Effect of Extreme Arctic Cold on Materials: Encyclopedia Arctica 2b: Electrical and Mechanical Engineering
Effect of Extreme Arctic Cold on Materials
EA-I. (P . ^ almer^ W. Roberts)
EFFECTS OF EXTREME COLD ON MATERIALS
TABLE OF CONTENTS
| Page | |
| Water | 1 |
| Antifreeze Solutions | 2 |
| Fuels and Lubricants | 5 |
| Rubber-like Material | 6 |
| Plastics | 7 |
| Glass Materials | 15 |
| Fabrics | 15 |
| Leather | 16 |
| Concrete | 16 |
| Icecrete | 19 |
| Snowcrete | 20 |
| Explosives | 21 |
| Wood | 22 |
| Metals | 26 |
| Steel | 27 |
| Precautions for Equipment | 29 |
| Preparation of Equipment Specifications | 32 |
| Bibliography | 34 |
EA-I. Roberts: Effects of Extreme Cold on Materials
LIST OF FIGURES
| Page | ||
| Fig. 1. | Flow of coolant which carries heat from engine to radiator | 2-a |
| Fig. 2. | Relation between concentrations and freezing protections of various antifreeze solutions | 3-a |
| Fig. 3. | Effect of temperature on the compression strength of concrete during the curing period | 18-a |
| Fig. 4. | Strength, temperature, moisture relationships from Kollmann’s report | 23-a |
EA-I. (P . ^ almer^ W. Roberts) ^ ✓^
EFFECTS OF EXTREME COLD ON MATERIALS
An understanding of the effect of extreme cold on the elasticity,
durability, strength, and other physical characteristics of materials, and
the treatment that these materials should receive when exposed to such
temperatures is important. Where applicable and when required, information
on this subject can be obtained from manufacturers furnishing material or
equipment, and from qualified research laboratories.
Water
Fresh Water
. Under usual conditions, fresh water freezes at a tempera–
ture of 32°F., forming solid ice and expanding about 9% in volume. It takes
80 calories to raise a cubic centimeter of ice across the freezing point and
more to bring it to a temperature at which it is potable. Water weighs 62.5 lb.
per cubic foot and ice at 32°F. weighs 57.5 lb. per cubic foot. The strength
of ice is dependent on its structure (see “Strength and Uses of Fresh-and
Salt-Water Ice.”) Trautwin
d
^
e^
states that the expansive force of ice is probably
^
—^
not less than 30,000 per square inch. This force exceeds the yield strength
of cast iron (25,000
−
^
+^
p.s.i.). Fresh-water ice is 2 to 3 times stronger than
sea (salt) water ice. Pressure applied to ice causes momentary melting at
the point of pressure, producing a film of moisture. This is especially true
at temperatures near 32°F. At progressively lower temperatures, melting due
EA-I. Roberts: Effects of Extreme Cold on Materials
to pressure decreases to the vanishing point.
Sea (salt) water
freezes at approximately 28.6°F., depending on salinity.
Water with a higher salt content freezes at lower temperatures. Newly formed
sea-water ice is mushy because of high salinity; at lower temperatures later,
when some of
its
^
the^
salt has become eliminated, it is flexible as compared to
^
—^
fresh-water ice. Old sea-water ice is usually stronger than new sea ice, is
darker in color, and lighter in weight. So long as it contains appreciable
salt it has a rough surface.
Antifreeze Solutions
Approximately two-thirds of the energy in the gasoline used in operating
an automobile engine is converted into heat. It is, therefore, necessary to
provide special cooling facilities to prevent the metal parts from reaching
excessive temperatures. The method generally used is an indirect one in–
volving the transfer of heat from the engine to
[:
]
^
a^
liquid, usually water, and
^
—^
^
Fig. 1^
then cooling the liquid by air through the use of a radiator (see Fig. 1).
Water was naturally selected as a cooling medium because of its availability
and relatively high heat transfer properties. However, water has certain short–
comings, the most important of which are its high freezing point and its
corrosive action on metal parts of the cooling system, which may result in
rust clogging and metal perforation. These two major disadvantages are largely
overcome by adding materials to the water to prevent freezing in winter, and
special chemical ingredients to inhibit corrosion. Oils, sug
e
^
a^
rs, and inorganic
^
—^
salt solutions are generally regarded as unsatisfactory antifreeze materials.
In the United States and Canada, approximately one-third of the cars requiring
antifreeze are protected with ethylene glycol (glycol) base products and most
Fig. 1 — Flow of Coolant Which Carries Heat From Engine to Radiator
EA-I. Roberts: Effects of Extreme Cold on Materials
of the remaining two-thirds employ methyl alcohol (methanol) or ethyl alcohol (ethanol) type solutions. In the Arctic, ethylene glycol base products are used almost entirely.
The antifreeze effectiveness of methyl and ethyl alcohols and ethylene
glycol types is shown in Figure 2. These curves bring out several facts.
First, the methyl alcohol type give the greatest freezing protection per unit
volume, followed by ethylene glycol, and then the ethyl alcohol. Second, all
three liquids are capable of depressing the freezing point of water to the
lowest atmospheric temperatures likely to be encountered. The first reason
is based only on freezing protection per gallon, and does not take into con–
sideration the extra quantities of the low-boiling-point alcohol antifreeze
solutions required after the initial filling because of boil-away losses, or
the superiority of the comparatively high boiling point of ethylene glycol
solution in preventing such losses. For antifreeze solutions protecting
down to −20°F., the boiling point of the ethylene glycol solution is 22
8
^
3^
°F.
^
—^
while the boiling point of the alcohol-base solution is 180°F.
Unlike water, antifreeze solutions do not solidify when exposed to
temperatures slightly below their freezing points but instead tend to form
slush. The minimum temperatures to which solutions of the three types of
antifreeze having a freezing point of 0°F. may be exposed without giving
rise to overheating or other difficulties immediately after the engine is
started are: methyl alcohol, −2.5° to −5.5°F.; ethyl alcohol, −5.5° to −8.0°F.;
ethylene glycol, −8.0° to −11.5°F.
