SUBMARINE MEDICINE PRACTICE
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SUBMARINE HABITABILITY AND CLOTHING
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|18.1. ||HABITABILITY IN SUBMARINES ||266
| 18.1.1. ||General considerations ||266
| 18.1.2. ||Background ||266
| 18.1.3. ||Definition ||267
| 18.1.4. ||Factors of habitability ||267
|18.2. ||HABITABLE SPACE ||267
|18.3. ||THE ATMOSPHERE ||268
| 18.3.1. ||Volume ||268
| 18.3.2. ||Pressure ||268
| 18.3.3. ||Oxygen and carbon dioxide ||269
| 18.3.4. ||Atmospheric contaminants ||270
| 18.3.5. ||Battery gases ||271
| 18.3.6. ||Engine exhaust fumes ||271
| 18.3.7. ||Oil vapors ||271
| 18.3.8. ||Other impurities ||271
| 18.3.9. ||Odors ||272
| 18.3.10. ||Bacteria ||272
|18.4. ||THERMAL HABITABILITY ||272
| 18.4.1. ||Air-conditioning system ||272
| 18.4.2. ||Effective temperature ||274
| 18.4.3. ||Extremes of temperature ||274
|18.5. ||DESIGN OF COMPARTMENTS ||275
| 18.5.1. ||Lighting and color ||276
| 18.5.2. ||Working areas ||277
| 18.5.3. ||Recreation areas ||277
| 18.5.4. ||Sleeping spaces ||278
|18.6. ||NOISE ||278
|18.7. ||OTHER HABITABILITY FACTORS ||279
| 18.7.1. ||Food and nutrition ||279
| 18.7.2. ||Fresh water ||279
| 18.7.3. ||Sanitation ||280
| 18.7.4. ||Ship's motion ||280
| 18.7.5. ||Safety ||280
|18.8 ||SUBMARINE CLOTHING ||280
SUBMARINE HABITABILITY AND CLOTHING
18.1. HABITABILITY IN SUBMARINES
18.1.1. General considerations.
The submarine is primarily a vehicle for the
concealed transport and accurate delivery of torpedoes and other weapons. She also serves as a
domicile for a specialized complement of sailors
who must adapt themselves to stresses peculiar
to undersea warfare. Within her compact environs, crowded as they are with endless items of
material, there must remain some cubic footage
to be allotted for the duty stations, messing,
berthing, and varied activities of her crew.
Virtually every single technological advance in
modern naval vessels has represented a corresponding attrition in space or comfort to personnel. Larger propulsion plants demand more
fuel, stored in larger tanks; complex electronic
and hydraulic units require more men to be stationed aboard for operation and maintenance;
and more cooks and administrative rates are
necessary in proportion to any increase in complement.
It was demonstrated in World War II that a
considerable degree of inconvenience and discomfort can be endured by strongly motivated submariners who possess the stamina required to do
reliable work under adversity. But infringement
upon the fundamental organic and psychic personal needs of man cannot increase indefinitely
without encountering a point of diminishing return in human performance. The relentless influx of space occupying, heat generating, and noise
making equipment aboard ship can invade and
usurp habitable room between unyielding bulkheads until that critical level is reached beyond
which the ship's operational efficiency is jeopardized.
It is axiomatic that the fighting effectiveness of
any ship is the product, not the sum, of its integral
components. Not the least of these components
is its personnel, for without teamwork and spirit
even the most advanced equipment is negated.
A poor standard of habitability is a poor installation of personnel, equivalent to faulty installation of engines or torpedo tubes.
Early efforts at making life more tolerable for
the seafaring man were met by derision even by
the old salts themselves, who accepted the ways
of the sea as arduous and who regaled the land-lubber with chanteys and staunch sagas of hardship and endurance. Poor ventilation, scurvy,
bully beef and hard tack were only a part of his
test of mettle. Usually he was unaccustomed to
conveniences, having come from the hardy frontier
life of his day. Since the Industrial Revolution,
however, the sailor has had to make a greater adjustment to shipboard life, as he represents a
people who have come to take for granted modern
conveniences and creature comforts as a part of
their national life.
As long ago as 1891, a naval officer essayist
wrote, "There are positive faults in the internal
arrangements of our newer ships which will neutralize the allurement of any pay table * * * and
in the end drive out of the service the very class
of men and boys that we are now so earnestly
endeavoring to attract into it. The more modern
the ship and the greater the need for intelligence
in her crew, the more objectionable she seems to
become in point of quarters for the men, until we
have about reached the point where it is well to
call a halt on certain disastrous tendencies in the
direction of the utter disregard of what intelligent
men are capable of putting up with." And as
recently as 1891, a senior officer in discussing this
essay remarked: "Although believing in all comforts possible for the men, it is thought that the
essayist places too much stress upon them The
old saying might be slightly changed to read, 'He
who goes to sea for comfort ought to go to _ _ _ _ _
for pastime'; given good pay and prospects for
advancement, and young men will cheerfully give
Webster's Unabridged Dictionary defines habitability as the capability of being inhabited or
dwelt in; specifically of a dwelling, reasonably fit
for occupation by a tenant of the class ordinarily
occupying such a dwelling.
This is a word with an abstract definition which
has assumed diverse meanings, having been incorporated into various professional and industrial jargons. Improvement in habitability
is the direct concern of countless sciences, trades,
arts, and industries, each branch of which appends
its own specialized concepts until the term has
become almost nebulous. The wide variety in
design of homes reflects the several opinions of
builders and architects regarding styling, arrangement, and standards of livability of dwellings.
The problem is vastly multiplied when it comes
to the manufacture of a submarine, one of the
most complex environmental structures which man
has ever been called upon to occupy.
To its inhabitants, a submarine is a steel capsule
which encloses them as they venture into a completely artificial environment beneath the surface
of the ocean. Only by taking along the "external
milieu" to which mankind is adapted, encased in
a pressure-proof hull, is it possible for man to
exist indefinitely in the "internal milieu" of
his phylogenetic prototypes.
Because of the development of radar and sonar
and the improvement of antisubmarine weapons
in recent years, submergence times became increasingly prolonged. The fleet submarine has
evolved through the snorkel and guppy stages,
with manifold intensification of stress upon the
crew. The ultimate in this trend is a true submersible, capable of avoiding detection for weeks
or months without surfacing. This is the goal of
the project officers of the nuclear powered submarine. Among the crucial determinants of how
true a submersible she will be is this question: Can
she make sufficient allowance for the limitations
of her crew?
