Military reference books and manuals (2009-2023, Volume 3)

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eastwards into the Barents Sea, and the West Spitsbergen Current, which continues northwards

past Vestspitsbergen to enter the North Polar Basin where the Atlantic water forms an intermediate

warm layer. Part of the West Spitsbergen Current turns westwards off the northern part of

Vestspitsbergen and flows towards the Greenland Shelf. It then turns south and proceeds below

the East Greenland Current as a warmer, more saline, intermediate layer at 175-350 m (95--190

fathoms) depth.

d. The main cold current of the region is the East Greenland Current. This carries ice and Arctic

water, with subzero temperatures and low salinity, from the North Polar Basin along the whole

length of the East Greenland Shelf to round Kap Farvel and enter Davis Strait. There are two

branches of the East Greenland Current: the first, the Jan Mayen Current, flows eastward to the

north of Jan Mayen in the region of the Mohn Ridge. The second, the East Icelandic Current,

flows southeastwards past the northeast coast of Iceland to sometimes reach the north coast of the

Faroe Islands and beyond. A smaller source of Arctic water and ice are the Bjornoya and East

Spitsbergen Currents. These originate in the northeastern part of the Barents Sea and move

southwestwards over the Svalbard Shelf, the former to reach Bjornoya and the latter to round

Sorkapp in Vestspitsbergen and flow northwards between the Vestspitsbergen coast and the West

Spitsbergen Current. The distribution of the sea ice is deterrnined by the East Greenland Current

and its two branches, and to a lesser extent by the East Spitsbergen Current.

e. The speeds of the various currents are not well established. There is evidence to suggest that

there are frequent changes because of the wind. Some estimates put the speeds of the Atlantic

Current and East Greenland Current at 12-24 nautical miles (22-44 km) per day. Locally the East

Greenland Current can reach very high speeds, for example, 3 knots (150 cm/sec) just south of the

Denmark Strait. The basins of the Norwegian and Greenland Seas contain a very nearly uniform

deep water with a salinity of about 34.92 parts per 1000 and a temperature of about-1°C. Seventy

percent of the combined basins is below 550m (300 fathoms) depth and filled with this Norwegian

Sea Deep Water. The mixed water in the upper layers, primarily in the Greenland Sea and to a

smaller extent in the Norwegian Sea, is cooled in winter, but before it can freeze it reaches a

higher density than that of water below it and so sinks to form the Deep Water. In the region of the

Iceland-Jan Mayen and Mohn Ridges, Arctic Intermediate Water appears above the Norwegian

Sea Deep Water and below the Arctic Water of the East Greenland Current system. It has its core

at about 400 m (220 fathoms) depth and has a temperature between 0 and 2° C and a salinity

between 34.8 and 35.0 parts per 1000. It is formed by the cooling of Atlantic Water and mixing

with the Deep Water and, to a lesser degree, Arctic Water. Further south in the Icelandic coastal

area, vertical mixing of Atlantic Water and Arctic Water in winter results in a homogeneous water

in the uppermost 175-350 m (95-190 fathoms). This water has a temperature of 2-3°C and a

salinity of 34.85-34.90 parts per 1000, and is called North Icelandic Winter Water.

f. The Norwegian Sea Deep Water escapes into the North Atlantic Basin through the channel

between Faroe Bank and the Faroe Islands. It flows at the bottom of this channel at a speed in

excess of 2 knots (100 cm/sec) and as it does so the Northeast Atlantic Water, which lies above it,

is entrained into the flow. The resultant mixing produces the Northeast Atlantic Deep Water. This

water mass has minor constituents because, at times, the Arctic Intermediate Water flows through

the same channel and the Norwegian Sea Deep Water, Arctic Intermediate Water and North

Icelantic Winter Water overflow the Faroes-Iceland Ridge, particularly near Iceland, proceed

down its southern flanks, entraining overlying Northeast Atlantic Water as they do so, and

eventually join the outflow from the Faroe Bank Channel as it flows westwards at the foot of the

ridge.

g. The Northeast Atlantic Deep Water eventually turns south when it meets the Reykjanes Ridge;

at about latitude 63°N it breaks through this ridge and flows northwards along its western flanks to

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fill most of the Irminger Sea at a depth of 1750-2500 m (950- 1360 fathoms). Above it, in the

Irminger Sea, is Labrador Sea Water with its core at 500-1275 m (275-700 fathoms). This water is

formed as the result of the vertical mixing from the surface to a 1500 m (820 fathoms) depth of

low-salinity water in the Labrador Sea in winter. Below the Northeast Atlantic Deep Water in the

Irminger Sea is the Northwest Atlantic Bottom Water, which originates with the overflow of water

from the Norwegian Sea across the Iceland-Greenland Ridge, in the region of the narrow deep

channel in the Denmark Strait. The overflowing water is at times Norwegian Sea Deep Water and

at times Arctic Intermediate Water. In both cases the overflow proceeds at high speed down the

East Greenland Continental Slope and entrains, first, overlying Irminger Atlantic Water and, later,

Labrador Sea Water and Northeast Atlantic Deep Water, to produce a water mass of high density

which fills the bottom part of the basins of the Irminger and Labrador Seas. Thus, in addition to

there being a counter-clockwise horizontal circulation in the upper part of the water column, with

the Northeast Atlantic Water entering our area and the East Greenland Current leaving it, there is

also a circulation in the vertical plane with the inflow of the Northeast Atlantic Water being

compensated by deeper outflows, over the Scotland--Greenland Ridge, of Norwegian Sea Deep

Water and Arctic Intermediate Water.

Table 3-1 Temperature and Salinity Characteristics of the Water Masses of the European and

American Arctic and Subarctic Seas

Northeast Atlantic Water

9.5°C; 35.35 parts/1000

Irminger Atlantic Water

4.6°C; 34.95-35.10 parts/1000

Arctic Water

< 0°C; < 34.0 parts/1000

Labrador Sea Water

3.4°C potential temperature; 34.89 parts/1000

Northeast Atlantic Deep Water

3.0°C potential temperature; 34.95 parts/1000

Northeast Atlantic Bottom Water

0.8°C 1.5°C; 34.91 parts/1000

Norwegian Sea Deep Water

< 0°C; 34.92 parts/1000

Arctic Intermediate Water

0° - 2°C; 34.8 - 35.0 parts/1000

North Icelandic Winter Water

2° - 3°C; 34.85 - 34.9 parts/1000

Skagerrak Water

3°- 16° C (according to season); < 34 parts/1000

309 EURASIAN COASTAL WATERS

1. Bathymetry

a. The Barents Sea occupies nearly 1 400 000 km2 on the continental shelf of Eurasia. It has free

contact with the Norwegian Sea on the west and with the Arctic Ocean on the north, and it is

deeper than the other peripheral seas, much of it being greater than 185 m (100 fathoms) deep. The

bottom is more like a continental borderland than a shelf, as it has both exceptionally shallow and

deep areas scattered through it. The flat shelf areas are east and southeast of Svalbard and in the

southeastern part of the sea. An east-west ridge at a depth of 185 m (100 fathoms) connects the

shore areas around Z. Frantsa Iosifa with Svalbard, and a north-south ridge at 300 m (165

fathoms) separates the western Bjornoya basin with depths of over 350 m (190 fathoms) from the

eastern basin. The eastern depression extends southwest between Z. Frantsa Iosifa and Novaya

Zemlya with general depths over 275 m (150 fathoms) and occasional depths over 350 m (190

fathoms). In the extreme north there is a third depression between Svalbard and Z. Frantsa Iosifa.

b. The White Sea is a large arm of the Barents Sea that projects more than 270 NM (500 km) into

the European mainland. The approach from the Barents Sea is appropriately called Voronka

(Funnel), and is about 60 NM (110 km) wide. The entrance narrows to the southwest until

between the Kol'skiy P-ov. and the mainland it becomes a strait, called Gorlo (the Throat), 27 NM

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(50km) wide, where ice obstructs navigation even when the western, inland and wider part of the

White Sea is reasonably ice-free. The White Sea is mostly less than 100 m (55 fathoms) deep.

Figure 3-4 Water Masses--Norwegian and Adjacent Seas

c. The Kara Sea is exceptionally shallow in the east but relatively deep for its position on the

continental shelf in the west. Off the east coast of Novaya Zemlya there is a 43 NM (80 km) wide

basin that in some places is 550 m (300 fathoms) deep. A ridge in the north of the Kara Sea

separates the basin from the Arctic Ocean. Between Yamal P-ov and Novaya Zemlya there is

another trough of deeper water. There are two more basins in the north of the sea, which have

maximum depths of about 550 m (300 fathoms) and are separated by a ridge. O. Uyedineniya,

Vize and Ushakova form the highest elevations of this ridge. In the southeast of the Kara Sea

depths average only 50 m (27 fathoms) 50-135NM (93-250km) from the shore. The water adjacent

to the Ob and the Yenisey rivers is also exceptionally shallow.

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2. Currents

a. The surface characteristics of both climate and sea ice in the Barents Sea result primarlly from

an lnflux of warm water from the Norwegian Sea. This warm current flows north along the coast

of Norway; a southern branch enters the Barents Sea along the north coast of Norway and Kol'skiy

P-ov. as the North Cape Current; the northern branch flows north of Bjornoya and then turns

northwest, passing along the south and west coasts of Svalbard as the West Spitsbergen Current.

Off Varanger Halvoya, the North Cape Current flows at 8 nautical miles (15 km) a day but the

velocity decreases to the east. The current splits at Varanger Fjord, one part flows in a belt 40-50

NM (75-90 km) wide to the entrance of the White Sea, the other curves northeastwards across the

Barents Sea and passes north of Novaya Zemlya into the Kara Sea. This branch is weak in the

north and south of its course, but between 36°E and 44°E it runs at approximately 18 nautical

miles (33 km) a day.

b. The major inflow of cold water into the Barents Sea is between Novaya Zemlya and Z. Frantsa

Iosifa. This current also branches into two parts: one part flows southwest of the archipelago, and

the other west, as the Bear Island Current. In the southeast the general movement of water is

towards the Kara Sea except for the Litke Current, which has the reverse direction. It moves west

through the northern half of Proliv Karskiye Vorota, and then northwest along Novaya Zemlya,

joining the general northerly movement there. In the White Sea is a weak outward current in the

spring and summer, and an equally weak counter-clockwise eddy within the basin.

c. The only important current in the Kara Sea forms a closed counter-clockwise circulation in the

west. The gyre begins in the east with Ob and Yenisey waters which broaden as they leave the

estuaries. One branch flows to Novaya Zemlya where it turns southwest to Proliv Karshiye

Vorota. Within the main circulation are two small weak counter- clockwise eddies. Water also

enters the Kara Sea around the north of Novaya Zemlya from the Barents Sea and eventually

mixes with the Ob-Yenisey waters.

d. Tides in the Kara Sea are semi--diurnal and relatively weak. They come from the Barents Sea

along eastern Novaya Zemlya and from the Arctic Ocean along western Severnaya and progress

southwest. The average amplitude is 0.5 to 1 metre. Winds commonly increase the tidal range by 1

metre or more.

310 EASTERN SIBERIAN COASTAL WATERS

1. Bathymetry. Both the Laptev and the East Siberian Seas are shallow basins with gentle shores.

The edge of the continental shelf is up to 430 NM (800 km) offshore. Only in the northwest Laptev

Sea, off Severnaya Zemlya, are depths greater than 90 m (50 fathoms). The western sector of the East

Siberian Sea south of the Ostrova Novosibirskiye and east to the Kolyma River, is exceptionally

shallow with many shoals. Between the Indigirka and the Kolyma Rivers, and almost continuous

shorebank, defined by the 5.5 m (3-fathom) curve, extends about 24 NM (44 km) out from the shore.

From the Kolyma east to Mys Shmidta, the coastal water is deeper. There are only a few islands, and

these, with the exception of Ostrova Medvezh'i, are close to the shore. The sea deepens slowly to the

northeast; maximum depths are 45-55 m (25-30 fathoms).

2. Currents

a. The general flow of water in both the East Siberian and Laptev Seas is counter-clockwise.

There is a weak, easterly coastal current which is modified by water from the large rivers which

forces it offshore in a northeasterly direction at 1 kt (2 km/h); counter-clockwise eddies develop

when it is caught in coastal indentations. The major current entering the Laptev Sea comes through

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Proliv Vil'kitskogo between M. Chelyuskin and Severnaya Zemlya. It is joined by a cold current,

flowing southeastward along Severnaya Zernlya, at 0.2 kt (0.4 km/h) and the combined waters

move along the Taymyr coast into the shallow part of the Laptev Sea. At the Lena Delta the

current splits. One part, flowing along the west side of the Ostrova Novosibirskiye at 0.5-1 kt (1-2

km/h), sets to the north of the archipelago and joins the main Arctic drift. The other part flows

through Proliv Dmitriya Lapteva and other straits into the Eastern Siberian Sea.

b. The waters that pass through the straits separating Ostrova Novosibirskiye and the mainland

spread out on reaching the East Siberian Sea. The main branch near the coast flows at

approximately 0.3 - 1 kt (0.5-2 km/h). A branch of this current is believed to pass north and west

of Ostrov Vrangelya. In summer a current reaches through Bering Strait and flows northwest to

the middle of Proliv Longa; its direction may be reversed in the winter.

c. North of the coastal currents in both the Laptev and the East Siberian Seas, the water flows in

large counter-clockwise eddies. Father north still is a west-northwest current, which runs

northwest at the Ostrova De-Longa and passes north of the Ostrova Novosibirskiye into the

Laptev Sea. It continues northwest across the northern margin of the sea and flows north of

Severnaya Zemlya.

d. Tidal progression is southwards from the Arctic Ocean in both seas. Tides are semidiurnal and

their range is 30 cm, although it may be raised to 3 to 3.5 m with an onshore wind. Tidal currents

flow from 0.5 to 0.8 kt (1 to 1.5 km/h) in the Laptev Sea, but are weaker in the East Siberian Sea.

311 CENTRAL POLAR BASIN

1. Bathymetry and Submarine Topography

a. The Arctic Ocean is a true ocean. Beneath the deepest parts, the crust of the earth is about 10

km thick, a figure that is fairly typical of the other oceans. The Arctic Ocean also shares with other

oceans the characteristic that relief occurs at two predominant levels: the continental shelves with

depths of a few hundred metres, and the deep basins with depths of several thousand metres. A

sharp break in slope between the continental shelf and the continental slope marks the boundary

between the shelves and basins, and defines the edge of the Central Polar Basin. In most oceans,

the shelf break is at about 185 m (100 fathoms) depth, but in the Arctic it is deeper in some

localities (365-475 m: 200-260 fathoms). First recognition that the Arctic Ocean was not a shallow

sea but contained a true deep basin came from the soundings of the Norwegian North Polar

Expedition during the drift of the Fram (1893-1896). The North Pole has been reached twice by

ice-breakers and Arctic exploration has been conducted with aircraft, drifting ice stations, and

nuclear submarines. Oceanographic research proceeded slowly after the successful voyage of the

Fram and it has only been in the last two decades that renewed efforts by the USA and USSR have

resulted in our present level of understanding.

b. Early bathymetric maps of the oceans usually showed smooth and unrealistic contours based

on wire soundings. With the introduction of the continuous echo-sounder, it became clear that the

contours often cut across regions with quite different bottom characteristics. Recently there has

been a trend to analyse the ocean floor in terms of physiographic provinces which cover areas of

similar topographic textures and which contrast with surrounding areas. Almost all the various

provinces found in other oceans, except deep-sea trenches, are known in the Arctic Ocean. The

first--order features are the continental margins and the ocean basins. The continental margin is

made up of the continental shelf, continental slope, continental rise, and marginal plateaux. The

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ocean basin consists of ridges, rises, and abyssal plains. A map of the major physiographic

provinces of the Arctic Ocean is shown in Figure 3-5.

