acts as an anchor and, keeping a

    taut wire, another man walks or swims through the swift current to the

    other side, or the wire can be used to lash logs together to and make a

    temporary raft.

    023      |      Vol_IIB-0203                                                                                                                  
    EA-I. Sanford: Prospecting


    1. Brooks, A.H. “Outline of economic geology; the gold placers of parts of

    Seward Peninsula, Alaska,” U.S.Geol.Surv. Bull . 328. Wash.,D.C.,

    G.P.O., 1908, pp.114-45.

    2. Dobeny, L.C. “Placer valuation in Alaska and dredge screen testing,”

    Engng.Min.J . vol.142, no.12, p.47.

    3. Gardner, E.D., and Johnson, C.H. Placer Mining in the Western United States .

    Wash.,D.C., 1934-35. 3 pts. In l. U.S.Bur.Min. Inf.Circ . 6786-6788.

    4. Heiland, C.A. Geophysical Exploration . N.Y., Prentice-Hall, 1940.

    5. Jakosky, J.J. Exploration Geophysics . Los Angeles, Calif., Times-Mirror Press,


    6. Leach, Paul, Jr. “Uranium ore; how to go about finding and mining it,”

    Engng.Min.J . vol.149, no.9,pp.75-77, Sept., 1948.

    7. Leffingwell, E. de K. The Canning River Region, Northern Alaska . Wash.,

    D.C., G.P.O., 1919. U.S.Geol.Surv. Prof.Pap . 109.

    8. Lindgren, Waldemar. Mineral Deposits . 4th ed. Rev. N.Y., McGraw-Hill, 1933.

    9. Longyear, R.D. “Recovery and interpreting diamond-core drill samples,”

    Min. & Metall . May, 1937, pp.239-43.

    10. Lorain, S.H., and Mihelich, Miro. “Hand auger rapid, cheap to 140 ft. depth

    in clay,” Engng.Min.J . Sept., 1944, pp.78-80.

    11. Lundberg, Hand. “Mining geophysics. Progress reported from many countries —

    airborne m e a gnetometer outstanding new development,” Min. & Metall .

    Feb., 1947, vol.28, pp.91-95.

    12. Peele, Robert ed. Mining Engineers’ Handbook . 3d ed. N.Y., Wiley, 1941,


    13. Purington, C.W. Gravel and Placer Mining in Alaska . Wash.,D.C., G.P.O.,

    1905. U.S.Geol.Surv. Bull . 263.

    14. Sanford, R.S., and Pierce, H.C. Exploration of Coal Deposits of the Point

    Barrow and Wainwright Areas, Northern Alaska . Wash.,D.C., 1946. U.S.

    Bur.Min. Report of Investigations k 3934. Nov. 1946.

    15. Thomas, B.I., and Wright, W.S. Investigation of the Morelock Creek Tin

    Placer Deposits, Fort [ ?] Gibbon District, Alaska . Wash.,D.C.,

    U.S.Bureau of Mines, 1948. The Bureau. Report of Investigations

    4322. Aug. 1948.

    024      |      Vol_IIB-0204                                                                                                                  
    EA-I. Sanford: Prospecting

    16. Thurman, C.H. “Costs in dragline gold dredging,” Amer.Inst.Min.Metall.Engrs.

    Tech.Publ . July, 1945.

    17. Wimmler, Norman. Placer Mining Methods and Costs in Alaska . Wash.,D.C.,

    G.P.O., 1927. U.S. Bur.Min. Bull . 259.


    Robert S. Sanford

    Gold Dredging in Subarctic and Arctic America

    Unpaginated      |      Vol_IIB-0205                                                                                                                  
    EA-I. (Roy B. Earling)




            With the manuscript of this article, the author submitted 2

    photographs for possible use as illustrations. Because of the high

    cost of reproducing them as halftones in the printed volume, only a small

    proportion of the photographs submitted by contributors to Volume I,

    Encyclopedia Arctica , can be used, at most one or two with each paper;

    in some cases none. The number and selection must be determined later

    by the publisher and editors of Encyclopedia Arctica . Meantime all

    photographs are being held at The Stefansson Library.

    001      |      Vol_IIB-0206                                                                                                                  
    EA-I. (Roy B. Earling)



            The history of gold dredging in subarctic North America dates back

    to 1899 when a small dredge was built on the Snake River at Nome and one

    on the Lewes River in Yukon Territory.

            Large-scale dredging started in 1905, with the construction of a

    7 1/2-ft. dredge by the Canadian Klondike Mining Company, Ltd., at Dawson,

    followed, between 1906 and 1913, by the building of 9 dredges by the Yukon

    Gold Company and 3 more by the Canadian Klondike, all at Dawson. During

    this same period several small ones were built in the Iditarod, Circle,

    and Fairbanks districts in A laska and, by 1914, there were more than

    50 dredges operating in Alaska and Yukon Territory.

            The permanently frozen condition of the muck, gravel, and bedrock,

    so general in all these districts, was a serious obstacle during this period.

    The art of thawing frozen gravel with steam and hot water had been perfected

    by the earlier drift miners on a small scale but its application to the

    thawing of the large volumes and depths required for dredging proved

    difficult. The overburden of frozen barren muck, which in most places

    overlaid the pay streak, was an equally serious problem. The usual method

    of removing was ground sluicing, but the results were unsatisfactory where

    the much was deep, and the costs under all conditions high. There were,

    however, few areas outside of the Klondike rich enough to justify these rich

    enough to justify these high costs for thawing and muck removal, so most of

    the dredges built during this period were on thawed creeks or in thawed areas

    where no thawing or stripping was required.

    002      |      Vol_IIB-0207                                                                                                                  
    EA-I. Earling: Gold Dredging

            In 1918, the cold water thawing process for the thawing of frozen

    gravel was conceived and tried out by John Miles and others. This process

    eliminated the need for fuel as a source of heat, produced more uniform

    results, reduced the cost per cubic yard to a fraction of what it had been

    for steam thawing, and removed the depth limitations. It required, however,

    large quantities of water and brought with it other new problems such as the

    diving of the thaw pipes to bedrock, and the development of methods to

    determine the progress and completion of thawing. While these were being

    solved, experimental work was going on with improved methods for removing

    the muck overburden, and this was solved by the substitution of hydraulic

    methods for ground sluicing.

            The gradual development, in the succeeding years, of these new methods

    of thawing and stripping opened a new era for gold dredging and paved the

    way for the exploitation of many larger, deeper, and lower-grade deposits

    which had previously been regarded as undredgable, including the present

    large operations of the Yukon Consolidated Gold Corporation at Dawson, the

    United States Smelting Refining and Mining Company at Home and Fairbanks,

    and the MacRae-Patty interests in A laska and Yukon Territory.

            The operating conditions and practices at all of them are similar.

    Before a new property is acquired and put into operation, it is optioned and

    thoroughly examined and drilled to determine the available yardage and gold

    content, character of the gravel, character and conformation of bedrock,

    thickness of much, and other critical facts. If they are favorable, the

    option is exercised, the ground purchased or leased, and plans made for

    preparation of the ground and equipping of the property.

    003      |      Vol_IIB-0208                                                                                                                  
    EA-I. Earling: Gold Dredging

            If the deposit is overlaid by the usual heavy layer of muck, the

    first step is the construction of a ditch or pump station to supply water

    for hydraulicking. Such ditches range in length from 2 or 3 to 90 miles

    and deliver water at a pressure preferably over 60 pounds per square inch.

    The largest have a capacity of 5,000 or 6,000 miner’s inches or 125 to

    150 sec.-ft.

            The limits of the area to be dredged are then carefully staked out,

    the brush, trees, and moss are scraped off with bulldozers, and No. 2

    hydraulic giants or monitors are set up at intervals of 200 to 400 ft. in

    both directions so that, with the pressure available, the streams of water

    from them will reach all parts of the area. The giants are connected with

    the ditch or other source of water by large slip-joint pipelines. The muck

    overburden that has to be removed consists of fine silt of aeolian or

    water-borne origin, containing considerable amount of vegetable matter and

    moss but little or no gravel or coarse-size material. Where permanently

    frozen, as it is in most places, it contains large vertical seams of pure

    ice, frequently as much as 20 ft. in thickness.

    004      |      Vol_IIB-0209                                                                                                                  
    EA-I. Earling: Gold Dredging

            The stripping operation consists of operating the giants long enough

    to remove the accumulation of thawed material within reach down to perma–

    frost, which ordinarily takes 2 or 3 hours, then turning the water off and

    moving on to the next, and so on, until the areas around 10 or 11 giants

    have been cleaned up. This sequence ordinarily requires 24 hours, after

    which the operator returns to the first giant and repeats the process.

    Since the sun and exposure to the atmosphere cause the muck to thaw to a

    depth of about 4 inches each 24 hours, this means that the maximum downward

    progress of stripping in any given area is 4 in. per day, or about 40 ft.

    in the normal stripping season of 120 days, and if the muck is 100 ft.

    thick, its removal requires 2 1/2 seasons. The removal of large quantities

    of muck, therefore, requires the setting up of a large number of giants to

    cover very large areas.

            If the muck overburden is not permanently frozen, the rate of progress

    is not limited by the rate of sun thawing and, in that event, it is customary

    to set up fewer giants and operate them continuously with only such shutdowns

    as may be necessary for moving them.

    005      |      Vol_IIB-0210                                                                                                                  
    EA-I. Earling: Gold Dredging

            The material dislodge s d by the giants is washed away into drains

    having a minimum gradient of 0.2%, into the nearest stream or river where

    it is diluted and carried away without deposition. If the natural drain–

    age level is too high for gravity disposal of the muc h k -laden runoff water,

    it is sometimes elevated with a pump to the drainage level. This is only

    practical, however, where cheap electric power is available. The average

    duty of the water used in the giants is 20 to 30 cu.yd. per miner;s-inch-miner;s-inch- apostrophe delete underscore ✓

    dayday and the solid content of the runoff water at some operations average

    30% solids by weight for a full season’s operation. The prewar cost per

    cubic yard removed ranged from 2 to 6 cents. Experience has shown that

    the duties and costs for thawed muck are not materially different from

    those in frozen muck due to the larger solid matter content in the thawed


            The masimum thickness of muck now being removed is at the Gold Hill

    stripping operation near Fairbanks where 160 ft. of muck is being removed

    to expose 30 ft. of gravel, and large areas elsewhere in the same district

    have been stripped to a depth of 120 or 130 ft. To justify the removal of

    such great thicknesses, the underlying gravels must, of course, be

    relatively high grade and of considerable extent.

            In recent years the hydraulic stripping method described has been

    superseded in many places, particularly where the operation is small and

    the water supply is limited, by bulldozer stripping, either alone or

    in conjunction with ground sluicing.

    006      |      Vol_IIB-0211                                                                                                                  
    EA-I. Earling: Gold Dredging

            An interesting phenomenon connected with stripping in many districts

    is the occurrence in the frozen muck of well-preserved bones and the skeletal

    remains of extinc e t Pleistocene animals, such as the mammoth, mastodon, and

    super bison, dating back to the ice age.

            After the overburden has been removed, if the underlying gravel is

    g f rozen, the next step is the thawing of the gravel. This is accomplished,

    if the gravel is less than 50 ft. thick, with 3/4 - in. pipes called “thaw

    points,” driven vertically to bedrock on 12- or 16-ft. triangular centers.

    Water at atmospheric temperature is introduced into each point by means of

    a 16-ft. length of hose attached to a 4- or 6-in. header or supply pipes

    laid on the surface of the area to be thawed. These draw their water from

    gravity ditches or recirculating b pump stations. The temperature of the

    ingoing water ranges from 36° to 60° F., and in most localities averages

    between 45° to 50° F. for the season. Of the available heat in the water,

    i.e., the heat that would be released by cooling it to 32°F., not more

    than 40% is extracted and usefully employed in thawing the gravel, and

    frequently it is as low as 5%. The flow per point varies with the com–

    pactness and depth of the gravel and averages between 3 and 5 gal. per min.

    007      |      Vol_IIB-0212                                                                                                                  
    EA-I. Earling: Gold Dredging

            The driving of the thaw points is done manually or by machine, with

    additional 10-ft. lengths of pipe added as they go down. After the points

    have reached bedrock they are allowed to remain in the ground with the

    water escaping from the lower end and returning to surface. This thaws

    the ground around the points in the form of cylinders, which gradually

    grow in size until they have joined, and the ground is all thawed. The

    arrival at this stage is recognized by probing with solid bars. The length

    of time required for thawing with equipment of this kind varies from 5 to

    15 weeks, depending upon the depth and tightness of the ground and the

    spacing of the points.

            Where the gravel is over 50 ft. in depth, the driving of small points

    becomes impractical and they are set instead in drill holes drilled during

    the winter with Keystone or other types of churn drills. Because of the

    higher cost of putting in points this way, they are set farther apart,

    usually on 28- or 32-ft. centers and the pipe used is 1 1/4- or 1 1/2-in

    standard pipe. With this spacing the time required for thawing varies

    from 2 to 3 full thawing seasons, each starting in May and ending in

    September. The progress and completion of thawing are followed and

    recognized by setting temperature pipes to bedrock at regularly spaced

    intervals at the time of drilling, and backfilling them and allowing them

    to freeze back. After the thawing has commenced, temperature readings

    are taken in these pipes at regular time and depth intervals by means of

    electric resistance thermometers. With these procedures and methods,

    ground as deep as 130 ft. is now being thawed at Nome and Fairbanks and

    this could probably be increased to 150 ft. or more if the occasion arose.

    008      |      Vol_IIB-0213                                                                                                                  
    EA-I. Earling: Gold Dredging

            The cost of cold water thawing is largely independent of the depth

    of the ground thawed and averaged before the war from 4 to 8 cents per

    cubic yard with the water duty from 5 to 10 cu.yd. per miner’s-inch-day.

            Gravels over 15 ft. deep, which have been artificially thawed, seldom

    show any tendency to freeze back after they have been completely thawed

    and it is considered good practice at most operations where the depth

    of the ground exceeds that figure to carry the thawing a year and a half

    or two years ahead of the dredging. This improves the conditions of the

    ground by allowing small frost remnants to disappear, saves water by

    making it unnecessary to carry the thawing to 100% completion, and pro–

    vides a reserve of prepared ground for the dredge in case of an accident

    or a poor water season. Thawed ground, allowed to stand over in this

    way from one season to the next, freezes each winter, of course, to a depth

    of 3 or 4 ft. but the frozen crust thaws out early the following spring and

    disappears completely by May.

            For shallow frozen gravel less than 15 or 20 ft. in depth, artificial

    thawing is frequently unnecessary if the moss or muck can be removed

    several years ahead of the dredging to allow the sun to warm the surface

    and if there is enough gradient and drainage to produce a free circulation

    of underground water. Increased attention is being given to this method

    because it eliminates the artificial thawing cost. It is ordinarily

    impractical, however, in gravels over 20 ft. deep or in poorly drained


    009      |      Vol_IIB-0214                                                                                                                  
    EA-I. Earling: Gold Dredging

            After the gravel has been stripped and thawed, either artificially

    or naturally, it is sometimes necessary or more economical to remove a

    portion of the upper part of the gravel, either because the total thick–

    ness of the gravel is greater than the dredge can handle, or because it

    contain ed s insufficient gold to justify putting it through the dredge. This

    is usually done in small operations with a bulldozer. Where the yardage to

    be removed is large, more satisfactory results and lower costs are obtained

    with carryall-type scarpers or draglines, either with or without belt con–

    veyers. The largest operation of this kind in the North is at Cripple

    Creek near Fairbanks where a 12-cu.yd. dragline and conveyer are being used

    to remove 50 ft. of barren top gravel. The maximum capacity of the system

    is 12,000 cu.yd. per 24-hour day or 3,000,000 cu.ft. per season.