Much can be done toward decreasing the limitations of the submarine crew by assessing the
men as they apply for duty in submarines, selecting
in advance those who manifest the least likelihood
of maladjustment. As a complementary consideration, it is essential that a crew so chosen
should not be subjected to unnecessary environmental strain. Good habitability must be attained and maintained by a continuous organized
program of appraisal and revision in design of
submarines-those which are active in the fleet,
as well as those still on the drawing boards.
18.1.4. Factors of habitability.
The salient facets of habitability are mentioned
insofar as they pertain to submarines. A recommended list of references is appended for detail
which cannot be covered here.
18.2. HABITABLE SPACE
Space is at a premium in any type vessel;
particularly is it critical in submarines, which are
noted for their compactness. Overcrowding
causes a lack of "elbow room"; decreased freedom
in moving about the boat; absence of privacy;
limited availability of head and shower facilities,
bunking room and personal stowage room. Deprivation of these factors gives a man a sense of
futility in commonplace activities which may be
reflected in his performance of duty. Usually
there is just no place to go except to his bunk
when he leaves his watch station. He becomes
aware of the mannerisms of others, and becomes
irritated at the nervous habits of himself and
his shipmates. Paucity of space accentuates the
friction which arises after everyone has run out
of jokes and sea stories.
Nowhere has there been more effort in making
the most efficient use of space than in the submarine. Dual use is made of space wherever possible by such ingenious devices as bench lockers,
folding or convertible tables, overhead lockers and
brackets, and hinged lavatory basins. The commissary department must be especially inventive
in putting away provisions for a long cruise, often
campaigning and bargaining for cubic feet which
have been contested by other departments. More
than one ship has eaten salty potatoes which have
been stowed in the superstructure.
A logical way to provide additional space would
be to build larger submarines. This would make
the ship less maneuverable and more vulnerable
unless accompanied by an extra round of
propulsion equipment, personnel, etc., which again
revive the vicious spiral.
Large quantities of space are occupied by equipment which has been placed aboard in an attempt
to improve comfort for the crew. The ventilation
and air-conditioning systems in particular are
examples; also the washing machine, ice cream
freezer, recreational gear, electric heaters, and
walk-in chill boxes. Strange to say, it is felt by
many submariners that the value obtained from
even some of these items does not repay the sacrifice in space. The ice cream freezer iv. not used in
cold climes during peacetime, nor is the commercial
model washing machine when frequent port calls
It is a problem to curtail the accumulation on
board of unnecessary equipment, back issues of
logs and publications, and excessive inventories
of spare parts and provisions. With the current
specialization of submarines into types (SSK, -R,
-P, -O, -N), there may be a tendency for required
allowance lists to become all-inclusive, containing
items which are essential aboard some types, but
only supernumerary or unnecessary aboard others.
This decrement in space can be compensated in
part by designers, but there is no substitute for
periodic and rigorous paring down of excessive onboard material.
Efforts have been made to miniaturize equipment, and the aircraft electronics field reports the
saving of space by "miniaturizing miniatures."
To simplify a number of installations without loss
of their function, e. g., eliminate experimental
features upon adoption of production marks and
models, would render some of the maintenance
men dispensable. Automatic devices have tended
often to reduce the number of operating personnel,
but at times this advantage has been lost by an
increase in maintenance men required. Increased
durability of equipment would permit its upkeep
during availability periods by shore-based personnel, with fewer breakdowns at sea for ship's
force to remedy.
Reduction in number of equipment operators
can be effected by human engineering improvements; design of controls, dials, manifolds, panels,
and switchboards, with better lighting, readability,
and convenience of handling. If one watchstander thereby can do proficiently the work of
two, it is possible that the three crewmen standing
watch on the second piece of gear can be eliminated
from the crew, leaving more habitable space per
man. A notable example of this is seen in the new
diving station arrangement aboard submarines,
whereby one man can serve simultaneously as
helmsman, bow planesman, and stern planesman.
The end results of most of these efforts are to
have fewer billets and more habitable space within
the same floodable volume. Leaving operators
and maintenance personnel ashore lessens the
demands for provisions and fresh water; there is
less requirement for feeding (fewer cooks needed),
for administrative supervision, and for medical
care. There is more generous apportionment of
head, shower, and recreational facilities; more
cold storage room per man for frozen foods and
meats; higher permissible standards of sanitation
and hygiene; more personal locker space; and more
room to walk around in.
18.3. THE ATMOSPHERE
The amount of air contained in a submarine is
about equal to the floodable volume and proportional to the barometric pressure. It is circulated
throughout the ship by centrally located supply
and exhaust blowers of large capacity, usually
found in the forward engine room. Supply suction
can be taken from outside the ship through the
main induction line while on the surface, at which
time the inflow of air is supplemented by the powerful suction of the diesel engine scavenger blowers.
An outside source of air for ventilation is also
available to snorkel-equipped submarines when
the -mast induction is rigged at snorkel depth.
Otherwise during submergence the air inside the
ship is recirculated by setting the blower loeuvers
so that the exhaust blower discharges into the
supply blower intake. This affords a diffusion of
the air, the oxygen tension dropping and the
carbon dioxide tension rising fairly uniformly in
all compartments. Vitiating components are
disseminated and diluted in the same fashion,
their localized concentration rising relatively
slower than if there were no recirculation.
Contrary to popular belief among the laity, there
is not much fluctuation of pressure inside the
submarine. The barometric reading varies an
inch or two at most in the routinely operating fleet
type submarine. Extensive use of the torpedo
tubes as while laying mines causes somewhat
higher pressure which can be returned to normal
by using the air compressors in the pump room
to return the excess air to the high pressure storage
There is sudden but not drastic fluctuation of air
pressure during snorkeling. If the top of the
snorkel mast should dip beneath the water's
surface, e. g. because of high waves in rough seaway or loss of depth control, there is automatic
closure of the head valve to prevent flooding of the
snorkel and a quick vacuum is drawn in the boat
by the diesel engine intake. The head valve will
again open when it clears the surface with a sudden
equalization of pressure with the outside. A low
pressure trip will shut down the engines automatically if they should pull a vacuum equivalent
to an aircraft altimeter reading of 6,500-7,000
feet above sea level.