2. The Continental Margin

a. Shelves, Slopes and Canyons. The continental margin on the Eurasian side contains some of

the broadest continental shelves in the world. The East Siberian Shelf is 270-485 NM (500-900

km) wide and the Barents and Kara shelves are 380-50 NM (700-1200 km) wide. In contrast the

shelves off Greenland and northwest Canada are only 16-38 NM (30-70 km) wide. North of

Alaska the continental slope has a gradient (1:15 to 1:40) which is comparable to that in other

parts of the world. In contrast, the continental slope between the New Siberian Islands and the

Chukchi Sea is apparently formed of several level surfaces and has been likened to a "giant

staircase". Submarine canyons cut across continental shelves and slopes in the Arctic as in other

oceans. Two prominent ones, Barrow Canyon and Harald Canyon, incise the Chukchi Shelf

between Wrangel Island and Point Barrow. SSN Nautilus, during her 1958 Arctic cruise, made use

of the deeper water of Barrow Canyon to cross the shelf below the ice.

b. Rises and Plateaux. A gently sloping continental rise usually lies at the foot of the continental

slope. North of Alaska, this rise is 27-54 NM (50-100 km) wide. Much greater widths of 160-270

NM (300-500 km) occur in the continental rise off the Canadian Archipelago. A system of deep-

sea channels with a relief of 5 m crosses the Canadian continental rise. A marginal plateau is a

level feature which borders the continental shelf at a greater depth. Several are known in the

Arctic Ocean. The Chukchi Rise is crowned at its outer end by the Chukchi Plateau or Cap which

has a flat summit with a diameter of about 54 NM (100 km) at depths of 300 m (165 fathoms). The

surface is marked by a small-scale relief of 5-30 m. Two submarine canyons indent the southwest

side of the plateau. Southeast of the Chukchi Plateau is an area of rough topography which has

been described as a "continental borderland". Within this area is another plateau, the Northwind

Cap. Other marginal plateaux include the Beaufort Terrace, which on its outermost edge, is

similarly elevated above the saddle which connects to the continental shelf, and the Morris Jesup

and the Yermak rises in the Greenland-Svalbard area.

3. The Ocean Basin

a. Lomonosov Ridge. The Central Polar Basin is crossed by three submarine mountain ranges.

The ridges and rises are nearly parallel to one another and span the basin from the Eurasian to the

Canadian side. A bathymetric profile (Figure 3-6) based on SSN Nautilus soundings, shows two of

these ranges, the Lomonosov Ridge and the Alpha Cordillera. The Lomonosov Ridge stretching

970 NM (1800 km) between the New Siberian Islands and the Greenland-Ellesmere Shelf, was

discovered by Soviet scientists in 1948. It is a single continuous feature, 54-108 NM (100-200 km)

in width. Available echograms show a steep-sided ridge with a rather smooth profile. Minimum

depth reported is 950 m (520 fathoms). Saddles along the crest have depths of 1500-1600 m (820-

875 fathoms). A flat surface near the crest of the ridge has been noted on two different crossings.

An offshoot of the Lomonosov Ridge is known as the Marvin Spur.

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is rough, with many anomalies exceeding 1000 gammas, while there is little disturbance over the

Lomonosov Ridge. Neither of these ranges is seismically active. The Nansen Cordillera is an

extension of the Mid-Atlantic Oceanic Ridge into the Arctic Ocean. Where the topography has

been sampled, it is rough, as it is on the Mid-Atlantic Ridge. The most distinctive characteristic of

the Nansen Cordillera is the narrow earthquake belt along its crest (Figure 3-7). The belt of

earthquake epicentres crosses Iceland and then changes direction abruptly north of the island,

where a large east-west fracture zone intercepts the mid-oceanic ridge near Jan Mayen Island.

Between northeastern Greenland and northern Siberia, the earthquake belt is narrow and straight

for a distance of over 1080 NM (2000km). Within Siberia, the earthquake zone spreads out and

disappears. In the Atlantic a similar earthquake belt coincides with a central rift valley at the crest

of the mid-oceanic ridge.

c. Abyssal Plains. These are the ultimate repositories for sediments, which have been transported

across the continental shelves and down the continental slopes via the submarine canyons. In the

deep basins the sediments collect to form the most extensive level surfaces on the globe, with

gradients of 1:1000 or less. Four of the abyssal plains in the Arctic Ocean are arranged in step-like

pairs. Each pair is connected by an abyssal gap through which sediments are transported from the

upper to the lower plain. The Canada and Chukchi Abyssal Plains are connected by, the Charlie

Gap. The complete route of sediment flow is from Herald Canyon to the Chukchi Abyssal Plain

and then through the Charlie Gap to the Canada Abyssal Plain; Wrangel and Fletcher Abyssal

Plains are connected through the Arlis Gap. Abyssal gaps are commonly named after the ship of

discovery. In this case, the discovering "ships" were drifting ice stations, Charlie and Arlis,

respectively. Seismic reflection profiles show that a prominent sub-bottom basement ridge exists

in the vicinity of the Arlis Gap. Sediments move from the Siberian Shelf to the Wrangel Abyssal

Plain and then through the Arlis Gap to the Fletcher Abyssal Plain. A system of interplain

channels funnels the flow across the plain and into the gap. The right bank of these channels is

higher than the left bank, apparently due to the influence of the earth's rotation.

Figure 3-6 Topographic Profile Across the Arctic Ocean

d. The most extensive plain in the Arctic Ocean is the Canada Abyssal Plain which covers an

area of 254 000 km2. It is remarkably flat, with depths ranging from 3750 m (2050 fathoms) in the

north to 3850 m (2100 fathoms) in the south. On its northern and western edges, it is bonded by

the scarps of the Alpha Cordillera and Chukchi Rise. The eastern and southern boundaries grade

smoothly into the continental slope. The Pole Abyssal Plain is deeper than the four plains

previously mentioned. In the neighbourhood of the North Pole it is flat and smooth with a depth of

4085 m (2230 fathoms). Away from the Pole the depth of the plain increases to 4575 m (2500

fathoms).

4. Bottom Sediments

a. Light-brown foraminiferal oozes are generally intermixed with sands and gravels on elevated

topography such as ridges and rises. This is known as, a glacial marine sediment. The ooze

represents normal pelagic sedimentation. The sands and gravels are ice-rafted material, which has

been carried out from shore on ice floes and ice islands to be dumped when the ice melted or

broke up. Rocks are often observed strewn over the bottom in deep-sea photographs. The unsorted

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ice-rafted rocks range greatly in size. A cobble weighing over 7 kg has been dredged. In bottom

photographs, rocks with dimensions of about one metre have been seen. These rocks show

faceting and striation, which are typical of glacial deposits. On the ridge and rise areas,

sedimendation is extremely slow, only a few millimetres accumulating in 1000 years. Thus many

thousands of years are required to bury an ice--rafted rock. Signs of bottom life are rare in these

regions.

b. Sediments on the Canada Abyssal Plain are greyer in colour and lack the ice-rafted debris

found on the elevated areas. The sediments of the abyssal plains presumably also contain the

pelagic and glacial components but these have been inundated and diluted by turbidity-current

deposits. Turbidity currents originate on continental slopes when oversteepened sediments slump

and flow down submarine canyons a, a slurry of mud and water. They flow and spread out on

reaching the abyssal plain, depositing the mud over the level surface. The coarsest material settles

first so that the beds are usually graded. No rocks are found in photographs taken on the Canada

Abyssal Plain. Signs of animal life, such as intricate patterns of tracks and burrows, are abundant.

c. Seismic reflection profiles give a thickness of about one kilometre for the unconsolidated

sediments near the northern edge of the Canada Abyssal Plain. The thickness must be greater near

the centre of the plain. The same technique has shown at least a 3.5 km thickness of nearly

horizontally stratified sediments underlying the Wrangel Abyssal Plain. The layer of

unconsolidated sediment is much thinner on the ridges and rises. Measurements on the Alpha

Cordillera generally give thickness between 300 and 500 metres.

5. Water Masses. Four water masses are recognized in the Central Polar Basin:

a. The Arctic Surface Water lies between the surface and a depth of 200 m (110 fathoms).

Salinity may be as low as 30 parts per 1000 in this layer at the surface, but it increases rapidly

below 55 m (30 fathoms). Temperature is generally close to the freezing point.

b. On the Alaskan-Canadian side of the ocean, there is a small temperature maximum (-0.7°C) at

about 70 m (38 fathoms), which is known as the Pacific Water. The temperature maximum

decreases with distance from the Chukchi Shelf.

c. The Atlantic Water is marked by positive temperatures between -relatively uniform salinities

of 34.9 to 35.0 parts per 1000 are attained. The depth of the maximum temperature in the Atlantic

Layer increases with distance from its source northwest of Svalbard. It is initially at 300 m (165

fathoms) but increases to 500 m (275 fathoms) north of Alaska. The temperature maximum

decreases with distance from Svalbard from an initial value of 3°C to 0.5°C north of Alaska.

d. The Arctic Deep Water lies between the Atlantic Water and bottom. Temperatures are below

0°C and salinities increase very slowly with depth, from 34.93 to 34.99 parts per 1000. Below

1375-1500 m (750-820 fathoms), the temperatures are 0.5°C warmer on the Canadian side than on

the Eurasian side. These deep waters are presumably formed during cold winters in the Norwegian

Sea. They first enter the basin on the Eurasian side of the Lomonosov Ridge. Some of the water

flows over the saddles in the Lomonosov Ridge to form the warmer bottomwater of the Canadian

side.

6. Tides. Tides in the Arctic Ocean are small. For example, the mean spring tide range at Point

Barrow, Alaska, is only 15 cm. The semi-diurnal tide is derived almost entirely from the Atlantic. It

enters the Arctic Ocean between Svalbard and Greenland, travelling across the Arctic Ocean in about

12 hours as a progressive wave. On the Siberian shelves the tidal currents usually rotate clockwise.

Storm surges may exceed the height of the tides and can cause damage to low-lying Arctic coasts.

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7. Underwater Sound

a. The propagation of underwater sound in the Arctic Ocean differs in several ways from that in

non-polar oceans. In the Atlantic and Pacific Oceans, the SOFAR channel lies at depths of 1000-

1375 m (550-750 fathoms), but in the Arctic it is at the surface. Low-frequency sound is

propagated to great distances in the Arctic SOFAR channel. Sound rays are alternately refracted

upward in the water and reflected downward from the base of the ice. At great ranges signals

consist predominantly of low frequencies, 8-100 Hz. Roughnesses on the lower surface of the ice

strongly attenuate the high frequencies but have a negligible effect on the low frequencies. Signals

generated by small explosions have been recorded clearly at distances from 43 NM up to about

1620 N M (80-3000 km). Beyond a range of 325 NM (600 km), waves above 100 Hz are very

weak. The Arctic SOFAR signal is dispersed so that an impulsive signal increases in duration as

the range is increased. At a range of 325 NM (600 km) the duration of a signal from a small

explosion is about 5 seconds. At shorter ranges, and over smooth bottoms such as abyssal plains,

bottom-reflected arrivals can be of importance. They are late signals and increase still further the

duration of the signal.

b. In the shallow water of the shelves, propagation characteristics depend strongly on bottom

parameters. In general, long-range transmission is much more strongly attenuated along shallow-

water paths than it is along deep-water paths. Dispersion is even more pronounced in shallow-

water transmission. A shallow sound-scattering layer has been observed beneath the central Arctic

Ocean during the summer months. This scattering layer appears on echograms made at a drifting

station with a 12 Hz sounder. Information on the sound velocity structure of the ocean can be

obtained from measurements of temperature, salinity and depth. For very precise measurements of

these factors at specific depths, Nansen bottles and reversing thermometers are employed.

Information thus obtained can be converted into sound velocity by various methods.

312 ARCTIC OCEAN FRONTS

1. General

a. Ocean fronts are, boundaries separating one water mass from another somewhat like weather

fronts in the atmosphere. Unlike atmospheric fronts however, ocean fronts do not move great

distances, but rather remain in a given area. Because of this, "regional" characteristic ocean fronts

can be classified by the region where they are found and by the characteristic water masses they

separate (See Figure 3-8).

b. Ocean fronts themselves are usually associated with cold or warm currents and can be

influenced by subsurface topographic features such as submarine ridges. In any case, they are

boundaries between water masses of different temperatures, salinities or both.

2. Iceland-Faeroe Front

a. The Iceland-Faeroe Front forms the boundary between the warm, saline Atlantic water and

cold, relatively fresh Arctic water. The front is located near the extension of the submarine ridge

that runs between Scotland and Greenland with depths over the ridge shoaling from 360 to 550 m.

The ridge forms a wall separating the deep waters of the Atlantic Ocean and the Norwegian Sea. It

blocks the flow of most of the nearly homogenous Norwegian Sea Deep Water into the North

Atlantic, thereby affecting the formation and dynamics of the front.

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b. Although the surface reflects a rather complex mixing pattern, sea-surface temperature

gradients across the front are present during all seasons. Frontal intensity increases and shows

more definition with increasing depth. At depths of 180 to 275 m, the horizontal temperature

gradient reaches its maximum of -8°C in the winter and -12°C in the summer. Below 275 m,

frontal features weaken and become less defined due to the influence of the nearly homogeneous

Norwegian Sea Deep Water.

c. Although the position of the front is mainly determined by the Iceland-Faeroe Ridge short

period meandering within a 45 NM envelope is not infrequent.

3. Greenland-Norwegian Sea Front

a. The Greenland-Norwegian Sea Front is sometimes referred to as the North Polar Front and is

associated with the Norwegian Current. The Norwegian Current is an extension of the North

Atlantic Current. The current flows northward along the eastern Norwegian Sea at speeds

averaging 0.5 knots and brings warm, saline Atlantic water with it.

b. Like all ocean fronts the Norwegian Sea Front, is the boundary between two water masses of

different temperature-salinity combinations. Atlantic water with temperatures of 6 to 7°C and

salinities slightly greater than 35 parts per thousand are found east of the front. The colder, less

saline waters of the Norwegian-Greenland Seas are found to the west of the front.

c. The Norwegian Sea Front is present year-round, and shows significant short term variability (2

to 3 days). This variability takes the form of cyclonic and anticyclonic meanders and eddies on the

order of 16 to 32 NM. The surface expression of the front is difficult to locate due to wind mixing

of the near-surface waters and the extensive cloud cover limiting the usefulness of satellite

imagery. Because the maximum horizontal temperature gradient is found at a depth of 200 to 300

m, SXBT traces can be extremely useful in determining position.

4. Bear Island Front

a. The Bear Island Front is located midway between Spitsbergen and the Norwegian coast and

results from the interaction of the Bear Island Current and the eastern branch of the Norwegian

Current. The Bear Island Current carries relatively cold, low-salinity Arctic water down into the

northeastern Norwegian Sea. The Norwegian Current, also known as the North Cape Current in

the region, carries modified Atlantic water around the North Cape into the Barents Sea. The

temperature of the modified Atlantic water ranges from 1-7°C at a salinity of about 35 parts per

thousand.

b. The Bear Island Front lies in shallow water in the vicinity of the Bear Island shelf break near

the 90-m curve. The front is closely linked to the bathymetry and shows some light meandering of

about 30 NM from year to year. This phenomenon may be due to periods of northeasterly or

southwesterly winds that favor the transport of Arctic or Atlantic waters respectively, or tidal

effects.

c. Typically, temperatures across the front range from 4-5°C and salinity changes about 1 parts

per thousand. The associated sound speed change is on the order of 21 m/sec. Also, one may

expect a shoaling off the bottom to 185 m in the vicinity of the front.

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5. West Spitsbergen Front

a. The West Spitsbergen and Greenland Sea Fronts form the northern and western boundaries of

the large cyclonic gyre. The West Spitsbergen Front forms the boundary between the modified

Atlantic water found adjacent to the southwest coast of Spitsbergen and the colder, less saline

water found in the interior of the Greenland-Norwegian Sea.

b. The temperature gradient associated with the front is evident at the surface where the

temperature changes from an average 7 to 1°C. The warmer temperature is associated with the

modified Atlantic water, which, has a salinity greater than the 34.88 parts per thousand found in

the Greenland-Norwegian Seas.

6. East Greenland Front

a. The East Greenland Front is the result of the East Greenland Current, which is the western

extension of the Spitsbergen Current. The front separates the cold, less saline waters adjacent to

the east coast of Greenland from the warmer, saline water of the Greenland Sea.

b. The water off the coast of Greenland is characterized by seasonal temperatures ranging from-1

to 0°C and salinities from 30 to 34 parts per thousand owing to ice melt. In the summer, strong

vertical salinity gradients may be expected to depths of 15 to 23 m. The intermediate and deep

waters are made up of Atlantic Intermediate Water found to depths of 730 m, temperatures of 0°C,

and salinities of 34.88 to 35 parts per thousand. Below 730 m, Norwegian and Greenland Sea deep

water is found with temperatures less than 0°C and salinities between 34.87 and 34.95 parts per

thousand.