The lower the freezing point of the antifreeze solutions used, the further
below this freezing temperature is it possible to expose the solution without
fear of overheating, resulting from circulation restricted by ice crystals
of
^
—^
Fig. 2 — Relation Between Concentrations and Freezing Protections of Various Antifreeze Solutions
EA-I. Roberts: Effects of Extreme Cold on Materials
or slush ice, after the engine started. From Figure 2 it is noted that antifreeze protection can be determined in volume per cent concentration in water and easily reduced to pints per gallon of solution (see Table I).| Table I. Pints of Antifreeze per Gallon Soulution s for Protection ^ —^ down to Various Temperatures. | |||
|---|---|---|---|
| Protection to, °F. | Methyl alcohol | Ethyl alcohol | Ethylene glycol |
| − ^ +^ 10 | 1 3/4 | 2 1/4 | 2 |
| 0 | 2 1/4 | 3 | 2 3/4 |
| −10 | 2 1/2 | 3 3/4 | 3 1/4 |
| 20 −20 | 3 | 4 | 3 1/2 ^ —^ |
| −30 | 3 1/4 | 4 1/2 | 4 |
| −40 | 3 3/4 | 5 1/4 | 4 1/4 |
| −50 | 4 | 5 3/4 | 4 1/2 |
In the case of ethylene glycol, the greatest freezing protection that
can be obtained is −62°F. which is given by a solution containing 60% anti–
freeze and 40% water. Solutions containing more than 60% ethylene glycol
give less protection.
Glycerim (glycerol) is one of the acceptable nonvolatile antifreeze
materials, but because of its relatively high cost compared to ethylene glycol,
and its many other important commercial uses, it is not used to any great extent.
Kerosene, freezing point −60°F., had been used in standard automotive
cooling systems in localities with extreme cold climates. Its heat capacity
is approximately one-half that of water, but automobiles operating with kerosene
as a coolant are subject to overheating in warm weather. Additional disadvantages
are its unpleasant odor, flammability, and severe action on rubber hose.
EA-I. Roberts: Effects of Extreme Cold on Materials
Care should be taken to select an antifreeze containing heavy-duty
inhibitors. Two general types are in general use: soluble oils and salts.
The oil types are considered generally to be the most satisfactory. Vehicle
radiators filled with antifreeze should be tagged showing type of antifreeze.
Fuels and Lubricants
During World War II, special fuels and lubricants were developed to
overcome the difficulties in star
g
^
t^
ing gasoline and diesel engines previously
^
—^
encountered in the Arctic. (See “Petroleum Products for Arctic Winter Use
in Automotive Equipment” and “Tractor-Type Transportation Units for Arctic
Operations” for details on the improvements made on the various properties
of fuels and lubricants for low-temperature use.)
In shipping fuels in drums it is important that only extra heavy export–
type drums be used. This is necessary as this type drum can be handled easier
in the cold and facilitates roping for dropping by parachute from planes. The
smooth drum is slippery when wet or covered with ice or snow and it is difficult
to rope and attach to a parachute.
The recommendations of the manufacturer of any equipment should be
consulted regarding lubrication under cold conditions. Many excellent lubricants
have been developed and used successfully in northern operations. However, it
must be realized that at extreme temperatures oils and greases become stiff.
If an engine has been shut down for any period of time the lubricant may have
become so stiff that a fully charged battery will not turn the engine over.
This situation may be further aggravated because at such temperature batteries
lose much of their energy.
EA-I. Roberts: Effects of Extreme Cold on Materials
Rubber-like Material
The general effect of reduced temperatures is the same for all rubber-like
materials. As the temperature is decreased the rubber passes from a soft
(easily deformed) and elastic state to a more rigid state and finally to a
brittle glasslike condition. The various commercial rubbers differ appreciably
as to the temperature ranges in which they pass through these various states.
None of the available commercial rubbers are truly elastic at extremely low
temperatures (below −40°F.). New rubber products stand up better under cold
conditions than old rubber. The effect of temperature on rubber materials is
predominantly physical and any chemical changes which may take place can, on
a practical basis, be ignored.
Some new natural rubber materials are usable at low temperatures approaching
−50°F. but in the course of their use it is imperative that they be not
subjected to any force at an excessive velocity. That is, rapid bending or
flexing at or near such low temperatures will result in breaking or even
shattering of the rubber part. For example, rubber tires will develop flat
spots at low temperatures. The tread of old rubber tires will chip due to
cold embittlement when subjected to force or flexing. New tires show less
tendency to crack than do tires of old rubber.
Lower-temperature rubber-like materials are made by specifically compounding
the integral parts for low-temperature service. Two general classes of these
have been developed: normal natural rubber material to operate (with care)
down to −40°F., and special rubber-like material (natural rubber and butyl
rubber) for extreme low temperatures to −70°F. Many of the large rubber and
chemical companies that specialize in rubber and synthetic rubber products
are working on the problem of providing rubber-like materials for use under
extreme cold conditions.
EA-I. Roberts: Effects of Extreme Cold on Materials
Plastics
Most plastics contain a base material, the properties of which have been
modified by the incorporation of plasticizers or fillers. Each base material
is the foundation for a group of compositions related in general behavior but
differing from one another in individual physical properties. Such basic
groups of plastics are: acrylics, celluloses, nylons, ethylene
,
polymers,
^
—^
vinyl ester polymers, polyvinyl acetals, phenolics, urea resins, caseins,
alkyds, neoprene, etc. groups which contain several different compositions
are subdivided into types. Each type represents one or more compositions,
each of which is designed to give superior value of some specific property
even at the expense of some other property. There is, for example, Type
L
^
I^
,
^
—^
g
^
e^
neral; Type II, temperature resistant; Type III, impact resistant; Type IV,
^
—^
moisture resistant; etc. Where further subdivision is required, the types
are subdivided into grades. Each grade represents, at broadest, a very
restricted number of common commercial materials which are quite similar
both chemically and physically. These groups, types, and grades usually
correspond to those given in the specifications of the American Society for
Testing Materials.
The service success of an article of any plastic often depends as much
upon the design and fabrication processes as on the material itself. The
importance of selecting items of good workmanship in both design and fabrica–
tion for cold-weather operations cannot be overemphasized. The plastics
industry has developed a background of practical experience in design,
fabrication, and testing of plastics, and should be consulted regarding
specific cold-weather problems. The importance of selecting the proper
material and consulting with plastic manufacturers concerning cold-weather
EA-I. Roberts: Effects of Extreme Cold on Materials
problems cannot be overstressed. It is important not only to select the proper material but to use it properly in the field. Too frequently, good plastics improperly handled in the field failed, when the same material properly utilized would have been entirely satisfactory.
As an aid in understanding this field of material, a list of the more
important plastics by resin group and subgroup, trade names, available forms,
and commercial uses is given in Table I. (The code for the available forms is:
F, filaments; M, molded; R, rods; S, sheeting; T, tubing.) where applicable,
comments on the effects of extreme temperatures and care in use in the field
are given in the text.
The
acrylics
are perfectly clear and transparent. They have the best
resistance of all transparent plastics to sunlight and outdoor weathering, and
will tolerate years of exposure without significant loss of properties. They
possess a good combination of flexibility with shatter resistance and rigidity.