Rapid opening and closing (cycling) of the snorkel
head valve with prolonged intermittent pressure
changes can be annoying to the crew, especially
during sleep hours. Resulting incidence of aero-otitis media and sinusitis is high when there is
prevalence of respiratory infections; these may be
controlled by mucous membrane shrinking agents
and antihistamines. Isolated instances of recurrent ear pain may be due to exuberant lymphoid
tissue at the Eustachian tube ostia often relieved
by radium treatments after diagnosis by nasopharyngoscope.
Early snorkel exercises in 1947 were begun with
misgivings about these E. N. T. and psychological
complications, but it was soon found that crews
were very adaptable to continuous snorkeling on
prolonged cruises exceeding 30 days and for distances approaching 6,000 miles.
18.3.3. Oxygen and carbon dioxide.
Once the submarine is sealed, the point at which
clinical asphyxia would be reached is determined
by three variables: (a) the number of people
aboard; (b) the floodable volume of the ship, and
(c) the rate of gaseous metabolism per person,
taking into account heavy work and amount of
smoking. A formula containing these variables is
employed to determine the time at which there
should be revitalization, or artificial addition of
oxygen and removal of carbon dioxide, as an
alternative to obtaining ventilation from surface
X=number of hours after thorough ventilation until the oxygen concentration is
expected to be about 17 percent, CO2
about 3 percent.
C=floodable volume of the ship; this is about
35,000 cubic feet in the fleet type hull.
N=number of men aboard.
If submerged time of over 24 hours is anticipated, CO2 absorption should be begun soon after
diving, with replenishment of oxygen at the time
designated by the formula.
Aviators' oxygen is carried in commercial
containers in each compartment, from which a
measured volume of oxygen can be released into
the boat when indicated by the revitalization
Carbon dioxide absorbent is stowed in canisters
of thin metal in all compartments. Each canister
contains about 15 pounds of lithium hydroxide
which should be spread on a flat surface such as a
mattress cover, and stirred at intervals to promote
absorption. The hands should not be used for
stirring because of the heat generated in the chemical absorption, and the stirring should be gentle
to avoid scattering caustic dust. The chemical is
deliquescent, losing its activity when it becomes
moist. The cans of absorbent are weighed
periodically; a weight gain indicates water absorption and loss in chemical effectiveness of the agent.
The air can also be freshened by bleeding fresh
compressed air from the banks into the boat ; this
increases oxygen tension and dilutes the carbon
dioxide without reducing its tension.
The onset of asphyxia is very insidious because
it is so gradual under these circumstances. When
a fleet submarine has been submerged over about
16 hours, depending on the variables mentioned
above, a cigarette will go out quickly if set aside,
and a match will go out as soon as its head has
burned. About this time several of the crew
begin to complain of headaches; someone notices
that everyone is breathing rapidly and deeply;
and the manifestations of irritability and impaired
judgment become evident. These premonitory
signs correspond roughly to about 3 percent concentration of carbon dioxide. The natural feeling
of one who does not realize the gravity of these
signs is, "We'd better save the soda lime for the
next time, when things might be a lot worse." By
this time revitalization is already overdue.
A Dwyer chemical carbon dioxide analyzer,
figure 129, is found on each submarine, for determination of the gas in percent. Beckman oxygen
meters are useful and accurate, but are not carried
aboard usually because of their sensitivity to
damage and loss of calibration.
Future plans for air regeneration methods include the use of chemical carbon dioxide "scrubbers" which can be activated by automatic monitor circuits to maintain carbon dioxide at the
tension desired, and large banks of oxygen with
manifolds and electronically controlled solenoid
valves for release of oxygen into the living spaces
as required. It is at least theoretically possible
to manufacture oxygen from sea water. All of
these projects will be limited by their weight,
complexity, and the space they utilize.
18.3.4. Atmospheric contaminants.
Objectionable and harmful contaminants of the
atmosphere inside the submarine accumulate
from many sources during long submergence.
Whereas the brief diving times of earlier submarines were not usually long enough for the
building up of toxic levels, the prospect of a true
submersible in the immediate future poses the
reappraisal of gases which have not been even
thought of before as being toxic. Industrial
medicine authorities have set standards for exposure to toxic gases and vapors in factories, in
terms of "maximum allowable concentration"
(m. a. c.) for intervals up to a full 8-hour working
day. No one, however, has previously considered
Figure 129.-Analyzing the submarine atmosphere for carbon dioxide by the Dwyer analyzer.
the possibility of people being exposed to these
materials for weeks and months without interruption.
18.3.5. Battery gases.
Very large lead storage batteries are depended
upon for underwater propulsion ; the cells discharge
at variable rates as the ship is driven through the
water at different speeds, and are recharged by
diesel driven generators. Water from the electrolyte is hydrolyzed at the poles, in large amounts
if there is a rapid rate of charge or discharge,
and/or a high cell temperature. Rapidly evolved
gases then bubble to the surface, and the cell is
said to be "gassing." Each of the battery wells
is continuously ventilated by its own set of exhaust
blowers, to forestall the buildup of high concentrations of these gases at any point in the ship.
Hydrogen, which evolves from the cathode plates,
is highly explosive at or above the 4 percent level.
It is physiologically innocuous.
Antimony is added to the lead sulfate of the
cathode plates to improve their durability and
length of life. Hydrogenation of antimony during
gassing produces stibine (SbH3), an explosive gas
with a characteristic unpleasant odor, which dissociates rapidly at room temperature, and which
acts toxicologically as a lower respiratory irritant
and a hemolytic agent, with traces of antimony
excreted in the urine. An impurity in lead storage
battery plates is arsenic, which forms arsine
(AsH3) upon contact with nascent hydrogen; this
gas is more stable than stibine, has a garlic-like
odor and, after a delay of a day or two after
exposure, causes such symptoms as malaise,
dyspnea, headache, fainting, nausea and vomiting,
dark urine, anemia, and jaundice. Arsine is
spoken of as a "blood and nerve poison." Neither
gas has been positively incriminated in the present
Pollution of battery electrolyte by sea water
produces chlorine gas in large amounts, the effects
of which are well known in chemical warfare.