            The dredges now operating in Alaska and Yukon Territory vary in size

    from 2 1/2 cu.ft. to 16 c.ft. capacity. With the exception of two of the

    Yukon Gold dredges built in 1908-1909, all of g t hese built before 1925 had

    wooden hulls. Most of those built since then have steel hulls either of

    conventional or pont e o on type, the tendency in recent years being strongly

    toward pontoon construction. The disadvantages of the wooden hull, which

    have led to its abandonment in most places, are the tendency to leak badly

    after they get old, particularly around the spuds; the danger that a plank

    may be pulled off by the ice during the winter; and the greater fire hazard.

    010      |      Vol_IIB-0215                                                                                                                  
    EA-I. Earling: Gold Dredging

            The importance of this last item is indicated by the fact that in

    several cases in the past when new dredge operations were being planned,

    it was found that the saving in insurance premiums alon d e during the expected

    life of the dredge would pay for the difference in cost. Experience has

    shown that the digging machinery on dredges designed for the North must be

    sturdy because of the severe conditions encountered. The actual wear on

    the buckets and lips does not appear, however, to be any heavier than else–

    where because the bedrock in most localities is comparatively soft and the

    frozen gravel, after it is artificially thawed, is usually less compact

    than naturally thawed gravels, which have had an opportunity to settle and

    pack thoroughly.

            The power used on most of the dredges is either diesel or electric.

    On the small dredges the diesel units are usually mounted on board, in which

    case the drive may be either direct or diesel electric, the latter being

    preferred because of the greater flexibility. For the larger dredges at

    Fairbanks, Nome, and Dawson, power is generated at a central plant and

    transmitted to the dredges via high-tension power p l ines and taken aboard

    through rubber-covered power cables.

    011      |      Vol_IIB-0216                                                                                                                  
    EA-I. Earling: Gold Dredging

            The central power plant at Dawson, which supplies the 9 dredges of

    the Yukon Consolidated Gold Corporation, is a hydroelectric plant located

    on the north Fork of the Klondike River. Notwithstanding the low tempera–

    tures prevailing at Dawson in the winter, this plant operates both summer

    and winter with only slight periods of power shortage in the spring and

    fall when the ice in the power ditch is forming and breaking up. The

    central power plant at Fairbanks, which supplies the 8 dredges of the

    U - . S - . Smelting, Refining & Mining Co., is a steam turbine plant with steam

    made from lignite coal from the Healy River district, 120 miles from Fairbanks.

    The power plant at Nome, which supplies the 4 dredges of the U.S. Smelting,

    Refining & Mining Co. there, is a diesel-electric plant using diesel oil

    shipped in by tanker.

            For gold recovery equipment, most of the dredges have revolving

    screens, and tables with Hungarian riffles, which are usually followed

    or preceded by short sections of coco matting and expanded metal. The only

    dredge with jigs is Cripple Creek No. 10, near Fairbanks, and in that in–

    stance they are followed by a large table area with Hungarian riffles. At

    Dawson only a few Hungarian riffles are now used and all of the gold is

    recovered in its natural form on coco matting and expanded metal without

    the use of mercury.

    012      |      Vol_IIB-0217                                                                                                                  
    EA-I. Earling: Gold Dredging

            In all of the dredging districts in Alaska and the Yukon the climatic

    conditions are an important factor, limiting as they do the length of the

    season. The smaller dredges, particularly those operating on creeks where

    the water supply dries up during the winter, are limited to a 120- to

    150-day season. The larger dredges, because of their greater ability to

    buck freezing conditions and the fact that they are usually working in

    deeper ponds, are able to get considerably longer seasons and if an expen–

    diture is made for removing the ice from the pond in the spring and steam

    thawing the surface crust of winter frost, the season can be stretched to

    an average of 250 or 255 days per year as is regularly done at Fairbanks.

    In order to get this length of season it is necessary to start repairs,

    ice removal, and steam bank thawing the latter part of February, and the

    dredges ordinarily get started during the last week in March, after which

    the steam thawing is usually continued for several more weeks. In the fall,

    if the dredges are equipped with sufficient steam boiler capacity, they can

    continue to operate with temperatures as low as −30°F., but 3 or 4 successive

    days colder than −20°F. usually forces a shutdown. This results from the

    fact that as the dredge swings back and forth in a pond where heavy ice is

    forming, it piles the cakes on top of each other and eventually builds them

    up to such a thickness that the dredge can no longer get into the corners of

    the pond. The ice also builds up on the hull stacker, digging ladder, and

    in the buckets, and decreases the freeboard. It can be removed with steam

    and hot-water jets, and one of the large Canadian Klondike dredges at Dawson

    ran all winter, in 1915, with temperatures down to −50°F., but the expense

    of operating under such conditions proved excessive and the experiment was

    not repeated.

    013      |      Vol_IIB-0218                                                                                                                  
    EA-I. Earling: Gold Dredging

            The procedure during the winter shutdown varies with water conditions,

    depth of ground, and type of dredge. Many of the small dredges are set on

    benches during the winter but a most of the large ones are allowed to float

    and freeze in. There was some doubt about the effect of this on pontoon

    hulls when they were first introduced, but no damage has been reported,

    and it is now common practice to let them float during the winter. After

    the dredges have shut down, the crews are usually kept on for several weeks,

    making repairs that have accumulated during the previous season and removing

    parts that have to be sent to the shop for rebuilding or repairing during

    the winter.

            The removal of ice from the ponds in the spring is accomplished by

    rigging up a cable from the rear gantry to a deadman on the shore and

    hoisting the ice out with a trolley and jitney line. The ice is cut into

    blocks approximately 4 ft. square for this purpose with steam ice cutters

    of special design. The thawing of the winter crust of frost ahead of the

    dredge is done with short hand-driven steam points using steam from a

    portable 60- to 85- hp. boiler located on the shore.

            All of the dredges now operating in Alaska are continuous bucket-line

    dredges. A Becker-Hopkins single bucket dredge was tried out a number of

    years ago near Talkeetna without success. No dragline dredges have been

    tried in the north country up to 1949, the preference seeming to be for a

    combination of dragline and movable washing plant on skids or caterpillar

    tracks. These have the advantage that the bedrock can be kept drained and

    visible while it is being cleaned, and there are many successful operations

    of this kind in Alaska at the present time.

            2 last paragraphs of original are missing, (cf. original p.6, bottom), Insert !

            [ ?]


    Roy B. Earling

    014      |      Vol_IIB-0219                                                                                                                  
    EA-I. Earling: Gold Dredging

            The great length of time required to strip and thaw frozen ground for

    dredging (4 to 5 years) and the fact that these 2 steps represent approxi–

    mately two-thirds of the total cost, makes it necessary, where frozen ground

    is to be worked, to prospect the ground much more thoroughly before work is

    started than would otherwise be required. It also means that usually more

    initial financing is required and the failures to appreciate this has

    probably been the cause of more disastrous dredge failure than any other

    factor except low values.

            The outlook for gold dredging in Alaska is dependent to a large extent

    upon economic conditions. The districts that were best known and most pro–

    ductive during the early day drift-mining era are all being dredged at the

    present time, and another 20 years will probably see most of them worked out.

    Undoubtedly other lower-grade deposits will be found, but the extent to which

    they can be worked will depend to a large extent upon the future cost trends

    and gold price.


    Roy B. Earling

    Construction for Placer-Mining Operations

    Unpaginated      |      Vol_IIB-0220                                                                                                                  
    EA-I. ( G George . W. Rathjens)




    Fig. 1 Vertical Section illustrating some of the conditions

    which may be found in a permafrost area
    Fig. 17 Pier illustrating the use of “ice butter” 11-a
    Fig. 22 Mat foundation on tundra 13-a

    Unpaginated      |      Vol_IIB-0221                                                                                                                  
    EA-I. Rathjens: Construction for Placer-Mining Operations



            With the manuscript of this article, the author submitted 21

    photographs for possible use as illustrations. Because of the high

    cost of reproducing them as halftones in the printed volume, only a small

    proportion of the photographs submitted by contributors to Volume I,

    Encyclopedia Arctica , can be used, at most one or two with each paper;

    in some cases none. The number and selection must be determined later

    by the publisher and editors of Encyclopedia Arctica . Meantime all

    photographs are being held at The Stefansson Library.

    001      |      Vol_IIB-0222                                                                                                                  
    EA-I. ( Colonel G. George W. Rathjens)



            Construction for placer-mining operations in the Arctic includes

    much that is common to all types of construction problems. Therefore,

    much to be discussed here concerning placer-mining operations will also

    be applicable to other construction problems arising to in the arctic and

    subarctic regions.

            Usually construction problems in the Arctic or Subarctic require

    methods, designs, and materials that are different from those used in more

    temperate zones. The key to success in dealing with problems in arctic

    regions is cooperation with nature. This cannot be emphasized too strongly.

    Nowhere in the world is such c ooperation so important. The thermal conditions

    and subsurface relationships of an area should not be materially disturbed

    and if the work in the area causes or requires disturbing such relationships,

    provisions should be made for reestablishing them.

            This section will be particularly concerned only with these and other

    problems that are peculiar to the arctic and subarctic regions. The problem

    here is to indicate how these factors may be properly evaluated in designing,

    developing, or operating a facility in the Arctic.

            Permanently frozen subsurface material, called “permafrost,” is common

    throughout northern North America and northern Asia. Altogether about one–

    fifth of the land area of the world is underlain by permafrost. In many

    permafrost regions where ground water is present, such water and its

    migration are very important factors.

    002      |      Vol_IIB-0223                                                                                                                  
    EA-I. Rathjens: Placer Mining

            The movement of ground water must not only be evaluated as ground

    waters are in more temperate zones, but here consideration must be given

    to the fact that these waters are conveyers of heat units, which materially

    affect their migration; furthermore, always present in varying degrees, is

    the effect of these waters when sufficient heat units have been abstracted

    to change their state to ice.

            Fig 1 Using Figure 1 as an illustration, the zone A , usually a moss, is

    the insulating cover over the frozen muck, B , and the gravel, C . The depth

    of seasonal freeze in zone A will vary with the following: ( 1 ) character

    of the material comprising this zone and the compaction of these materials;

    ( 2 ) amount and temperature of ground water moving within this zone; and

    ( 3 ) temperatures to which the surface of this zone is exposed. A good snow

    cover will modify the effects of such exposure to the winter cold. (See

    “Power Plant Development and Electric Transmission and Distribution Systems,”

    Fig. 27.)

            The muck is permanently frozen and consists of fine materials deposited

    by wind or water. Where this muc h k has been deposited from water, varying

    amounts of ice may be present. The water content, in terms of ice, in such

    muck, varies from a few percent to almost clear ice. In some instances

    2 lenses of clear ice occur in the muck (Fig.2.) Bands of volcanic ash may

    occur in wind-blown deposits. The temperature of all or only portions of

    the bedrock may be 0°C. or less.

    002a      |      Vol_IIB-0224                                                                                                                  

    Fig. 1 - Vertical Section illustrating some of the conditions

    which may be found in a permafrost area.

    003      |      Vol_IIB-0225                                                                                                                  
    EA-I. Rathjens: Placer Mining

            g 3 Water from glaciers (see Fig.3) and water from rain, melting snow,

    and ice on its way to the river, D , moves over the surface a and a ' (Fig.1).

    During this movement the water is exposed to the sun, absorbing some heat.

    Portions of this water may enter the insulation cover A slowly moving

    toward lower elevations. Usually such waters move most freely in the

    lower portion of the insulating cover and on the contact between it and

    the bedrock; on the contact between A and the gravels C , if they are frozen;

    and on the contact between A and the frozen muc h k B . The water may move

    through the gravel s C where they are thawed; it also may move on the contact

    between frozen gravel and the bedrock.

            The sands and gravels may be permanently frozen or only partially

    frozen and when partially frozen may contain kidneys of permafrost. The

    power plant of the Fairbanks Exploration Company is built on such a kidney.

            Frequently, gravel and small pieces of fractured bedrock will be found

    at the contact between the cover and the underlying bedrock, as at b (Fig.1).

    As the water moves along such contacts and through the lower portions of the

    cover, a portion of the water may find its way not only into the thawed

    gravels and sands, but also into the joints and pervious planes in the

    bedrock. Here it may lose some of its heat; in other cases additional heat

    may be taken up by the water.

            The movement of ground water in permafrost areas ha v s e established

    a temperature equilibrium which should not be disturbed if practicable.

    Should it become necessary to disturb such equilibrium locally, it is

    recommended that provision be made to reestablish same.

    004      |      Vol_IIB-0226                                                                                                                  
    EA-I. Rathjens: Placer Mining

            During each year a portion of the cover will freeze and restrict

    the movement of ground water in the area to the winter or seasonal move–

    ment through ( 1 ) thawed gravels in the area, ( 2 ) joints and planes in

    the bedrock, ( 3 ) the unfrozen lower portion of the cover, and ( 4 ) along

    the contact zone between the cover and the underlying materials.

            Should a construction project cause any change in established

    water channels, an adjustment should be made. For example, should a

    building or a road be constructed on the moss covering, A , immediately

    over b (Fig.1), such loading might cause greater compaction in A A at this

    g 22 location or change the limit of seasonal freeze. (See also Fig.22.)

    Where greater compaction results, the movement of water is restricted

    and such restriction may result in the development of a greater hydro–

    static head on the frozen cover above the restriction. Such heads fre–

    quently become so great that they cause a rupture at a weak spot in the

    confining frozen cover with the result that water spills out of over the surface

    and, because it is then exposed to the cold, it quickly freezes into ice.

    As the ground water now finds its way to the surface through the rupture

    in the cover, successive layers of ice are built. The writer has seen this

    happen at the foundations of camp buildings with the result that the build–

    ings were wrecked. This may happen on the upstream side of a road so that

    the road becomes covered with successive layers of ice, making travel


    005      |      Vol_IIB-0227                                                                                                                  
    EA-I. Rathjens: Placer Mining

            Ice blisters also result from hydrostatic pressure from ground water;

    the pressure increase slowly, sometimes resulting in the fracture of the

    blister, and the subsurface water then finds its way to the surface through

    cracks similar to A .

            A study made by the writer during the winter of 1925-26 to determine

    the practicability of storing water in the form of ice developed the fact

    that in certain selected valleys, when compaction of the moss was accom–

    plished after an early freeze-up and before the fall of much snow, ice

    fields of considerable thickness could be developed. In some cases skiing

    over certain portions of the moss caused sufficient compaction to start

    the formation of ice from ground water. This experience is mentioned to

    illustrate the fact that comparatively slight compaction, under critical

    conditions, may be sufficient to start the formation of winter ice from

    ground water, which formation may continue to build in successive layers

    during the entire winter and late into the spring.