7. Kolbeinsey Front

a. In the region between Iceland, Jan Mayen, and Greenland known as the Iceland Sea, colder,

lower-salinity Polar water exists. The Kolbeinsey Front is the boundary between the Iceland Sea

Water and warmer, saline water adjacent to the west and northern coast of Iceland. The surface

temperature of the Atlantic water ranges from 2°C in the winter to 5°C in the summer.

b. Even in the winter, surface ducts and sound channels should be expected in the Atlantic Water

along the Iceland shelf. North of the front in the Iceland Sea Water, either very weak surface

ducting or half-channel conditions prevail.

8. Denmark Strait Front. The Denmark Strait Front is the boundary between cold Polar water

carried southward by the East Greenland Current and warm Atlantic Water carried north into the

Irminger Sea along the west coast of Greenland. The Front follows the ice edge and continental shelf

break fairly closely, but is known to vary from 30 to 60 NM (See Figure 3-9).

9. Jan Mayen Front. The Jan Mayen Front is located south of the Jan Mayen Island and forms the

boundary between two Arctic intermediate waters of slightly different temperatures and salinities. To

the west of the Front, the water temperature is less than 0°C and the salinity is less than 34.9 parts per

thousand, and to the east of the front temperatures are greater than 2°C and salinity is greater than 34.9

parts per thousand.

10. Norwegian Sea Coast Front. This front is formed when North Atlantic water flowing northward

along the western slope of the Norwegian Trench makes contact with colder, low-salinity waters

flowing from the Norwegian Fiords and the Danish shelf around the Skagerrak. A decrease in the sea-

surface temperature of about-13°C occurs along an eastward crossing of the front. Although the front

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characteristics are strongest along the southern coast of Norway, the front is detectable on satellite

imagery all the way to North Cape and into the Barents Sea. The front meanders and generates

numerous eddies on the scale of 54 NM.

11. Murmansk Front

a. The Murmansk Front, also known as the polar Front, forms the boundary between Atlantic

water and Polar water. The Atlantic water flows into the Barents Sea over North Cape with

temperatures ranging from 4 to 12°C and salinities of 34.8 to 35 parts per thousand. As the

Atlantic water moves eastward it begins to cool. Over the central/eastern Barents Sea, the flow

turns northward and splits into two branches south of Franz Josef. The main branch curves west

and further cools and sinks deeper. The smaller branch flows over the north coast of Novaya

Zemlya.

b. The front is rather weak and separates waters of similar temperatures but different salinities.

The Atlantic water has a salinity of about 34.8 parts per thousand in this region while the Arctic

surface water has a salinity of less than 34 parts per thousand. Intense, vertical circulation of water

has been observed in the frontal zone. This mixing provides a good supply of nutrients to the

surface waters, resulting in increased biological activity in the vicinity of the front.

12. Novaya Zemlya and Kara Sea Fronts

a. The extension of the North Cape current that flows over the north coast of Novaya Zemlya

carries highly modified Atlantic water with temperatures around freezing and salinities of 34 to

34.8 parts per thousand into the Kara Sea. The Atlantic water then flows southwest along the coast

of Novaya Zemlya and into the southern Kara Sea.

b. Coastal fresh water input from the Obskaya and Yenisey Rivers amounts to about 940 cubic

km annually. This water is relatively warm and has salinities of from 2 to 20 parts per thousand.

The general flow for this water is northerly into the central Kara Sea. In the southern Kara Sea, the

Novaya Zemlya Front is the boundary between the Atlantic water and the river runoff. A diffuse

front, the Kara Sea Front, exists over the central Kara Sea and forms the boundary between the

Arctic and river runoff waters.

c. Both the Novaya Zemlya and Kara Sea Fronts are seasonal features that begin to develop soon

after the ice melts in the late spring. They reach their peaks in the summer and persist through the

fall.

13. Laptev Sea Front

a. A weak front similar to the Kara Sea Front exists in the Laptev Sea. Fresh water input into the

southern Laptev Sea from the Lena and Olenek Rivers amounts to 554 cubic km per year. This

amount is augmented by the inputs of the Khgatanga and Anabar Rivers into the western Laptev

(no data available on their output). The river runoff water is relatively warm and has salinities that

range from 2 parts per thousand coastally to 28 parts per thousand near the central Laptev Sea.

b. The Laptev Sea Front forms a diffuse boundary between the southern fresh water and the

northern Arctic water, and is more or less a continuation of the Kara Sea Front. Like the Kara Sea

Front, the Laptev Sea Front is seasonally diffuse and therefore not tactically significant.

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14. East Siberian Sea Front

a. There are two general types of water masses found in the East Siberian Sea; Arctic and

Siberian Coastal waters. The Arctic water is the same basic water mass found in the northern

Laptev and Kara Seas and has a temperature near freezing and salinities of from 28 to 33 parts per

thousand. The Siberian Coastal water begins to develop after the spring melt and is composed of

input from the Indigirka and Kalyma Rivers. This water is fresher than the Arctic water, with

salinities less than 20 parts per thousand.

b. The East Siberian Sea Front separates the two water masses and extends eastward from the

New Siberian Islands to Ostrov Vranglya (Wrangel Island). The front continues east of Wrangel

Island into the western Chukchi Sea where it serves as a boundary between the Siberian Coastal

water and the Bering Sea water flowing into the Chukchi from the Bering Strait.

c. The East Siberian Sea Front is a weak seasonal front, sharing the same basic characteristics,

which are found in both the Laptev and Kara Sea Fronts.

15. Alaskan Coastal and Beaufort Sea Fronts

a. The Alaskan Front is the boundary between central Chukchi and Alaskan coastal waters

flowing north along the eastern side of the Bering Strait and coastally in the eastern Chukchi Sea

to Point Barrow. Alaskan coastal water originates with fresh water input from Katzebue Sound.

The central Chukchi Sea water is composed of Bering Sea and Arctic waters. The central Chukchi

water is colder and more saline than the Alaskan Coastal water.

b. The Alaskan Coastal Front extends from the Kotzebue Sound coastally to Point Barrow, and is

a relatively weak front (even compared to the East Siberian Sea Front).

c. East of Pont Barrow, the Colville and Mackenzie Rivers provide fresh water input into the

coastal water of the Beaufort Sea. The Beaufort Sea Front forms the boundary between the coastal

water and the Arctic water of the Central Beaufort Sea.

d. The Beaufort Sea Front is a continuation of the Alaskan Coastal Front and is a rather weak

front.

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CHAPTER 4

SEA ICE

401 INTRODUCTION

1. The single feature that makes the Arctic Ocean markedly different from most of the world's oceans

is the presence of a perennial cover of sea ice.

2. Ages and Stages of Development of Sea Ice. There are four broad categories of sea ice age: new,

young, first-year, and old. There are several stages of development that occur within these ages:

a. New Ice. New sea ice is very elastic sea ice that may be up to 10 cm thick. Depending upon

the conditions under which it was formed, new sea ice may have several different stages:

(1) Slush, shuga, frazil and grease ice are all comprised of unconsolidated ice crystals or

platelets.

(2) Nilas is a consolidated form of new ice that remains very elastic. It is divided into dark

nilas (0-5 cm) and light nilas (5-10 cm).

b. Young Ice. Young ice is considerably harder, thicker (10-30 cm), and more brittle than new

ice. There are two subdivisions of young ice:

(1) Grey ice (10-15 cm); and

(2) Grey-white ice (15-30 cm).

c. First-Year Ice. Once ice has grown past 30 cm in thickness, it is considered to be first-year

ice. Although there is no upper limit on the thickness of first-year ice, it generally does not exceed

2 metres. First year ice is subdivided into three categories based on thickness:

(1) First-year thin (30-70 cm);

(2) First-year medium (70-120 cm); and

(3) First-year thick (greater than 120 cm).

d. Old Ice. Old ice is ice that has survived at least one summer's melt. This ice is considerably

less saline and harder than first-year ice. There are no thickness limits on multi-year ice as the

distinction is based on physical properties and not thickness. There are two categories of old ice:

(1) Second-year ice - ice that has survived one summer's melt; and

(2) Multi-year ice - ice that has survived two or more summers' melt.

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3. Concentration. The amount of ice or the area coverage of sea ice is measured in tenths. The

following descriptions apply to various concentrations:

a. Very open ice - 1 to 3 tenths;

b. Open ice - 4 to 6 tenths;

c. Close ice - 7 to 8 tenths;

d. Very close ice - 9 to less than 10 tenths; and

e. Compact or consolidated ice - 10 tenths.

4. Floe Size. Floe size varies greatly with location and time of year. A descriptive representation of

floe size is found in Figure 4-1.

5. Ice Topography. When driven by the forces of wind, seas and currents, sea ice may take many

forms. As the ice is forced together, it will fracture to raft or ridge on top of itself. When the ice is

forced apart, it will break to form fractures and leads. Similarly, at the ice edge, the forces of nature

may create "ice tongues", "belts and strips", or a "diffuse ice edge". During the summer melt, melt

ponds and thaw holes will appear on the ice.

402 ICE FORMATION

1. When salt is added to fresh water, the temperature at which it freezes is lowered. The higher the

salt content, the lower the freezing point of the salt solution. Seawater, with a salinity of

approximately 32 parts per thousand in the Arctic, freezes at about -1.8°C.

2. Unlike fresh water, the temperature of the maximum density of seawater is lower than the freezing

point (for salinities greater than 24.7 parts per thousand). Consequently, as seawater cool, it becomes

more dense and sinks. Theoretically, in order for ice to form, the entire water column from the surface

to the bottom must be cooled to the freezing point. In reality, only the upper layers of the water

column must be cooled because deep water that is more saline provides the water column stability that

is necessary for ice formation.

3. As the ice forms, there is no room in the crystal structure for the dissolved salts. As a result, these

salts are expelled from the ice. If the ice were formed very slowly it would be practically pure.

However, the freezing process is never a slow one and the salts are trapped within the ice structure as

it freezes. The salinity of sea ice is on the order of 4 to 6 parts per thousand.

403 STRUCTURE AND PROPERTIES OF SEA ICE

1. When seawater is cooled to its freezing point and more heat is removed, ice forms initially as very

thin disks or platelets known as frazil ice. These platelets average 2-3 mm in width and about 0.5 mm

in thickness but vary considerably in shape from hexagonal "snow flakes" to almost square plates. As

further heat is removed, these pure ice crystals grow and multiply. They are less dense than water so

they float to the surface and give the water a slightly oily appearance (grease ice). Further cooling

results in growth of the ice crystals and mechanical entrapment of small brine cells between them.

Ultimately, these cells become separated from the water below the ice by selective downward growth

of the ice crystals.

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2. The physical properties of sea ice are almost entirely dependent on its salt content. The detailed

crystal structure, which results dominates these properties to the extent that one can relate any of them

to "brine volume". The brine volume is defined as the fraction of the volume of sea ice occupied by

fluid (liquid brine or air bubbles).

3. The strength of the ice is dependent upon the brine volume. The larger the brine volume, the

weaker the ice is. For this reason, old ice has a much lower salinity than first-year ice, and is much

stronger.

404 ANNUAL ICE CYCLE

1. The process of ice formation has been discussed in some detail in article 402, but this is only the

initial stage of ice growth, which is always dependent upon heat loss from the sea. This heat must flow

upward through the ice layer and through any snow lying on the ice so that the insulating qualities of

these two materials are important factors in determining the rate and amount of ice growth. Air

temperature and the amount of radiant energy falling on the surface are also important factors.

2. In the Arctic, radiation is almost completely dominant in determining the ice surface temperature

and hence the duration of ice growth. This will continue until some time in spring when the increasing

solar radiation changes the heat budget of the ice from a loss to a gain. This usually happens before the

air temperature rises above the melting point of the snow cover. Pure white snow reflects as much as

90 percent of the radiation falling on it, and although the quantity of heat absorbed by the ice is small

at first, the 24 hours of daylight soon result in a gradual increase in the temperature of the ice. When

the air temperature reaches the melting point, the snow surface begins to melt rapidly; it absorbs about

60 percent of the radiant energy and puddles of melt-water become very extensive.

3. In temperate latitudes, the air temperature can contribute to the change from heat loss to heat gain

by the ice, for it can rise above the melting point for appreciable periods, if only in the daytime. The

situation is thus more complicated but the reversal of heat flux is still the controlling factor.

4. Puddling is the first apparent stage of deterioration of the ice cover. The water surface absorbs heat

readily, permitting the puddle to widen and deepen and also to warm the ice. Later, flaws and cracks

develop in the floe through which much of the surface water drains away, leaving dry hummocks of

ice separated by ponds and streams of melt-water. When the ice has this appearance, operations on it

must be carried out with caution for the bearing strength is uncertain and a wind can cause it to break

up rapidly.

5. In temperate latitudes the ice is reduced to a grey, water-saturated matrix (rotten ice), which finally

melts, and the cycle is complete. Farther north, the summer is too brief for complete melting to take

place, and by late August or September puddles begin to freeze and new ice forms between the floes.

After a time the floes themselves start growing again. A floe formed in one year, which survives

through the following summer differs chemically and physically from ice that is less than one year old.

During the summer most of the brine drains out of the ice so that the typical salinity of old ice

(secondary multi-year ice) is about 0.5 to 1 parts per thousand. Melt-water from this ice is quite

potable. The crystal structure of the ice becomes less regular, the crystals themselves are smaller, and

the ice is extraordinarily tough, even in summer.

6. In summer, old floes may be distinguished from first-year ice by their color. The melt-water

puddles on an old floe have a very characteristic pale-blue color, which persists after they freeze. On

first-year ice, these puddles have a green-to-brownish appearance. The old ice itself has a pale-blue

color whereas first-year ice is much more a greenish-white color. The surface of first year ice is

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comparatively smooth except for pressure ridges and hummocks. Old ice has a characteristic uneven

surface as a result of the differential melting of puddles and old hummocks.

405 OCCURRENCE OF SEA ICE

1. In the Arctic there are no generalizations that can be made about the occurrence of sea ice in

relation to latitude. This is evident when comparing the winter maximum extent of sea ice in the Sea

of Okhotsk and the Gulf of St. Lawrence, which extend south to 45 degrees North, and winter

maximum extent in the Norwegian Sea, which never penetrates south of 70 degrees North. The

amount of seasonal variation in the sea ice cover is considerable and varies markedly from region to

region. The Permanent Sea Ice Zone is the region that is perennially covered with sea ice. The

seasonal sea ice zone is the region that is ice covered only part of the year and extends from the

summer minimum sea ice extent to the winter maximum sea ice extent.

2. The mean thickness of sea ice varies greatly by region. The average thickness for undisturbed old

sea ice in the central Arctic is about 3.5 m. These thickness averages are misleading because the

dynamic nature of sea ice creates ridges and the corresponding keels in the ice. Ridges of up to 15 m

and keels of over 45 m have been found. This type of ridging is particularly evident where the ice

pressure is impinging upon a coast. Submarine and, ice-breaker observations show that the normal

ratio between ridge height and keel depth is between 1:4 and 1:6, with ridge/keel ratios being observed

over a very wide range.

406 ICE FORECASTING

1. The date of freeze-up of the sea depends on both the oceanographical and meteorological regimes

encountered in the area. Only rarely is the knowledge of water currents, and of the actual temperature-

salinity variations with depth, available for forecasts of this type to be made. The rate of ice growth on

the other hand can be predicted with fair accuracy from meteorological data, as can the maximum

thickness, which will be obtained. It is much more difficult to predict rates of decay, for the process is

slow and long-range predictions of both wind and cloudiness are required for accurate results.

2. One of the most important forecasting problems is ice motion. The general pattern of sea ice

motion in the Arctic is indicated in Figure 4-2. Recent studies have revealed that 70 percent of the ice

motion is due to wind forcing. This pattern is of course affected by tides and currents as well as, land

masses, and bathymetric features such as shoals. A general rule of thumb is that the ice will drift about

45 degrees to the right of the wind direction at about 2 percent of the wind speed.