Chlorine is absorbed by soda lime, which is the
active agent in the ship's SEA's (Submarine Escape Appliance-currently the Momsen lung) ;
scrubbers should also remove chlorine from the
atmosphere. The battery well is sealed off when
chlorine is detected.
18.3.6. Engine exhaust fumes.
Leaky exhaust manifolds or fittings, cracked
cylinder liners, intake of exhaust fumes through
the snorkel induction while cruising downwind, or
excessive back pressures in the snorkel predispose
the collection in the submarine atmosphere of
irritation gases which are products of combustion
in the diesel engines. These are oxides of sulfur,
hydrogen sulfide, methane, ozone, and most deadly
and insidious of all, carbon monoxide. It is said
that the latter will not be found in great quantity
in the absence of the typical exhaust gas odor;
unless, of course, the CO has come from some other
18.3.7. Oil vapors.
Hydraulic oil leaks from high pressure lines
form an atomized spray or "toxic mist" of saturated
hydrocarbons, glycols, higher alcohols, and butyl
cellusolve, causing eye irritation, respiratory irritation, headache, dizziness, and nausea. Another
danger of some of these mists is their explosibility.
Fuel oil or grease evaporating from hot surfaces
such as engines or ranges add a nauseating odor.
Oil films collecting on the skin promote dermatitides venenata, and chronic aspiration of oil vapors
may conceivably result in lipoid pneumonia, especially if the ciliary activity or the cough reflex
is depressed by other agents. In order of increasing carbon chain length, the gaseous hydrocarbons
are asphyxiants and strong anesthetics, and the
long chain liquid hydrocarbons are primarily skin
and respiratory irritants.
18.3.8. Other impurities.
Mercury vapor, from gyrocompasses, clinical
thermometers, and especially from mercury vapor
bulbs which are broken while hot, reaches m. a. c.
in infinitesimal amounts. Freon-12, leaking from
the refrigeration and air-conditioning units, is not
an inert gas as was commonly supposed. It is an
anesthetic gas; also when oxidized by flame, as
when a halide torch is used to detect freon leaks,
deadly phosgene gas is formed. Acrolein, one of
the most toxic gases known, is given off by hot
cooking grease and fats, also from electrical insulation as it ages. Ether, if stored in cans in the
medical locker, is hazardous if the cans are ruptured or left open.
Another source of carbon dioxide is from the use
of the fire extinguishers. Carbon monoxide is also
liberated from aging phenolic paint and varnish
compounds, and from smoking of tobacco. Both
these gases are given off with caustic smoke and
acrid phenolic fumes if an uncontrolled fire occurs
inside the ship.
Many persons are hypersensitive to tobacco
smoke if exposed for long periods, especially if not
accustomed to smoking. Radiation decomposition products from luminous dials and radon
plaques have only recently been found to be a
definite health hazard.
The principal cause of objectionable odors has
been due to the design of heads and sanitary tanks,
which does not feature a water trap or other seal
to prevent "pervasion of the ship with an aroma
resembling in no way the attar of roses." Defective flapper valves permit flies to breed in warm
climes and to enter and leave the sanitary tanks
freely. In order to empty a sanitary tank to sea,
as is done about twice a day routinely, all drains
into the tank are closed, an air pressure is built up,
and the contents of the tank blown overboard
through a discharge line. The tank must now be
vented, either outboard when on the surface, or
inboard when submerged. An activated charcoal
air filter is in the inboard vent line, which removes
much of the odor when the venting is done slowly
and when the filter unit is replaced often.
Other odors come from fuel oil, chemical agents,
tobacco smoke, cooking, and those emanating
from human bodies. Man has an ability to detect
the presence of odors which is much more acute
than any chemical or physical means known.
There is no clear definition of the physiologic
effects of disagreeable odors, except that there is a
definite reduction in appetite and a disinclination
to physical exertion.
Pathogenic microorganisms may live briefly in
the atmosphere, and conduction of communicable
disease in the form of droplet infection is a real
problem in the recirculated air of sealed submarines. Air sterilization methods have not been
18.4. THERMAL HABITABILITY
Man is a homeothermic animal; i.e., he maintains his own internal milieu at a constant temperature by regulatory centers in the central
nervous system, located chiefly in the anterior
and posterior hypothalamus. These centers exert
their control in heat balance through the autonomic nervous system, with regulated dissipation
of heat from the metabolic processes in the muscles and viscera. There is a relatively constant
loss of heat through the lungs and a fairly fixed
amount of heat loss in the excreta; the skin is the
primary factor in the regulation of body heat.
Some heat transfer to the outside occurs by
radiation; a little by conduction to garments and
to cooler surfaces with which the body may come
into contact; a larger amount by evaporation of
sweat, with a giving up of latent heat of vaporization as this aqueous material evaporates; but
mostly heat is transferred by the process of
convection, as steady movement of air over the
skin replaces the warm layers next to the skin with
If the relative humidity of the air is low, as
evidenced by a wide difference in dry and wet bulb
thermometer readings, the amount of water vapor
which it is carrying is well below saturation, and
the process of vaporization becomes more significant because evaporation from the skin surface is
promoted. This is the end accomplishment of
the air-conditioning units which have been used
with such great success in submarines.
18.4.1. Air-conditioning system.
Large refrigerant coils are placed in the main
ventilation supply conduits in submarines, with
freon expanded into the coils to absorb heat from
the atmosphere. As the ship's air passes freely
over the coils, its temperature drops below the
dew point, so that moisture condenses on the coils
from the now supersaturated air, collecting in
drip pans below and draining into the bilges or
into condensate water collecting tanks. When
the refrigerated air moves into the compartments
its relative humidity drops as it becomes warmer.
The ship is thereby made more comfortable because the air has been both cooled and partially
dehumidified. It has been found paradoxically
by some fleet units that in practice the boat is
made more comfortable by running at least one
air-conditioning unit during very cold weather;
opinions have been expressed that dehumidification of the air decreased the incidence of colds
among the crew, even with the heat loss entailed.