    006      |      Vol_IIB-0228                                                                                                                  
    EA-I. Rathjens: Placer Mining

            In 1926, the writer built a number of siphons in a permafrost area,

    one of which consisted of a 6 - 0 -in. pipe designed to operate under a head

    of approximately 300 ft. The valley was U-shaped and the pipe was carried

    across the floor of the valley on pile-bent structures so that the pipe

    where it crossed the lower portion of the valley was 10 to 12 ft. above

    the moss. During the first winter sufficient ice filled the valley to lift

    the pipe off its support, causing appreciable damage. During the next

    summer provision was made to reestablish, as nearly as practical, the

    original drainage and arrange for a point of weakness where the formation

    of ice from the f g round water would cause no damage. This work was done in

    1927, and the siphon has operated satisfactorily for twenty years with no

    reoccurrence of excessive ice formations in the valley in the vicinity of the


            There are present, in some frozen gravels in the Arctic, the spores

    of crenothrix and similar bacteria. Any change in the thermal balance of

    the zone in which these spores are present may result in the development

    of the organism and cause a change in the permeability of the sands and


            Where thawed sands and gravels occur in permafrost areas, they are

    those that most readily permit the movement of ground water. The frozen

    portions consist of the tighter and therefore less permeable sands and


    007      |      Vol_IIB-0229                                                                                                                  
    EA-I. Rathjens: Placer Mining

            It is important in most construction problems to determine whether

    the frozen portions are in close or open packing, whether the material

    is “dry frozen” or whether the interstices between the sand and gravel

    particles are wholly filled with ice. If the mass is “dry frost,” then

    usually the material is in close packing and will, when locally thawed,

    result in practically no subsidence. If not dry frozen, subsidence in

    varying degrees may be expected when and if the sands and gravels are

    thawed. When thawed, these usually act as good insulators and can be

    used to assist in maintaining temperature stability.

            For example, in the area where the Fairbanks power plant is

    located, there is a very definite movement of ground water, as evidenced

    by the hydraulic gradient maintained by this ground water. Where this

    ground - water movement takes place, there are a number of frozen kidneys

    of sand and gravel, one of which was selected as the site for the power

    plant. Drilling and studies indicated that, although the kidney was

    surrounded by a relatively large amount of moving ground water, the

    kidney itself was dry frost. Therefore, an area one hundred feet greater

    in each dimension tha t n the size of the power plant was thawed to a depth

    of approximately 30 feet greater than the depth of the concrete foundation.

    Steam from locomotives was used for this thawing. The power plant, a

    reinforced - concrete and steel structure, was built with its foundations

    in this “pocket” of thawed sand and gravel. Wells for measuring tempera–

    tures in the sands and gravels were put down at all four corners of the

    building. The power plant has been in operation since 1928 and, to date,

    there has been no evidence of settling (although in an earthquake area)

    and no indication of “back-freezing.”

    008      |      Vol_IIB-0230                                                                                                                  
    EA-I. Rathjens: Placer Mining

            Large California-type wells, varying in depth from 150 to 360 ft.,

    were put down, upstream from the power plant, to furnish water for cool–

    ing condensers and other purposes. Perforations were made in the wells

    at elevations where the gravel strata were relatively open and indicated

    a source of good water. Approximately 9,000 gallons per minute were

    pumped from the subsurface flow. Studies made for twenty years indicate

    that the over-all temperature balance has not been materially disturbed.

            Whenever sands or gravels are thawed, either by steam or cold water,

    they should be carefully studie s d as to size, relationship of various sizes,

    materials in the interstices, and packing, to determine the probable effect

    of the thawing, taking into consideration that these gravels after being

    thawed may be subjected to tremors from earthquakes.

            Areas where ground-water movement occurs only during portions of

    most years may present problems similar to those previously discussed.

    They are frequently indicated by the character of the vegetation or they

    may be indicated by a stain in the lower part of the cover, the contact

    zone between the cover and permafrost, or in sands and gravels forming a

    contact zone between the cover and permafrost below.

    009      |      Vol_IIB-0231                                                                                                                  
    EA-I. Rathjens: Placer Mining

            The character of the vegetation in a permafrost area frequently

    indicates the presence of moisture from underground water. For example,

    in one area trees in the lower section of a valley (before clearing this

    section preparatory to excavation) were mostly Sitka spruce, which indi–

    cated frozen muck under the insulated covering and no ground-water

    movement. The valley filling, in this case, was mostly wind-borne brown

    muck and water-borne black muck containing ice lenses. The average

    elevation of the surface of the lower section of the valley, where Sitka

    spruce was growing, was 120 ft. above a thawed gravel, the gravel below

    the permafrost varying in depth from a few inches to 200 ft. On the

    higher land of the valley the trees were mostly birch and poplar, which

    indicated a thawed zone where there was an upward migration of moisture

    to the surface, probably because of a fault. Animal trails led to salt

    licks among the birches and poplars.

            Drilling of wells in the area for study purposes resulted in some

    artesian flows of relatively warm water and the liberation of some

    methane gas. In the frozen surface of a small l i a ke, which was in line

    with the birches and poplars, there were three openings, which were the

    result of the upward movement of warm water and methane gas from the

    faulted bedrock below. These openings remained open all during the winter.

    The writer visited this lake for three or four winters and each time found

    the same condition present.

    010      |      Vol_IIB-0232                                                                                                                  
    EA-I. Rathjens: Placer Mining

            Construction work in areas where there is no ground-water movement

    presents problems quite different from those in permafrost areas where

    ground-water movement occurs throughout the year or the major portion of

    some years. A typical condition is one where the terrain is covered with

    hummocks directly over permafrost. Investigation of such areas shows that

    there is no movement of ground water between the insulating cover and the

    permanently frozen muck or permanently frozen sand and gravel.

            Any construction work in these hummocky areas should be so designed

    and accomplished that the temperature equilibrium of the area is not

    disturbed. Here, however, one does not have to give consideration to the

    movement of ground water, since practically all waters in the area can be

    treated as surface waters.

            Ice may form first on the bottom of certain portions of some rivers

    in permafrost areas. Therefore, this fact must be considered in develop–

    ing details of the design of certain structures in such rivers.

            For instance, in building a diversion dam, investigation revealed

    that, in portions of the stream, ice formed on the bedrock and on some

    of the gravels in the bed before the freeze-up of the river surface

    occurred. It was deemed advisable to cut off any flow of water in the

    thawed gravels; therefore, an interlocking sheet-piling cutoff wall was

    driven across the valley. Where frozen gravels were encountered, they

    were first thawed by using steam points before the piling was driven.

    The piling was then “driven home” into the schist bedrock of the valley.

    This cutoff wa ss ll s successfully sealed off the water movement in the thawed

    gravels in the valley.

    011      |      Vol_IIB-0233                                                                                                                  
    EA-I. Rathjens: Placer Mining

            Provision was made in the design and construction to reduce as much

    as practical the effect of a lifting force at the face of the piling from

    the freezing of gravels and ice. This was accomplished by building

    aprons above and below the sheet piling so that any appreciable thrust

    would be resolved into two components, one having a downward thrust.

    t T hese aprons were not rigidly fastened to the sheet piling. Each winter

    for more than twenty years this dam has been entirely covered with ice.

    The provisions made to protect the structure against existing conditions

    have been very satisfactory and the cost of maintenance has been exceed–

    ingly small.

            The effect of swelling because of freezing in the “frost zone” can

    be lessened by sloping the exposed fac t e of masonry and other structures

    g 17 as illustrated in Figure 17. The force , A , developed through freezing of

    the materials adjacent to the pier, is resolved into a thrust, B , and a

    lifting force, C . The thrust at the slope resolves itself into two

    components, one horizontal, BH , and one downward, BD . The downward

    component resists the lifting force, C .

    011a      |      Vol_IIB-0234                                                                                                                  

    Fig. 17 - Pier illustrating the use of “ice batter”.

    012      |      Vol_IIB-0235                                                                                                                  
    EA-I. Rathjens: Placer Mining

            In setting the piles for foundations of the dam, steam points were

    used to thaw the frozen muck and, after thawing to a proper depth, the

    piles were driven home and permitted to freeze in place. The muck in

    this area contained a large amount of water in the form of ice; also ,

    here and there, ice lenses. It was, therefore, necessary to do the work

    in cold weather so as to reduce to practical limits the exposure of the

    permafrost to the warm air and sun. (The thawing of a hole for a pile

    or pole can be reasonably controlled when steam points are used, but when

    the surface of the muck is exposed to the sun and warm air, the control

    of the thawing is not very practical.) The insulating cover of moss was

    removed and piled to avoid packing of the moss so that its insulating

    properties would be least disturbed. After removal of the moss, sufficient

    muck was thawed to permit the placing of the pile. This pile was then

    driven home in the thawed muck and permitted to stand with the thawed area

    exposed to the cold. As soon as the seasonal freeze of the exposed muck

    had penetrated to the proper depth, the insulating cover was carefully

    replaced. After careful study, because of the element of time, it was

    deemed advisable in this case not to depend wholly on back-freezing

    under an insulating cover of moss. The writer built several hundred

    pi p l e bents in this manner during the fall and winter of 1925, 1926, and

    1927, using the foregoing procedure and the results obtained were very


    013      |      Vol_IIB-0236                                                                                                                  
    EA-I. Rathjens: Placer Mining

            Protection against heat transfer by conduction must be given careful

    consideration in all construction problems in the Arctic. To maintain a

    thermal balance requires the careful study of various insulating materials

    for their specific adaptability to each problem. In many cases locally

    available moss, if not too compacted, is an excellent insulator.

            Gravels and sands can also be used as insulators if their particles

    are of such size and shape that they can maintain the maximum amount of voids

    while in close packing. Provision must be made to maintain these insulating

    22 qualities, as indicated in Figure 22. The coarse gravel fill, free from

    sand or fines, b , was placed on the moss cover, c , for two purposes; ( 1 ) to

    provide insulation in an amount equal to or greater than the loss of insula–

    tion because of compaction of the moss due to loading, and ( 2 ) to maintain in

    the section under load a water-carrying capacity, above the permafrost, equal

    to or greater than that which existed before the compaction of the material.

    In Figure 22, a represents a fine, tight sand and gravel cover compared to

    the coarse, open gravel fill, b; c is the original surface of moss or tundra;

    d is the depressed surface of the moss or tundra after same was loaded;

    e represents the original lower limit of seasonal freeze; f is the original

    zone of possible water movement at maximum penetration of frost; g is the

    zone of possible water movement at maximum penetration of frost after loading.

    The upper limit of permafrost under a loaded area may change in time because

    of back-freezing.

    013a      |      Vol_IIB-0237                                                                                                                  

    Fig. 22 - Mat foundation on tundra.

    014      |      Vol_IIB-0238                                                                                                                  
    EA-I. Rathjens: Placer Mining

            In many instances it is desirable to build a mat of sand and gravel

    on the moss or tundra to provide a foundation for a superimposed load

    without removing the insulating and water-conducting cover over the

    permafrost. The writer has built a number of structures on mat founda–

    tions with very satisfactory results. These structures include camp

    buildings, such as bunkhouses, mess halls, and hospitals.

            In making studies of bank stability of thawed materials in perma–

    frost regions, consideration must be given to the fact that the exposed

    faces are usua o l ly not well insulated and, therefore, there is a relatively

    deep penetration of seasonal frost at the face. Usually at the toe of

    such faces there is an accumulation of granular material in relatively

    open packing and/or drifted snow, which results in a lesser penetration

    of seasonal frost than in the exposed face of the bank.

            Where there is a migration of ground water, an increasing hydrostatic

    head may develop against the frozen bank face sufficiently great to cause

    rupture, usually at the toe of the slope. In sections where strata of

    cohesive materials are present, the practical height of such banks may be

    materially changed because of the freezing of the face and surface of the

    ground and/or cover.

    015      |      Vol_IIB-0239                                                                                                                  
    EA-I. Rathjens: Placer Mining

            In building canals for the transportation of water over permanently

    frozen materials, consideration must be given to the proper insulation

    of the permanently frozen materials, especially ice lenses. This can

    frequently be accomplished by the use of local moss, which is usually

    available in the area. The writer was instrumental in the building of

    a canal 93 miles long, carrying 125 sec. - ft.; the water temperature at

    place of diversion was in the vicinity of 35°F. In developing the canal

    section, economical hydraulic properties of the section were subordinated

    to a section that would result in maximum exposure of the water surface

    to the sun. The water was delivered from the canal in midsummer at a

    temperature of approximately 55°F. and used for cold water thawing. In

    a number of places along the canal it was necessary to carry the water over

    ice lenses. This was successfully accomplished by using local moss for


            The earth section of a canal near Fairbanks, Alaska, totaling

    approximately 70 miles, is mostly a side - hill structure. A value for n

    of . 0 0276 was i u sed for the coefficient of roughness in Kutter’s formula

    for the determination of the empirical coefficient “c.” C . The calculated

    value of “c.” C was then used in Chezy’s formula for the determination of

    flow. Actual measurements of flow compared favorably with the calculated


    016      |      Vol_IIB-0240                                                                                                                  
    EA-I. Rathjens: Placer Mining

            Heaving of road surfaces may be the result of creep, ground water,

    and/or freezing of contained moisture. However, since many studies have

    been made as to the cause of heaving of road surfaces, this detail will

    not be discussed in this section. The reader is referred to C.A. Hogentogler,

    Engineering Properties of Soil (N.Y. McGraw-Hill, 1937), and to recent

    publications of the America Society of Civil Engineers, the Bureau of

    Public Roads, and the Corps of Engineers, U.S. A rmy , etc .

            Provision must be made that the egress from buildings is not inter–

    fered with by huge icicles or ice which may form in front of doors as a

    result of melting snows on the roof. In sections where very high winds

    occur, the writer has seen many squares of roofing lifted from the leeward

    side of the roofs. In such sections, special provision must be made to

    secure the roof covering.


    George W. Rathjens

    Design of Dredges for the Far North Placers

    Unpaginated      |      Vol_IIB-0241                                                                                                                  
    EA-I. (Charles M. Romanowitz)




    Fig. 1 Elevation of 9 cu.ft. dredge 2-a
    Fig. 2 Plan of 9 cu.ft. dredge 2-b

    Unpaginated      |      Vol_IIB-0242                                                                                                                  
    EA-I. (Charles M. Romanowitz)





            With the manuscript of this article, the author submitted two

    photographs for possible use as illustrations. Because of the high cost

    of reproducing them as halftones in the printed volume, only a small pro–

    portion of the photographs submitted by contributors to Volume I,

    Encyclopedia Arctica , can be used, at most one or two with each paper;

    in some cases none. The number and selection must be determined later

    by the publisher and editors of Encyclopedia Arctica . Meantime all

    photographs are being held at The Stefansson Library.

    001      |      Vol_IIB-0243                                                                                                                  
    EA-I. (Charles M. Romanowitz)



            For the most successful operating dredge on any property, experience

    has proved the dredge must be especially designed to meet the conditions

    to be encountered. This is particularly true of dredges for operation

    in Alaska and other northerly countries where there are usually found

    conditions that make dredging operations extremely difficult.

            Frozen ground, extremely low temperatures, remote locations causing

    difficult transportation problems, and power [ ?] d evelopment conditions are

    the main items that must be given consideration in designing a dredge for

    the North.

            Frozen ground and bedrock must be thawed for dredging, and if not

    properly thawed and seasoned, pyramids of frost will be found that cause

    difficulties and reduce unit yardages. It has also been found that frozen

    ground, when not properly thawed and containing a large percentage of gritty

    fines, has caused more wear on bucket lips than any formation found in other

    dredging fields throughout the world. In some operations where dredging

    ponds have banks containing seasonal frost, large quantities of serious

    damage can be caused if these banks are high and permitted to cave in.

    002      |      Vol_IIB-0244                                                                                                                  
    EA-I. Romanowitz: Design of Dredges

            A dredge properly designed for the North should operate for

    approximately the full anticipated season regardless of intermittent cold

    weather conditions. The design should be such as to prevent a costly

    shortening of the dredging season due to the dredge freezing up prematurely.

    With the proper equipment, the length of the season is determined by the

    economics of operating under severe cold conditions. Remote locations

    also affect the dredge design. Transportation facilities can determine

    and limit the size of dredge equipment to be used.