Their impact strength is lower than the celluloses, but the effect of extreme
low temperatures upon this property is much less pronounced; hence, articles
designed for use at ordinary temperatures will not show excessive embrittlement
at −50°F.
Cellulose nitrate
is the toughest of all thermoplastics. It has low water
absorption and is resistant to mild acids. At −50°F., its impact strength
is about 35% of its impact strength at normal temperatures (77°F.). Cellulose
nitrate is very flammable; it is not suitable for prolonged service in outdoor
sunlight for it turns yellow and becomes brittle.
Cellulose acetate
is comparatively tough. Its low temperature impact
strength and embrittlement characteristics are inferior to those of cellulose
nitrate. Cellulose acetate is superior to cellulose nitrate in resistance to
outdoor exposure and to burning. Sunlight has little effect on this material.
Since there are many commercial compositions of this material, it is advisable
for a given application to indicate the application and desired properties, for
example, for general use, resistance to heat, cold, impact, or moisture.
EA-I. Roberts: Effects of Extreme Cold on Materials
| Table I. Some Important Commercial Plastics^.^ ^—^ | |||
|---|---|---|---|
| Resin group and subgroup | Trade names | Forms available | Uses |
| Acrylics: Methyl methacrylate resin | Lucite Plexiglas | M, R, S, T M, R, S | Windshields, goggles, dentures, artificial eyes, drafting in– struments, automotive parts, aircraft enclosures |
| Celluloses: Cellulose nitrate | Celluloid Nitron Nixon C/N Pyralin | R, S, T, F R, S, T R, S, T R, S, T | Fountain pens and pencils, drawing instruments, spectacle frames, bottle caps, toilet seats, tool handles, shoelace tips, film |
| Cellulose acetate | Fibestos Lumarith Nixon C/A Plastocele | R, S, T R, S, T, M R, S, T, M R, S, T | Containers, luggage, food cases, truck curtains |
| Chemaco Hercules Koppers Tenite I | M M M M | Knobs, goggle frames, combs, brushes, tool handles, safety goggles, eye shields, automotive parts and housings | |
| Cellulose acetate butyrate | Tenite II | M | Telephones, steering wheels, film spools, radio housings, knobs and pulls, light supports, coil spools, brush backs |
| Ethyl Cellulose | Celcon Chemaco Ethocel Hercules Koppers Nixon E/C | M M M, S M M M, S | Radio housings, toothbrushes, pen and pencil barrels, tool handles, knobs and pulls, flashlight cases |
| Nylon: Textile filament types | F | Textile fiber, ropes, lines, hose, tents, stockings, clothing, bristles, surgical sutures | |
| Injection, extrusion and alcohol-soluble types | M, S | Injection and compressed molding, covering for wire and sheets, solution castings, small bearings, specialty containers, electrical coil forms and insulators, small gears, cams, coatings |
EA-I. Roberts: Effects of Extreme Cold on Materials
| Table I. Some Important Commercial Plastics (contd). | |||
|---|---|---|---|
| Resin group and subgroup | Trade names | Forms available | Uses |
| Ethylene plymers: Polyethylene Polythene | F, M, S, T ^ F, M, S, T^ | Films, liners, closures, wrappings for frozen food, primary cable, ^ —^ insulating material, coating for weatherproof wire | |
| Polytetrafluoro– ethylene | Teflon | M, R, S, T | Films, tubes, tapes and special applications made by rolling, drawing, or machining |
| Polyvinyl acetals: Polyvinyl formal | Formvar | M | Insulating enamel, base for electric wires, phonograph records |
| Polyvinyl butyral | Butacite Saflex Vinylite | M, S S M, S | Plastic interlayer, laminated for safety glass, sheeting, and coatings for dustproof and waterproofing fabrics |
| Vinyl ester polymers: Polyvinyl chloride | Geon Marvinol Pliovic Ultron Vinylite | M, S M M, S M, S M, S | Jacketing material on electric wires and cables, water-repellent garments, shower curtains, garment bags, upholstery, belts, floor coverings, overlays for maps, phonograph records |
| Polyvinylidene resins: Finylidene chloride | Saran | F, M, T | Hoses, flexible tubing, rigid pipe, lined steel pipe, moisture-resistant films and fabrics for upholstery and transportation seating |
| Polystyrene | Bakelite Cerex Chemaco Koppers Loalex Loalin Lustrex Styron | M M M M M M M M | Standoff insulators, antenna in– sulators, radio coil forms, telephone equipment, fluorescent light fixtures, wall til s ^ e^ , combs, ^ —^ knobs and pulls, shaver housings, camera cases, refrigerator parts, bottle caps |
| Polystrene expanded | Styrofoam | S | Insulating material in refrigera– tion construction, buoyancy agent for life rafts and small metal boats |
EA-I. Roberts: Effects of Extreme Cold on Materials
| Table I. Some Important Commercial Plastics (contd). | |||
|---|---|---|---|
| Resin group and subgroup | Trade names | Forms available | Uses |
| Phenolics: Phenol-formaldehyde resin | Bakelite Durez Durite Resinox | M M M M | Camera cases, photographic film spools, handles, instruments, boxes, radio cabinets, ignition parts, instrument panels, pulleys, housings, terminal blocks, telephone parts, goggle frames, wheels |
| Melamine resin: Melamine-formalde– hyde | Melmac Plaskon Resimene | M M M | Compression moldings, electrical fittings, sockets, food containers |
| Urea resins: Urea-formaldehyde | Beetle Plaskon | M M | Buttons, tableware, boxes, electrical parts and lighting reflectors |
| Synthetic rubber: Chlorobutadiene | Neoprene | M, S, T | Hose, molded parts, weather strip– ping, wire and cable jacketing adhesive, coated fabric, electrical cable construction, inflatable gear, sealing strips |
Cellulose acetate butyrate
material is tough and has dimensional stability.
Fluctuation in dimension must be considered when articles are made of a com–
bination of this material and glass or metal.
EA-I. Roberts: Effects of Extreme Cold on Materials
Ethyl cellulose
material possesses toughness, high impact strength at
low temperatures, and excellent dimensional stability. When the article is
in combination with glass or steel, assurance must be made that the wall
thickness of the plastic is sufficient to withstand the strain caused by
temperature changes. Type II of this plastic is specifically designed for
low-temperature resistance. At −50°F., its impact strength is about 40% of its
impact strength at normal temperatures.