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3. Ice routing information for the Arctic can be obtained from the following national agencies:

Nation

Agency

Services Offered

CAN

Environment Canada,

Information on ice conditions such as ice hazard bulletins and

Canadian Ice Center, Ottawa

special warnings for ships are freely available through weather

and marine radio broadcasts. Commercial products including

detailed ice analysis charts and radar and satellite imagery are also

available. A detailed listing of products and services can be

accessed at http://www.cis.ec.gc.ca.

CAN

Canadian Coast Guard Ice

Ice routing information for the Canadian Arctic can be obtained

Operations

via any Coast Guard Radio Station. Further information on

contacting Ice Operations may be obtained from the Ice

Navigation in Canadian waters (TP 5064E).

DNK

Danish Ice Information

Ice charts of the areas East, West and South of Greenland are

Service (DIIS),

promulgated on a regular basis. Ice charts and ice reports can be

Narssarssuaq, Greenland

obtained from all Greenland Coastal Radio Stations and on the

internet at http://www.iserit.greenet.gl/isc/ice.

DEU

Federal Maritime and

Ice routing information can be obtained from this civil agency.

Hydrographic Agency

E-mail: ice.at.bsh.d400.de. Internet site at

http://www.bsh.de/oceanography/ice/ice/htm.

CINCGERFLEET does not maintain a special agency but can

provide ice routing information upon request. This information is

primarily available for the North Sea and Baltic but is also

available for other areas. Messages should be sent to

CINCGERFLEET for GEOPHYS, SIC JOG.

GBR

CINCFLEETWOC

The position of 10 percent of the ice edge is shown on routine Sea

Surface Temperature fax charts. This data is not available west of

045W.

USA

National Ice Center (NIC),

The NIC provides operational sea ice analyses and forecasts for

Washington

the Arctic, Antarctic, Great Lakes and Chesapeake Bay. Their

products and services can be accessed at

http://www.natice.noaa.gov.

USA

US Coast Guard

The USCG IIP monitors ice conditions in the vicinity of the Grand

International Ice Patrol (IIP),

Banks of Newfoundland, and pending severity, broadcasts the

Groton CT

Southeastern, Southern and Southwestern limits of all known ice

in two daily message bulletins. The IIP can also provide a daily

fax chart containing ice information. For a comprehensive listing

of products and services and instructions on accessing them use

the IIP homepage at

http://www.uscg.mil/lantarea/iip/home.html.

Sea ice

information is encoded according to the World Meteorological Organization

(WMO)

symbology known as the egg code, due to the oval shape of the symbols. The egg code shown in

Figure 4-3 provides information on types and concentrations of ice in each area of the chart. Figures 4-

4 and 4-5 are examples of charts distributed by the Center using egg code symbology.

407 OTHER ICE ENCOUNTERED AT SEA

1. River Ice. There is appreciable difference in the strength of freshwater ice and sea ice, and

consequently, in or near the estuaries of major rivers an additional hazard to shipping may be

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encountered in the spring when river ice is carried into the sea. This is particularly true of the rivers of

the Soviet Arctic.

2. Ice Islands. These are masses of ice that have broken away from an ice shelf and have an

undulating surface. They may have thicknesses of up to 60 m with areas of up to 400 km2. In the

final stages of melting they usually break up into a group of tabular icebergs.

3. Icebergs. Icebergs are large masses of freshwater ice and compacted snow that have broken away

or "calved" from a glacier. The Greenland Ice Cap is the single largest source of icebergs, with the

largest concentration of icebergs found in Baffin Bay and the Davis Strait. In the East Greenland Sea

icebergs are found imbedded in and sometimes outside the drift-ice, particularly south of Scores by

Sound. Icebergs have been found in excess of 90 m in height and 500 m in length. Their draft varies

from two to more than 10 times their height due to their irregular shapes. Iceberg location information

can be obtained from the International Ice Patrol. Icebergs do not always travel in the direction of the

wind. They have a small sail area relative to total size and travel in the direction of the current, which

may be against the wind. Figure 4-6 shows the general drift pattern of Atlantic icebergs. Figure 4-7

shows typical areas where icebergs can be anticipated in the Pacific region.

Figure 4-2 General Pattern of Ice Movement in the Arctic Ocean

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CHAPTER 5

GENERAL PREPARATIONS FOR ARCTIC OPERATIONS

501 GENERAL

1. Weather conditions in the North Atlantic, particularly during winter, can be more severe than those

experienced above the Arctic Circle during the short navigation season. Indeed, the Arctic summer can

be quite pleasant, with warm sunshine, temperatures well above freezing, dear skies, little wind, and,

because of the dampening effect of ice, calm seas. There is, in fact, a threat of sunburn and a definite

need for sunglasses.

2. Climatic and other environmental conditions affecting ships and their equipment during Arctic

operations includes:

a. Low surface air temperatures at certain seasons.

b. Sudden changes in air temperatures.

c. High winds.

d. Low seawater injection temperatures.

e. Low humidity.

f. Ice conditions ranging from slush and brash to solid pack.

g. Snow, sleet and freezing rain.

h. Fog and overcast, occurring at the ice/water interface.

i. Heavy seas with attendant spray in areas clear of pack-ice.

j. The possibility of heavy and rapid ice accretion, with consequent loss of stability.

k. Abnormal magnetic conditions and low directivity of magnetic compasses.

l. The possibility of gyro compass errors.

502 TOPSIDE PREPARATIONS

1. Prevention of Slippery Decks

a. Ensure that deck tread ladders, and deck nonskid areas meet safety standards (renew

necessary). Non-skid areas can be expanded to enhance traction.

b. Thin ice can be removed most effectively from decks and other flat surfaces by the use of dry

chemicals such as sodium chloride (rock salt), calcium chloride and urea. These materials are

simply spread over the frozen surfaces in a thin layer as required. Rock salt is the most economical

material and is effective above -9øC. Calcium chloride gives off heat when mixed with water so it

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acts faster than rock salt. A mixture of one part calcium chloride and three parts rock salt will be

effective to temperatures of-18°C.

c. Urea

(granular or pellets) is effective for melting thin layers of ice above-9°C and for

preventing ice accumulation in freezing rain.

d. Sand can be used alone or in combination with any de-icing chemicals to improve traction on

ice-covered decks.

2. Develop procedures for entry, egress, and safety of topside personnel:

a. Topside personnel must use two-man buddy system.

b. Topside personnel will need to be tethered with tended safety lines during heavy weather.

c. Temporary lifelines and guide-ropes can be run along flight-decks attached to tiedowns (during

non-flying hours) to permit watch personnel crossing on LPDs and LPHs.

3. Lubricate all topside fittings with appropriate cold-weather greases.

4. When selecting covers for equipment, the most important characteristics to look for are strength,

durability and water resistance. Non-porous, fire-retardant covers are recommended for

(at a

minimum):

a. Ship's boats. (Complete boat must be covered.)

b. Davit winches.

c. Capstan/windlass and associated controls. (Because of exposure to severe weather forward,

extra covers will be required.)

d. Unheated combat system equipment.

e. Sound-powered phone boxes.

f. All outside (exposed) command, control, communications stations.

5. Precautions taken to protect hydrostatic release mechanisms on life rafts should include the fitting

of polyethylene sleeves over the devices and sealing them.

6. Develop and promulgate ice accretion removal procedures and instructions to avoid damage to

equipment or undue hazard to personnel during removal operations.

7. Obtain and install, when necessary, temporary shelters or windscreens for exposed personnel and

topside watch-keepers.

8. Rig, when necessary, additional life and safety lines for protection of personnel. Heavy-weather

lifelines should be rigged well in advance to facilitate early identification and correction of

deficiencies. Set up cargo lines on lifelines at UNREP stations to prevent line handlers from falling

overboard.

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9. Ice removal equipment and de-icing materials should include those items listed in Tables 5-1 and

5-2.

10. Firemain valves topside will have to be cracked sufficiently to prevent freezing. Run an old hose

section over the side to prevent ice buildup. Securing the risers from below deck is effective, as is

filling piping and stations with antifreeze.

11. Topside Damage Control Equipment

a. Fire hoses and nozzles will perform satisfactorily at freezing temperatures and below, provided

water is kept flowing and a good pressure is maintained. If the pressure is reduced or the hose is

secured, the nozzle and plug may become frozen. If a long lead of hose is to be secured at

temperatures below -12 øC, stop the flow only for the time necessary to disconnect each length of

hose. After securing, hoses and nozzles should be taken below decks and completely dried prior to

returning to topside stowages.

b. Duplex proportioners should be drained after use, dismantled, dried, oiled, and the chamber

change-over valves reassembled. Oxygen-breathing apparatus (OBA) with spare canisters should

be returned to below-decks stowage as soon as no longer needed.

c. Portable water pumps should be stowed below decks.

d. External connections on the firemain will need to be isolated and drained or kept on a tickle

flow. Dead ends or low flow spots such as magazine or cargo storeroom sprinkles on the firemain

should be watched closely to avoid freezing.

503 SHIP'S BOATS PREPARATION

1. The use of boat engine heaters (engine block, oil system or cooling system) will ensure easier

starting. Equipment from auto parts stores such as dipstick heaters are effective. Other means to keep

boat engines warm include heat lamps, flood lights, drop lights and insulation blankets.

2. Utilize antifreeze in engine cooling water system to prevent freezing. Cold-weather lubricants and

oils should be used for engines and transmissions. Circulating water heater and heat strips around

engine block and oil pan is effective. Ethylene glycol (60/40) in the bilges and saltwater pumps will

prevent ice buildup.

3. Install and utilize boat jump-start connections. A constant trickle charge is recommended.

4. Obtain spare boat batteries.

5. Lubricate and protect davits and winches. Boat falls can be prevented from birdcaging by keeping

them clean, and running the winch machinery to heat lubricants prior to use.

6. Fabricate boat covers for each boat. The cover must protect the entire boat down to the water-line

and should be made out of heavy canvas, not herculite.

7. Ensure that procedures are developed to drain salt-water cooling systems and top off fuelling

systems daily.

8. Ensure that adequate repair parts are available.

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9. During very cold conditions, provisions must be made for periodically starting and warming boat

engines if no use, is expected to be made of them. Time frame varies from once daily to once per

watch, depending upon the weather.

10. Lubricate entire boat throttle cable to prevent freezing and binding.

11. Not only may boats become damaged by ice, they can also be cut off from their parent ship by

poor visibility or by drifting ice floes brought down by a change of wind or tide. Thus all boats should

be equipped with emergency rations and survival kits including first-aid supplies, sleeping bags,

firearms, and a suitable selection of hand-held pyrotechnics. In addition, all boats ought to be radio-

equipped. Boats' crews should always have their cold-weather clothing with them while away from

their ship. For larger boats, an inflatable life-raft ought to be carried, and all boats should be fitted with

radar reflectors.

12. Additional suggestions include:

a. Hoisting slings may need reinforcement for rough-weather handling of boats.

b. Wooden boats should be copper-sheathed along the water-line, especially forward.

c. Foam flotation material (e.g., styro-foam), which must remain impervious to both water and

fuel, should be applied to boats to provide an additional measure of buoyance in the event they are

holed by ice. Boats in excess of 9 m should have some form of watertight subdivision for the same

reason.

d. In Arctic service, outboard motors are reliable and efficient. While damaged propellers can be

easily repaired or replaced, consideration should also be given to the fitting of some form of

propeller guard.

e. Fuel tanks should be kept topped up in order to minimize condensation.

f. Fill drinking water containers in boats to only

75 percent capacity to avoid bursting the

containers.

504 MOORING LINES AND ANCHOR GEAR PREPARATIONS

1. Mooring lines should be kept dry and stowed under cover when not in use. Manilla lines can freeze

and dry rot if exposed to cold for long periods. Polypropylene and polyethylene lines absorb little

water but are stiff and brittle in the cold. Nylon and darcon lines, particularly braided type, aborb more

water but remain easy to work with.

2. Particular attention should be paid to the small sizes of wire rope where the component wires are

of small diameter, since frost and ice can cause them to break.

3. When proceeding in waters calling for constant use of soundings, steps should be taken to ensure

that anchors and cables are ice-free and ready for use at short notice.

505 ENGINEERING PREPARATION

1. Window Heaters

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a. All heaters must be checked, and their operability ensured, before leaving port.

b. Overheating may cause lamination to separate on windows, so ensure that temperature

controlling mechanism is functioning.

c. Determine means to clear ice from area in front of bridge windows. Using the window wash

system, with a water/antifreeze (50/50) fluid mix, is an effective de-icing method. Ensure wash

system is operated after addition of water/anti-freeze solution to purge fresh water from system

piping.

2. Turbine and Ventilation System Intakes

a. Provisions must be made to ensure that intakes are cleared of snow and ice. Accumulation can

be controlled by the use of LP air to blow snow from demister pads.

b. Ensure that turbine de-icing systems and inlet heaters are operable and effective.

3. Sea-Chest Inlet and Outlet Blockage

a. Use steam blow-out connections or LP air to de-ice engineering intakes.

b. Monitor freezing of overboard discharges, such as CHT, and develop an ice removal plan for

these systems.

4. Main Engineering Plant Spaces

a. Check all air reducers by operating them at their proper pressure and ensure that they can be

adjusted so that a drop in air pressure in cold weather can be overcome.

b. Add sufficient antifreeze to diesel freshwater system to preclude freezing.

c. Obtain extra batteries for all requirements. Battery locker temperature should be maintained

above 15°C or store batteries elsewhere.

d. Monitor water/steam usage during ice removal operations. Inefficient ice removal may lead to

excessive water usage.

e. Install insulation behind and above main switchboards where condensation may form.

f. Ensure that a full allowance of damage control and repair material such as shores, plates,

clamps, wedges and plugs are on board.

g. Monitor temperature of idle machinery.

h. Prepare evaporators for cold-weather operations. Prior to sailing, hydro the freshwater side of

the evaporators. Locate and fix all leaks. Use new gaskets when reassembling the units. Check air

ejector nozzles for proper operation. The best way to maintain capacity is to start with a "tight

plant".

i. Very high vacuums occur during cold-weather operations. Throttling the main condenser

overboard valve to control condensate depression does not work well. Use of the masker belts

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causes air to be entrapped, and air may bind the main condenser. Venting of the condenser

regularly has proven effective in maintaining vacuum and efficient engine operations.

5. Interior Space Heating and Ventilation

a. Ventilation heater controls should be adjusted to maintain space temperatures of 19- 20°C in

lieu of 21-27°C. This will minimize the drying effect in living compartments, since the relative

humidity of the compartment air will be greater at the lower space temperature differential for

personnel going to and from topside or exposed locations.

b. Machinery space ventilation fans should be operated to give a slight positive pressure within

the area. This will avoid creating drafts through the ship proper and will conserve the heat in the

interior of the ship. All living space ventilation supply fans should be operated on low speed to

reduce the amount of outside air taken into the ship.

c. To avoid freezing of ventilation heaters, it is essential that condensate lines are kept open and

that traps are in proper operating condition.

d. To ensure that blowers are operated at low speed, that thermostats are not tampered with, and

that thermostatic traps or preheaters are operative, it is suggested that a heating patrol be

established as part of each watch. This procedure is particularly recommended for large ships

engaged in low-temperature operations. A roving watch, checking berthing spaces, fan rooms and

heating boundaries, has proven effective.

506 TOWING CONSIDERATIONS

1. Long Stay. Ships operating in Arctic waters should be equipped and ready to tow or be taken in

tow at short notice. Towing at long stay can be difficult because ice, if there is any present, can get

between the ships involved. Some ice-breakers are equipped with a notched stern, suitably padded, in

which the stem of the ship to be towed can be secured. Ships with high freeboards, however, are

unsuited for this method.

2. Short Stay. Towing at short stay can be undertaken though the ship towed should not use its

engines because of the risk of overrunning and striking the towing vessel.

507 ICE PREPARATIONS/CONSIDERATIONS

1. Removal Techniques

a. Topside icing can result in a dangerous loss of stability, reduction in reserve buoyance, and

critical impairment of a ship's ability to withstand damage. Other adverse effects are the increased

load on decks, masts, and other structures, and the danger that men will slip on icy decks or be

struck by falling ice from aloft.

b. There are various methods by which ice can be removed:

(1) Manual. Ice is broken away and chipped off using mallets, clubs and scrapers. Caution

must be exercised to avoid damage to metal surfaces, electric cables (including degaussing

cables) and equipment. Ships should lay in a stock of wooden mallets, shovels, wire brooms

and scrapers suitable for the removal of ice and snow. Table 5-1 provides a list of ice removal

equipment.