            The power to be used on a dredge depends upon the location of the

    properly property and what fuel can be most economically delivered to the property.

    Wherever possible electricity should be used for power after a determination

    has been made as to the best method of generation. On a one-dredge property,

    the diesel electric-generating plant aboard the dredge is usually the most

    economical. On small one-dredge properties, the use of diesels with belt

    drives to the units have been used a great deal.

            It has proved economical to design the wearing parts wherever possible

    to give a life in multiples of operating seasons so that the replacements

    during the operating seasons should be kept at a minimum. As the dredge

    operations cannot be carried on economically for a full calendar year, a

    shutdown for replacements during the operating period is costly.

            The following will give a general description of the main units

    making up a dredge , (Figs. 1 and 2), which are affected by the above conditions, and these

    are also subject to certain changes to meet local conditions.

    002a      |      Vol_IIB-0245                                                                                                                  

    Fig. 1

    002b      |      Vol_IIB-0246                                                                                                                  

    Fig. 2

    003      |      Vol_IIB-0247                                                                                                                  
    EA-I. Romanowitz: Design of Dredges

            The bucket line including the complete digging system is one of the

    important units of the dredge. The buckets vary in size from 1½ cu.ft.

    capacity to 18 cu.ft., although, up to the present time, buckets with

    more than 10 cu.ft. capacity have seldom been used. For large operations

    the 9-ro 10- cu.ft. buckets have proved economical. In many cases the

    bucket design has not been given enough attention, and as a result the

    digging cannot be carried on efficiently, al rt tr ough in many cases the

    operators do not realize the improvements that could be expected by

    improving the bucket design.

            The buckets, consisting of a body or base, lip, and bushing, should

    all be of ca x s t manganese steel. The body should be bowl-shaped for all

    formations and of standard pitch except where large quantities of boulders

    are to be found. In these cases the buckets should be of the rock type,

    using a long pitch to be able to handle the big boulders without cramping

    3 & 4 and jamming (see Figs. 3 and 4). The bottom of the bucket body (or base)

    should be as large as possible to reduce the pressure on the tumblers,

    thereby giving a long life to the t i u mbler plates as well as to the buckets.

    The lips should be of the patented bolted type to permit easy and quick

    replacements. The shape of the body and lip is determined by the speed

    of the bucket line, swinging speed, and formation, and when properly

    proportioned will give a good digging and dumping unit and will practically

    eliminate the trouble of the bucket line working off the lower tumbler.

    The dept y h of the lip should be such as to produce minimum changing during

    operating season and still keep the bucket capacity as great as possible

    at all times. The bushings having a length of 1/2 to 3/4 in. shorter

    than the back eye width, but of one piece, give the best results.

    004      |      Vol_IIB-0248                                                                                                                  
    EA-I. Romanowitz: Design of Dredges

            The pins should be as large in diameter as possible and made of

    forged heat-treated alloy steel, preferably nickel-chrome steel.

            The digging ladder should be of the plate girder-type design for

    operation in cold weather, including a heating system for the upper

    portion of the ladder and steam outlets for external thawing. The

    ladder suspension should be designed to reduce as much as possible the

    bad effects of freezing.

            The ladder roller bearings and lower tumbler bearings should be

    equipped with automatic lubrication, such as the Farval and Trabon

    system, and Yuba- ½ p atented underwater-type seals.

            The main drive , which actuates the bucket line, is subjected to

    continuous hard service. Therefore, all parts of this unit must be

    strongly built. Several arrangements are possible for this drive. For

    the smaller size dredges in shallow digging, the drive on one side of

    the tumbler is satisfactory. However, for the larger size dredges digging

    into tough and deep formations, the main drive should consist of a set or

    train of gearing on each side of the center line leading to two bull gears,

    one on each end of the upper tumbler shaft.

            If transportation facilities permit, the upper tumbler shaft should

    be cast integral with the tumbler, with replaceable wearing plates.

    Otherwise, the upper tumbler is a separate casting fitted to a 3-1/2%

    nickel-steel shaft. In either case the casting should be mild steel.

    The wearing plates should be forged and heat-treated nickel-chrome-alloy

    steel, although sometimes these are made of cast manganese steel.

            All gearing should have cut teeth with the intermediate gears and

    pinions having herringbone cut teeth. The shafting should be 3-1/2%

    nickel-steel, and all bearings cast steel, babbitted.

    005      |      Vol_IIB-0249                                                                                                                  
    EA-I. Romanowitz: Design of Dredges

            If the driving power is by means of electric motors, then for the

    best arrangement the main drive motor or motors should be located on

    the same plane as the main drive gearing but aft of it, and connected

    by means of V-belts.

            When the formation is such that the values are on or near bedrock

    with no values in the overburden, then the direct current variable voltage

    drive, such as the Ward Leonard control equipped with either Roto-trol or

    the Amplidyne excitation on the one or more d.c. generators, would be

    advantageous to provide optimum speed for the barren overburden and

    slower speeds for the pay gravel, bedrock, and unthawed portions of the


            For other properties where values are found throughout the digging

    depth, and where digging conditions are fairly uniform, it is hard to

    justify the first cost of a Ward Leonard control, and therefore, the

    alternating current variable speed drive has many advantages and should

    be installed. The a.c. variable speed motor drive is more widely used

    to power the main drive because of its simplicity, lower first cost, and

    lower maintenance cost. The maintenance crew does not have to be especially

    trained to service or trouble-shoot the e quipment on the a.c. drive, as is

    required on the d.c. Ward Leonard control system.

            A special 2-speed a.c. motor drive has been found practical. In this

    case each motor is arranged with a variable speed winding and a constant

    speed winding. The variable speed winding serves to accelerate the drive

    and is employed to operate at a slow speed in tough conditions where the

    formation is especially hard and only partly thawed. The constant speed

    winding is engaged during easy digging conditions, providing higher

    operating speeds for greater yardage gains.

    006      |      Vol_IIB-0250                                                                                                                  
    EA-I. Romanowitz: Design of Dredges

            When the power is to be obtained direct from diesel engines, the

    above refined controls are not possible and the usual belted drives

    are used.

            Revolving Screen and Drive . The revolving screen, having perforated

    screen plates is used for the purpose of sizing the dredged materials,

    in order to treat the smaller finer sizes (usually under 1/2 in. in diameter),

    and to obtain the precious metals. The screen should be as large in

    diameter and have as long a length of perforated sections as possible.

    This is also a very important unit on a dredge because, if all the values

    are not washed clear and delivered to the treating system, the purpose for

    mining the gravel has been at least partly defeated. In many cases the

    details of this unit, especially the type and size of holes, have not been

    given enough attention. The perforated plates should either be machine–

    drilled abrasion-resisting steel or cast manganese steel, depending upon

    the materials to be treated. The size, type, and number of holes depend

    upon the materials treated and the method used in the treating plant for

    obtaining the precious metals. When nuggets are present, slotted tapered

    holes are necessary, the size depending upon the size and shape of the

    nuggets. When slotted holes are necessary, the plates should be made of

    cast manganese steel.

            The screen drive using one friction roller for driving is most

    desirable, especially for the larger size screens. For the smaller screens

    the use of rubber-tired drive rollers is proving very efficient.

    007      |      Vol_IIB-0251                                                                                                                  
    EA-I. Romanowitz: Design for Dredges

            Treating System . The selection of the proper treating system for

    obtaining the precious metals depends upon various conditions that are

    present in the property to be dredged. Wherever possible the standard

    gold saving table system should be used, as it is the most practical,

    requiring less manpower. The use of Hungarian-type riffles of other

    means of obtaining the precious metals on the gold saving tables depends

    upon local conditions. When a thorough study of the conditions relating

    to obtaining the precious metals indicates that the standard tables, no

    matter how equipped, will not be an efficient unit, then jigs should be

    used. The final determination for the use of jigs requires an extensive

    study and the use of a preliminary testing unit, if possible, as there is

    no set rule to determine the total number of jigs required for all dredging

    properties. Therefore, each property is a problem in itself. While the

    use of the jig system may be indicated, unless the proper number of jigs

    and arrangement is employed, serious losses could occur. This also is the

    case when standard tables are used inefficiently. When jigs are used,

    additional manpower is necessary for handling the system in the most

    efficient manner. However, this should not with-hold the use of the jig

    system when it is found to be required.

            For the treating system, all parts must be confined to the inside

    of the housing, except the tail sluice discharging at the stern. This

    is a common practice now to avoid unnecessary freezing conditions.

    008      |      Vol_IIB-0252                                                                                                                  
    EA-I. Romanowitz: Design for Dredges

            Hull. The selection of the type of hull to be used depends upon

    the location of the dredging property. The hull design should take into

    consideration the heavy pressures that come from ice conditions. On

    account of the high labor costs, the type of hull should be selected

    that is most economically delivered and erected in the field. The

    pontoon-type hull requires less labor for erection, but the ocean freight

    costs usually make this type prohibitive. The Yuba-patented cellular-type

    hull, while costing more to erect than the pontoon type, has the advantage

    that the freight charges are low and the field erection is lower than for

    a standard riveted or welded hull. In some cases conditions make necessary

    the use of the standard riveted or welded hull, where the hull is shipped

    in small units and assembled in the field, requiring considerable field

    labor and erection equipment but low ocean freight costs. The use of

    wood hull, or composite hull of wood and steel, depends upon conditions

    at the time the dredge is being built. The disadvantage of this type of

    hull is that it cannot be moved readily from one property to another.

            The housing can be either or wood, i.e., wood framing with wood

    covering, or all steel, or a combination of both. Wherever possible

    the housing should be lined on the inside the insulation material used.

    It is important that the housing be extended over as much of the dredge

    as possible. This includes a necessary covering or housing over the

    stacker ladder.

    009      |      Vol_IIB-0253                                                                                                                  
    EA-I. Romanowitz: Design for Dredges

            The heating system is also an important unit, and sufficient heating

    capacity should be provided to enable the operating crew to be well sup–

    plied with heat and live steam during the coldest operating weather. A

    liberal number of outlets should be provide for hose connections, for

    quick thawing. Steam radiators of the Modine type are preferable; however,

    those made of piping are used a great deal.

            The boiler for the heating system should be a heavy-duty horizontal–

    return tubular type, although in some cases the transportation facilities

    and limited deck space make the use of a vertical-type boiler necessary.

            Swing Winch. This winch should have enough power and strength to

    enable the dredge crew to maneuver the dredge properly during bad ice

    conditions in the pond.

            Running Line Sheaves. On all sheaves for running lines there should

    be installed ice fingers to prevent the building up of ice in sheave grooves.

            The above deals only with the main units of the dredge that should

    be given special attention for operation under conditions known to exist

    in the Far North. The units of the dredge not mentioned can be of the

    usual conventional design unless special local conditions dictate otherwise


            No mention has been made herein of the flume-type dredge, which in

    some cases have been found necessary, although its use should be eliminated

    wherever possible and account of its inefficiency.

    010      |      Vol_IIB-0254                                                                                                                  
    EA-I. Romanowitz : Design for Dredges


    1. Averill, C.V. Placer Mining for God in California . San Francisco,

    Calif. State Printing Office, October, 1946. Calif.Div.Mines Bull .


    2. Peele, Robert, ed. Mining Engineers’ Handbook . 3d ed. N.Y., Wiley, 1941,

    vol.1, art.127, 128.

    3. Wimmler, N.L. Placer-Mining Methods and Costs in Alaska . Wash.,D.C.,

    G.P.O., 1927. U.S.Bur.Min. Bull . 259.


    Charles Millichamp Romanowitz

    Coal Mining in Spitsbergen

    Unpaginated      |      Vol_IIB-0255                                                                                                                  
    EA-I. (Scott Turner)




    Geographic Position 1
    Far Northern Mining Areas 2
    Status of the Archipelago 2
    The Island of West Spitsbergen 3
    The American Base of Operations 4
    Topographic Mapping 5
    Geographical Studies 6
    Exploration 6
    Estimates of Coal Tonnages 6
    Description of These Spitsbergen Coals 7
    Exploitation - Mining Methods 9
    Room and Pillar Mining 12
    Safe Mining Practices 14
    Labor 18
    Efficiency and Health 21
    Stockpiling Coal 23
    Markets for Coal 25
    Ships and Shipping 26
    World War I. 27
    End of American Operation 29

    001      |      Vol_IIB-0256                                                                                                                  
    EA-I. (Scott Turner)



            This article describes, in part, the coal mining operations of an

    American group, the Arctic Coal Company, a West Virginia corporation

    financed by John Monroe Longyear and Frederick Ayer of Boston, and managed

    by Scott Turner on territory flying the American flag, on the west coast

    of the island of West Spit z s bergen. It covers an area of 175 square miles

    on the south side of Advent Bay, off the Ice Fjord, during 1911-15,

    inclusive, after which date World War I interfered. Subsequently, in 1916,

    the mines were sold, and passed from control of the American owners and

    operators. Afterward, in 1919, the Supreme Council at Versailles gave to

    Norway a mandate over this land, and Norwegian sovereignty became effective

    in 1925. This article is the story of the American operations.

            Geographic Position . Since Svalbard, the Spitsbergen Archipelago,

    areas about 25,000 square miles (almost one- w q uarter that of the British Isles),

    is little known to the average man, a short description of this group of

    islands seems to be in order before recounting the first extensive explora–

    tions and mining operations carried on there by the Americans.

            This archipelago lies north of Norway. North Cape, Norway (Europe’s

    most northern point, latitude 71°11′ N.), lies 356 statute miles south of

    South Cape (latitude 76°27′ N.) on the island of West Spit z s bergen, the

    002      |      Vol_IIB-0257                                                                                                                  
    EA-I. Turner: Coal Mining in Spit z s bergen

    southernmost point in the Spits z s bergen group. The American mines near

    Longyear City were at latitude 78°15′ N., in Advent Bay, off Ice Fjord, the

    latter being a deep indentation on the west coast of West Spitsbergen.

    Troms o ő (latitude 69°38′ N.) was the original transshipping point in Norway,

    and the mainland office of the company; the mines lay 600 miles farther

    north than Troms o ő . Troms o ő is 80 miles farther north than Narvik ( L l attitude

    68°30′ N.), the most northern rail port in Norway, and the western rail

    port for the important Kiruna iron mines in Swedish Lapland; Troms o ő is

    425 land miles north of the north terminus of the principal Norwegian rail

    line at Trondhyem (now Trondheim) (latitude 63°26′ N o .); it should be noted

    that the coal mines herein described lay 1,025 miles farther north than the

    nearest trunk-line railhead. Since the Arctic Circle is at latitude 66°30′ N.,

    which is also the latitude of the north tip of Iceland, it is apparent that

    these mines were 815 miles north of both the Arctic Circle and of Iceland,

    and an equal distance from the North Pole.

            Far Northern Mining Areas . Prior to the American venture herein described,

    no mining on an extensive scale had ever been attempted anywhere so far north.

    when it is remembered that the Yukon River touches the Arctic Circles at only

    one point, and that the northern outpost of sizable placer-gold mining opera–

    tions was at Nome, Alaska, lying south of the Arctic circle, it is immediately

    apparent that this Spit z s bergen venture, carried out about 1,000 miles farther

    north than Nome, was unique in the history of mining, and was the pioneer

    large operations under true arctic conditions.