Figure 130.-Effective temperature chart showing normal scale of effective temperature, applicable to inhabitants of the United States under the following conditions:
A. Clothing: Customary indoor clothing.
B. Activity: Sedentary or light muscular work.
C. Heating Methods: Convection type, i.e., warm
air, direct steam or hot water radiators,
18.4.2. Effective temperature.
Four basic thermal factors in the environment
have been found to exert an influence on human
comfort. These are: (1) The air temperature,
as measured by the dry bulb thermometer; (2)
the relative humidity, or percent saturation of the
air with water vapor at the given temperature, as
measured by the differential readings of the dry
and wet bulb thermometers; (3) the air movement
in cubic feet per minute, determined by an air
velocity meter (velometer); and (4) the mean
radiant temperature, derived by formula from
the Kata globe thermometer, whose fluid bulb is
in the center of a hollow ball which absorbs
radiant heat from surrounding surfaces, integrating it as a human body would, independent of the
heat content of the atmosphere.
Attempts have been made to correlate all four
of these into one measuring device, and such
instruments as the thermointegrator and the
eupatheoscope have been abandoned because it
was found that the thermal needs of man varied
so widely at different points of the temperature
scale. Instead, various formulae and nomographs
have been devised for integrating the four thermal
factors into workable standards of comfort.
Probably the most widely accepted index of
thermal comfort was prepared by the research
laboratory of the American Society of Heating and
Ventilating Engineers in 1937. This index is
the effective temperature, which is a sensory
scale arrived at empirically using the votes of
human subjects while the temperature, relative
humidity, and air movement were changed in
stages as independent variables during carefully
In finding the effective temperature (fig. 130),
the chart is entered with a line connecting the
wet and dry bulb readings; the point of intersection of this line with the recorded air velocity
is extended obliquely to be read on the effective
temperature scale. This graph has become standard practice in the air-conditioning industry, and
gives satisfactory results under hot working
conditions. The fact that it does not take the
heat radiation factor into consideration is not of
importance if the air and the walls are at the same
temperature. But this is never the case in submarines. Therefore it must be stated that there
is no single thermal index capable of combining
all thermal factors into a single value which is
applicable to all situations. By adapting the
mean radiant temperature into the graph, it is
possible to improve the validity of the effective
temperature, so that it becomes the best index
for heat stress on the human body. Humidity is
still weighted too heavily in the graph for use in
Study of the graph shows the results on the
effective temperature of changing a thermal factor. The effective temperature is raised by increasing the thermometer reading, by increasing
the relative humidity, or by decreasing the velocity
of air flow. These factors, as well as estimates
of the radiant heat factor, must be appreciated
by the medical officer who is reporting on the
thermal habitability in any specific situation.
He must also record physiological findings such
as pulse rate, body temperature, and subjective
reactions of the crew. Only by being able to define
and recognize satisfactory air conditions will he
be enabled to make valid recommendations which
have meaning to the design engineer.
The optimal effective temperature is 71° F.;
most naval vessels are designed not to exceed 78°
optimally in the tropics, and submarines at
75-78°. A normal person can rest and sleep well
at 78° effective, and can do light work at temperatures up to 80° effective if he can rest well when
off watch. Sweating occurs with an effective
temperature of 78° and a rise in body temperature
begins with an effective temperature of 85°.
He cannot do prolonged heavy work if the effective
temperature is over 80°, at which temperature
there is appearance of heat rashes, sleeplessness,
and impaired performance. Above 85° it becomes almost impossible to work efficiently, and
above 90° effective temperature the individual
becomes susceptible to heat stroke.
18.4.3. Extremes of temperature.
If the atmosphere is exceedingly cold, heat is
retained in the body by intradermal vasoconstriction, and heat production is increased principally by the skeletal muscles which "shiver."
These compensatory phenomena are involuntary.
Extra layers of clothing are put on and electric
heaters are used, although running the heaters
is sometimes discouraged on the premise that it is
a needless waste of valuable ampere hours from
the battery in the endeavor to "heat up the whole
ocean." The heaters are stowed or secured during
the finishing rates to avoid overloading them
with high voltage from the battery bus.
It has been found in submarines that in the
presence of elevated carbon dioxide tensions there
is a decreased ability for the human organism
to adapt to extremes of either heat or cold. This
is postulated to be a result of the depression of
the hypothalamic heat regulatory centers by
When the effective temperature becomes so hot
that the individual cannot lose heat to his environment, he becomes poikilothermic. The downward
thermometric gradient from the body has become
reversed at this time, and heat passes into the
body rather than out of it. A condition of hyperthermia exists, which progresses to high fever
and heat stroke; the syndrome of heat exhaustion
intervenes, however, if the person is engaged in
any work. Perspiration drips from the skin
without evaporating thereon; radiation, conduction, and convection all tend to increase the body
temperature. Under experimental conditions,
the metabolism has been shown to rise, creating
a vicious cycle by contributing to the hyperthermia, until the regulatory centers themselves
The ordeal of a damaged fleet submarine undergoing continuous submerged evasive maneuvers
for 37 hours, when almost all machinery was secured for silent running, is cited:
"With the air-conditioning shut down the temperature within the ship went to a high figure.
A temperature of 125° F. was reported in the
maneuvering room. The after torpedo room
and the engine room were the coolest parts of the
ship. The forward torpedo room was practically
unbearable * * *. The decks and bulkheads
became clammy with condensed moisture. Rivulets of sweat would form and follow right behind
a towel rubbed over a man's body.