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(2) Steam Jet. A steam lance can be used to undercut layer ice as, for example, in freeing an

anchor which has become frozen in its hawse pipe. It can also be used for spot heating.

(3) Anti-Icing Coatings. These coatings can be used to protect comparatively small areas or

items. Anti-icing compounds retard the formation of ice and contribute somewhat to the ease

of its removal.

(4) Heated Salt Water Under Pressure. This is sea water heated to at least 50°C, or higher

if possible. It is used in high- pressure steams to slot, undercut, and break up large

accumulations of ice. No attempt is made to melt ice directly, but rather to break it up or

weaken it to facilitate removal. When using water to clear ice, scuppers and overboard drains

must be clear.

(5) De-icing. Use of Ethylene Glycol, Methanol or other de-icing chemicals can be used to

remove ice build-up on exterior surfaces.

2. Superstructure Icing Considerations

a. When severe topside icing occurs and ice continues to accumulate, despite all attempts to

remove it, it may become necessary to alter course, heave to, or make for an area of more

moderate weather. Icing can occur when heading into strong winds and heavy seas and in

conditions of low air and seawater temperatures. Smaller ships having low free boards and reserve

stability are particularly vulnerable.

b. The rate of ice accretion from ocean spray is related to surface wind speed roughness of the

sea, air temperature

(below

1.67°C), and duration of exposure. Figure

5-1, the Overland

Monograms, offer the most current prediction method for icing conditions.

c. The smaller the vessel, the more serious the problem of ship icing. Any prolonged exposure to

gale-force winds and below-freezing air temperatures could ultimately result in the vessel

capsizing. Fishing trawlers approximately 52 m long have capsized and sunk as a result of rapid

ice accumulations on the hull and superstructure; freezing spray accumulating at a rate of two tons

an hour over a period of 24 hours has been reported. Meteorological observations taken in the

vicinity of Iceland indicate that storms of gale force accompanied by freezing air temperatures and

lasting as long as three days may occur as often as three times a year. Sparseness of synoptic

meteorological information in this area makes forecasting of such prolonged periods of gale-force

winds and below-freezing temperatures quite difficult.

d. The use of aircraft engines can be effective in removing snow from around closely parked

aircraft. Rock salt should not be used because of its corrosive effect on metals.

508 CARGO HANDLING CONSIDERATIONS

1. Cargo should be stowed in such a manner that it cannot shift as a result of repeated impacts between

the ship and the ice. It should be stowed well away from the sides of the ship thus allowing easy

access to the side plating in case of damage and to permit passage of water to the bilges. Ships

operating in ice, should be so loaded that they will be trimmed by the stern. If in ballast, consideration

should be given to flooding so as to immerse the rudder and propellers to minimize the risk of damage

to them by ice.

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CHAPTER 6

HULL, ENGINEERING AND ELECTRICAL

601 COLD-WEATHER PREPARATIONS

1. Check all heating and cooling systems.

2. Check coolers for leaks. Weather leakage can occur because of contracting of the tubes in the

cooler tube sheet/plate due to colder salt-water inlet temperatures.

3. Identify unheated or inadequately heated spaces. Air, cooling-water, salt-water, and other lines

running through spaces should be insulated for protection. Heaters should be installed. Portable items

subject to freezing should be moved to heated spaces. Other ad hoc measures to improve temperature

control include fans and other ventilation techniques to draw warm air from other areas. Additional

heating will be needed to maintain crew comfort.

4. Check areas where condensation and frost may form on interior metal surfaces adjacent to exterior

bulkheads.

a. Hatches, doors and lagging buttons are likely to be most frequently affected. If interior ambient

temperature is cool, heavy frost will form. If interior spaces warm up, condensation will drip onto

deck and equipment.

b. More insulation may be needed on exterior bulkheads, overheads, and especially on doors and

hatches.

c. Check all watertight doors' gaskets and knife/sealing edges.

5. Where it is determined that spaces require portable heaters, check wiring set-ups. Ensure that vital

electronic equipment (navigation gear, etc.) is not wired to the same circuit breaker as a high-

amperage portable heater.

602 EXPOSED PIPING AND SCUPPERS

1. Overflow pipes from fresh water gravity tanks should be led inside the ship to a warmed scupper

and not be allowed to drain onto an open deck. Deck-edge waterways should be kept clear of

obstructions so that a clear passage will exist when snow is being washed down.

2. Lagging by itself will not keep liquid in a pipe from freezing if the ambient temperature falls

below the freezing point. Liquid must be warmed and kept in continuous motion; failing this, heating

of all the piping lying outside the insulated structure will be necessary.

603 HULL DAMAGE AND REPAIR IN THE ICE

1. Ice damage can take the following forms:

a. Bending or loss of propeller blades.

b. Steering gear damage, including the rudder head and/or the rudder.

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c. Propeller shaft fracture.

d. Damage to the stem, puncturing and tearing of plating.

e. Buckling of plating and the tearing out of rivets due to ice pressure.

2. Should the steering gear break down in a single-screw ship, it may be possible to steer with the aid

of two rudder pendants secured to the rudder and led to a stern capstan or cargo winch.

3. Although every reasonable precaution may have been taken against damage to a ship, it is possible

that damage or breakdowns will occur which will be of such a nature as to necessitate major repairs. In

such circumstances, ships should be detached and directed to the nearest shipyard or be taken under

tow.

604 STOWAGE SPACE REQUIREMENTS

1. Additional stowage space will be required to accommodate Arctic equipment and material. Space

will also be required for the stowage of anti-ice compounds and liquids.

2. Crew members will need extra stowage space for their gear. Space should also be set aside for

Arctic clothing in living spaces or in compartments immediately adjacent thereto. Similarly, suitable

facilities should be provided for the drying of heavy Arctic clothing.

3. Allot additional stowage space for food storage since a 10 percent increase in food consumption

will be experienced.

605 FRESH WATER SUPPLY

1. Suction pipes in freshwater storage tanks should be insulated to prevent ice from blocking the

lower ends.

2. Freshwater gravity and any similar tanks fitted in exposed positions should be heated and amply

lagged. Arrangements should also be made to warm the pressure switch gear if fitted. Leads of

freshwater supply and drain pipes must also be lagged and heated if they lie outside an insulated

structure.

606 SALT WATER SUPPLY

1. Leak-offs should be fitted at the ends of the firemain to assure a continuous circulation of water.

These leak-offs must be at least 13mm in diameter, be well lagged, and discharge either directly

overboard or into a scupper with a warmed non-return flap valve.

2. Firemain risers can have water secured at the main deck, or for flight deck supplies use antifreeze

in the riser itself.

3. Salt-water hydrants fitted in exposed positions should be isolated inside the main structure, and

arranged so that the exposed length of the hydrant supply pipe can be drained and left empty in cold

weather.

4. Careful attention must be paid to the lagging of salt-water supply pipes which, although not

directly exposed to weather, can be subject to low temperatures, e.g., those fitted in the hangar of

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aircraft-carriers near lift openings.

5. Careful attention must also be paid to spraying arrangements in ready-use magazines, to similar

compartments in exposed positions, and to magazine-flooding lockers if these are located on weather

decks.

6. Fire pumps should be capable of taking their suction from the discharge side of a main engine or

generator condenser or cooler, so that warm water can be delivered to the fire main.

607 GENERAL INSTRUCTIONS FOR MACHINERY

1. Machinery space temperatures should be maintained at or above 4.4^oC.

2. In systems containing a mixture of glycerine and water, a check on the homogeneity of the mixture

should be made by taking samples from both the top and the bottom of the mixing tank, and testing

with a glycerometer. A homogeneous 50/50 mixture will remain completely fluid down to -27^oC. A

60/40 mixture will remain fluid down to -40^oC.

3. When engines which have salt-water cooling systems are not required for immediate use, the

circulating water system should be kept empty. Engines with a freshwater cooling system should have

the system charged with an approved antifreeze solution. The raw water side of the heat exchanger

system should be drained. Glycerine and water should not be used as an antifreeze solution. Because

of the fine clearances in the water pumps of both types of cooling systems, drops of water remaining

after draining may cause seizure of the pump, so pumps should be warmed before turning the engines.

608 EXPOSED EQUIPMENT

1. Particular attention should be given to equipment on deck, to guard against congealing of lubricant

or formation of ice. Covers should be used, where possible, to maintain all equipment at operable

temperatures.

2. Pressure gauges in exposed positions should be disconnected when non-essential.

3. When removing ice from any mechanism by use of steam jet, care should be taken to avoid ingress

of steam which will condense and freeze on interior working parts.

609 GENERAL INSTRUCTIONS

1. Fire Hoses. Hoses should be drained, dried, and stowed below deck.

2. Fire Extinguishers. Foam-type and soda-acid extinguishers should be stowed in a warm place.

Arrangements should be made to ensure that the supply from the firemain for continuous foam is

warm and that foam compound is stowed in a position protected from the cold.

3. Arrestor Gear and Safety Barrier System. Heating should be provided to air-reducing valves

fitted in the arrestor gear and barrier system to prevent freezing.

4. Telemotor Systems and Hydraulically Operated Mechanisms. These should be charged with a

50/50 mixture of glycerine and water or a national approved liquid as directed, and be tested

periodically.

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5. Pressure Gauges. Except where they are essential, pressure gauges in exposed positions should be

removed.

6. Motor Boats. To prevent damage to the engines and to ensure that they can be started when

required, the following precautions should be taken:

a. An external source of heat should be provided to maintain the engines and pipe systems at a

reasonable temperature. It may also be necessary, under conditions of extreme cold, to warm the

lubricating oil and diesel fuel tanks.

b. When engines are not in use, or at "short notice", the seawater circulating system should be

kept empty. Engines with freshwater cooling systems should have them charged with an approved

anti-freeze solution. To facilitate draining the system, drain cocks should be fitted where necessary

to drain water from any pockets in the system. On account of the fine clearances in the water

pump, small drops of water remaining after draining may be sufficient to cause seizure of the

pump if the temperature has not been above -2.2^oC. To avoid damage to the pump, special

measures should be taken to warm the pump before turning the engine.

c. Full use should be made of devices fitted to assist cold starting of diesel engines, such as

heater plugs, ether, etc.

610 INSULATION

Thermal insulation should be applied to the shell and bulkheads behind and above switchboards if

such areas suffer from condensation. All cold-weather piping and equipment such as fire, sanitary and

freshwater systems, soil pipes and freshwater tanks should be insulated where damage to equipment or

discomfort to personnel may result from dripping condensate. All ventilation supply and exhaust

ducting and heaters, including flanges and joints, must be insulated to prevent sweating and heat loss.

611 GAS CYLINDERS

Pressure in compressed gas cylinders subjected to cold temperatures will drop considerably and may

be insufficient for practical use. Therefore, bottled gases should be stowed inside if safety regulations

permit. If they are used directly from an outside stowage in cold weather, as much as 2m³(75ft³) of

volume can be lost.

612 BATTERIES

1. Cold temperatures drastically reduce the output of all types of batteries (both dry cells and storage

batteries). For example, at -18^oC, the ampere-hour capacity of a typical dry cell battery is reduced to

about 25 percent of the 20^oC rated capacity. At this temperature, capacities of lead-acid and nickel-

cadmium storage batteries are down to about 35 percent and 50 percent respectively.

2. The lowest temperature for reliable cranking is about -18^oC. The output of all batteries reaches

essentially zero at about -34^oC to -40^oC. The rate at which storage batteries can accept a recharge is

also reduced in cold temperatures. To obtain a good recharge in a reasonable amount of time, the

temperature of the battery should be about 15^oC or higher.

3. The sulphuric-acid electrolyte in a discharged acid battery can freeze at -15^oC. If the battery is

fully charged, the electrolyte freezing point is depressed to

-60^oC or below. Freezing may damage the

plates, crack the battery case, split the cover-to-case seal or the terminal-to-cover seal, thus leading to

electrolyte spillage. Freezing of electrolyte may also form crystals which can pierce separators,

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eventually leading to internal short-circuits and premature failure of the battery.

4. The potassium hydroxide electrolyte in a nickel-cadmium battery does not vary significantly with

the state of charge and the freezing point is essentially constant at -60^oC. Freezing of this type of

battery is not a problem.

5. Storage batteries should be kept fully charged and stowed in a heated space or equipped with

heaters.

6. Flashlight and other dry cell batteries should be kept warm when not in use.

7. For more detailed information on handling of batteries in a cold environment, see Annex D.

613 SHIP COLD WEATHER SOAKING

1. Ship cold weather soaking is defined as long-term exposure of the ship to sub-zero temperatures

and near freezing seas. The ship gradually reaches thermal equilibrium with its environment after

about a two to three week exposure. The ship is considered cold-soaked when the heat loss rate drops

to the same point as the heat production rate. The net heat transfer rate is zero and therefore the

amount of heat the ship contains is constant.

2. When a ship transits from a moderate climate to a cold climate, its exterior and topside equipment

will cool down to ambient temperatures. Low seawater temperatures may cause high vacuums in

condensers, condensation on air and seawater pipes and low temperatures in cooling systems. Spaces

near the skin of the ship and interior spaces containing seawater piping and/or unheated ventilation

will cool rapidly, particularly unheated spaces. After an initial rapid drop, air temperatures in these

spaces will stabilize into a slow downward drift until the soak is complete.

3. Spaces below the waterline have a low temperature limit of approximately -2.2^oC. However, heat

is lost more easily at the water/hull interface than at the air/hull interface. One effect of this is that

ship's skin temperatures above the waterline may be higher than those below the waterline even

though air temperatures are well below freezing. Topside exterior spaces, subject to solar heating,

wind and weather, can experience temperatures far below seawater temperatures and wider, more

frequent temperature variations.

4. As temperatures in the outer spaces fall, temperature drops will progress toward the ship's interior.

In general, once soaking is complete, the spaces farthest from the exterior of the ship will be the

warmest; however, the locations and sizes of heat sources and/or whether the fresh air supply is heated

will have the greatest effect on which parts of the ship will have cold problems.

5. Exterior Effects of Soaking. The exterior of the ship (and all equipment located there) is

essentially at the temperature of the environment.

6. Non-Arctic internal combustion engines, such as those found on small boats, will be difficult to

turn over without Arctic-grade oil. Engine fuels will thicken and suffer from wax formation. Water in

the fuel will freeze causing fuel flow blockage. Diesels, in particular, become increasingly harder to

start as the weather gets colder. High fuel viscosity may prevent proper oil flow through the engine,

once it has been started. Tighter clearances due to cold-induced contraction can exacerbate these

effects. The film of lubricant protecting engine internals and separating surfaces such as

journal/bearing and piston ring/cylinder breaks down more quickly at cold temperatures, allowing

adhesion (engine seize) and corrosion to occur.

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7. Unprotected freshwater engine cooling systems may experience fractured heat exchangers and/or

popped freeze plugs.

8. Interior Effects of Soaking

a. Unheated Spaces. Because many unheated spaces are infrequently occupied, damage to items

in those spaces could go unnoticed. Cold spaces containing low or no-flow water lines are of

particular concern. An example of such a space is an unused head, often found on ships designed

to carry embarked troops. Prolonged cold weather could also cause damage to the contents of

storage spaces.

b. Heated Spaces. Ships have reported that typical heated space temperatures reached the 10^oC

range during long-term Arctic exposure. Living and working in temperatures of around 10^oC

increases fatigue, as has been reported from previous ships operating in a cold-soaked condition.