            Status of the Archipelago. Spit z s bergen during this period of American

    activities was no man’s land, terra nullius . It was uninhabited, unclaimed,

    unproductive. All operations herein described were on the 175-square mile

    003      |      Vol_IIB-0258                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    tract of the Arctic Coal Company. This area included all the high-grade

    coal then known to exists here. American sovereignty was claimed and main–

    tained over this as well as over three tracts of similar size all fronting

    on the Ice Fjord, which were held by Ayer and Longyear, for whom Turner was

    European manager. Thus, more than 600 square miles of this arctic land were

    staked and claimed in manner similar to mining claims in public land in

    western United States, plus the unique difference that American sovereign i ty

    was also established thereby. The American claims were filled with the

    State Department at Washington, D.C. Each year the manager made a report

    for that department; an attorney residing in Washington, D.C. was employed

    on a yearly basis to represent the company there. The company’s rights and

    titles were never seriously questioned, and the claims were in good standing

    in Washington. Events transpiring 30 years later suggested the possibility

    that a mistake was made at Versailles when the United States consented so

    readily to renounce its territorial rights in Spitsbergen. This point was

    urged in Washington as early as 1911 by the manager of the company, but

    officials were apathetic; the land then seemed to them to be too barren and

    remote to be of any real interest to the American government.

            The Island of West Spitsbergen . This is the principal island of the

    archipelago, as to size, accessibility, and significance. On the west side

    lie all the known d c oal deposits of consequence. The island has an area of

    about 15,000 sq.mi. Fortunately, its west coast is free of troublesome ice

    for longer periods than any other waters bordering on the archipelago. Were

    it not for this fact, developments there could not have proceeded as they did.

    Had these waters been infested with heavy ice, as are those off the east

    coast, and between it and Edge Island, Barents O I sland, and Northeast Land,

    004      |      Vol_IIB-0259                                                                                                                  
    EA-I. Turner: Coal Mining in Spit z s bergen

    sea commerce at any time would have been hazardous, if not impossible.

    Most of the island is perpetually covered by snow and ice, although glaciers

    develop only locally. The highest altitude is 5,600 ft., but the general

    elevation of the interior is 2,000 to 4,000 ft. During the summer, all the

    snow melts away in some coastal valleys, but the ground even in the valleys

    does not thaw more than a few inches deep. There were no trees, no bushes,

    but there were grass and flowers in summer, some moss, and lichens. There

    were polar bears, white foxes, small reindeer, ptarmigan, seals, an occasional

    walrus, and numerous sea fowl in the spring and summer. Fossils, chiefly

    Tertiary, were abundant.

            The American Base of Operations . The mining town (78°15′ N.) built by

    the Americans was called Longyear City, after J. M. Longyear, the prime mover

    in the venture. There was continuous sunlight from April 24 to August 23,

    and a corresponding though shorter winter period of the absence of sun.

    Perpetual frost would be encountered from the surface to a depth of 2,200 feet

    below the surface. There was no timber; the largest tree found was an arctic

    birch growing flat on the ground with a diameter of less than one-half inch.

    There was no transportation except by ships owned or chartered by the Arctic

    Coal Company.

            All food, material, supplies, and workmen had to be transported from the

    Norwegian coast. The only code of laws was the labor contract signed by each

    workman before he left the mainland, at which time he and his luggage were

    searched, and liquor and lethal weapons were confiscated. The only policing

    done was by the operating officials. Judicial procedures were only such as

    were provided by the management. The company operated the only mail or wireless

    services. Except during the short summer, no fresh water was available, except

    that made by melting snow or ice. Norway had to be relied on for the bulk of

    the workmen.

    005      |      Vol_IIB-0260                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

            This preliminary description of conditions is a necessary introduction

    to an account of mining operations at Advent Bay. It is also necessary to

    know that docks and loading terminals were constructed by the American Company;

    aerial ropeways were erected; coal-storage space and pockets were provided; a

    steam-driven electric-generating station was built; industrial railways,

    machine shops, warehouses, bunkhouses, cottages, offices, stores, messes,

    and pit-mouth equipment were erected; and a small but complete mining community

    was created.

            Topographic Mapping . As a preliminary to geological work, exploration,

    development, and eventual exploitation, experienced topographers were employed

    by the American company. They established base lines, triangulation stations,

    monuments, and bronze bench marks; they prepared three basis topographic maps.

    The first, covering about 31 sq.mi., drawn to a scale of 1,000 ft. to the inch,

    showed 25-ft. contour lines, and included the area centering about Longyear

    and Bear valleys. The second map s was drawn to the scale of 1 in. equals 400 ft.,

    with a contour interval of 25 ft., and showed in detail an area of about 5 sq.mi.

    around Longyear City and mines. The third map was drawn to the scale of

    1 in. equals 50 ft., contour interval of 10 ft., covered an area of about

    50 acres, including the region about the mine, stockpile, wharf, and loading

    dock, and showed 5-ft. underwater contours for some distance offshore. All these

    maps were printed. Using these as bases, the results of subsequent geological

    studies were plotted, and exploration to determine the outcrops or positions

    of various coal seams was conducted. Subsequently, many other topographic

    and geologic maps were made, covering areas of especial interest. Thus,

    dependable engineering information was secured from which proper development

    and exploitation could be planned.

    006      |      Vol_IIB-0261                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

            Geological Studies . Using these topographic maps as the basis for

    geological field work, a competent American geologist spent two summers

    gathering data for plotting on the maps the position and extent of the

    various sedimentary beds, together with the probable traces of the out–

    crops of the various coal seams under consideration by the Arctic Coal

    Company. This work was extended, in less complete manner, far outside the

    31 sq.mi. covered by the large topographic map.

            Exploration . Slide rock, talus slopes, loose rubble, and masses of

    ice frequently obscured the outcrops of coal in place. in some places,

    landslides had carried downward large blocks of sandstone containing the

    three upper coal seams, thus falsely making them appear to lie at a lower

    horizon. Several crews were put to work at critical points, to uncover

    the outcrops of coal actually in place. As a result of this exploration

    work, which included driving 54 short entries into coal at widely scattered

    points, the facts regarding the position of the coal seams in the mapped

    areas were ascertained. With this knowledge, the company was ready to

    exploit the best seam in the best location.

            Estimates of Coal Tonnages . Sampling the measuring the coal in the three

    seams outcropping on the property, plus a decision as to the most convenient

    place to start the first and second mines in the light of transportation to

    loading-depth tidewater, resulted in the choice of No. 2, or middle, coal

    seam as the best, and the east and west sides of Longyear Valley as the

    proper positions for these two main entries. A preliminary estimate of

    available coal in this No. 2 seam, lying within the limits of the mapped

    31-sq.mi. portion of the Arctic Coal Company tract, resulted, in the field

    engineers; report of 14,000,000 tons of assured coal within this area,

    007      |      Vol_IIB-0262                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    25,000,000 tons of probable coal, and 14,500,000 tons of possible coal,

    all in No. 2 seam. Geological and engineering work to the southeast and

    southwest of the ma n p ped area increased these preliminary estimates to a

    total of 97,000,000 tons in 31 sq.mi., which was about one-sixth of the

    area controlled by the Arctic Coal Co. These figures did not include coal

    in the two other known seams occurring on the tract, or the coal in the

    older seam, which undoubtedly underlay the area at a depth of about 500 ft.

    below the floor of Longyear Valley. When it is remembered that the American

    principals, Ayer and Longyear, controlled three other areas of the same size,

    it can be seen that there was no shortage of coal underlying the American


            Description of These Spitsbergen Coals . Underlying the Arctic Coal Co.

    tract, at least four seams of coal were identified and studied. The lowest,

    called Carboniferous in age, could not be seen on this tract, but it was

    found and studied on the north shore of Advent Bay, where it had been opened

    by an English company with disastrous results. It was estimated that this

    seam lay about 500 ft. below sea level vertically under the pit mouth of the

    No. 1 American mine, which would make it about 1,250 ft. vertically below

    the No. 2 seam exploited by the Arctic Coal Co. through its main slope.

    No evidence was found that any coal occurred between these two horizons,

    except for the No. 1 seam of the American company.

            Of the three Tertiary seams outcropping on the Arctic Coal Co. tract,

    No. 1, the lowest of the three, was opened at elevations between 465 and

    600 ft. above sea level. Where exposed, it was clean coal, c v arying in

    thickness from 2½ to 4 ft. It would probably be found at vertical distances,

    008      |      Vol_IIB-0263                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    varying from 50 to 100 ft. below NO. 2 seam. This coal appeared to be of

    good quality, but was not judged to be as promising as that in No. 2 seam.

            No. 2 seam, the one with which we are principally concerned, lay from

    50 to 100 ft. above No. 1, and was explored along a line of outcrop varying

    from 1,000 to 750 ft. above sea level at a great many widely scattered place.

    It appeared to be the best seam of all, and the company concentrated on its

    development and exploitation. No. 3 seam lay about 45 ft. vertically above

    No. 2, but was not considered to be as good as No. 2, and the decision was

    made to disregard it, for the time being, in favor of No. 2 seam.

            While float coal was found at some places above No. 3 seam, it was

    judged that it had been transported by glaciers, and its source was not


            Careful sampling of No. 2 seam coal in place, as exposed in No. 1 mine

    workings, showed in analysis the average results listed in Table I, which

    can be taken as accurate for this coal mine as opened by the end of 1913.

    Table I. Analysis of No. 2 Coal Seam.
    Moisture at 105°C., % 1.47
    Volatile Matter, % 37.74
    Coke, % 60.79
    Ash, % 3.78
    “Fixed carbon,” % 56.30
    Total sulfur, % 0.17
    Gross calorific value, B.t.u. 14,403
    Gross calorific value , evaporative

    Power, lb

    009      |      Vol_IIB-0264                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

            The results of the separate analyses of many check samples showed

    little individual variation from the average. Thus, chemically, the coal

    was remarkably uniform in character and of excellent quality. Where mined,

    it was clean with no included rock or extraneous matter. It was black,

    shiny, and would probably be classed as high-grade semibituminous. It was

    so clean that it required no picking or sorting after being mined. Since

    the fines agglomerated on the grate bars, they could be loaded out with the

    lump coal. None of the coal was screened or washed. All of it was shipped

    and burned just as it came from the mine. As it burned, the ash, red in

    color and fine in size, sifted steadily through the grate bars. Very few

    clinkers were formed. All this made firing easy. The coal was a favorite

    with the fireman on the vessels using it.

            Exploitation - Mining Methods . Of the three coal seams explored on the

    tract, the middle one was chosen for initial exploitation. This seam out–

    cropped in the faces of cliffs about 750 feet vertically above the bottom

    of Longyear Valley. A gravity ropeway connected the pit-mouth storage bins

    with the stockpiling yards and with the loading staiths. This coal was free

    from bends of slate or include impurities, with good smooth roof and floor;

    it dipped at 3° into the mountain, and averaged 3 ft. 8 in. in thickness.

            No. 1 mine, on the west wide of Longyear Valley, was first opened by

    a double-entry incline running North 70° West in coal, from the outcrop

    above Longyear City, on a grade of about 3° into the cliff, utilizing main–

    and-tail-rope haulage. The portal was at an elevation of 756 ft. above

    sea level. Break-throughs were spaced 75 to 90 ft. apart. The main entry

    was protected by a pillar approximately 200 ft. wide. When the face reached

    a slope distance of 2,200 ft., it was approximately 900 ft. vertically below

    010      |      Vol_IIB-0265                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    the surface. By the time 100,000 tons of coal had been raised through this

    entry, the company had in its possession adequate data as to methods and

    costs on which to base its plane for future operation.

            The rock temperatures were the same summer and winter, increasing from

    22°F. near the outcrop of 27°F. at the 2,200-foot slope distance, indicating

    that the surface zone of perpetual frost extended to a vertical depth of

    about 2,200 ft. Therefore, there was no water in the mine — only small seams

    of fossil ice; this condition would prevail at least until the workings reached

    many thousand feet from the outcrop. There were no explosive gases.

            Provided with the efficient office force, a cost-accounting system was

    installed whereby the costs of producing coal by various methods, and using a

    variety of equipment, could be ascertained. Since no one, anywhere, had mined

    coal under such extraordinary conditions, and since the behavior of the coal

    in this seam, when opened in various ways, was unpredictable, the first mine

    was divided for experimental purposes into several panels, in each of which

    a different method was used.

            The first method utilized was long wall advancing, using electrically

    driven English-made diamond disk cutters, manned by English and Scottish

    machine men. To continue to reach the various loading points along the

    working face with mine cars, it was necessary to carry finger roadways fanning

    out from the cross-entry, as the latter advanced. Because the seam was narrow,

    and there was some roof settling and occasional small rolls in the roof or

    floors, a continuing amount of rocks work was necessary to keep these roadways

    open for the passage of the mine cars. All the broken rock was used for wall

    or pillar packing to support the roof — a considerable item of handling

    expense. The face was protected by two or three rows of wooden props, most

    of which were recovered and used again and again.

    011      |      Vol_IIB-0266                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

            A little later, to avoid so much rockwork, another panel was opened,

    longwall advancing, machine-cut as before, but equipped with electrically

    operated face conveyers (something new in those days), each 300 ft. long.

    A pair of these fed to a single roadway, thus greatly reducing the amount

    of rockwork necessary. Another panel, similarly undercut, utilized the

    method of longwall retreating. This involved more preliminary preparation,

    and its use came more slowly.

            The manager had great faith in the common American method of room-and-

    pillar mining, and a portion of the mine was opened and prepared for this

    manner of operation. American-made shortwall chain cutters, electrically

    driven, manned by American-trained operatives, were utilized. It was found

    that this method was admirably adapted to this seam and this coal, and these

    operating costs proved to be the lowest of all. Pillars were readily

    recoverable. The smooth flat floor was excellent for moving equipment, for

    shoveling the broken coal, and for tramming.

            Modifications of the above-described methods were tried, sometimes

    machine-cut, but often hand-cut, as skilled machine runners were scarce.

    Some variations in the seam required special methods of mining. In fact,

    nothing applicable was left untried. Ultimately, the conclusion was reached

    that the machine-cut, hand-trammed, room-and-pillar method was the cheapest

    and best for winning coal from this seam.

            On the east side of Longyear Valley, No. 2 mine was opened, in order

    to prepare for increased production, to learn more about the coal, and to

    have a mine in reserve in case of a serious catastrophe in No. 1. The portal

    was 900 ft. above sea level; 4 to 4½ ft. of clean coal showed in No. 2 seam;

    it was fully as good as the best showing in No. 1 mine. The main entry was

    012      |      Vol_IIB-0267                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    driven south 20° E., to give it a very slight upgrade as it advanced. Work

    here was pushed as rapidly as conditions permitted, but significant data as

    to mining methods and costs were not obtained in mine No. 2 during the

    period of American operation. However, this work went smoothly and well,

    and no adverse conditions were encountered at this point.

            The important point to be noted is that the minability of this Spitsbergen

    coal was thoroughly demonstrated; no especial difficulties were encountered,

    no unusual problems presented themselves underground, and the responsible

    officials were convinced that, as far as technology was concerned, no one

    need hesitate to engage in similar coal mining in this or any similar arctic

    area. This conclusion is noteworthy; it was reached after more than five

    years of well-planned, carefully controlled, and properly executed mining

    operations much farther north than ever had been tried before.

            Room and Pillar Mining . The first room-and-pillar panel lay in the

    northeast corner of No. 1 mine, and thus was bounded by the outcrops on the

    north and east. Rooms were turned at 50-ft. centers, and were first driver

    to 30 to 35 ft. wide, leaving 15- or 20-ft. pillars. These rooms were run

    200 to 300 ft. long, depending on the location. To complete the panel, some

    rooms were turned at 45° from the cross-entry. Pillars were robbed retreating.