"Although the temperature in the after torpedo
room was probably well over 100° F., men going
from the maneuvering room to the after torpedo
room reported that they shivered and shook with
the chill * * *. The liquids available for drink,
fruit juices, coffee, or water, soon reached room
temperature. Frequently, swallowing these liquids induced immediate vomiting, yet thirst was
so great the men were constantly drinking, vomiting, and then drinking again. All of the men were
nauseated. Seventy-five percent were vomiting,
especially the diving officer. Profuse sweating and
difficulty in keeping liquids down produced severe
dehydration in many cases. No one cared to eat
"The bucket brigade struggled against the
mounting water in the motor room bilges and
against extreme fatigue, being practically out on
their feet. As the hours wore on the air commenced to get bad. Both carbon dioxide absorbent and oxygen were used, but despite that the
air was very foul toward the end of the dive. Prior
to the attack, the cooks removed rabbits from the
icebox so that they might thaw preparatory to
cooking. The odor from them became extremely
disagreeable. Breathing was very difficult and
headache was severe * * * many of the men were
in a state of physical collapse * * * stupor * * *
impossible to arouse men to go on watch * * *
stations manned by volunteers * * * men who
had the stamina and the will to move and
think * * * others past the stage of caring what
Under such conditions, the discharging batteries may attain temperatures of 130° F. or higher
when not ventilated, radiating copious amounts
of heat into the ship. The heat from endlessly increasing electronic installations is enough to overcome the beneficial effect of the air-conditioning
units. It is not surprising to note that these men
in retrospect thought it "a mistake to shut down
the air-conditioning * * * would all take the
noise of the air-conditioning machine and ventilation blowers in preference to enduring the heat and
humidity * * * the additional noise is less dangerous than the slowed down mental reaction of
extreme fatigue * * *"
18.5. DESIGN OF COMPARTMENTS
Rigorous measures to improve the livability of
the compartments in a submarine are justified, if
there is the probability thereby of improving
morale. There has been resistance to the "pampering"
of sailors by those who do not consider the
impact of weeks of incarceration on the human
organism, which are incident to a largely or totally
submerged war patrol. Glamorous as life aboard
submarines may appear to the outsider, there may
be long days of monotony in going about routine
tasks and waiting for those few moments of contact with the enemy which come almost as a respite
from boredom. In the absence of good hunting,
the submariner cannot help but feel that his efforts
are fruitless; it is understandable that he should
tend to feel the effects of his confinement more
acutely. His environment has been compared unfavorably with that of a third rate factory or a
second rate jail.
18.5.1. Lighting and color.
Until recent years submarines were lighted
completely by incandescent bulbs; three or four
centrally located bare bulbs with wide angle reflectors were spaced in standard fashion about each
compartment. With the installation of more and
more dials, gauges, and cathode ray scopes to
visualize for hours at a time, eyestrain increased.
Tests conducted in 1944-45 at Medical Research
Laboratory, New London, indicated that the
visual acuity of submarine personnel following sea
duty of several years had fallen below that of recruits to an extent not accountable by differences
Early attempts to improve lighting of compartments were along the lines of generally established
principles of visual engineering. However, it was
learned that standard lighting methods required
drastic modification for small shipboard compartments. The customary rules for indirect lighting,
calling for high reflectance overhead and low matte
finish about the bulkheads, proved infeasible because of the low overheads; the glare was great
from indirect fixtures which had to be placed at
eye level. It was then decided that direct lighting
only must be used.
The three most prominent faults of direct lighting are glare, shadows, and high brightness ratios,
the latter referring to extremely uneven distribution of light intensity in the room. The incandescent bulb, with its bright spot source of light, has
been replaced by the fluorescent bulb, which emits
light along a bar or line, reducing both glare points
and shadows. Fluorescent light is inherently diffuse; diffusion can be increased by use of "egg
crates" or metal diffusers in the light bracket.
This type of light can be made directional without
loss of diffusion by the use of properly designed
parabolic reflectors which concentrate the light on
Figure 131.-Poor instrument panel lighting by
improper illuminating source.
work areas. High banks of dials, previously difficult to read, can now be illuminated fairly uniformly by sources placed overhead and very close
to the panel (figs. 131 and 132).
Fluorescent bulbs make more efficient use of
Figure 132.-Improved instrument panel lighting by
proper illuminating source.
electric current, so that less energy is lost in production of unwanted heat within the compartment. More light sources than before can be
installed, for improved uniformity of light distribution, without increasing demand on the batteries
or generators. The fixtures are smaller than the
old wide angle reflectors, enabling them to be
"tucked in" between ventilation lines and pipes
in the overhead.
Attention to the walls, overheads, and to all
surfaces in the compartment is necessary in the
improvement of eye comfort and ease of seeing.
High gloss paints and bright surfaces are undesirable because they produce glare, which is classed
as the most harmful effect of illumination. White
paint on ceilings is no longer recommended. The
gleaming "bright work" which has been the pride
of the Navy for years is being reduced to a minimum. Plastic laminates of low reflectance are used
for table tops and for rub boards in passageways,
in place of CRS.
The color of walls, ceilings, and equipment has
been shown by interior decorators to have a
definite effect on production and morale in all
types of industrial plants. Color is a psychological
experience; it is the perceptual response of a person
to the release of energy within the visual spectrum.
Some colors appear cool, receding, restful; these
are the blues, greens, and violets, used in the rest
and recreational areas. The warm, advancing
shades of red, orange, and yellow are probably
stimulatory to work, and used in work areas,
offering a "change of pace" between work and rest
areas. A color is said to be "as cool as it is blue
and as warm as it is red;" pale colors are "cooler"
than dark colors.
Here again drastic modifications in established
principles have been found necessary in small
compartments. Distribution of the warm and
cool colors was used as prescribed for industry,
as well as deliberately in reverse order, with
about equally good results. Identical color schemes
to those acceptable for some crews might be generally disliked when used aboard other ships.
The matter of individual taste in colors may enter,
it being hard to please everyone; however, it is
known that colors change with the type of illuminant used in the particular compartment, and that
the spectral distribution of paints must be specified in conjunction with the spectral emission of
Lighting can be used to advantage as a morale
factor in removing pallor from faces, making the
men look more healthy to each other and to
themselves as they view the mirror.
It has been estimated that about one-third of
the man-hours spent during the average war
patrol in World War II were spent in compartments which were "rigged for red." Red lighting is necessary in order for the adaptation of
scotopic vision of those who are about to stand
topside or periscope watches at night. Illumination by low levels of red light permits the continuing of regular duties, but under difficult working
conditions. The true submersible is expected to
minimize this problem.
18.5.2. Working areas.
Much has been written in texts and manuals of
human engineering about the application of hum an
anatomy, physiology, and psychology to the designing of machinery. Only in recent years have
the designers of equipment begun to think of the
operator as the master rather than the slave or
an afterthought to the machine he operates.
Formerly there was apparently little consideration given to the readability of dials, arm reach,
reaction time, and other performance limits of
Fatigue factors are to be considered while the
crewman is at his job. The motions he is required to make should be natural and efficient,
with a minimum of needless movements and decisions to make. Fine adjustments are made
better with fingers alone than with the forearm
and wrist also. There should be proper placement of tools, materials, and controls. Any
alleviation of unnecessary tiring and frustration
removes a detriment to proper habitability.
