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    Power Plant Development and Electrical Transmission and Distribution Systems

    Encyclopedia Arctica 2b: Electrical and Mechanical Engineering

    Unpaginated      |      Vol_IIB-0146                                                                                                                  
    EA-I. (G eorge W. Rathjens)




    Hydroelectric Power 1
    Transmission Lines 3
    Electrical Distribution 4
    Electrical Grounds 5
    Bibliography 6

    Unpaginated      |      Vol_IIB-0147                                                                                                                  
    EA-I. Rathjens: Power Plant Development



    Fig. 1 Precipitation, Fairbanks, Alaska 1904-1946.

    From records Fairbanks Station U.S. Weather Bureau
    Fig. 2 Temperature, Fairbanks, Alaska 1904-1946.

    From records Fairbanks Station, U.S. Weather Bureau.
    Fig. 4 Lifting forces from swelling of ground because of

    Fig. 5 Collars or muffs around pole to assist in preventing

    lifting of pole
    Fig. 6 Lifting of pole because of freezing water at foot

    of pole
    Fig. 7 Pole anchor in permafrost 4-c

    Unpaginated      |      Vol_IIB-0148                                                                                                                  
    EA-I. Rathjens: Power Plant Development



            With the manuscript of this article, the author submitted 4

    photographs (Figs. 3, 8, 9 & 10) 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 con–

    tributors 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

    . Meantime all photographs are being held at The Stefansson


    001      |      Vol_IIB-0149                                                                                                                  
    EA-I. (G. W. Rathjens)



            Since the problems of power development and electrical transmission and

    distribution systems in the Arctic and Subarctic have much in common with

    those in more temperate zones, no attempt will be made here to give a full

    treatment to the problem, but rather only those phases peculiar to the

    arctic and subarctic regions will be discussed.

            It is first of all to be emphasized that, in these regions, solutions to

    problems will vary with local conditions to a much greater extent than is

    general in more temperate zones. Much of the discussion in the article

    “Construction for Placer-Mining Operations” is applicable to power plant

    development and electrical transmission and distribution systems. Power plant

    development as used in this article contemplates the generation of electrical

    energy by one or more of the following methods: ( 1 ) hydraulic turbines and

    the development of water power; ( 2 ) internal-combustion engines; and ( 3 )

    steam turbines or steam engines (this is discussed in article “Analysis of

    Design Factors for Power, Heating, Ventilating, and Refrigeration Systems

    for Alaska”).


    Hydroelectric Power

            In the development of hydroelectric power, the extent of stream flow

    which it is practical to develop requires careful and special study in each

    002      |      Vol_IIB-0150                                                                                                                  
    EA-I. Rathjens: Power Plant Development

    locality. The exposure of an arctic river and storage or pondage area

    are extremely important. Much water will have to be stored as ice and the

    exposure of such masses of ice will largely determine whether or not the

    water so stored will be available when required. The writer has in many

    instances seen flowers blooming on one hillside of a valley while ice was

    still present in relatively large quantities on the other side of the same

    valley, or over the crest of a small hill.

            The amount of water stored in the moss and tundra and above the permafrost

    area will not only depend upon the rainfall, character and details of the

    surface and its ability to retain moisture, but also upon the timing of the

    fall rains with respect to the freeze-up of the surface of the ground, moss,

    or tundra, and depth of seasonal thaw with respect to the upper limits of

    permafrost; also whether or not the water available in thawed lenses or

    pockets of gravel in the permafrost can be used at critical seasons of the


            From a study of Figures 1 and 2 and Table I, it will be apparent that

    storage or pondage and deep seepage present quite a different problem than in

    a temperate zone, requiring careful detailed study of each individual area.

    In most cases such studies will indicate that the capacity of development is

    considerably less than for like stream flows and precipitation in milder

    climates and that relatively large installations of supplementary or auxiliary

    power will, in many cases, have to be given consideration.

            In areas where permafrost and frozen much are present, any change in the

    thermal equilibrium of the materials may result in releasing from confinement

    large volumes of much which, because of the particle size of the solids, are

    readily carried in suspension in moving water. When the water with such solids

    reaches storage areas serious silting problems may result.

    002a      |      Vol_IIB-0151                                                                                                                  

    Fig. 251. - Precipitation, Fairbanks, Alaska 1904-1946.

    From records Fairbanks Station, U. S. Weather Bureau.

    002b      |      Vol_IIB-0152                                                                                                                  

    Fig. 262. - Temperature, Fairbanks, Alaska 1904-1946.

    From records Fairbanks Station, U. S. Weather Bureau.

    002c      |      Vol_IIB-0153                                                                                                                  

    Table I

    003      |      Vol_IIB-0154                                                                                                                  
    EA-I. Rathjens: Power Plant Development

            Anchor ice and ice forming on permafrost must be considered when design–

    ing intakes. Such ice is frequently released in large blocks, carrying with

    it sand and gravel.