    Initial tramming was by hand; and main-and-tail-rope haulage was utilized

    in hoisting up the main slope to the surface. The whole system worked

    smoothly and well, so similar panels were opened in other parts of the mine.

    The use of this method of mining would have been expanded had the Arctic

    Coal Company continued its operations.

            Since this article was written primarily to describe mining practices

    in Spitsbergen, and because the room-and-pillar method winning coal on

    013      |      Vol_IIB-0268                                                                                                                  
    EA-I. Turner: Coal Mining in Sp ti it sbergen

    the island was proved by the Americans to be the best, as is unqualifiedly

    declared here, probably a more complete statement of the reasons for this

    choice is required. There seems to be no better source than the annual

    company report of Turner for the period September 1, 1913, to May 31, 1914,

    in which he had the following to say regarding this matter:

            “During the past year, mining according to the American room-and Pillar

    method has been carried on extensively in order to prove whether or not this

    method is superior in Spitsbergen to the English Longwall system used since

    your property began to produce.

            “The comparative costs of mining have been before discussed in this report,

    in the paragraph headed COST OF MINING. The comparison showed that room-and-

    pillar mining, machine-cut, was the cheapest method yet used, and this surely

    is the best test to apply. There are, however, other reason which make the

    working of coal out by rooms the best method. Briefly and in part, these are:

            “In this system, more working faces, and therefore space for more miners,

    are available in a given coal-area.

            “Each pair of men can have two or three rooms, and keep their own working

    places for weeks at a time. This encourages mining in a workmanlike manner,

    and enables them to have their tools, tracks, and coal faces in good order.

    In longwall mining, each man gets a different place to work each day.

            “The men work independently, and at their own speed. On a longwall face,

    the quickest can work no faster than the slowest, and progress on a face

    300 ft. or more long may be held up while one man gets his cut loaded out so

    the machine can cut the whole length of the face again. Even with conveyor-

    tramming, the men work in gangs of 8 men, and one poor man may delay the rest.

    014      |      Vol_IIB-0269                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

            “When working in the same place day after day, the men become more

    familiar with the nature of the roof at the particular point, and are

    better able to guard against being caught by falling rock, or other inci–

    dents. It also lessens the danger arising from misfires.

            “Working on contract in rooms, it is easier to keep track of the

    quantity of coal produced, for correct settlement; and also to judge of


            “With many rooms opened, it is possible to keep quite a reserve in

    the mine, both as to coal under-cut, and ready to be shot and loaded out,

    and also as to coal already broken but not loaded. Thus a breakdown of

    power is not immediately felt as in longwall; coal can be hoarded for quick

    use in case steamers and coming shortly, or the ropeway is out of order

    for the moment; and there is always a place for the machine-runners to

    continue cutting, or the miners to continue loading.

            “There is much less rock-work and rock-packing than in longwall mining,

    and the saving in this item alone is large.

            “For these and many other reasons we are in favor of this method of

    mining, and it seems probable that better results and lower costs would

    have been had throughout your operations on Spitsbergen if room-and-pillar

    mining had been adopted from the first, instead of longwall.”

            Safe Mining Practices . At best, underground mining is a hazardous

    occupation. No measure can be adopted which will make it completely safe.

    The greatest publicity is always given to major disasters (lose of five or

    more men at a time), such as mine explosions, but few laymen realize that

    these explosions account for a relatively minor number of underground injuries

    and deaths. The real killer, falls of roof and face, causes about 50% of

    015      |      Vol_IIB-0270                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    fatal accidents in bituminous mines, and 20% of nonfatal; but since these

    accidents seldom affect more than one or two men at a time, they do not make

    the newspaper headlines, and the public does not hear of them.

            The second largest killer is haulage (mine cars and locomotives), where

    perhaps only one man is killed at a time, but the annual total amounts to

    about 20% of all fatal injuries. These two alone cause to 70 to 75% of mine

    deaths. Next in importance are explosions of gas and coal dust, which account

    for about 13% of the fatalities. After that come the hazards of explosives,

    electricity, machinery, mine fires, shafts, and inclines; flying particles,

    stumbling, falls of persons, hand tools, etc., all cause accidents, maybe

    injuries, perhaps fatalities. In an operating coal mine, there are hazards


            In a previous paragraph, the difficulty of starting a flow of workmen

    to the new Spitsbergen coal mines was described; it was obvious that if the

    news of a major mine disaster reached Scandinavia, or if working in the mine

    proved unduly hazardous to individuals, the venture could not succeed. There–

    fore, an initial requirement in securing labor was to make mine operation safe.

            As stated, from the first the management was safety-mined and took

    every precaution possible at that time to insure the safety of the men. Many

    factors were in their favor. Since the coal was frozen, there was no water,

    and no underground pumping problem. Since there was no gas, the danger of

    fire or explosion from this cause was absent. However, only safety lamps

    were allowed underground; open lights were taboo (at that time the electric

    cap lamp had not been perfected). Since the miners all used snuff orally

    and did not smoke, they did not carry matches. Since there was no electric

    haulage, there was no bare trolley wire or cable-real locomotive to cause

    016      |      Vol_IIB-0271                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    fires and electrocutions. Since gathering was done by hand or horse

    tramming, and the main-and-tail-rope haulage was not high speed, there

    was little danger of serious haulage accidents. Since the amount of elec–

    tric wiring in the mine was relatively small, this cause of electric shock,

    fires, and explosions was at a minimum.

            However, there was always present the danger of a coal-dust explosion,

    which, once started, might be propagated throughout the mine, causing great

    damage and loss of life; this problem had to be dealt with vigorously and

    correctly, since its solution was so vital to the whole Spitsbergen enter–

    prise. At the beginning of the American operations, Turner sent samples

    of coal dust to England and to the United States for analysis and for tests

    on explosibility of the dust; formulas for permissible explosives were

    worked out, and orders for blasting powder conforming to the indicated

    requirements were placed. No nonpermissible explosive were allowed in

    the mine.

            Fine particles of bituminous coal are potentially violently explosive

    when suspended in an atmosphere of normal oxygen content, and may be

    touched off by a spark of flame; the local explosion may then be propagated

    with cumulative force throughout the mine workings. All coal mining unavoid–

    abl e y produces coal dust, as the result of cutting operations by hand or

    machine; blasting produces coal dust, as does loading and handling. The

    finest of this is air-borne for considerable distances before it settles

    on the floor, in crevices of the walls, on timbers, and in every irregu–

    larity of the coal or rock surfaces. In tramming, the fine material sifts

    from the cars and is distributed along the roadways. If a gas pocket is

    ignited, an improperly loaded or stemmed shot blows out, or enough vibration

    017      |      Vol_IIB-0272                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    or puff results from any cause, this fine coal dust rises again in the mine

    air, and conditions may be right for a serious and far-traveling explosion,

    which gathers force as its face advances.

            To deal with this menace, complete rock dusting was considered. This

    meant sprinkling finely ground, inert rock dust on timbers, ribs, and floors;

    this would dilute and partially cover the coal dust and thus help prevent it

    from rising. Experience shows that, to prevent the propagation of coal-dust

    explosions, a minimum of 65% of incombustible material in the dust must be

    maintained to within 40 ft. of the coal face. When the mixture of dust did

    rise and float for a time suspended in the air, if the proper quantity of

    the fine inert rock were present it would serve to cool an advancing flame

    below the ignition point of the coal dust, and retard and eventually stop

    the advance of the explosion. This process is aided by having self-tripping

    troughs of containers of rock dust suspended from the roof, to add their

    cloud of inert material to that already sprayed through the workings.

            In the early stages of the operations, machines to grind the rock and

    others to distribute the resulting dust were not available. Likewise, it

    was found that the moisture in the introduced fresh air during the summer,

    and at all times that produced by the breathings of men and horses, condensed

    on roof, walls, and floor, in the form of small crystals of ice, which

    remained as a permanent coating and thus partially, if not completely,

    obviated the necessity of complete rock dusting at that time. Additional

    precautions against dust explosions included: rock blasting only on the

    night shift when men and horses were out of the mine; coal blasting at a

    different time, with sufficient time elapsing to allow resultant coal dust

    to settle; removal of cutting before blasting; scattering o r f rock dust or

    018      |      Vol_IIB-0273                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    fine sand in each working face before blasting coal; detonating electrically,

    and one at a time, all shots in coal; proper loading and stemming of all

    shots by an experienced workman; rigorous supervision by skilled men of all

    blasting operations It should be recorded that all these precautions

    afforded adequate protection, and no mine explosion of any sort occurred

    during the American operations.

            Many of the hazards of coal mining can be avoided only by the care,

    caution, and cooperation of the individual miner. Competent instruction

    was given the new men, adequate supervision was provided at each working

    face, experienced miners were employed to do the most dangerous jobs, and

    great emphasis was put upon adherence to rules of safe practice. The results,

    for the five years of American operation, were exceedingly satisfactory; a

    few injuries occurred among the men, but these were due to disregard of

    instructions given by the bosses. This is apt to be the case even in long–

    established mines worked by experienced men.

            By strict adherence to recognized safe mining practices with high-grade

    supervision, coal mining was carried on in this newly opened arctic mine with

    a minimum of injury to the men. As a result, an adequate supply of workmen

    was secured and the labor requirements of the Arctic Coal Company were met

    with an increasing influx of more and more experienced and dependable

    workmen, many of whom worked for years in these mines.

            Labor . To establish and maintain mining operations is an unknown,

    uninhabited, cold, and distant land, an immediate problem is to secure,

    develop, and expand a supply of acceptable workmen, if these men are free

    to make their own decisions, and are not to be drafted or recruited under

    compulsion. The unknown character of such employment naturally makes

    019      |      Vol_IIB-0274                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    change numbering on this and subsequent pages prospective recruits, especially if they are simple country folk such as

    small farmers and fishermen, wary and suspicious. They are reluctant to

    sign their first contracts and to push off into the unknown, to and from

    which they can travel only on ships operated by the employer, and from

    which they cannot depart during the season of closed navigation, approxi–

    mately eight months in the year. The face working under strange bosses

    and supervisors who speak a language unknown to them.

            Therefore, from the beginning, labor must be handled carefully, and

    the confidence and respect of the workmen must be gained and kept. Other–

    wise, no free arctic venture of this sort could succeed in the long run.

    This point also has an important bearing on the choice of mining methods.

    Given proper food, lodging, and medical attention, each man must learn to

    feel safe in the mine; accidents must be avoided. Unless this is accom–

    plished within reasonable limits, the working force will dwindle and the

    mining venture will fail. Therefore, it has been thought wise to include,

    in former paragraphs, a description of necessary and proper safety measures

    which should be adopted and rigidly adhered to when mining commercially

    under conditions such as described here.

            Since there was no coal mining in Norway, and very little in Sweden

    (less than 75,000 tons of brown coal annually), no experienced coal miners

    were available. Neither were men to be had who were experienced in any

    sort of underground work, outside of a small number of troublesom e metal

    miners listed as undesirable by the Scandinavian mining companies, who

    could fin e d no employment nearer home.

            Considering the isolated locality, the necessary crudity of living

    conditions, the reputedly hazardous nature of the employment, the strangeness

    020      |      Vol_IIB-0275                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    of the foreign bosses, the lack of military police or judicial protection,

    the absence of recr e ational, educational, and religious facilities, and the

    long and complete separation from family and friends, it is not surprising

    that, at the beginning, difficulty was encountered in procuring satisfactory

    labor for the Spitsbergen coal mines. However, as time progressed as the

    men found themselves well house s d and fed, as the superintendents and bosses

    established reputations for fairness and competence, and workmen lost their

    reluctance to take jobs in the Far North. Later, men were gladly returning

    year after year; in fact, a considerable selective screening could be applied

    by the company. Eventually, it seemed to be considered a privilege to work

    on the island.

            The manager, superintendents, and some operating officials, bosses,

    and skilled workmen were brought to Spitsbergen from various parts of the

    United States. Other bosses, machine runners, timbermen, loaders, and shot

    firers were imported from England and Scotland, largely from Northumberland,

    with Sheffield as a recruiting base. The chief medical officer, master

    mechanic, and head electrician were usually English, but sometimes American.

    About 75% of all surface and underground labor was Norwegian. As indicated

    before, embryo miners were recruited from small Norwegian coastal villages,

    where they worked as farmers or fishermen. They had to be taught to mine.

    There were some Swedes and Finns, and occasional Dane or German, and rarely

    a Russian. Labor turnover was necessarily high. About one out of three

    American engineers employed was able to adapt himself satisfactorily to

    the rigorous conditions. The skilled English miners generally did well.

    A competent force of Norwegian miners was gradually developed, and some

    became machine runners or sub-bosses. Surface and cargo-loading bosses

    021      |      Vol_IIB-0276                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    were generally Norwegian or Swedish, and some of them were very good.

    Labor gradually became stab i lized so that an adequate force of picked men

    could be regularly maintained at Advent Bay.

            Efficienty and Health . The question has been raised whether there was a

    drop in the efficiency of the min d ers during the long sunless season, from

    October 25 to February 17. The writer has expressed his opinion that there

    was not. He supports his view with charts of monthly coal-production rates

    per man per shift, and with monthly cost sheets, which still bear convincing

    testimony to its correctness. The middle of the dark season was often the

    period of highest underground efficiency.

            It was also asked whether the closing of navigation, and the resultant

    necessity of staying for eight months at the company’s camp, disturbed or

    worried the miners enough to interfere with their work. Again, the writer

    replied in the negative; he explained that the opposite was the case.

    During the summer, when ships were arriving or departing almost daily,

    there was a feeling of restlessness and uncertainty among the men; it was

    a constant temptation to quit the job, step aboard a ship, and be back in

    Norway within two or three days, to spend the savings and procure things

    not available in the austere mining camp. When the last ship had left and

    travel was no longer possible, the men settled down in earnest for the

    long pull, and often did their best underground work in February or March.

            Others have inquired as to the health of the men in this high latitude,

    without sunlight for many months (on the other hand, the midnight sun

    persisted from April 24 to August 23), and with diets necessarily somewhat

    restricted. It was believed by some that scurvy would be a menace, and

    that pathological conditions might arise caused by the unusual climatic

    022      |      Vol_IIB-0277                                                                                                                  
    EA-I. Turner: Coal Mining in Spitzbergen

    circumstances. To these and similar questions, the author says: There was

    no case of scurvy in Longyear City during these years; the health of the

    men during the winter was unusually and uniformly good. The return of day–

    light and the coming of high winds affected some of the men adversely. With

    some, it was a period of melancholy; there was a tendency to lie in bed and

    brood. Others became uncontrollably restless; occasionally one ran wild

    into the hills and had to be pursued and brought back to camp. Perhaps

    these were naturally unstable individuals; there were all kinds at Advent Bay.

            Unfortunately, no reliable medical data or dependable notes based upon

    skilled medical observation are available. Competent or successful doctors

    would not take the island job; the chief medical officer, generally English,

    while he was the best available, did not rate very high professionally or

    otherwise. Thus was lost a fine chance to accumulate accurate data regarding

    the effect on health of living in high latitudes.

            Because of long experience in isolated mining camps, the manager knew

    that the boarding house often caused more trouble than the mine. Therefore,

    the best available food was obtained, cooked, and served in the best manner

    possible. Since the men were charged only $0.40 per day for board and lodging,

    the company lost money in this department. Housing was good. Medical atten–

    tion was the best that could be had. The company store was well stocked, and

    goods were sold at cost. There was a lack of recreational facilities, but

    this was not important at that time.