18.5.3. Recreation areas.
There is no space in the submarine assigned
for the sole purpose of recreation, because of the
dual use principle for all room. About the only
place where men can play card games or write is
at the tables in the crew's mess, which of course
is not available during meals or preparation for
meals (figs. 133 and 134). Games, reading, hobbies, and other pursuits must be confined to
semisedentary activities because of space limits.
Space for movies is made usually in the forward
torpedo room, the screen being placed across the
Figure 133.-The submarine crew's mess compartment
during meal hours.
18.5.4. Sleeping spaces.
A man's bunk in a submarine, a steel frame
with springs and mattress with plastic mattress
cover and zippered ditty bag, is about the only
home he can lay claim to, the only "castle for a
home" which he possesses. Usually there is no
privacy at all here. If there are not enough
bunks to go around, a man awakened to go on
watch is replaced in the same bunk by another
coming off watch; this is called "hot bunking."
Sometimes the interval between the top of his
mattress and the bunk above is as little as 15
Figure 134.-The submarine crew's
during recreation periods.
inches, depending on the amount of sag in the
springs and the weight of the occupant. If he is
large he may have to get out of his bunk in order
to turn over. Some top bunks cannot be occupied because of inadequate clearance of pipes
above them. There are often not as many personal lockers as there are bunks, and some of
these are inaccessible; most lack the capacity to
stow adequate personal gear.
A recent welcome innovation is a small individual fluorescent reading lamp, mounted on an
adjustable arm at the head of each bunk.
Studies aboard fleet-type submarines have disclosed ambient noise levels of the order of 75-95
decibels even during submerged operations, the
intensity depending on ship's speed and one's
location in the ship. Increases well over 100
decibels were noted in the control room during the
surfacing procedure; at a time when verbal transmission of information is often crucial, the low
pressure blower noise rendered it difficult for
shouted voices to be heard.
Engine noises, especially those made by the
newer types of diesels, are believed to be immeasurably loud; that is, above 140 decibels. This
degree of loudness exerts at least a temporary
influence on human hearing, sufficient to impair
listening acuity noticeably for hours afterward.
The extent of individual susceptibility is
undetermined, but it is generally accepted that the
upper limit of tolerable noise for the average
person is 130-140 decibels, for short exposure
times. Hearing loss may become permanent with
increased intensities and durations of exposure.
Fortunately, the noise spectrum in the engineroom is peaked at relatively low frequency, which
fortunately is least conducive to auditory deficit
and annoyance. However, it is believed that the
increased incidence of hearing loss among engineroom personnel following years of chronic exposure
to noise may have a traumatic basis.
Noise at all levels has an influence on general
work output. The presence of relatively high
noise levels in all compartments goes almost unnoticed by personnel except in the enginerooms,
probably because it is constant in nature, and
sudden blast-type noises are infrequent. But even
low noise amplitude has a definitely distracting
influence on individuals who are attempting to
concentrate on a job, and more errors seem to
occur in proportion to the increase in noise. Loud
noise causes irritability and tiredness sooner, with
increase in metabolism and muscle tension in
general; sympathetic stimulation is evidenced by
the demonstration in some subjects of decreased
saliva and gastric juice flow, decreased peristalsis,
and slower visual accommodation. It is difficult
to study noise apart from other accompanying
stress factors in submarines, but, beyond doubt,
noise may be considered a stimulus which lowers
the human threshold to other types of stress.
The solution of the noise problem might seem
simple at first glance; merely the attenuation of
noises at their source, the dampening of reverberations in the compartments, and the shielding of
people from noise effects by ear defenders or noise-proof watch stations. There are many obstacles
to all these. It appears that a plateau has been
reached in the muffling of combustion explosions
in the engine by hoods, which must be detachable
and portable if there is to be maintenance of the
engine on board. Compartments were cork-lined
long ago to reduce dripping of water from condensation, which accomplished the secondary
beneficial effect of noise dampening. Ear defenders
at best attenuate noise no more than 10-30
decibels; they offer protection against high frequency noise, but are of relatively little avail
against the engineroom spectrum, which is peaked
at 350-600 cycles per second. Resistance is
encountered to the wearing of all types of ear
defenders; those sailors who think them uncomfortable or inconvenient, or brag of their ability to
withstand the noise manfully, must be educated
and reminded of the need for these devices.
18.7. OTHER HABITABILITY FACTORS
Other items are mentioned here only briefly because they are problems not peculiar to submarines
except as noted, or because they are covered elsewhere. They are still of vital importance to the
welfare of persons living in a submarine.
18.7.1. Food and nutrition.
Overcrowding, confinement, excitement, limited
exercise, and other environmental factors usually
have an effect, but an unpredictable one, upon the
appetites of the crew. There may be decreased
caloric intake because of emotional tension. More
often there is boredom, and eating may serve as
an escape from monotony, a diversion or pastime.
For no reason there may be fads for almost any
type of food, from fudge to sauerkraut; these are
believed to be manifestations of group psychology,
for no physiological basis has been shown to be
responsible for these cravings.
Dietary dissatisfaction of any kind among a
group which is subject to stresses may have an
adverse effect on morale. Though the submarine
service maintains a reputation for the high quality
of its regimen, thanks to the increased subsistence
allowance for submarine rations and to procurement priorities allowed by the supply departments
of bases, the submarine sailor is quick to find fault
with the chow. He may be very finicky at times,
indulging in a socially acceptable way in a rebellion
against his incarceration.
Complements in excess make such demands on
the cold storage facilities of the submarine that
only enough fresh fruits, vegetables, and milk can
be carried to last a few days, and frozen meat for
a few weeks. A casualty to the refrigeration system is a tragedy to morale, but there is a cross
connection between the air-conditioning and refrigeration machines to afford maximum protection
against that eventuality.
18.7.2. Fresh water.
The amount of potable and battery water stored
in the fresh water tanks upon departure from port,
supplemented by the output of two electric vapor
compression distilling units, is designed to render
the fresh water supply of a modern submarine self-sustaining indefinitely, provided restrictions are
placed on quantities used for bathing and laundry.
It is safe to say that the water of condensation,
which precipitates in large amounts on the
evaporator coils of the air-conditioning units and
drains from the drip pans to the bilges or to collecting tanks, can be used for these purposes. It
is also felt that with the taking of certain precautions it is possible to use this condensate water for
any purpose, including cooking and drinking.