            [ 3 we be hold is used. ?] It must be borne in mind that the capacity of pipes and other similar

    hydraulic structures may be materially reduced by the formation of ice on

    the interior walls. Figure 3 illustrates a 60-inchs pipe which collapsed

    during cold weather. An ice plug had formed at the intake and when one of

    the lower valves was opened to drain the pipe, portions of the pipe collapsed

    because the provisions for admitting air into the pipe failed to work.


    Transmission Lines

            In designing transmission lines (pole or tower) for the distribution of

    electrical energy in areas where permafrost is present, especially if the

    permafrost extends upward so it makes contact or nearly a contact with the

    lower limit of seasonal thaw, additional factors other than those usually

    evaluated in the development and design of transmission lines should be given


            The reconnaisance survey for a line should include an investigation of

    ( 1 ) the character of the cover which acts as an insulator to the permafrost

    immediately below such cover, ( 2 ) the depth of seasonal thaw, ( 3 ) the character

    and packing of the materials in place, immediately above the upper limit of the

    permafrost, ( 4 ) the relationship between freeze-up and rainfall, and ( 5 ) the

    general characteristics of the terrain, giving special attention to the possible

    movement of water on the surface in the zone of seasonal thaw and the zone

    between the seasonal thaw and permafrost.

            The freezing and swelling of the materials in the “frost zone” may develop

    forces which tend to lift a pole as illustrated in Figure 4. The effect of

    003a      |      Vol_IIB-0155                                                                                                                  

    Fig. 294. - Lifting forces from swelling of ground because of freezing.

    004      |      Vol_IIB-0156                                                                                                                  
    EA-I. Rathjens: Power Plant Distribution

    [ ?] such lifting forces can be materially reduced by placing collars or muffs

    Fig. 5 around the pole as illustrated in Figure 5 or by providing a weak or slip

    plane around the pole.

            In the setting of poles, consideration must be given to the surface

    water as indicated by arrows in Figure 6, and the groundwater from b which

    may seep along the contact between the pole and the ground until it reaches

    the foot of the pole where it freezes, lifting the pole. Successive layers

    of ice at the foot of the pole results in successive lifting of the pole.

            Adhesion between a pole and permafrost may be assisted, to overcome the

    Fig. 6, 7 lifting force a (Fig. 6), by fastening an anchor near the base of the pole

    in the permafrost as illustrated in Figure 7. Where this construction is

    used, care must be taken when back-filling the excavation to avoid the

    development of a contact surface at a (Fig. 6), which may permit the migration

    of groundwater. Wherever practical, the writer recommends that this type of

    anchorage be avoided.

            In the Arctic, tripod construction over the tundra has been effectively

    used for temporary and semipermanent telephone lines where first cost and

    time are the governing factors. This construction is especially applicable

    in areas where small native timber is available.

            In using tripod construction at angle points, it may be advisable to

    suspend a rock or basket of rocks from the tripod or from the legs of the

    tripod in order to assist in the prevention of overturning. The tripods are

    usually set on the tundra during cold weather when the surface is frozen.


    Electrical Distribution

            Consideration must be given to the large range of temperatures in the

    Arctic in the calculation of sags and spacing of wire when designing electrical

    004a      |      Vol_IIB-0157                                                                                                                  

    Fig. 305. - Collars or muffs around pole to assist in

    preventing lifting of pole.

    004b      |      Vol_IIB-0158                                                                                                                  

    Fig. 316. - Lifting of pole because of

    freezing of water at foot of pole.

    004c      |      Vol_IIB-0159                                                                                                                  

    Fig. 327. - Pole anchor in permafrost.

    005      |      Vol_IIB-0160                                                                                                                  
    EA-I. Rathjens: Power Plant Distribution

    distribution lines. Because of the high cost of properly preparing foundations

    and maintaining them, long spans are indicated. Large temperature ranges re–

    sulting in relatively great sags require careful consideration of resulting

    tensions (1; 2; 3; 4).

            Careful study of local weather conditions in any particular area is

    recommended because wind and ice conditions vary greatly in different section.

    The writer has experienced local winds in Greenland which were greater than

    any winds of which he has knowledge in either the temperate zone or Alaska.

    When investigating the corona limit of high-tension lines in the Arctic, the

    investigation should not be limited to the fair-weather value. Local and

    seasonal conditions at which it will operate should be considered.


    Electrical Grounds

            In permafrost areas the grounding of electrical equipment is not as

    readily accomplished as in a temperate zone. It has been the writer’s prac–

    tice, wherever practical, to carry the grounds to a zone of assured and

    continuous groundwater movement; otherwise, the system was treated as


    006      |      Vol_IIB-0161                                                                                                                  
    EA-I. Rathjens: Power Plant Development


    1. Copperweld Steel Company, Glassport, Pa. Sags and Tension Charts for

    Conductors in Overhead Lines .

    2. General Electric Company. “Performance charts for 60 cycle transmission

    lines,” Gen.Elect.Rev . Oct., 1932.

    3. Graybar Electric Company. Calculations by Direct Use of the Catenary

    Curve .

    4. Pender, Harold, and DelMar, William. Handbook for Electrical Engineers .

    N.Y., Wiley, 1922.


    G . eorge W. Rathjens

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