Nylon
is a generic term for any long-chain synthetic polymeric amide which
has recurring amide groups as an intergral part of the main polymer chain, and
which is capable of being formed into a filament whose structural elements are
oriented in the direction of the axis. Nylon textile filament materials are
noted for their toughness. The effect of extreme cold on the mechanical
properties of cords and ropes is small: tensile strength increases and elongation
decreases. Woven fabrics will not be stiffened or embrittled by extreme
cold and remains soft and pliable at −40°F. The effect of prolonged exposure
to sunlight and outdoor weather is not enough to impair practical utility.
Several different types of nylon
g
plastic
^
s^
are involved here and their
^
—^
^
—^
properties are not identical. Impact strength is measurably decreased by ex–
treme cold but toughness and impact strength at low temperatures are still so
good that nylon plastics have been successfully used at low temperatures. At
−40°F., the impact strength of nylon is about 55% of its impact strength at
normal temperatures. The electrical properties of nylon plastics are better
at low temperatures than at normal temperatures. Prolonged exposure of nylon
plastics to sunshine and weathering is not recommended.
Polyethylene
and
polythene
materials are tough and durable. Their
toughness is not seriously effected by low temperatures. These materials
EA-I. Roberts: Effects of Extreme Cold on Materials
remain fairly flexible at moderately low temperatures, stiffen slightly at temperatures of −30°F. and lower, and become brittle at −94°F. They have excellent electrical properties, extremely low moisture vapor transfer qualities, resist solvents and strong acids, and have other desirable qualities such as nontoxicity. / ^ —^
Polytetrafluoroethylene
has potential utility owing to its excellent
thermal stability, resistance to corrosive reagents, and low dielectric loss.
It is not embrittled by extremely low temperatures. Films can be flexed at
temperatures as low as −148°F. without breaking. Its resistance to outdoor
weathering is excellent.
Polyvinyl acetal
material provides a tough impact-resistant adhesive layer
for safety glass over a wide range of temperatures down to about −40°F., is
stable to light and heat, relatively insensitive to moisture, and has good
adhesive qualities. It is an excellent thermoplastic adhesive for leather,
rubber, paper, wood, canvas, laminated cellophane, and glass. It is also
excellent for coating fabrics for raincoats, water-repellent garments, tentage,
food and clothing bags, etc.
Polyvinyl chloride
compositions are noteworthy for their heat resistance,
exceptional toughness, and ability to withstand continued exposure to maximum
temperature differences. Some of these compounds have a low-temperature
brittleness approaching −40° and −50°F. when subjected to bending. However,
such material if subjected to sudden shock would fail at higher temperatures,
possibly approaching −30°F.
Vinylidene chloride
material is tough, resistant to chemicals and prolonged
immersion in water, nonflammable, and useful over a wide range of temperatures.
EA-I. Roberts: Effects of Extreme Cold on Materials
Polystyrene
has good electrical properties, good resistance to acids and
solvents, excellent dimensional stability, low unit weight, and general stability
satisfactory at extreme low arctic temperatures (below −50°F.). Many of the
materials have good outdoor weathering properties.
Polystyrene Expanded
. One outstanding property of this material is its
low thermal conductivity (0.27 B.t.u. per hour per sq.ft. per °F. per inch).
Another is its low water absorption and moisture transmission rate, which
enhances its usage as an insulating material under extremely cold conditions.
This material has good structural strength and is easy to handle, it may be
bonded to itself, concrete, brick, wood, or metal. It has a minimum buoyancy
of 55 lb. per cubic foot.
Phenol-formaldehyde resins
are thermosetting and the molded types are
shaped and hardened by heat and pressure. They are hard, strong, rigid, and
are light in weight. They are not readily flammable, have good electrical
insulating properties, but are not suitable for prolonged outdoor exposure as
the lighter colors fade and the material may change in water content with
resultant slight expansion and contraction. Types are made to provide general–
purpose shock and electrical, heat, and chemical resistance. The shock-resistant
types show best combination of flexual and tensile strength at extreme low
temperatures. The cast phenolic-type resins are not recommended for outdoor use.
The laminated phenolic products include some of the strongest materials in the
plastic field.
Melamine-formaldehyde resins
are thermosetting, rigid, posses a hard
surface which resists wear, have good electrical properties, and water absorption
is low. These materials have good dimensional stability plus good strength and
shock resistance. The laminated melamine products are used widely for elec–
trical instrument panels.
EA-I. Roberts: Effects of Extreme Cold on Materials
The
urea-formaldehyde resins
are of the thermosetting type. They possess
a high degree of translucency and offer unlimited color possibilities. They
have good mechanical and electrical properties. They have been widely used
within a temperature range of −70° to 170°F.
All
neoprene
products when exposed to temperatures in the range of 0° to
−50°F. will stiffen and lose some of their flexibility and resiliency. However,
by proper compounding of neoprene, it is possible to make compositions that
retain sufficient flexibility to be practical in the range of −50° to −60°F.
Glass Materials
Ceramics
are not ordinarily effected by extreme cold temperatures. How–
ever, a warm blast of air or a sudden change of temperature may cause frozen
material to shatter.
Window glass
does not show any visible reaction to cold. Thin sections
are susceptible to sudden changes in temperature but they are designed to
withstand average thermal shock of 150°F.
Laminated safety glass
(plate and sheet) does not show a visible reaction
to cold. It is designed to withstand 150°F. average thermal shock and to
meet minimum requirement of −65°F.
Structural glass
shows no visible reaction to cold. It is designed to
withstand average thermal shock of 150°F.
Fabrics
Untreated and water-repellent textiles give satisfactory service down
to −40°F. Canvas and heavy materials lose their pliability at low tempera–
tures and when frozen
h
^
sh^
ould be bent or stretched with caution. Loss of
^
—^
elasticity should not be mistaken for shrinkage.
EA-I. Roberts: Effects of Extreme Cold on Materials
Leather
At low temperatures leather becomes stiff and cracks, often tearing
easily. When wet, untreated leather becomes frozen, it will not stand tension,
bending, or impact. Leather items that are to be subjected to extreme cold
should be carefully tanned and then treated with a light coat of good shoe oil
or lard. Tanned skins are less easily injured by wetting and subsequent
freezing than untreated skins. Much has been said about the difference between
skins scraped and prepared by the Eskimos and those tanned by commercial methods.
Commercial-tanned skins weigh more per square unit than Eskimo-prepared ones.
Commercial-tanned items tend to stiffen, thereby reducing utility. For
clothing, commercial-tanned skins are not as warm as the E
[: a]^
s^
kimo-prepared ones.
^
—^
However, since commercial tanning is cheaper, commercially tanned items are
more frequently used. Where leather and fur clothing items are required for
midwinter chill occupations, on the trail or away from main encampments, it
would be advisable to use clothing made from Eskimo-prepared skins.