The constant discomfort has generally diminished the ability of the crew to perform at its best.

c. Engineering Spaces. Under normal conditions, engineering spaces do not require additional

heat to maintain acceptable living temperatures. However, during cold weather operations, a

number of ships have experienced the need to shut down part of engineering space ventilation in

order to keep ambient temperatures above freezing.

d. Ships have reported the need to make impromptu modifications to the ventilation system line-

up in order to keep engineering space air above freezing temperatures. Only the waste heat

emanating from the various engineering systems keeps conditions in these spaces from being as

severe as the exterior of the ship.

e. Condensation/Standing Water. During prolonged cold weather operations, condensation can

occur on the coldest interior surfaces of the ship, leading to preservation problems, water damage

and slippery surfaces. Freshwater in contact with the hull will freeze, including bilge water and

condensation. Ice build-up can occur on the inside, especially in humid spaces. Frozen bilges will

impair the ship's dewatering capability if the bilge suctions are covered. Hatches and scuttles will

become frozen shut down from the inside.

f. Condensation will occur on any piece of equipment taken from a cold storage area into a warm

space. Of particular concern is electronic equipment. Condensation hazard to electronic gear arises

when a cooling medium operates at temperatures below the design point. Significant delays can be

expected during start-up while electronic gear warms up and stabilizes. Condensation occurring

inside fuel tanks can freeze. Prevent condensation by insulating or lagging cold surfaces and using

a desiccant to lower humidity in small spaces.

9. In-Port Effects of Soaking. A ship tied to the pier in a cold weather environment gets colder

faster than when it is at sea. A large amount of heat-producing equipment is normally shut down.

Likewise there can be a lack of sufficient shore power and use of the ship's own resources means the

use of fuel and watchstanders.

614 YELLOW GEAR

1. Operational yellow gear in cold weather is very important. Failure of vehicles, which move aircraft

equipment, supplies or ammunition could interrupt ship's operation.

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2. Normal greasing, filter cleaning, electronics and hydraulic checks are extremely important. Just as

essential are the use of fuel, oil and lubricants designed to allow the vehicles to operate effectively and

efficiently in cold weather.

3. The use of ether starting systems already installed on the vehicles or manual applications of ether

to the air intake regions will provide the necessary cold weather starting assistance. Ether canisters

should be stocked in sufficient quantities to ensure quick starts throughout the deployment. Excessive

use of ether damages the internal seals and gaskets of the engine. An engine may need to be

overhauled in warmer temperatures after being started with ether.

4. Air tanks on all yellow gear vehicles should be drained daily. The air drain should be left open to

allow all condensate to drain and to prevent freezing the air lines. Use of air dryers and their

maintenance will be covered in vehicle maintenance manuals.

5. Cold weather affects pneumatic equipment as much as diesel or gas equipment or vehicles, so

preventive maintenance and daily checks for moisture in the system needs to be accomplished.

Pneumatic systems should be fitted with dryer units which use methanol.

6. Cold weather can cause severe stress on metal. Inspections of the yellow gear stress points, the

fork lift carriage and points where hydraulic cylinders attach to the frame need to be completed to

ensure no corrosion or stress fractures are evident prior to the deployment.

615 UNDERWAY REPLENISHMENT

1. Training. Before a cold weather cruise, personnel should receive training on special aspects of

cold weather Underway Replenishment (UNREP) operations, including:

a. Cold weather hazards of hypothermia and frostbite.

b. How to function in special cold weather clothing.

c. Proper relieving procedures.

d. General cold weather UNREP operations.

2. Preparation for UNREP. As a preventive measure, covers for deck equipment should be

provided, where possible, to reduce the penetration of water and subsequent formation of ice. Because

of cold weather effects on UNREP equipment, more time and effort must be devoted to getting the

equipment ready to begin UNREP operations:

a. Ice and snow must be removed from covered and uncovered equipment, including decks and

hatches.

b. De-icing chemicals will be needed to remove ice from equipment and decks.

c. Equipment must be started and operated at low speed to check for proper operation and to

allow warm-up prior to full speed operation.

d. The non-skid surface should be extended to cover as much deck area as possible.

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e. The technical manuals for all UNREP equipment exposed to the weather should be reviewed to

determine what cold weather lubricants and hydraulic fluids will be needed.

f. Some specific preparations for UNREP include:

(1) Grease wire ropes and sheaves.

(2) Put cold weather hydraulic fluid in winches and cold weather lubricating oil in the winch

gear boxes.

(3) Drain the water and purge the moist air from compressed air systems to prevent freezing

of on-deck pneumatic equipment. Check air dryers to ensure that the dew point temperature of

the compressed air is maintained within the proper range.

(4) Make room below decks to store all small equipment and fibre ropes used during UNREP

operations. Break equipment out when needed and replace it below when the operation is

completed.

(5) Procure winch covers to protect UNREP equipment from spray and to facilitate de-icing

without damage to equipment by ice removal tools. These covers should be part of the ship's

"Cold Weather Kit".

(6) Check the gaskets in refuelling probes and bellmouths to preclude leaks during refuelling

operations. Stock extras because gaskets may become brittle and crack in cold weather.

(7) Stock a large supply of chemlites because they will lose intensity after an hour or two in

cold weather, and because of the reduced number of daylight hours.

(8) Fiberglass reinforced plastic traction mats may be obtained which give effective traction

even when partially iced over.

(9) Stock alkaline flashlight batteries rather than the ordinary cells. Alkalines are degraded

less by cold temperatures.

(10) Conduct an electrical check to ensure traffic lighting and other necessary control

measures are operational.

g. Provide for portable, topside heaters or enclosures for personnel involved in extended topside

evolutions. Hangar space heaters have proven effective.

h. Anticipate that routine evolutions could take twice as long in cold weather.

i. Periodically inspect berthing spaces for warmth and ventilation. Ensure that adequate bedding

materials are available.

j. Provide for additional heaters for particularly exposed areas, such as the Signal Bridge and

Pilot House.

k. Hot beverages and soup should be available on the mess deck 24 hours a day and distributed to

look-outs, RAS and flight-deck crews.

l. Stripping of waxed decks and the addition of non-skid strips is recommended.

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CHAPTER 7

COMBAT SYSTEMS

701 COLD-WEATHER PREPARATIONS

1. Gun Mounts, Missile Launchers and Torpedo Tubes.

a. Check topside mounts for watertightness.

b. Check drive motors.

c. Ensure that heating coils/base ring heaters are operable.

d. Obtain additional seals, plugs, and O-rings to provide redundancy, since cold temperatures

increase the failure rate.

e. Ensure that window heaters are operable.

f. Lubricate with required oils and greases. (Old grease will have to be purged.)

g. Verify that the installed heating system can maintain hydraulic oils above 15^oC, or provide

supplementary heaters.

h. Check the magazine sprinkler systems for proper operation and insulation of piping in

unheated spaces. Pipework to upperdeck magazine lockers should be insulated and is best drained

down to an isolation valve within the ship.

i. Ensure that instructions for the operation of these systems in extreme cold weather are

prepared. Include the following:

(1) Protection of exposed hydraulic lines, high-pressure air piping, and gas ejection piping.

(2) Use of heat strips in gun barrels. (Insert/retract from breech.)

(3) Protection of electrical cables.

(4) Use of cold-weather hydraulic fluids and lubricants.

(5) Monitoring of cooling and other fluid systems for leakage.

(6) Regulation of inlet pressure on CIWS cooling water to maintain required temperature.

(7) Increase of frequency of routine checks and movement of systems through full arcs. If

seizure is considered possible, operate systems initially in "hand control".

j. Openings into mountings of breech mechanisms should be fitted with removable canvas

covers, including separate covers for gun sights and breeches of guns.

k. Due to cold moisture in air systems, valves may freeze open, causing constant HP air leaks.

Secure valves until weather improves. This will lock snubbers and retaining latch, requiring delay

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in firing.

l. Torpedo tube heating system must be checked. It may be necessary to regularly fire air slugs.

m. Launcher barrels should be checked for build-up of condensation after heaters have been left

switched on for 2 days or more.

2. All Sonars, Torpedo Countermeasure Hoists and Towed Arrays

a. Verify operability of installed heaters.

b. Obtain spare seals, particularly for topside, exposed hoists.

c. Lubricate with cold-weather greases.

d. Ensure that hydraulic oil is maintainable above 15^oC, or obtain supplementary heater.

e. Equipment cabinets and other components may develop condensation because of cold

temperatures. Transmitters may have to be dried out before applying full power.

f. Towed Array System/VDS

(1) The hoist motor can be operated to keep the hydraulic fluid warm, and the drum rotated

in case retrieval or adjustments to scope are required.

(2) Minimize body/tail surface time. The array could be damaged by floating ice if allowed

to remain near the surface for any length of time.

(3) The electrical components of the hoist are exposed to icing and mechanical damage when

towed body array is deployed. Additional covers should be added.

(4) Ensure that transom door latches are checked. A means of "dogging" the doors securely,

allowing an absolute minimum of play, is highly advised. Chain falls are one possibility.

(5) Strive to maintain interior spaces water-free during towing operations.

(6) Have available means of de-icing (chemical/thermal) for the towed body and cable if

required. (De-icing fluid is preferred.)

3. Prairie Masker

a. The use of the forward masker belt, particularly below cavitation speeds, may result in the air

binding of intakes for cooling fire pumps.

b. When a masker must be used, it may be necessary to find alternate cooling or fire pump

intakes, or reconfigure supply arrangements for cooling/firemain.

4. Canister Launchers

a. Cover exposed launchers to reduce icing and remove prior to use.

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b. Protect canister seals and covers to prevent cracking.

c. Maintain canister temperature in accordance with technical manuals, and monitor periodically.

d. Check vent dampers' operability during cold-weather operations. Cycling weekly is effective.

702 FIRE CONTROL RADARS

1. For simple tachymetric directors, suitable switch sockets should be fitted near each director for use

with electric blankets and portable electric heaters.

2. Prior to entering cold weather, the antenna drive motors should be tested and lubricated with cold

weather grease. Grounding straps should be insulated with RTV compound.

3. Shafts and bearing surfaces will operate more effectively if they are buffed and polished. Such

surfaces should be lubricated sparingly.

4. More detailed guidance is provided at paragraph 803.1.g.

703 RECOIL MECHANISMS

Recoil mechanisms containing a glycerine and water mixture will function satisfactorily in cold

weather. However, sluggish action and a short recoil may become apparent at those temperatures

below freezing when crystals form in the mixture, although the solution will not freeze until

temperatures below the pour point are reached. Heat must be applied as soon as unsatisfactory recoil

action is experienced. The orifices in recoil mechanisms are designed for a specific mixture of

glycerine and water and no substitution is permitted.

704 AIRCRAFT GUNS

1. For reliable operation at low temperatures, guns must be clean and properly lubricated. When

firing in sub-freezing temperatures, gun heaters are required and should always be turned on just

before take-off.

2. Before firing, guns should be disassembled, cleaned, inspected for defects or part breakages, and

lubricated. While disassembled, it should also be determined that all traces of hard-drying

preservatives have been removed from all working parts of the gun.

3. It is important that all springs be within their prescribed tolerances of free length.

4. All traces of solvent used in cleaning must be removed before reassembly. Incomplete removal of

the bore cleaning solvent may result in malfunctioning at low temperatures. Immediately after

cleaning, if guns are to be ready for firing, they should be lubricated with the prescribed lubricant. If

guns are to be stored after cleaning, a suitable preservative must be applied.

5. Apply oil sparingly. Never dilute lubricating oils with kerosene. Cold-temperature tests have

shown that gun operation at low temperatures is not improved by diluting the lubricating oil in such a

manner. Further, at temperatures warmer than -29oC, this mixture is not a satisfactory lubricant.

6. Guns rust rapidly from condensation when taken from the cold into a warm building. After

reaching room temperature, they should be stripped, their parts wiped thoroughly dry and clean and

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immediately oiled. This procedure must be repeated every time guns are brought into a warm space

from the cold outside.

705 GUN SIGHTS AND AIRCRAFT FIRE CONTROL EQUIPMENT

All gun sights and aircraft fire control systems should be capable of operating at temperatures as low

as -48oC, provided the correct lubricants are used.

706 BOMB SIGHTS AND BOMB DIRECTORS

Most bomb sights will perform satisfactorily at low temperatures. Some have proved to be satisfactory

-54^oC while others, of a less elaborate type, will operate at temperatures to -40^oC.

707 AMMUNITION

1. Ammunition must be kept in protected storage at temperatures not below the minimum safe values

prescribed for the explosives concerned. Ensure wet ammunition is wiped down prior to stowage to

prevent icing. Propellants should be maintained at a temperature above -17.7^oC. Rocket motors are

subject to the same requirements as smokeless powder cordite, as far as storage temperatures are

concerned. Some rocket motors are susceptible to cracking if handled at low temperatures.

2. Safe firing temperatures for rocket and Jet-Assisted Take-Off (JATO) units should be stencilled on

the rocket motor or the JATO unit. These temperatures represent the minimum temperatures at which

the rocket motor or JATO unit should be used and are not necessarily the ambient air temperature. If

the temperature of the JATO unit has been permitted to drop below the prescribed minimum, it cannot

be considered safe for firing at any temperature. All aircraft gun ammunition must be capable of firing

-54^oC.

708 LUBRICANTS

Under Arctic conditions, certain lubricants prescribed for normal use tend to congeal and cause

unsatisfactory operation. In general, lubricants approved for use in ordnance service should meet

specification requirements at temperatures to -18^oC. Changes in lubrication required for use in Arctic

service include the dilution of high-viscosity oils and heavy greases with low-viscosity oils, or

replacement with a suitable low-temperature lubricant. Excessive amounts of lubrication must be

avoided. Cold-weather re-lubrication of ordnance should be completed before entry into low-

temperature areas, i.e., before temperatures drop to -18^oC and below. However, if cold weather is

encountered before re-lubrication has been completed, special methods for removing the congealed

lubricant must be used.

709 TORPEDOES AND TORPEDO TUBES

1. In surface vessels, torpedoes are protected from cold weather by the torpedo tubes or the magazine

environment. Submarine torpedoes are protected by the normal ship environment.

2. In surface vessels, heaters

(preferably electrical) are required for exposed torpedo tubes and

muzzle door and training mechanisms, if fitted. Heating should be used at ambient temperatures below

5^oC.

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CHAPTER 8

ELECTRONICS AND CHARACTERISTICS

OF ELECTRONIC EMISSIONS

801 GENERAL REQUIREMENTS

1. The following is an outline of some of the requirements for electronic equipment applicable to

most types of ships:

a. All exposed shipboard equipment should be capable of operating at temperatures down to -

50°C.

b. All exposed electronic equipment should be capable of withstanding wind velocities of 100 kt

at any temperature down to -50°C.

c. All mechanically operated equipment must be lubricated with low-temperature lubricant and

adequate space heating fitted in spaces where this is feasible, e.g., inside radar pedestals.

d. Electric heaters should be installed in inside covers of electronic equipment fitted on weather

decks.

e. Insulators should be lengthened approximately 10 percent or the next higher voltage rating

over the normal standard as extra protection against shorting caused by ice formation.

f. Antennas should be designed to withstand an ice load, up to 5 cm thick around the component

parts of each antenna. The diameter of wire rope antennas should not be less than 1 cm. All whip

antennas should be capable of withstanding wind velocities of 100 kt when coated with ice 5 cm

thick.

g. Cables and cords should be handled with care to prevent fracturing. At extremely low

temperatures, cables should be unreeled in a warm space before use.

802 EXPOSED ELECTRONIC EQUIPMENT

1. With the foregoing requirements in mind, all equipment should be appropriately winterized and

preheaters used wherever possible. The practice of lengthy warm-up periods under no-load or light-

load conditions is also recommended.

2. Equipment not in regular use needs to be heated periodically to drive out moisture. Waveguides

(and other non-pressurized lines where condensation can accumulate) should be fitted with drain cocks

and drained at regular intervals. Planned maintenance schedules for ships should include checks of all

drain cocks. Waveguide dryers, should be used as directed.

3. Equipment used in exposed positions, then returned to warm spaces for stowage, must be

thoroughly dried to remove all moisture. After drying, the equipment should be allowed to reach the

ambient temperature of the space prior to stowage.

4. Ice formation can be a hazard on all types of external antennas, causing breakage or changes in

antenna characteristics and reduction of operating range. Ice, which has formed should be knocked off

with a thin pole. Ice and snow should also be removed from strain insulators to prevent excessive

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transmission losses. Wire antennas should be secured loosely, so any slight whip action can crack ice

build-up.