            Other favorable health factors were: the sterile nature of air, soil,

    and water; the lack of exposure to crowds, and thus the avoidance of communi–

    cable or infectious diseases; the rugged simplicity of the life; the necessity

    of working and keeping physically fit; the lack of alcohol and of chances for

    023      |      Vol_IIB-0278                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    dissipation in various forms; the opportunity for close control of living and

    health conditions by the operating officials. On the whole, it was a healthy

    existence. Officials did not permit loafing; lying idly in bed for days and

    eating heartily of the heavy food was not permitted.

            When the first boat arrived in the spring, often during the latter part

    of May, bringing a change of crew, all the winter men immediately were afflicted

    with severe head colds; they seemed to be completely without immunity. This

    was annoying but never serious.

            To summarize, it was found that most men could keep in good health and

    maintain customary efficiency, despite the severe climate and the long winter

    night, if ordinary and reasonable rules of living and working were observed.

    This was the unqualified opinion of the top officials of the Arctic Coal

    Company; the practical demonstration of this fact was an important step

    toward more complete knowledge of the practicability of industrial coloniza–

    tion in the Far North.

            Stockpiling Coal . Since the waters are sufficiently ice-free for steel

    colliers for at most four months of each year, and since the production of

    coal can best be accomplished during the season of closed navigation, the

    large-scale producer Spitsbergen coal would be confronted ultimately with

    two storage problems.

            The first is on the island. Here, more than two-thirds of the annual

    production must be stockpiled. This must be done in the open. Early in

    the American era, it was feared that coal piles would be covered with snow,

    which would melt with the coming of the summer sun, the resulting water would

    trickle down around the frozen coal and again become ice, so that the loading

    shovels would have to work on a mass of solidly compacted coa l. To eliminate

    024      |      Vol_IIB-0279                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    this danger, the topography was studied, and a large natural flat area, or

    bench, completely exposed to the winds, lying between the mines and the

    loading dock, was chosen. There, the high winds swept the snow away and kept the

    stockpile bare.,

            coal was brought down from the mine by a gravity-run aerial tramway,

    and a cross ropeway was installed to operate along the major axis of the

    storage space. Thus, an inexpensive device for stocking the winter coal,

    sufficient for the initial stages of production, was obtained. When ships

    were under the loading chutes, coal came direct from the mine storage bins,

    and at the same time, the steam shovels loaded into the surface cars which,

    by gravity, in balance with the empties, were lowered down a double-tracked

    inclined plane, and then moved by power-driven main-and-tail ropes the length

    of the bridge and up to the loading staiths. Thus, coal from the mine and

    from the stockpile was loaded at the same time.

            During the five-year period under consideration, when elaborate and

    expensive permanent large-scale installations were avoided because money

    outlay had to be limited during the pioneering trial operation, this equip–

    ment proved adequate and economical. For permanent, large-scale operations,

    more extensive and expensive storage equipment would be needed on the island

    but the same result would be expected, and the coal would not deteriorate in

    the pile, as it would remain frozen throughout its stay. No danger of heating

    or of spontaneous combustion was to be expected.

            The second storage problem was encountered in north Norway, where most

    of the coal was delivered. This coal was used largely for bunkering coastal

    vessels; some was for domestic purposes. Since these Norwegian waters are

    ice-free all the year, coal could be brought from England or from Germany,

    025      |      Vol_IIB-0280                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    as needed, throughout the year. So all storage yards were small. If a

    considerable tonnage was top com d e to Norway from Spitsbergen in short

    four months, adequate company-owned storage yards would seem to be required.

    However, this problem did not become acute during the period herein described,

    and existing facilities and local yards managed to handle all shipments. If

    large supplies of Spitsbergen coal had been acc o u mulated in Norway, a long

    stay in the milder climate would probably have resulted in the gradual

    thawing of the coal, and the consequent disintegration of some of the lump

    coal and the production of more fines. However, this contingency did not

    have to be faced by the American company.

            Markets for Coal . At the start of coal production by the American company,

    no market for Spitsbergen coal had been developed. Some abortive attempts

    by small, unstable groups of Europeans had been made f t o mine coal on the

    island, such as the disastrous try by an English company on the north side

    of Advent Bay, where small quantities of dirty, intensely shattered and

    faulted, low-grade coal (supposed to be of Carboniferous age) were won from

    a seam lying about 1,250 feet vertically below the Tertiary seam of clean,

    high-grade coal outcropping on the south shore of Advent Bay, which was

    chosen for exploitation by the American company. The little coal that had

    reached Norway through those channels was found to be of such poor quality,

    and the deliveries were so irregular and small, that a prejudice against

    Spitsbergen coal had been engendered.

            At first approach by the American company, consumers doubted the quality

    of coal that was offered by it, and questioned the ability of the company to

    deliver regularly and in quantity. These objections were overcom d e when the

    company guaranteed the analysis of the coal to be delivered, agreed either

    026      |      Vol_IIB-0281                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    to deliver Spitsbergen coal or like amounts of Davisons-Cowpen-Bot b h al

    (then the standard of high-grade steam coal shipped from Northumberland),

    and sent trial cargoes for tests by actual utilization. The story of the

    gradual establishment of a ready market for this Longyear Valley Spitsbergen

    coal would be so long as to be out of place here, although it was a basic

    factor in the organization of a commercial mining operation by the Americans.

            Ships and Shipping . The most useful all-purpose vessel owned and

    operated by the Arctic Coal Company was the S.S. W. D. Munroe , a wooden

    vessel 153 ft. long and 26-ft. beam, double planked with oak, with the bow

    strongly reinforced inside and shielded by heavy steel strips outside for

    protection when forcing its way through thick ice. It had a Norwegian

    certificate for 150 passengers; its registered tonnage was 433 gross, and

    about 380 tons dead weight on an 18-ft. draft; it was classed by the

    Norwegian Veritas. This vessel was used for the first and last trips;

    transported most of the men, supplies, and equipment to and from the island;

    and carried coal to Norway when not otherwise employed. It was a typical

    old-style arctic whaling vessel converted to industrial use; it flew the

    United States flag. This ship withstood a great deal of very rough treat–

    ment in the arctic ice pack, and was found to be staunch, sturdy, and

    dependable. It was operated without insurance, entirely at the owner’s


            The largest ship owned and operated by the company was the steel

    turret-type collier Kwasind , 4,400 tons dead weight, flying the Canadian

    flag. It was classed by the British Corporation, and spent about three

    months in the year transporting Spitsbergen coal, and the remaining mine

    months running in European coal, iron ore, and timber trades.

    027      |      Vol_IIB-0282                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

            Arctic Coal Company time-chartered or trip-chartered, annually, a

    number of steel colliers of an average coal-carrying capacity of 2,200 tons

    dead weight. This proved to be an ideal size as it fitted well with the

    receiving docks and yards in north Norway.

            World War I . Just as the American mining operations in Spitsbergen

    were becoming stabilized, and coal production was increasing with lower

    unit costs, World War I began in Europe. Perhaps no better description of

    the immediate effect on the Spitsbergen venture can be given than that written

    by the manager in his annual report of the Arctic Coal Company, covering the

    period June 1, 1914 to May 31, 1915. In part, Turner’s report was as follows:

            “The coming of the European war in August, 1914, created momentarily

    a general panic in Norway; the immediate effect of this was: To make our

    ship-owners and operators panicky; to withdraw all banking facilities, both

    as to cheques and commercial paper and exchange; to cause prohibitions of

    export and restrictions of telegraph and post service; to start a food–

    panic which ran the prices of all food-stuffs up alarmingly; to make all

    our customers clamor for immediate delivery, and change their orders as to

    receiving ports for various cargoes; and to make some of our wholesalers

    cancel their contracts with us for supplies; all import of foreign machine–

    supplies, as from Germany and England, was stopped.”

            Further on, he explains how adjustments were made to meet the new

    conditions, and says:

            “Ship-owners were quickly induced to continue their trading to

    Spitsbergen at their contract rates; our office want at once on a cash basis

    with a large reserve of currency; special permission was secured from Kristiania

    for certain exports; our food-stocks on Spitsbergen were so ample by the first

    028      |      Vol_IIB-0283                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    of August that no supplies had to be bough except perishables such as

    fresh meat and vegetables; we increased our loading-speed and made full

    deliveries on all outstanding coal-contracts, and made customers pay the

    extra freighting costs when they demanded longer hauls; and most of the

    wholesalers and manufacturers were forced to deliver goods to us according

    to contracts. Our position as to stocks on hand of explosives, store-goods,

    machine-supplies, and food-stuffs was so strong that we really felt but

    little effect of the war, relying on materials already on Spitsbergen.

    However, this position was wholly altered by the end of May, 1915, after

    running nearly a year on our reserves, and in 1915 it would have been very

    difficult to increase our stocks to the normal and provide for a large crew

    for the coming year. Therefore, we should conclude that the effect of the

    European war is to make operation on Spitsbergen increasingly difficult,

    if not impossible, and certain special war-legislation now pending in the

    Norwegian storthing may close Spitsbergen to operations by foreigners for

    at least the duration of the war. While coal-prices will probably be good

    during the war, yet tonnage is scarce and expensive, often difficult to get

    at all, and the costs of all supplies have gone up so that a new system of

    charges for board, etc., would have to be introduced on the island. The

    whole position in Europe is so unsettled and problematical, that this

    factor alone would seem to be decisive in the matter of farther large-scale

    operation on Spitsbergen.”

            Turner recommended drastic curtailment of production, decrease of

    personnel, and closer attention to the inquiries from interested European

    groups who had stated they might buy the mines. In his next report to the

    company, covering the period June 1, 1915 to October 31, 1915, he stated

    029      |      Vol_IIB-0284                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    that on the last ship to leave Advent Bay, on September 23, 1915, all

    the men but three Norwegians were taken to Norway. The report records

    that two horses, eight dogs, two pigs, and one cow were also left at the

    camp. The stockpile then contained 21,096 tons of coal, which could not

    be shipped until the following summer. He also wrote:

            “The mine has been closed and boarded up, after putting all machines

    and tools in order and in place; the mine is clean and in excellent condi–

    tion, and operations could be resumed there at a day’s notice. The camp

    is in good order, and in addition to supplies for the three men, in the

    warehouses are provisions, supplies, and store-goods enough for 100 men

    for three months, to take care of the entire crew necessary to load the

    remaining coal in 1916. The power-plant and all machines are dismantled,

    painted, greased, covered, and stored in good order, and no damage should

    come to any of the equipment this Winter.”

            End of American Operation . As it turned out, this marked the end of

    American coal mining in Spitsbergen, as increasing difficulties of operation

    arising from the war, including the government prohibitions to prevent men

    of military age from leaving Norway or Sweden, the growing submarine menace,

    and the export bans on explosives and on many items of supply and equipment,

    made it impossible to continue.

            Employees were paid off, extra supplies were marketed at high prices,

    all the ships were sold on a very strong war market, and, steps were taken

    which resulted in the sale of the mines to a Norwegian group. At that time,

    the Norwegians were particularly keen to own their own source of coal supply,

    as none was mined in Norway, and wartime imports from Germany and England

    dwindled in amounts until an acute shortage existed. The Norwegian govern-

    030      |      Vol_IIB-0285                                                                                                                  
    EA-I. Turner: Coal Mining in Spitsbergen

    ment needed fuel for the navy, for the government-owned railways, and

    for many other official purposes.

            The Russian government had taken an option on the mines in 1915, as

    coal was sorely needed for the operation of the recently completed Murmansk

    railway. Turner went to Petrograd to close the deal, but responsible

    officials and fled that capital by the time he arrived.

            He then went to Christiania (Oslo) for a conference with the Prime

    Minister and a group of banking and shipping leaders, out of which negotia–

    tion came the sale and transfer to a new Norwegian company of all the rights,

    titles, and interests of the Arctic Coal Company.

            Here ends this short description of arctic exploration by the Americans,

    the outline of results obtained, and conclusions reached as to the feasibility

    of mining coal within eight hundred miles of the Pole. Detailed office

    records of the whole venture are still in existence, including the compre–

    hensive periodic reports of the manager, with tables and charts of production

    and costs. (More recent information, regarding later operations by other

    nationalities, is given in another volume of the Encyclopedia Arctica Encyclopedia Arctica .) ✓ underline

    This record ends in 1916. This chapter is a condensed story of the first

    successful large-scale exploration and commercial exploitation so far north.

    Unlike most polar exploration, this one had to pay its own way; the purpose

    was to make money, and the final result was satisfactory. Leaders of polar

    exploration seldom have to face the necessity of commercial success. There

    appears to be no question but that this was the first large pioneering more

    to colonize and industrialize an area so far north, and to establish there a

    successful mining operation. The record of the Arctic Coal Company seems to

    constitute an important chapter in the history of polar exploration.


    Scott Turner

    Blasting in Surface and Drift Operations in the Far North

    001      |      Vol_IIB-0286                                                                                                                  
    EA-I. (L. G. Anderson and P. R. Moyer)


            The permanently frozen ground in Alaska has been mined chiefly for

    gold and its alloyed silver, although some coal is extracted for local con–

    sumption. Future extraction of other minerals is problematical and will

    depend upon demand and cost. Generally, placer-mining methods are used in

    recovering gold although some drift mining is followed to some extent in

    recovering rich, moderately thick, pay streaks that are overlain by a deep

    barren or low-grade overburden. Drift mining is best applied in permafrost,

    where the gold deposits are found near or in the upper few feet of bedrock.

            The use of explosives in placer mining is limited, as the frozen ground

    must be thawed before the gold can be recovered. The usual practice is to

    thaw the ground with steam or warm water to facilitate removal and treatment

    of the gravel. Explosives are used to break up the large boulders and to

    blast unthawed sections; in some instances, explosives are used to hasten

    the thawing action of water. Explosives are used in sinking shafts for drift

    mines, and for breaking the frozen ground and bedrock in the actual extraction

    of the ore or coal. Explosives are also used in excavating test pits and

    channels in prospecting and exploration work, and for geophysical exploration.

            In the early days, only a small amount of explosives were used in

    blasting in surface and drift operations as the kinds of explosives available

    002      |      Vol_IIB-0287                                                                                                                  
    EA-I. Anderson and Moyer: Blasting

    were not suitable for the conditions encountered and the cost was excessive.

    Available explosives froze readily and were exceedingly hazardous to handle

    as thawing was necessary before they could be used. Refinements and improve–

    ments in the manufacture of explosives, and added knowledge of the results

    that can be obtained through efficient manipulation, have resulted in an

    increase in use for blasting purposes. However, the cost is still excessive

    and, as a result, explosives are not used to an extent comparable in mining

    operations in more temperate regions.

            Special consideration must be given in the selection of the kind of

    explosives to be used in any operation, and this is particularly true where

    extreme conditions are present as in the region of permafrost. Explosives

    used in blasting operations where cold climates prevail must have a low

    freezing point for safety in transportation, storage, handling, and use.

    Precautions must be taken during transportation and storage periods to prevent

    freezing or deterioration, as frozen dynamite is hazardous to handle and

    thawing is a dangerous procedure; frozen dynamite must be thawed before use.

            Formerly, nitroglycerin, which has a fairly high freezing point, was

    the only explosive ingredient used in the manufacture of dynamite. In recent

    years, other explosive ingredients have been added to the nitroglycerin,

    chiefly to lower its freezing point. Nitro-substitution compounds, such as

    dinitromonochlorhydrin, dinitroglycol, and tetranitrodiglycerin, prevent the

    solidification of nitroglycerin at low temperatures and the mixture is called

    an explosive oil. This explosive oil is similar to nitroglycerin in detonating

    strength. Virtually all active-base dynamites manufactured in the United States

    at the present time, whether straight, ammonia, or gelatin, are of the low–

    freezing variety and will resist freezing at temperatures considerably below

    003      |      Vol_IIB-0288                                                                                                                  
    EA-I. Anderson and Moyer: Blasting

    the freezing point of nitroglycerin. When special precautions are taken

    during transportation and storage, they can be used with safety and effi–

    ciency in subzero temperatures.