Concrete
The problem of the construction engineer in cold areas is similar to that
of engineers in more temperate climates, that is, to produce concrete of the
quality specified and assumed in design with the materials available. Aggre–
gates, meeting requirements as to qualities of hardness and toughness, are
usually available but these may be limited in the desired shape, size, and
graduation of the particles. The most dependable and readily available natural
sources of aggregates are river banks and old terraces, sand and gravel bars,
river deltas, and coastal beaches. Due to the handling difficulties imposed
by permafrost, the availability of such materials must always be a consideration.
EA-I. Roberts: Effects of Extreme Cold on Materials
On all work Portland or high-early-strength cement, meeting the speci–
fications of the American Society for Testing Materials, should be used.
High-early cements are preferred to the portland as the concrete need not
be heated as long in curing. Due to the rough abuse to which containers may
be subjected, cement should be double-bagged in heavy durable bags. Where
possible bags should be palletized for loading, unloading, and storage.
Proper consideration should be given to storage; cements protected from moisture
may be kept indefinitely without loss of strength.
Various admixtures are sometimes used in concrete to increase workability,
to prevent freezing, to hasten setting, to facilitate curing, to increase
watertightness, etc. the use of such admixtures is not ordinarily harmful
if carefully and judiciously controlled. Admixtures to prevent freezing con–
sist of common salt (NaCl), calcium chloride (CaCl
2
), or a mixture of these.
These admixtures may be used with judgment in moderately cold weather but
should not be relied upon to prevent freezing in extremely cold weather or
when such weather is expected immediately following the placement of concrete.
Increasing the temperature of concrete in cold weather is commonly accom–
plished by heating the aggregates or the water or both. The most readily
available item in the Arctic is water which, except during a shot time during
the summer, will require heating. The temperatures to which the water must be
raised in order to provide the desired temperature for the concrete can be
calculated by the formula:
EA-I. Roberts: Effects of Extreme Cold on Materials
<formula>T = S ((TaWa + TcWc) + TfWf + TmWm)/(S(Wa + Wc) + Wf + Wm)</formula>
where:
T
= temperature of concrete (should not be greater than 80°F.
for most work)
S
= 0.22 (assumed specific heat of dry material)
W
a
= weight of aggregates (surface dry);
T
a
= temperature of aggregates
W
c
= weight of cement;
T
c
– temperature of cement
W
f
= weight of free moisture in aggregates;
T
f
= temperature of
free moisture in aggregates
W
m
= weight of mixing water;
T
m
= temperature of mixing water
Mi
z
^
x^
ing water is commonly heated in a boiler by live steam o
f
^
r^
by heating coils.
^
—^
^
—^
The temperature of the water is usually held between 90° to 120°F. and should
not exceed 165°F. because of the danger of causing a flash set of the cement.
Concreting can be successfully accomplished in cold weather without
adversely affecting the final quality of the product. The rate of development
^
Fig. 3^
of the strength increment is slow at low temperatures as shown in Figure 3.
If actual freezing is prevented during the setting process, and if supports
are left in place until the concrete has reached a compressive strength of
1,500 p.s.i., there should be no detrimental effects of the low temperatures
on the quality. To do this, it will be necessary to heat the aggregates and
water, place and tamp or rod it quickly, and enclose it with tarpaulins or other
housing. Heating by air, stoves, or steam will be required during curing,
and care should be taken that the concrete does not get too hot. In extreme
or severe weather it may be necessary to protect the work in an artificially
heated enclosure until the end of the moist curing period to prevent loss
of heat to the atmosphere.
Fig. 3. Effect of temperature on the compression strength of concrete during the curing period.
EA-I. Roberts: Effects of Extreme Cold on Materials
Special problems arise when concrete is poured against a frozen face or
in permafrost. Thaw ensues upon contact with the concrete, and the water
produced may initially cause settlement, and later freeze, with the possi–
bility of heaving and resultant damage to the structure. In the case of
vertical walls being required against a frozen face, precast sections may
prove more satisfactory. Slab construction in permafrost requires suitable
insulation between the concrete and the permafrost.
Fresh concrete when frozen may be recognized by its white color.
Ordinarily, concrete retains its dark slate color in cold weather for several
days. Badly frozen concrete may also swell or spall in spots. Concrete that
seems to be frozen can be tested by placing it over a stove or by immersion
in hot water. If frozen, it will sweat and become soft or crumble; if not
frozen, no change will occur.
Concrete that is frozen can be saved by enclosing and heating. After
thawing, the concrete will resume its setting from about the point it had
reached at the time that it was frozen. Concrete that has frozen after
setting has started is damaged to a certain extent due to the mechanical
expansion action of the ice crystals. The amount of damage will depend on
the degree of setting which has preceded the freezing. It is this action
of ice which makes repeated freezing of new concrete crumble and become
worthless. The ordinary case of frozen concrete is one in which the concrete
is placed at a low temperature and is allowed to freeze before setting action
occurs.
Icecrete
Icecrete is a term applied to a material made from aggregates with ice
acting as the cementing agent. During the period of no thaw, icecrete is a
EA-I. Roberts: Effects of Extreme Cold on Materials
dependable substitute for concrete in the regions of extreme cold. By mixing water and aggregate materials (sand and gravel), either by hand or in a con– crete mixer, a plastic and flowable homogeneous mixture may be made. The mixture may be poured, similar to concrete, into forms and rodded or tamped to assure compaction. Forms may be built from snow or ice blocks, brush, or wood, if available, and may be left in place.
Due to the presence of the aggregates, icecrete is darker in color than
ice and will absorb more heat from the sun, which may cause melting. To
minimize this action the icecrete structure or mass should be covered with
snow, ice, or canvas.
Icecrete is generally tougher than ice, does not crack readily, and is
comparatively shatter and impact resistant. This material is excellent for
construction of roads, protective barriers, foundations for structures to be
used only in winter, deadmen for “tie downs,” and as a substitute for mass
concrete construction required during no-thaw periods.
Snowcrete
Snowcrete is a term used to describe snow resulting from compaction by
natural or mechanical means. Until recently little work had been done in the
field of mechanical compaction of snow; however, natural compacted snow has
been used for a long time in the form of snow blocks. Such blocks have been
used primarily by Eskimos for the construction of snowhouses, shelters, and
windbreaks.
All the properties of compressed snow have not yet been determined by
experimental work. The hardness of snow is based on the strength which
attaches individual snow particles to each other. The mechanical value of
EA-I. Roberts: Effects of Extreme Cold on Materials
compacted snow depends on its density, temperature, and texture. Snow, like soil, must be compacted in thin layers. Snow may be compacted easily and reached its highest density at temperatures approaching 32°F.; snow thus compacted will attain its greatest value of hardness.