803 COLD-WEATHER PREPARATIONS

1. Antennas. Radio equipment requires preparation prior to deployment for cold-weather operations.

Of particular note is the problem of antenna icing. Antennas should be coated with a silicone/oil-based

substance with sufficient on-board stock available for additional coating, if required. Antennas suffer

sea-spray icing in the northern latitudes. The thicker the ice on the antenna, the greater the loss

imposed on the signal. Factors such as air temperature, salinity of the water, structural shapes, and

wind velocity play key roles in the antenna icing process and should be taken into consideration when

operating in the area. Utilizing proper preventive-maintenance methods can aid in reducing the amount

of ice adhesion that occurs on an antenna. Wiping the antenna down, ensuring that it is free of dirt, and

checking the smoothness of the antenna's surface, are procedures, which can be used by radio

personnel to prevent icing. Additionally, all radio equipment

(transceivers/receivers) should be

brought up to technical manual standards prior to deployment It is imperative that all radio equipment

be checked and the necessary preventive maintenance be performed on all communication systems.

a. Test antenna drive motors.

b. Apply cold-weather grease, after purging old grease, about one week before getting underway.

Make sure grounding straps were properly insulated.

c. Obtain spare antennas and insulators to replace those which may be damaged from heavy

weather/ice.

d. A complete inspection and Planned Maintenance Schedule

(PMS) of antennas/topside

equipment is strongly advised prior to Arctic operations to minimize need for personnel to work

aloft.

(1) Check rotating antenna heater circuits and cooling systems.

(2) Verify weather-tightness of exposed antenna components.

(3) Check operating mechanism on all communications antenna safety switches.

(4) Check operating mechanisms on all antennas with lowering systems installed.

(5) Insulate anemometer as much as possible. Hand-held anemometers should be available.

(6) Inspect wire antennas (HF broadband fans) and slacken if required.

e. SATCOM antenna pedestal may freeze, preventing the antenna from tracking in azimuth The

following actions may be helpful:

(1) Place temporary heat strip around pedestal

(2) Place fibreglass insulation and herculite cover around pedestal.

(3) Place desiccant bags inside pedestal to absorb moisture

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(4) Rotate directors/illuminators at low speed every 8 hours. During extreme icing conditions

rotate antennas in azimuth and elevation every 30 minutes to prevent the pedestal from

freezing..

f. Fill antenna cooling systems with an anti- freeze solution.

g. Fire control radar antenna scanners (the stinger on the director) may ice over on the inner

rotating axis, holding the scanner in the conical scan pattern and preventing the spiraling motion in

automatic-track mode.

(1) Keep a coating of antifreeze on the areas between rotating and non-rotating areas.

(2) Train the director aft with elevation depressed during freezing conditions.

(3) Install a lightweight, non-reflective cover on the antenna, when Arctic operations are

planned.

h. Operate variable-spaced antennas at low speed for a short period before increasing rotation

speed. Do not change the direction of rotation or accelerate/decelerate rapidly, until gear trains and

drive motors are thoroughly warmed up. Installation of electric heaters in antenna pedestals is

recommended

i. Replace oil in the pedestals of rotating radar antennas with oil that will not congeal at low

temperatures. Consideration should be given to the installation of oil heaters.

j. Connect the radar antenna pedestal heater to a circuit that will remain energized when the radar

set it self is disconnected.

2. Slow-Moving Mechanical Parts. Slow-moving mechanical parts, such as shafts and bearing

surfaces, will operate more satisfactorily if the surfaces are buffed and polished. Such surfaces should

not be lubricated unless this is essential, and even then it should be done sparingly.

3. Covered Cables

a. Rubber-covered, flexible cable becomes stiff at temperatures lower than -6°C; the insulation

becomes brittle and can crack and shatter rather than bend.

b. Synthetic materials (e.g. polyethylene) are replacing rubber for insulating purposes because of

much improved cold-weather characteristics.

4. Electric Installations. Electric installations should be made with special care to minimize the

effect of cold, moisture, high humidity and stresses due to icing, as follows:

a. Increase wire size of radio antennas to compensate for high winds and ice loading of long

horizontal spans. Receiving antennas using small-size wire are vulnerable to damage by ice

b. Install double antenna suspension insulators for transmitting antennas to increase leakage path

and to prevent arc-over.

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c. Increase the size of mounting brackets and foundations of equipments in ships which may

become involved in ice-breaking operations.

5. Communications Equipment. Communications equipment for high-latitude operations should

include a transmitter with a high-frequency operating range of at least 26 MHz, and another, which

will operate on frequencies as low as 175 - 195 kHz. Both of these transmitters must have substantial

power capabilities. All transmitters and receivers should be calibrated on the several frequencies

expected to be used. To capitalize on the advantages of low-frequency operation and very low-

frequency reception during blackout periods, antenna systems additional to those already installed may

be required.

6. Telephones and Microphones

a. When using telephones or microphones in exposed locations, care should be taken to prevent

the speaker's breath from freezing the microphone. In general, the use of portable microphones

supplied with a transmitter station, which is in a protected space is preferable to those located in

the open.

b. Cover sound-powered telephone boxes.

804 CARE OF EQUIPMENT IN LOW TEMPERATURES

1. In general, special procedures will be required to ensure satisfactory operation of electronic

equipment at temperatures lower than -2°C.

2. Dry-cell batteries and electrolytic condensers will not work at low temperatures, but will probably

recover and resume normal operation when warmed. Maintenance will be required to prevent

corrosion from condensation caused by temperature changes. Components may require frequency

readjustment of critical circuits because of changes in electrical characteristics.

3. When temperatures fall below 2°C, heat should be applied to electronic equipment if it is to be

ready for immediate use. Batteries and electrolytic condensers, in particular, must be warm if they are

to operate efficiently. Continuous operation in the "standby" or "filament" position is good practice as

it keeps equipment at the correct operating temperature before plate voltage is applied, and it

eliminates condensation inside the equipment.

805 UNDERWATER ELECTRONIC EQUIPMENT

1. Echo-ranging equipment with retracting transducers requires an "ice-gate" to prevent entry of ice

into the transducer sea chest.

2. Radar waveguide and ECM antenna masts on submarines should be filled with pressurized

nitrogen and the heaters should be continuously energized.

806 PORTABLE POWER SOURCES (FOR ELECTRONIC EQUIPMENT)

1. A small aerosol-type can of ether should be included to facilitate cold-weather starting of portable

internal-combustion power-generated equipment.

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WARNING

• Extreme caution should be exercised to limit the quantity of ether injected in both gas-engine

carburators and diesel engine air intakes.

• To avoid the possibility of frostbite, do not allow ether to come in contact with exposed body

areas.

2. If equipments are to be shut down or left turned off for extended periods, the lubrication oil should

be drained while the engine is hot, then stored inside the ship or personnel shelter along with the

starting batteries, if so equipped. Often it is more advantageous to leave engine-starting batteries inside

and extended cables outside to the generator.

807 MAINTENANCE (PERSONNEL PRECAUTIONS)

1. No maintenance aloft should be attempted unless an emergency condition exists, and then only

after rigging an appropriate canvas windscreen protection cover against wind-chill, and installing

portable heaters inside to allow maintenance personnel an opportunity to remove gloves, masks and

attach safety harness, prior to attempting any electronic-type repairs. (Solder will not blow at-20øC

using conventional irons.) Gloves should be donned prior to leaving the shelter, to keep hands from

freezing to ladder rungs or handrails.

2. Safety belts/harnesses must be worn when working aloft. Positive footing is never available aloft

in northern waters and becomes more pronounced when personnel are required to wear cumbersome

clothing and footwear.

3. The installation of communication whip antennas in the vicinity of smoke stacks or boiler room

uptakes usually prevents the formation of ice. However, periodic cleaning is necessary to remove soot

accumulations and prevent degradation of antenna performance. The cleaning aspect does not present

a problem when the whips are of the retractable type and access to the top of the stack is gained

through an internal trunk-and-scuttle arrangement. Breathing masks and safety belts/harnesses must be

worn at all times to prevent smoke and stack gas inhalation and to conform to "safe working practice

aloft" criteria.

808 COMMUNICATION CHARACTERISTICS

1. Radio communications beyond "line-of-sight" limits in the Arctic pose certain problems that occur

only rarely at lower latitudes. These problems are mainly caused by ionospheric disturbances which

affect the behaviour of radio waves in the Low-Frequency (LF), Medium-Frequency (MF), High-

Frequency (HF), and Very-High-Frequency (VHF) bands.

2. The standard shipboard transmitter required for high-latitude operations usually covers a frequency

range down to 175-195 kHz, depending on the model. At the lower end of the range, the radiated

power obtained may be very small, being something of the order of 0.6 percent to 1.5 percent of the

rated output power. This is caused by the inability to load the antenna properly because of its short

effective length. Radiation is further decreased by the necessarily short vertical section of the antenna,

upon which radiation depends. Optimum radiation with current shipboard antennas is usually realized

at around 500 kHz, and effective radiation decreases as the operating frequency is decreased. It has

been found, too, that in operating the low-frequency transmitter at frequencies in its lower range at

substantial power (one or two kW), using a standard shipboard antenna, severe arc-overs and large

losses in antenna trunks will be experienced due to high standing-wave ratios, with high voltage

occurring at the insulators caused by inadequate effective lengths.

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3. For these important lower frequencies to be used during periods of ionospheric disturbances,

arrangements may have to be made to install temporary transmitting antennas of the greatest length

and height practicable. The possibility of paralleling existing antennas in series might be considered,

and emergency use of balloon suspension should not be overlooked.

809 ARCTIC ANOMALIES

1. Auroral Zones and RF Interference

a. Zones of extreme RF interference and "electronic storms" become increasingly prevalent and

severe in higher latitudes. Such "auroral zones" are believed to be due to charged particles ejected

from the sun and deflected by the earth's magnetic field.

b. It has been noted that the frequency and severity of electrical storms vary directly with the

number of sun spots observed on the sun. Communications in high latitudes are affected both by

electronic storms and ionospheric disturbances. In HF/MF bands, propagation becomes erratic; the

highest usable frequency decreases and the lowest usable frequency increases. Transmitters and

receivers will fade. At times, communications black out completely and may remain out from a

few minutes to several days. On the other hand, communications on VHF/UHF circuits may

extend beyond the line of sight. Radar may similarly be rendered useless for brief periods, or its

range extended by ducting.

c. A communication coordinating circuit should be included in all communications plans. The

coordination circuit should be covered using narrow-band and wide-band secure voice equipment

cryptographic systems.

2. Antenna Icing. Radio equipment requires preparation prior to deployment for cold-weather

operations. Of particular note is the problem of antenna icing. Antennas should be coated with a

silicone/oil-based substance with sufficient on-board stock available for additional coating if required.

Antennas suffer sea- spray icing in the northern latitudes. The thicker the ice on the antenna, the

greater the loss imposed on the signal. Factors such as air temperature, salinity of the water, structural

shapes, and wind velocity play key roles in the antenna icing process and should be taken into

consideration when operating in the area. Utilizing proper preventive-maintenance methods can aid in

reducing the amount of ice adhesion that occurs on an antenna. Wiping the antenna down, ensuring

that it is free of dirt, and checking the smoothness of the antenna's surface, are procedures which can

be used by radio personnel to prevent icing. Additionally, all radio equipment (transceivers/receivers)

should be brought up to technical manual standards prior to deployment. It is imperative that all radio

equipment be checked and the necessary preventive maintenance be performed on all communication

systems.

3. UHF Communications

a. Effective UHF ranges are significantly reduced. During heavy snow, absorption and fading are

common, further reducing UHF ranges. With unrestricted visibility conditions, maximum UHF

ranges are 15 - 16 NM (28-30 km); when visibility is reduced to 1-2 NM (2-4 km), UHF ranges

are reduced to 10-12 NM (19-22 km).

b. Few incidents of apparent UHF black-out have been noted. However, on some occasions UHF

communications have been good with a ship 10 nautical miles (19 km) away, while having no

communications with a closer ship.

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4. Satellite Communications. A major problem is the potential for the satellite receiver antenna to

freeze. Communications dependent upon satellites in geostationary, equatorial orbits will be degraded

above 70°N because the satellite is near or below the horizon.

5. Static. Continuous high-level static is rarely experienced in Arctic latitudes but sporadic noise is

common. Irregularly occurring steady rushes of increasing noise frequently signify auroral

disturbances on the frequency employed. Generally, LF is less affected by this type of atmospheric

noise than HF. Flakes or pellets of highly charged snow are occasionally experienced in the north

during periods of high winds. Charged particles of snow driven against metal vehicles, masts, and

antennas, discharge with a high-pitched static sound that can be heard on all received frequencies. This

form of noise is more severe on aircraft radios than on ground or vehicle stations.

6. Ground Conductivity. Ground conductivity in northern areas is generally poor. At HF and below,

effective ground-wave ranges are considerably reduced over ice, permafrost or snow-covered terrain.

Moreover, the efficiency of an antenna, especially when propagating in the sky-wave mode, is

lessened when installed over this kind of ground. Great care must be taken in siting to secure the best

available ground, and considerable effort may be needed to build an artificial ground system.

7. Communications Plans. Because of the foregoing, the following communication factors will

influence the tactical plan:

a. Extended communication ranges, which must be achieved are normally accompanied by a

reduction in communication capacity. Normal scales of communication equipment cannot usually

be maintained under these circumstances.

(1) Depending on the nature of terrain and other factors, ground rebroadcast stations for

voice operation may have to be deployed at very moderate distances. Airborne rebroadcast

may be required for greater ranges. Finally, carrier-wave (CW) operation may be necessary for

point-to-point communications at still greater ranges or during disturbed conditions.

(2) Range or terrain may dictate the use of sky-wave transmission. Although usually reliable,

it is not entirely so due to the unpredictability of atmospheric conditions.

(3) Where a higher degree of reliability is required at sky-wave transmission ranges, normal

HF links must be guarded, by parallel LF circuits. Where this is necessary, two stations must

be established at each circuit terminal. Extensive antenna systems may be required for

continuous day/night operation.

b. Because of the vagaries of sky-wave transmission, much greater attention must be paid to

protecting information than is usually the case. When voice codes are inadequate, ciphers must be

employed and these are likely to be of the manual type. Manual enciphering is time-consuming

and handling times are in proportion to the length and number of messages being transmitted.

c. In northern areas, the siting of headquarters to gain the extended communication ranges is

critical. Detailed ground reconnaissance and testing will probably be necessary to find adequate

transmission sites. In the absence of suitable retransmission facilities, a major headquarters or base

should not be deployed to a remote locality until a satisfactory site has been determined

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CHAPTER 9

PERSONNEL

901 INTRODUCTION

The success of any Arctic operation will ultimately depend upon the effectiveness of the officers and

personnel involved, who must be in good health, physically fit and mentally alert.

902 TRAINING/PREPARATION

1. Pre-sail training and briefings are the key to safe cold-weather operations, and should include:

a. Hazards of frostbite, wetness, snow-blindness or eyestrain, lung frosting, wind-chill and

hypothermia.

b. Precautions such as avoiding excessive perspiration, ensuring that clothing fits properly,

ensuring that enclosed shelters are ventilated properly, not handling metal objects with bare hands,

and using precautions when handling volatile liquids in cold weather.

c. Precautions for operating in lengthy periods of darkness.

d. Instructions on ice removal and safety.

e. Cautions that heavy clothing and cold may significantly reduce and limit body motion.

f. Hazards of trench foot.

g. Precautions for operating in areas of extreme glare and the use of tinted goggles.

903 FOOD AND WATER

1. Due to the risks associated with dehydration in high latitude environments, personnel should

increase fluid intake, especially water. Use caffeine drinks moderately since they will contribute to

dehydration. Electrolyte-replacement drinks are valuable and should be served warm.

2. Food is particularly important in the increase of metabolic heat production as well as providing

relief from monotony. For this reason, plan meals with high caloric content of sufficient quantity and

regularity to maintain an optimum metabolism and with as much variety and appeal as possible.

3. Inside stowage of provisions against an un-insulated hull should be avoided since temperatures can

cause condensation and may result in mould damage.

4. The consumption of alcohol, even in small amounts, causes increased blood flow to the skin,

which may artificially create the sensation of warmth to tissue that is at risk of frostbite. Furthermore,

this increased blood flow to the skin can decrease core body temperature and increase the risk of

hypothermia. Accordingly, the use of alcohol in a cold weather environment should be discouraged.