            High explosives which do not contain a liquid ingredient that can

    freeze are a decided advantage in cold climates and are useful for special

    purposes. However, such explosives have many disadvantages which preclude

    their use. They usually lack plasticity, are often somewhat dusty, and are

    low in density strength and sensitiveness. Explosives of this type have been

    tested in blasting operations in permafrost areas but have not given satis–

    factory results.

            High explosives classe s d as “Nitro carbo nitrate” contain no liquid

    ingredient but require a booster to start detonation. These explosives are

    composed mainly of ammonium nitrate, and when packaged in waterproof metal

    cans will store well. They are exceedingly powerful and are useful in

    seismograph exploration. The explosives cannot be detonated with an ordinary

    commercial detonator and require a booster or primer to start detonation.

    The primer is composed of amatol, a mixture of trinitrotoluene and ammonium

    nitrate, and can be detonated by a No. 6 detonator.

            Permanently frozen ground, because of the ice content, is not consoli–

    dated; therefore, blasting is not a major problem. There is no question

    regarding the size of the broken material and low-strength explosives are

    best suited for the work. In surface mining, explosives are used chiefly to

    fracture the permafrost as an aid in speeding the thawing process.

            Permissible explosives are high explosives that have been modified to

    lower the temperature of the detonation flame, and, in addition, have a very

    good fume classification making them suitable for underground use. They have

    004      |      Vol_IIB-0289                                                                                                                  
    EA-I. Anderson and Moyer: Blasting

    a low explosive-oil content but have sufficient strength for use in blasting

    permafrost. They are manufactured in a large range of strengths and sizes.

    The chief disadvantage is the large ammonium nitrate content, which requires

    precautions in storage to prevent deterioration. Humid atmospheres are also


            At one coal-strip mine, an adequate supply of water is available for

    thawing the frozen overburden. The water is pumped through 8- and 12-in.

    lines to hydraulic nozzles in the stripping area. Streams of water from the

    nozzles are continually played on the frozen ground to assist in thawing and

    dispose of the lighter and mucky material. Bulldozers are used to remove

    the larger rocks and debris that are too heavy for the hydraulic operation.

    The overburden of gravel and muck at this strip pit is approximately 30 ft.

    thick and removed entirely by the above method. The formation immediately

    overlying the coal bed is a more or less frozen, unconsolidated sandstone,

    which thaws and weathers very rapidly when exposed. From time to time it has

    been necessary to speed the thawing and removal of this sandstone, but this

    is not readily accomplished by playing streams of water on the freshly exposed

    frozen surface. The frozen sandstone is drilled and blasted to fracture the

    formation, after which the water is permitted to seep through the fractures

    and speed up the thawing action. This work is effected by drilling holes

    approximately 20 ft. in depth and 5 ft. apart in a horizontal line and

    inclined approximately at the same angle as the dip of the coal bed. A

    second row of holes is drilled above the first holes. The number of holes

    in each row ranges from 5 to 20. The holes are first “sprung” with a charge

    of 4 or 5 cartridges of explosives, after which each is loaded with 15 to 20

    cartridges of 20% dynamite. All the holes are fired simultaneously with

    005      |      Vol_IIB-0290                                                                                                                  
    EA-I. Anderson and Moyer: Blasting

    instantaneous electric detonators. After blasting, the hydraulic nozzles

    are played on the fractured sandstone for further thawing and erosion. The

    coal is frozen to a depth of approximately 30 ft; however, very little

    blasting is required to lo e o sen the coal before shoveling

            Coal-mining operations in one district are somewhat different from

    methods used in any other place. The overburden at one mine is approximately

    35 ft. thick and is frozen the year around; the underlying coal is below the

    level of the river. Considerable difficulty was encountered in applying

    stripping methods and after one trial was abandoned in favor of mining the

    coal by underground methods. Shafts are sunk through the overburden and the

    coal bed, which is 5 to 6 ft. thick. The coal beds are virtually level in

    this area and can be mined by underground methods. The coal bed is filled

    with lenses of ice, which when thawed, causes the coal to disintegrate into

    small pieces of one inch or less in size. The normal temperature of the under–

    ground workings is below freezing. The coal is mined by hand and blasted

    off the solid with permissible explosives. All mining operations are con–

    ducted during the winter months and are discontinued in the spring, when the

    mine is flooded by pumping water from the nearby river. The water freezes

    and fills the mined-out areas with ice, which supports the roof and prevents


            Explosives have been used successfully in drift-mining operations, in

    sinking shafts in permafrost, and I n developing and mining the frozen gravel

    and bedrock. Slow-acting explosives with good fume classification are

    essential for efficient operation. The explosives are fired with electric

    detonators or plain detonators and fuse. The shattering effect of the detona–

    tion is mainly responsible for preparing the material for sluicing without

    006      |      Vol_IIB-0291                                                                                                                  
    EA-I. Anderson and Moyer: Blasting

    the necessity of thawing; the heat evolved by the detonation plays a

    comparatively small part.

            Magazines for storing explosives and detonators should be well con–

    structed and provided with a safe method of heating to prevent freezing.

    Frozen explosives should be thawed before used, and care should be exer–

    cised during the thawing period. The best practice is to prevent the

    freezing of the explosives.


    Ludlow G. Anderson and Paul R. Moyer

    Safety in Mining in Alaska

    001      |      Vol_IIB-0292                                                                                                                  
    (H. B. Humphrey)




            The history of mining in Alaska is marked by struggle against adverse

    natural conditions that has menaced the life, health, and safety of pros–

    pectors and miners, and made the problem of winning the mineral wealth

    difficult and adventurous. Except in the southern coastal zone, freezing,

    heavy snows, storms, melting ice, floods, and impassable terrain, joined

    with the isolation of camps and individuals and difficulty in procuring or

    moving equipment and supplies are all factors that bring hazards not found

    in more settled and accessible mining regions. These handicaps were extreme

    in pioneer days and still exist in whole or in part in portions of the

    Territory, but the advent of roads, planes, and modern equipment has modified

    and modernized conditions so that the over-all mining safety record compares

    favorably with that of other mining regions in the United States.

            The individual miner or the mine operator was the only overseer of

    safety in the mines up to 1912, when mine inspection was inaugurated. Since

    that year, inspectors of the Bureau of Mines, the Geological Survey, and the

    Territorial Department of Mines have visited the mines in all districts of

    the Territory to see that existing hazards are corrected. Relationship of

    the above agencies has varied, and, at times, a single representative has

    002      |      Vol_IIB-0293                                                                                                                  
    EA-I. Humphrey: Safety in Mining

    combined the functions of all three or of two of them. Before 1912, the

    larger mining companies set up and enforced safety rules at their own mines,

    an example being the Alaska Treadwell mine, in 1904. These larger companies

    have continued the practice and have promoted and conducted safety programs

    in cooperation with the governmental officials.

            These safety programs included accident-prevention classes, mine rescue

    training, first-aid training, and safety inspections, as well as special

    investigations by Bureau of Mines engineers and safety instructors. Official

    inspections and investigations were made by inspectors and engineers of the

    Geological Survey and the Territorial Department of Mines, generally under

    the direction of the Territorial Commissioner of Mines, representing both

    agencies, since establishment of that office in 19 1 3 5. Mines operating by

    lease on government land, as the coal mines are, must comply with the safety

    and operating regulations for such operations. All mines are subject to the

    territorial mine laws. The combined accident-prevention activities of mine

    operators and the government agencies brought about a safety record better

    than the average for mines in the United States. This is noteworthy in view

    of the natural hazards confronting mining in the Territory. The record im–

    proved from 1918 through 1946, the last report available. The over-all

    favorable record was made through excellent management and methods at a

    majority of the mines, overcoming the unfavorable records of a few.

            Lode mines are characterized by great variation in size and, with the

    exception of the Alaska-Juneau mine, by limited spans of operation. The

    great Kennecott was another exception. Possibly the Treadwell mines on

    Douglas Island would have been worked for many more years had their flooding

    been averted. Their safety was improving at that time and would have followed

    003      |      Vol_IIB-0294                                                                                                                  
    EA-I. Humphrey: Safety in Mining

    the trend. Except for 1924, fatal accidents at lode mines were consistently

    reduced in number after 1921, and the nonfatal-accident rate was also improved,

    although to a less notable degree. In 1924, fatal accidents were due to

    explosives, haulage, falling down shafts, and rushes of ore and water from

    ore chutes. These accidents were almost all in the large mines in southeastern

    Alaska and resulted in changes in methods and practices. A rush of water from

    an ore raise caught five men in a haulage drift where they were loading ore

    from the chutes into care. After this disaster, a refuge drift and connection

    were provided at the chute level over the haulage drift, and drainage con–

    nections were made to the ore raises.

            In a period of about 30 years, safe working standards have been improved,

    as in other mining regions of the U.S. Ventilation that will provide a health–

    ful atmosphere is a requirement under territorial regulations. Exhaust venti–

    lation methods are used to remove blasting fumes from bulldozing chambers,

    and men are removed when heavy blasting is done. Exhaust dust-removing

    systems are provided where needed in mills. Wet drilling is required. A

    serious hazard from rushes of ore and water from ore chutes after a “hang-up”

    has been met by driving parallel raises, with frequent crosscuts to the ore

    chutes for drainage and access to hang-ups. Another cause of serious accidents

    in the large mines has been falls into ore passes or through grizzlies at

    bulldozing chambers. Progress in preventing these accidents was achieved

    before World War II and these mines have been inactive since then. Hazards

    from quartz dust have been reduced by requirements for more efficient ventila–

    tion and dust suppression. Suspected danger from arsenic compounds and the

    release of hydrogen sulfide from certain ores requires attention.

    004      |      Vol_IIB-0295                                                                                                                  
    EA-I. Humphrey: Safety in Mining

            Lode mines record most frequent injuries from use of hand tools,

    including air drills, and handling materials. Normally, frequent injuries

    are also caused by being struck by falling ore from bulldozing chambers and

    chutes, falls from of rock from the back, haulage, and slipping and falling of

    persons. Accidents from machinery and serious eye injuries have been few

    in number.

            Placer mines and opencut mines employ more than half of those engaged

    in mining in the Territory. Hazards at these operations have been controlled

    effectively since 1917. From 1918 to 1946, 34 fatalities were reported from

    placer mines compared to 189 from lode mines; nonfatal injuries at placer

    mines totaled 2,110, and at lode mines, 6,793. Accident rates for placer

    operations in the Territory are comparable with those in the U.S. Major

    causes of accidents are: falls of persons, handling of materials, falling

    objects, machinery, lines, and sheaves. These hazards are increased by icy,

    freezing weather, causing slipping and impeding movement. Accidents in early

    summer and in the fall are greatly increased by ice and frost on the dredges,

    and on the thawing and stripping areas. Slipping and falling while walking

    on pipelines or frozen paths is a common cause of injury. Other common

    injuries are particles in the eye, striking the foot with a pick while digging

    in icy ground, mashing fingers while driving thawing points, and burns from

    steam or hot water. The hazards in operation of hundreds of hydraulic giants

    are minimized by the expert handling by experienced operators.

            Attempts to operate underground placer mines, using hydraulic monitors

    in frozen gravels, were unsuccessful because of inability to advance the cut,

    or chamber face , rapidly enough to avoid excessive thawing and sloughing of

    the gravel in the back. The method was found to be dangerous, costly, and


    005      |      Vol_IIB-0296                                                                                                                  
    EA-I. Humphrey: Safety in Mining

            Coal mining in Alaska increased from a production of about 50,000 tons

    in 1917 to about 100,000 tons in 1930, and passed a total of 200,000 tons by

    1941. From 1943 to 1948, more than 300,000 tons a year was mined, approxi–

    mately one-fifth being taken from opencut mines. The number of active

    mines has varied from 3 to 7, and employment from about 100 to more than

    300 men. Although the industry is vital to the Territory, the mines are

    relatively small, and only two have been operated regularly for more than

    a few years. These two, the Suntrana mine at Healy and the Evan Jones mine

    at Jonesville, are opened in a series of coal beds pitching from 30° to 40°.

    The mining methods used in taking coal from these beds have given a good

    tonnage per man although means to mechanize these mines have not been devised.

            An exceptional safety record was achieved because no fatalities occurred

    in the coal mines from 1928 to 1936 and from 1938 to 1941. Two fatalities

    were reported before 1928. The nonfatal-accident rate of these coal mines

    varied greatly because of the small employment but was better than the record

    of the bituminous mines in the United States until 1938; since that year it

    has been generally higher, and the average from 1930 to 1947 is about the

    same for the Territory and the U.S. A disastrous explosion in the Evan Jones

    mine in 1937 caused 14 deaths; otherwise, the fatality rate has been less than

    that of the bituminous mines of the U.S.

            The mines are inspected and worked under the leasing regulations and

    control of the federal Geological Survey for mines on government land. The

    Territorial Department of Mines cooperates with the Survey in the inspection

    and control of the mines. The federal Bureau of Mines contributes safety

    training for employees. The small working crews at these mines allow close

    supervision by mine officials. At the larger mines this is given careful

    006      |      Vol_IIB-0297                                                                                                                  
    EA-I. Humphrey: Safety in Mining

    attention under present management. The explosion at the Evan Jones mine

    was caused by smoking in a place where methane accumulated at a fault with–

    out detection by mine officials. The operator, acting as superintendent,

    did not recognize the danger or the need for regular inspections.

            Pressure for production and employment of inexperienced miners during

    World War II resulted in neglect of safe and conservative mining practices,

    with a consequent increase in accidents. Mining done in 1948 and before at

    the two larger mines has opened too much ground in advance of pillar recovery;

    long rooms on a heavy pitch are difficult to handle and less safe than shorter

    rooms; loose coal left in the roof adds to the chances of accident. Faulted

    ground in the Moose Creek area is a natural hazard as are soft clay bottom

    and loose sandstone top in the coal bed at Suntrana.

            There is a constant menace of fire from spontaneous combustion at the

    Suntrana mine; areas are encountered where outcrop fires have burned out for

    lack of air, and new fires occur in the mine and on the outcrops. In 1942,

    two men were killed in the mine by a fire that shout down the mine for months.

    At the Evan Jones mine, gas and dust are explosion hazards. The use of black

    blasting powder is prohibited and electric cap lamps are used.

            Aside from the deaths caused by explosion and fire, fatal accidents

    were due to falls of roof, falling down chutes, and haulage. Nonfatal acci–

    dents are mainly caused by falls of rock or coal, falls of persons, and hand


            Flooding of mines has caused loss of the mines in several instances,

    although no loss of life is reported. The notable instances were the Cliff

    gold mine in 1913; the Treadwell gold mine, April 1917; and the Primer coal

    mine, November 1933.

    007      |      Vol_IIB-0298                                                                                                                  
    EA-I. Humphrey: Safety in Mining

            Conditions of climate, transportation, and certain physical aspects of

    mineral deposits add to the difficulties of mining in Alaska, but no important

    factor aside from human failure causes an unusual risk. The human failure

    arises from the attitude of management and men toward safe practices and due

    care to follow recognized standards. Mine workers in Alaska receive more

    individual attention for their welfare and safety than those of many States

    in the U.S. There is reason to expect a change from the attitude of individual

    reliance that has prevailed from early years.


    H. B. Humphrey

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