One of the notable properties of snow is that, at temperatures below
freezing, its hardness continues to increase if left undisturbed after having
been compacted. Compaction decreases the thin films of air between crystals
and thus increases the density and resultant contact between and growing
together of crystals.
The field of snowcrete utilization is being slowly developed. It is
apparent that compacted snow may be used in cold weather for temporary buildings,
windbreaks, road surfaces, and for air strips.
Explosives
All modern explosives used in the bricks are of the low-freezing variety
and are designed to eliminate freezing under ordinary conditions of exposure
at any temperature normally encountered. Gelatins and similar type explosives
will become quite hard when subjected to low temperatures but will not freeze.
Certain high explosives composed of a mixture containing mainly
of
ammonium
^
—^
nitrate are absolutely nonfreezing. Correspondence with principal explosives
companies indicates that no case of frozen dynamite has been reported in recent
years under severe Canadian and Alaskan conditions.
In the event that an explosive is suspected of being frozen, the employment
of the simple “pin test” will readily determine whether or not the explosive
is frozen. An ordinary pin will not penetrate a frozen column of explosive,
but can be inserted quite easily into one that is merely very hard.
EA-I. Roberts: Effects of Extreme Cold on Materials
All explosives should be stored and transported in accordance with
standard precautions recommended by the manufacturers.
Blasting caps and electrical blasting caps have withstood satisfactory
storage at laboratory temperatures as low as −110°F. (−78.9°C.). These
tests revealed little or no change in characteristics.
Safety fuses show no appreciable change in performance after storage at
extreme low temperatures except that the burning time may be slightly increased.
Caution is required in the handling of safety fuses after freezing as the
fuse covering, particularly the waterproofing, will crack at low temperatures.
It would, therefore, be necessary to uncoil the fuse and prepare the explosive
devices at normal temperatures. Primacord detonating fuse will perform
satisfactorily at low temperatures, providing it has not been wet previous to
freezing. Care must be taken, however, to prevent breaking or cracking. If
a detonating fuse becomes wet before freezing, it will be difficult to initiate,
and a booster will be required to insure detonation.
Wood
The results of a limited amount of research conducted on various woods and
a review of available literature indicate no significant effect on the physical
properties of wood due to extreme cold. No special precautions, therefore, need
be observed for the use of wood in the very cold climates. Wisconsin white oak
has been extensively used for sled runners for heavy-duty arctic sleds. Other
wood materials, built for use in more temperate climates, have been widely used
in the Arctic without noticeable failure.
Comprehensive investigations into the effects of extreme low temperatures
on the strength properties of wood were made in Germany by Franz Kollmann and
published at Eberswalde in 1940. Later the Forest Products Laboratory of the
EA-I. Roberts: Effects of Extreme Cold on Materials
Forest Service, U.S. Department of Agriculture, reviewed all literature on the effect of arctic exposure conditions on the strength properties of wood and published a report June 4, 1948. Parts of the ^ this^ report are quoted: ^ —^
“Discussion of Strength Tests
On the basis of the information gathered in the review of available
literature and in talking with the individuals mentioned previously, the
elimination of low temperature in itself as a probable cause of the trouble
seems justifiable. There is general agreement among the various investigators
that in most cases strength properties are actually improved by comparatively
short-time exposure to below freezing temperatures, a notable exception being
impact strength which was found to exhibit little change either way with
changes in temperature for wood at 7.5 percent moisture content and at 12 percent
in the range from about 75°F. down to −58°F. Whether long-time exposure to
low temperature or to fluctuating temperatures such as occur in the Arctic
would alter these strength-temperature relationships has not been determined.
^
Fig. 4^
(See Fig. 4.)
Another factor, one that is known to have considerable effect on strength
properties, is moisture content. Below the fiber saturation point most
strength properties increase with decreasing moisture content, an exception
being those properties representing toughness or shock resistance, which usually
exhibit little change with changes in moisture content at temperatures above
freezing. However, Kollmann found that impact strength of laminated wood in
the sub-frozen state is very materially affected by moisture content, but his
investigation was made on only one species (not specified) of laminated wood.
Since impact strength is such an important property, especially for wood used
^Fig. 4^ STRENGTH, TEMPERATURE, MOISTURE RELATIONSHIPS FROM KOLLMANN’S REPORT
EA-I. Roberts: Effects of Extreme Cold on Materials
in containers, the influence of moisture content in the sub-freezing temperature range upon this property should not be overlooked in the preparation of con– tainers for use in Arctic regions.
Observations that were noted in some of the tests but were not elaborated
upon concerned the suddenness and cleanness of the breaks exhibited by the
frozen specimens. In other words, there seemed to be a tendency for frozen
wood, even though somewhat stronger than in the unfrozen state, to break
abruptly without warning when the maximum load was exceeded. This may have
a bearing on the behavior of hammer handles reported to have failed in service
^
,^
^
—^
presumably due to exposure to extreme cold and the dryness of the atmosphere.
The reports from Alaska describing the failures of certain wood articles
to give satisfactory service all mentioned the extreme dryness of the wood in
connection with the failures. The moisture content of wood in equilibrium
with the surrounding atmosphere is dependent upon the relative humidity of
the atmosphere and is practically independent of temperature in the range below
about
[:
−
]
70°F. Thus, wood exposed to outdoor winter conditions at Fairbanks,
where the relative humidity averages about 83 percent during that season, should
attain an equilibrium moisture content of about 17 percent. Therefore, if low
moisture content is associated with the failure of wood articles to give
satisfactory service, it should not be so likely to occur with those store
s
^
d^
^
—^
and used outdoors or in unheated sheds. On the other hand, if wood articles
are stored in heated buildings they are subjected to conditions that will
result in extreme dryness, even less than 1 percent moisture content, if such
exposure is continued for sufficient time. For instance, if outdoor air at
−24°F. and 83 percent relative humidity is brought indoors and heated to 60°F.
without adding any moisture, the resulting relative humidity will be less than
EA-I. Roberts: Effects of Extreme Cold on Materials
2 percent and will result in an equilibrium moisture content for wood of about one-half of one percent, or practically even-dry. In fact, air at sub-zero temperatures contains so little water vapor, even at saturation, that regardless of its l relative humidity, when this same air is heated to room temperature without addition of moisture the resulting atmosphere will be capable of drying wood to less than one percent moisture content. This could explain the extreme dryness and brittleness mentioned in connection with the reported failures.