904 COLD-WEATHER CLOTHING

1. The first requirement for dressing for the cold is to keep warm without perspiring. If overheating

does occur, personnel need to shed clothing readily so that perspiration cannot accumulate. Clothing

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based on the layering principle, is now readily available and consists of various garments designed to

trap air in layers without being uncomfortably bulky. Clothing should be layered as follows: wool or

polypropylene next to the skin to absorb moisture, followed by wool for warmth, followed by

wind/rain protection gear. Multiple layers retain body heat better than a single bulky garment.

2. In conditions of extreme cold, it may be necessary to provide face masks. Anti-glare goggles or

sunglasses are helpful as a precaution against snow-blindness.

3. For operations ashore, provision must be made for certain essential needs: shelter (tents or snow

shelters), food and drink, first aid, cooking and heating equipment, sleeping bags, and a reliable means

of transport and communication.

4. Clothing for extreme cold weather should include:

a. Cotton or polypropylene long underwear.

b. Woolen or cotton socks.

c. Jacket.

d. Trousers.

e. Hood.

f. Mittens with wool liners.

g. Gloves with woollen liners.

h. Boots.

i. Face masks.

j. Goggles or sunglasses.

k. Immersion gear. For personnel working in exposed areas, well-decks, towed-array hoist

rooms, or flooded areas, wet suits are recommended.

l. Wind pants. If immersion gear is not available, wind pants must be worn over long underwear

and trousers.

m. Other Considerations

(1) The most effective outerwear is an anti-exposure suit; it has inherent buoyancy, without

restricting upper body mobility. It is recommended for helicopter operations, RAS, UNREP,

and other topside evolutions.

(2) The knit Balaclava is an effective head covering.

(3) It may be necessary to designate extra space as drying areas for cold weather clothing.

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Cotton undergarments easily absorb perspiration, become saturated and lose their insulation

properties. Most synthetic materials do not absorb moisture and are intended to wick away from the

body and, therefore, are excellent insulators.

905 PERSONAL WELFARE

1. Personal Protection

a. The rotation interval for exposed personnel standing topside watches may be varied with

weather conditions. However, it is imperative that such personnel be regularly and carefully

checked. The effects of exposure are not readily recognized. Watch rotation of 20 - 30 minutes is

effective.

b. Personnel who get wet on deck must go below immediately and change into dry clothing.

c. Whenever topside look-outs start feeling cold, they should flex fingers and toes. The look-outs

should be periodically checked by watch personnel.

d. Provide for portable, topside heaters or enclosures for personnel involved in extended topside

evolutions. Hangar space heaters have proven effective.

e. Anticipate that routine evolutions could take twice as long in cold weather.

f. Periodically inspect berthing spaces for warmth and ventilation. Ensure that adequate bedding

materials are available.

g. Provide for additional heaters for particularly exposed areas, such as the Signal Bridge and

Pilot House.

h. Hot beverages and soup should be available on the mess deck 24 hours a day and distributed to

look-outs, RAS and flight-deck crews.

i. Stripping of waxed decks and the addition of non-skid strips is recommended.

906 FROSTBITE

1. The term frostbite refers to the freezing of any part of the body. The tissue affected actually

freezes. Frostbite is caused by exposure to temperatures below 0°C. The water in the tissue cells turns

to ice and disrupts the normal functions and even the cellular structure of the tissue. Normally the

body's metabolism (burning of calories) produces enough heat to keep all parts of the body warm.

When exposed to severe cold, however, heat loss becomes very rapid and the blood supply to the area

reduces to conserve body heat. If the affected area is not reheated, the blood there may get very thick

and plug up the arteries. Without any source of heat, the area will begin to freeze. The extent of

damage depends on how much freezing occurs.

2. Identifying frostbite can be relatively easy. Usually there is an uncomfortable sensation of

coldness, followed by numbness. There may be tingling, stinging, aching or even a cramping pain.

Visible indications, which are used primarily to detect a buddy with frostbite, include the skin first

turning red, then later becoming pale or waxy white. The parts affected, in order of most common

occurrence, are:

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a. nose;

b. ears;

c. cheeks;

d. forehead;

e. exposed wrists;

f. feet, especially toes; and

g. fingers.

3. Superficial Frostbite involves only the skin or the tissue immediately beneath it. Mild cases are

sometimes referred to as frostnip, and can be easily re-warmed with little or no tissue damage. There

is a certain amount of whiteness or waxy appearance. After re-warming, the frostbitten area will first

become numb, mottled blue or purple and then swell, sting and burn for some time. In more severe

cases, blisters will occur beneath the outer layer of skin in 24 to 36 hours. These slowly dry up and

become hard and black in about two weeks. Generally, swelling of the injured area will subside if the

casualty stays in bed or at complete rest. Throbbing, aching and burning of the injured part may

persist for several weeks, depending on the severity of the exposure. After the swelling finally

disappears, the skin will peel and remain red, tender and extremely sensitive to even mild cold and it

may perspire abnormally.

4. Deep Frostbite is a much more serious injury and it damages not only the skin and subcutaneous

tissue but also goes deep into the tissue beneath and can even include the bone. It is usually

accompanied by the formation of large blisters. In marked contrast to superficial frostbite, these

blisters take from three days to a week to develop. Swelling of the entire hand or foot will also take

place and may last for a month or more. During this period of swelling, there may be marked

limitation of mobility of the injured fingers or toes, and blue, violet or grey (the worst) discoloration

takes place. After the first two days, aching, throbbing and shooting pains may be experienced for as

long as 2 to 8 weeks. The blisters finally dry up, blacken and slough off, sometimes in the form of a

complete cast of the finger or toe, nail and all, leaving beneath an exceptionally sensitive, red, thin

layer of new skin, which will take many months to return to anywhere near normal. Sometimes,

itching and abnormal perspiration persists for more than 6 months after the initial injury, and the part

will suffer lengthy or permanent sensitivity to cold. In extreme cases of severe frostbite that have not

been re-warmed rapidly, permanent loss of some tissue almost invariably occurs. In such cases the

skin does not become red and blistered after it has thawed, but turns a lifeless grey color and continues

to remain cold. If blisters occur they will probably appear along the line of demarcation between the

acutely frostbitten area and the healthy remainder of the limb. In cases of acute deep frostbite of the

foot, adjacent swelling can extend as high as the knee. In a week or two after the injury, the tip of the

injured area begins to become black, dry and shrivelled, but the rest of the damaged area may progress

in one of two entirely different ways: the tissue may shrivel to almost half the normal size and

become mummified right up to the beginning of the healthy flesh, or the tissue may become wet, soft

and inflamed if it becomes infected.

5. In the dry type of frostbite, the uninjured remainder of the limb usually does not become intensely

swollen or painful, and there is a clear line of demarcation between damaged and undamaged tissue.

In the wet type, the whole limb tends to become painful and swollen, and originally undamaged tissue

may suffer serious damage unless the infection is promptly checked. Surgical intervention is rarely

needed in less than 2 months. Even minor surgery on frostbite tissue should rarely be performed. In

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an extreme case in which the loss of some tissue is inevitable despite careful treatment, the dead

material will simply slough off at the proper point and at the proper time, with maximum saving of the

sound underlying tissue. Occasionally, hospitalization and professional surgical intervention may be

needed. However, if even this type of case is kept scrupulously clean and sterile, the proper use is

made of antibiotics and the patient stays constantly in bed at rest throughout the illness, the chances

are high that auto-amputation will eventually occur.

6. Chances of getting frostbite are increased by several factors in addition to duration of exposure and

freezing temperatures. These should be kept in mind, particularly when it comes to choosing people

for duties where they are susceptible to frostbite. Some at risk people include:

a. older people;

b. smokers;

c. those unaccustomed to cold weather;

d. injured people;

e. fatigued or sick people;

f. those with previous cold injuries;

g. those with poor nutrition habits; and

h. those having consumed alcohol.

907 TREATMENT OF FROSTBITE

1. The following is a summary of ways to treat frostbite. Always consult the corpsman before

performing more than basic treatment.

2. Superficial Frostbite

a. A minor case of superficial frostbite is fairly common and should serve as a warning.

However, unless operations mandate otherwise, superficial frostbite victims should be re-warmed

in a shelter and the individual not returned to duty until all secondary symptoms are gone.

b. A frozen nose is the most common type of minor frostbite. Holding the pile of the back of the

mitt over the lower face and breathing into it will warm the nose quickly. A scarf or mask worn

over the face will usually prevent frostbite.

c. Minor frostbite can usually be thawed with body heat. Place a bare warm palm against a

frostbitten cheek or ear or place frostbitten hands against the chest, between thighs or under

armpits.

3. Deep Frostbite

a. Move the victim to a heated area to avoid danger of further frostbite. If necessary, delay re-

warming until all danger of refreezing is eliminated. Frostbitten areas must not be allowed to thaw

and refreeze.

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b. Remove all constricting items of clothing such as boots, gloves and socks from the area of

injury if this can be done without causing further damage to the frostbitten part.

c. Rapid re-warming is the specific treatment which minimizes tissue loss. The extremity should

be thawed in a carefully controlled water bath at a temperature between 40 and 41° C until

affected tips turn pink or burgundy red (approximately 20 minutes to 1 hour). This is best

accomplished in a whirlpool bath or tub bath. If a bath is not available, thaw with warm wet packs

at temperatures ranging between 37.8 and 44° C.

d. Avoid infection by cleaning and dressing with dry sterile gauze loosely wrapped.

e. As early as operations permit, treatment by a medical officer is vital.

4. The following precautions should be observed when treating frostbite:

a. Don't rub or massage the injury. It will cause more damage.

b. Don't use any creams or ointments.

c. Don't rupture any blisters.

d. Don't allow the victim to smoke or consume alcoholic beverages, even though the pain may be

severe.

e. Don't allow an injury to thaw and refreeze.

f. Don't rub ice or snow on the injury.

g. Avoid excess heat when re-warming the injury.

908 IMMERSION FOOT

1. Immersion foot, also commonly called trench foot, is a cold injury to the feet (and possibly the

hands) resulting from prolonged exposure to dampness and temperatures below about 10° C. Note

that freezing temperatures are not necessarily associated with this injury. In the early stages of

immersion foot, the feet and toes are pale and feel cold, numb and stiff. Walking becomes difficult. If

no action is taken at this point, the feet will swell and become painful. In extreme cases the flesh dies

and may fall off, and amputation of the foot or the leg may be necessary. Other signs of trench foot

include pain and tingling insensitivity; blotchy, red and white, waxy skin; poor blood circulation.

2. Treatment of Immersion Foot. The earlier treatment for trench foot begins, the faster recovery

will be and the less damage will be done. Handle the affected part gently. Do not rub or massage at

this point. Immediately re-warm and dry the affected areas. Re-warming should be performed slowly

in air, and not in hot water. Apply powder liberally to remove any moisture remaining on the skin.

Elevate the feet slightly and air them out at room temperature. Circulating air around the feet with a

fan will help to keep them dry.

3. Prevention of Immersion Foot. Wet socks and boots, poor nutrition, fear, fatigue and

immobilization can all contribute to trench foot. The following practices will help to prevent such an

occurrence:

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a. A sweat suppressant, deodorant type powder or spray will help to keep the feet dry.

b. Dry socks are a must! Repeated changes during the day may be necessary to keep dry.

c. Exercise feet while out in the cold. Toe raises and walking will improve foot circulation, as

will wiggling toes and bending ankles. Tight boots, which reduce circulation must not be worn.

d. When socks are removed, massage feet and lower legs. This improves circulation and helps

dry feet.

e. Keep feet clean. Good hygiene will prevent fungus growth and keep feet healthy.

909 HYPOTHERMIA

1. In this condition the body temperature falls, as the body's capacity to generate heat can no longer

keep pace with the rate of body heat loss. This usually occurs in persons suffering from exposure.

2. The onset of this condition is insidious. An individual complains of feeling cold, becomes listless,

tired, and wants to lie down and rest. If the individual surrenders to this urge, hypothermia progresses

rapidly. Irrational behaviour is a serious sign and is often followed by unconsciousness. Additional

indicators of the onset of hypothermia are muscle weakness, cessation of shivering, loss of

coordination and poor decision making ability.

3. Treatment depends upon the severity of the condition, which can only be accurately determined by

a core temperature, normally a rectal temperature. If a rectal temperature is not available, each

individual case must be presumed to be serious. In the early stages, it is sufficient to get the person

into shelter, carefully remove wet clothes and provide external warmth to the body.

4. In severe cases, more aggressive treatment is required. Gentle handling of hypothermic patients is

mandatory to avoid cardiac arrhythmias. The patient should be re-warmed with blankets at room

temperature, warm intravenous fluids at 37 degrees Centigrade, and warm humidified supplemental

oxygen heated from 38.9 to 40 degrees Centigrade delivered as a mist. Hot, well sweetened

beverages, may be given by mouth if the patient is conscious. Immersion in a hot water bath may be

considered when the patient is coherent and the shiver response has returned, especially in those cases

caused by immersion. The initial water temperature should be 36 degrees Centigrade and should not

exceed 40 degrees Centigrade for patient comfort and to avoid the risk of peripheral vasodilation,

syncope and shock.

5. Rapid re-warming must be avoided as this predisposes to cardiac arrythmia and arrest. Re-

warming rates should not exceed 3-4 degrees per hour. If the core temperature is below 30 degrees

Centigrade, medical staff must be present to administer the re-warming procedure recognizing the risk

of cardiac arrythmias or cardiac arrests. Cardiopulmonary resuscitation or assisted respiration may be

required; however, defibrillation is often unsuccessful at body temperatures less than 30 degrees

Centigrade.

6. Prevention is the ideal state of affairs and should not be too difficult. Leaders must insist on

adequate dry clothing, ample nutrition, the avoidance of fatigue, and be on the lookout for the early

signs of hypothermia. Incipient cases should not be permitted to lapse into inactivity. There is always

the possibility of hypothermia whenever a person is forced into inactivity in the cold or as a result of

injury.

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910 SNOW-BLINDNESS

1. This is caused by the sensitivity of the eye to ultra-violet radiation. The Arctic sun is never high

above the horizon and its effect is intensified by reflection from snow and ice so that considerable

ultraviolet light can fall onto the retina. Although the dangers of snow blindness aboard ship are slight,

bridge watch standers and lookouts should be aware of the risk, particularly in areas of heavy sea ice

or snowy mist.

2. Early symptoms are a scratching sensation under the eyelids, deep pain in the eye with excessive

tear flow and blurred vision. These may progress to intense pain, aggravated by light, so that it

becomes impossible to open the eye. The white of the eye becomes reddened.

3. Treatment consists of keeping the eyes bandaged and the patient in darkness until the reaction has

subsided. Pain-relieving drugs, such as drops or ointment, will be required. Sedation, such as the

administration of benzodiazopines, may be indicated.

911 HYPOXIA

1. Hypoxia, or an insufficiency of oxygen, can occur when personnel attempt to live in a poorly

ventilated shelter.

2. Close observation of a burning candle is essential in any Arctic shelter. The shelter must have

ventilating airholes since candles consume oxygen. When the percentage of oxygen in the air drops

from 20 percent to 16 or 17 percent, a candle will go out. This occurs, however, before the occupants

themselves will be seriously affected by hypoxia and in time for them to get into fresh air.

912 CARBON-MONOXIDE POISONING

1. Everyone must be constantly alert for the possibility of carbon-monoxide poisoning resulting from

incomplete combustion of fuel. Use of petroleum products in internal-combustion engines and stoves

in the Arctic is a common source of carbon-monoxide poisoning.

2. Leaded gasoline burned in stoves produces lead oxides which are irritating but non-toxic in small

amounts. Burning eyes, a running nose, or coughing produced by these are a warning of carbon-

monoxide buildup.

3. Carbon-monoxide is odorless, tasteless, and colorless. Symptoms of poisoning are: a loss of

peripheral vision, dimmed vision, headaches, dizziness, nausea, exhilaration or lassitude, and chest

pain. Sometimes the most noticeable feature to an observer is that the lips or the entire body may

become "cherry red" in color. Treatment should be by delivering 100 percent oxygen via a tight-

fitting face mask.

913 AVOIDING COLD-WEATHER INJURIES

1. All parts of the body do not lose heat at the same rate. Those areas which loose heat the fastest

include:

a. The head and neck, which loose heat 10 times faster than the rest of the body;

b. The rib cage; and

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