It should be stated here that while most strength properties have been
found to improve as temperature and/or moisture content decreases, the tests
made to determine this fact were all made on clear straight-grained specimens
in which knots, cross grain, shakes and checks were entirely eliminated. In
actual practice, however, these defects are often present and their effect is
further accentuated by the shrinkage which accompanies drying in the range below
the fib
[:
]
^
e^
r saturation point. This is especially true in the lower grades of
^
—^
lumber used for container purposes.
Other properties of wood that are very materially influenced by moisture
content are nailing and nail-holding qualities. Dry wood is harder to nail and
splits more easily than does green wood. If the wood dries after the nail is
driven the nail-holding power is often seriously reduced. Thus, the service–
ability of wood articles, such as wooden shipping containers is materially
affected by the moisture content or the changes in moisture content of the wood
in response to exposure conditions.
In conclusion, it may be stated that the information assembled in this
survey fails for the most part to explain the reported reduction in the
serviceability of wood articles under Arctic exposure. Lacking specific
EA-I. Roberts: Effects of Extreme Cold on Materials
samples of the wood for examination and test, as well as more complete information regarding the history of those articles that failed to give satisfactory service and the frequency of such failures, it is not possible to reach a definite conclusion as to the cause of the trouble at this time.”
Metals
The properties of many metals undergo changes at extreme low temperatures,
particularly in strength, toughness, brittleness, and durability. In many of
the hard metals an increase in brittleness may result from exposure to extreme
cold. Caution must be exercised in selecting metals for service at extreme
low temperatures. In the selection of metal parts, attention should be given
to composition as well as to the fabrication of the finished metal article.
Preventive maintenance, including
^
a^
check of metal fittings and frames susceptible
^
—^
to extreme shock or impact conditions, is most important during actual field
operations.
An important precaution to personnel handling metals under extreme condi–
tions, and one that must be carefully followed, is not to contact the metal with
unprotected hands or other uncovered parts of the body. The perspiration of
the skin affords sufficient moisture to freeze the hand to the metal. Forcibly
removing the hand may result in removal of the skin and a possible resultant
painful injury. However, the hand must be torn away as quickly as possible,
unless there is instantly available a quick-heating means, such as a torch,
for the frostbite deepens with lengthened contact. Metal parts that need to
be handled frequently, such as the bolt, trigger, and trigger guard of a rifle,
should be covered with some such material as adhesive tape and can then be used
freely with bare hands.
EA-I. Roberts: Effects of Extreme Cold on Materials
Steel
A few properties of steel such as strength, eleasticity, hardness,
brittleness, and magnetism are at their highest point at very low tempera–
tures and decrease with temperature rise. However, the resistance of steel
to shock decreases very much with lowered temperatures. Certain ordinary
carbon and low-alloy-content steels exhibit a loss of toughness when low
temperatures near −40°F. are reached, so that some of these steels are too
brittle to use in impact service in cold climates.
Stainless Steel
. Chromium-nickel types of stainless steels are especially
well suited for low-temperature applications because their strengths and
toughness properties are improved at extreme low temperatures. Products made
from this material are those requiring toughness and resistance to corrosion
as parachute fittings, shackles, etc.
Hardenable chromium types show moderate loss of toughness at extreme low
temperatures. Sled runners, skates, etc., are made from this material because
of its high hardness and corrosion-resistance characteristics. Nonhardenable
chromium types show marked loss of toughness at 0°F. and lower. This material
is used primarily for parts requiring high resistance to corrosion such as
carburetor and fuel nozzles.
Cast Iron
. The general term cast iron includes gray irons, pig irons,
white cast irons, chilled cast irons, and malleable iron. Cast irons are
alloys of iron, carbon, and silicon with the carbon content usually not
more than 4.5% or less than 1.7%. Gray irons are the most widely used cast
metal and they vary in tensile strength from 20,000 to 60,000 p.s.i. Re–
sistance to impact usually increases with increased tensile strength; however,
at extreme low temperatures the impact resistance decreases greatly.
EA-I. Roberts: Effects of Extreme Cold on Materials
Lead
shows no visible or otherwise detectable effects of temperature in
the range of temperatures experienced in the Arctic. No special care is re–
quired for the maintenance of lead or lead-base alloys such as sheet lead,
lead pipes, and lead assemblies or shapes. Babbitted metals (lead-base bear–
ing alloys) can be expected to behave in a manner similar to that of various
solder alloys.
Solders
(lead and tin alloys). Soft or low-strength solders that contain
a high percentage of lead (65 to 97.5%) retain their ductility and increase
in impact strength at low temperatures. Tin contents up to 15% have no serious
embrittling effect. When the percentage of tin becomes as high as 50%, serious
embrittlement and decrease in impact strength occur.
The increase in tensile strength of solder alloys and in the breaking
load of soldered joints is linear with decreasing temperature. High-strength
solders, those containing the most tin (50%), show the greatest increase in
tensile strength, and the low-strength solders, those containing the most
lead (97.5%), show the least increase in tensile strength as temperatures
decrease below freezing.
Breaking loads of soldered copper tubing at low temperatures are nearly
independent of the kind of lead-base solder used. Impact strength and
ductility of such joints would pro
h
^
b^
ably be influenced by low temperatures,
^
—^
in view of the properties of individual solders.
Copper and Its Alloys
. All wrought copper alloys are alike in that the
effect of extreme low temperatures is to improve all useful mechanical
properties. Hardness, yield strength, and tensile strength show material
improvement, and the ductility is better at extreme low temperatures than at
room temperatures. Impact properties are practically unaffected. The
EA-I. Roberts: Effects of Extreme Cold on Materials
ductility of cold-worked alloys increases to a greater extent than does that of annealed material, and they are, therefore, the logical materials for stressed parts for low-temperature service. Castings of copper alloys show a small decrease in ductility at low temperatures.
Aluminum Alloys. Tests and field use of aluminum and its alloyw^s^ indicate
^—^
that they are admirably suited for extreme-low-temperature service. Tests
made to subatmospheric temperatures indicate that the tensile, yield, and
impact strengths of all aluminum alloys increase at extreme low temperatures.
Aluminum alloys retain ductility at these temperatures, corrosion resistance
is enhanced, and there is no increase in brittleness. No special precautions
regarding methods of handling at extreme low temperatures are required.
Precautions for Equipment
PRECAUTIONS FOR EQUIPMENT
General. All equipment should be winterized for extreme cold prior to
winter operations in the Arctic. Problems which must be considered for various
types of equipment are: insulation of fuel and hydraulic lines and ignition
systems; protection of batteries; change to selected grades of cold-weather
lubricants; provide protection for operators; eliminate the possibility of
ice forming on the inside of equipment due to “breathing of the equipment”;
and the provision for ice grousers on tractor-type units.
Storage Batteries. High acid content batteries give good performance at
low temperatures but will deteriorate rapidly at normal temperatures. This
should be considered in selecting batteries for arctic operations. On all
equipment using batteries, measures must be taken to maintain a reasonable
operating temperature for the battery by adopting the following precautions:
- 1. Install battery in a location away from the hull or frame which is in contact with the outside of^r^ the ground. ^—^
- 2. Insulate batteries with a rock wool, fiber glass, or celotex casing or jacket.
- 3. Provide heat for battery installation area if necessary. The output of batteries decreases because of increased internal resistance at low tempera– tures. A fully charged storage batta^e^ry at 70°F. will produce only 50% of its ^—^ rated capacity at 0°F., 20% at −40°F., and 10% at −60°F.
EA-I. Roberts: Effects of Extreme Cold on Materials
Batteries should be maintained carefully and hydrometer readings taken
regularly because lead-acid batteries falling below a 1.125 reading will
burst at 0°F. Storage batteries will not freeze at extreme low temperatures
if well charged.
Dry Cell Batteries. The life of such batteries is greatly shortened by
use at low temperatures, and lower voltages are developed. Less than 10% rated
capacity will be produced by the dry cell at 0°F. Battery cases should be
insulated and when not in use carried in warm places. An ordinary flashlight
that grows dim, when carried in a mittened hand on a cold day may brighten if
warmed by holding ^in^ the bare hand. However, there must be some such thing as thin
cloth between the hand and the flashlight to prevent a frost burn. Some
northerners slit the palm of one mitten so they can hold the inserted shaft
of the flashlight.
Cameras, Optical and Scientific Instruments. All cameras, binoculars,
and scientific instruments should be carefully cleaned, reducing the lubricant
to a minimum, and should be hermetically sealed or moistureproofed where
possible. Such instruments if to be used out of doors should be kept outside
during cold weather to eliminate alternate heating and chilling, which will be
a source of errors as well as tend to cause internal fogging. In using
binoculars, sextants, theodolites, etc., personnel should be warned against
EA-I. Roberts: Effects of Extreme Cold on Materials
fogging the lenses by breathing directly onto them or pressing the eye too close to the eyepiece. Lightweight nylon gloves, worn under mittens, are sometimes used by personnel to adjust instruments.
Firearms. Rifles function well at extreme low temperatures, providing a
minimum of precautions are taken to protect them. Grease should be wiped
from all mechanisms and the barrel cleaned when outside temperatures drop
below freezing. Firearms should be kept outside. This point is considered
crucial by all experienced arctic riflemen. Weapons should be carefully
checked before and after firing to see that no ice or snow has clogged moving
parts. A gun cover should be provided for each weapon, and a cap should be
used when hunting to cover the muzzle of the rifle to prevent snow entering
the barrel. Metal surfaces of the rifle which may be touched by the hand in
loading and firing are sometimes covered with tape, permitting use of bare
hands. Firearms should be cleaned and oiled with a light gun oil when tempera–
tures return to above freezing.
Blasting Machines. The push-down type of blasting machine is preferred
for use in cold weather. The machine should be cleaned and oiled lightly
with a cold-weather lubricant to obtain the best performance. The blasting
galvanometer, used to check electrical circuits, becomes completely inactive
at very low temperatures, but is not permanently injured and will function
properly if brought back to normal temperature conditions. It is essential
for best performance that the galvanometer be kept warm by some means until
the time for actual use.
Wire Ropes, Cords, and Strands. These items have been used successfully
in exposed operations at extreme cold temperatures both on the ground and in
the air. Precautions regarding the use of the wire-rope items will depend
largely on the material from which the item is made and the extreme temperature
EA-I. Roberts: Effe[: e]^c^ts of Extreme Cold on Materials ^ —^
to be encountered. Instructions should be obtained from the manufacturer regarding the use of the cable, and the effect of extreme cold on the brittleness, impact strength, metal fatigue, and other properties.
Bolts. Failure^s^ of connectors in structures and equipment have been a ^—^
problem. The Chairman of the American Society of Testing Materials Committee
on Low-Temperature Bolting advises as follows:
“Only ASTM Specification A 320 bolting, preferably Grade L7 is recommended.
This grade meets the impact requirement at −50°F by a wide margin. It is
possible that ASTM specification A 261 heat treated carbon steel bolting
would be satisfactory, although its impace^t^ resistance would be less, and ^—^
therefore this material would be borderline.”
PREPARATION OF EQUIPMENT SPECIFICATIONS
In the outfitting of personnel and organizations who are to engage in
operations under extreme cold conditions, it is oftentimes necessary to
purchase or design equipment under contract. The preparation of specifications
for equipment to be furnished under such a contract is of vital important.
These cannot be written casually but must represent the best experience in
the field on the subject and should be prepared only by or under the direction
of those who have had actual and repeated operational experience under extreme
cold conditions.
Properly prepared specifications should not only specify detailed design
information or criteria for the equipment but should describe fully the use
to which the equipment will be put, the extreme and average conditions under
which it will operate, and the difficulties that may be anticipated, citing
problems that may be expected and that may have arisen and have not yet been
EA-I. Roberts: Effects of Extreme Cold on Materials
solved. Such added information will assume proper design and performance and avoid the possibility of over design which ofttimes results from lack of proper information or understanding of the problem.
Specifications for other than proved equipment should include testing
under the conditions established in the design criteria and should provide
for corrective measures to produce the specified or desired equipment. New
equipment, once committed to arctic operations, should be followed carefully
and reports on such equipment should be returned to the originator of the
specification. Such experience will tend to provide the needed balance in
design which will ultimately result in providing the equipment most suitable
for use under year-round arctic conditions.
EA-I. Roberts: Effects of Extreme Cold on Materials
BIBLIOGRAPHY1. American Society for Metals. Metals Handbook . Cleveland, O., 1948.
2. Battelle Memorial Institute, Columbus. Low Temperature Properties of Lead-Base Solders and Soldered Joints . December, 1948. Laboratory publication No.198-48.
3. Smith, C.S. “Mechanical properties of copper and its alloys at low temperatures,” Am.Soc.Test.Mat., Proc ., 1939, vol.39, pp.642-48.
4. Stefansson, Vilhjalmur. Arctic Manual . N.Y., Macmillan, 1944.
5. U.S. Forest Service. Forest Products Laboratory, Madison, Wis. Survey of Available Literature on the Effect of Arctic Exposure Conditions on the Strength Properties of Wood . Madison, Wis., June 4, 1948.
Palmer W. Roberts
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