The submarine presents problems in sanitation
which are typical of all crowded ships. Air-borne
infections, dermatitides, and contamination of
food and eating utensils must be especially
guarded against. Garbage disposal units of various types have been tried; the currently approved
installation is a tube in the after battery compartment, with inner and outer doors, for discharge
of bags of garbage to sea by air pressure.
Bathing is infrequent on long cruises because of
limited shower and water facilities; this increases
odors and skin disease.
The submarine is well adapted to fumigation for
insects during availability periods at an operating
18.7.4. Ship's motion.
Seasickness is caused by periodic acceleration
on undetermined receptors in the inner ear.
Certain factors as the type of ship and state of the
sea are important, and the fact that most of the
submarine crew are crowded below decks while
the ship is on the surface might be contributory.
The submarine's roll is believed to be gentler in
comparison to surface vessels because of its round
hull and its low transverse metacentric height.
The ship motion is dampened below the surface;
below periscope depth there is almost no sensation of motion except in the presence of violent
seas. An interesting phenomenon which has been
described is the loss of "sea legs" during long
submergence periods, and a greater incidence of
motion sickness upon surfacing than before the
Because of the hazardous nature of undersea
duty, the fundamental principles of safety must
be upheld in the design of submarines and in the
familiarization of the crew with the safety features
of the ship for better handling of emergencies.
There are many "fail-safe" features in the construction of the machinery, and the operation of
almost any mechanical system or apparatus can
be taken over by standby units, cross-connection
of other equipment, or hand operation. It is
possible to isolate compartments and battery
wells in the event of fire, flooding, or chlorine
formation. Oxygen breathing apparatus, fire
extinguishers, battery disconnect switches, magazine and pyrotechnic locker flooding valves, and
internal salvage air lines are available to preserve
the basic habitability of the ship, if the crew is
adequately trained to use them efficiently when
The crowding of many men into a small space
predisposes to high incidence of accidents from
lifting and moving of heavy objects such as torpedoes, from falling down hatches, catching the
hands and feet in doors and hatches, striking the
head on overhead objects, and from stumbling.
In addition, the presence of multiple high voltage
electric circuits, high pressure air lines, small arms,
hot engines and ranges, and powerful hydraulic
equipment makes it necessary that a rigid and
continuous safety campaign be maintained aboard.
18.8. SUBMARINE CLOTHING
In general, the clothing requirements of submarines patrolling in warm climates are not complex. Officers above and below deck wear cotton
khaki trousers and shirt and sometimes in hot
weather wear shorts and short sleeved shirts. Enlisted men wear dungarees which are sometimes
abbreviated into shorts on tropical patrols.
Leather sandals, for wear with or without socks,
are popular. They are comfortable and cool and
by keeping the feet dry tend to curb the hazard
of fungus infection. The soles of these sandals
become slippery sometimes on greasy decks since
they are not made with a nonslip sole. Another
type of everyday footwear is the field shoe. This
is a strong, heavy shoe made of double-tanned
leather with treaded sole and heel, and it becomes
very comfortable with wear.
Officers and men wear regulation naval caps,
although many go bareheaded. The baseball cap
is very popular among those standing bridge
watch. The inner fabricated section of the steel
helmet can be used as a sun helmet and is extremely light and comfortable. During wet
weather, standard issue rain gear may be worn
together with suitable overshoes.
In cold climates and during cold weather in
temperate climates the clothing worn below deck
must be heavier. The clothing requirements in
the various compartments is different. During
cold weather the maneuvering room and the enginerooms
where the diesel engines are operating are
quite comfortable due to the heat given off from
the machinery in those spaces. Other compartments can become quite cool, particularly in the
conning tower when the upper conning tower hatch
is open while on the surface. Electric heaters are
provided in the various compartments, but since
they draw so much current from the batteries,
their use must often be curtailed. The hull which
is in contact with the cold surrounding water
tends to draw heat from the submarine, particularly in those areas of the hull which are not protected by cork. Much moisture may condense on
these cold surfaces and "sweating" results. Sweaters and foul weather jackets are popular and
Army issue wool khaki trousers are often worn
by the officers.
Topside watch standing on a submarine during
very cold weather is very uncomfortable. Standard issue cold weather clothing is considered to be
inadequate for use in the exposed submarine
bridge. This consists primarily of thick, water-resistant trousers which come well above the waist
and are secured by suspenders. A parka type
jacket of the same material which extends to the
midthigh is put on over this. The hood of the
parka has a drawstring to fit it closely about the
face. High buckle type rubber boots are worn
over the shoes. Hand covering is provided by
leather mittens with separate knit woolen liners.
Rubber mittens are also issued but these are not
satisfactory. The sleeves of the jacket are open
at the end and do not fit closely about the wrist.
This type of clothing is quite warm and wind-resistant, but not waterproof. On the exposed
bridge of a submarine it will absorb water and
chill the wearer. Such clothing is very difficult
to dry aboard a, submarine. The footwear is not
adequate to keep the feet warm throughout a
regular watch. It must be borne in mind that
there is relatively little activity of the watchstanders and thus the extremities can become
chilled easily. Aboard the newer type submarines
spray and green water comes over the bridge more
readily than in the fleet type submarine which
has more flare at the bow.
With these factors in mind it becomes obvious
that the modern submarine presents a special
problem in cold weather clothing. Extensive research and experimentation has been done to produce
cold weather clothing which will meet the
peculiar requirements of the modern submarine.
When properly clothed, in the most severe weather,
bridge personnel should remain comfortably warm
and dry to maintain a reasonably long and alert
watch. Since tolerance time for exposure depends
primarily upon the rapid cooling of the hands and
feet, adequate protection of the hands and feet is
fundamental. Design of the clothing must be
practical, tailoring neat, with a minimum of bulk,
to facilitate rapid and easy clearance of the bridge
and easy stowing of the garments. Quality of the
material must incorporate a minimum of weight
and bulk and a maximum of durability, practicability and safety. The garment should have rapid
drying qualities, and to be effective the outfit
should be waterproof, wind resistant, roomy
enough to permit wearing of cold-resistant undergarments, and yet nonrestrictive to necessary
movements. It may have safety measures incorporated-for example, a life preserver in case the
man is washed overboard.
Such a garment has been designed and tested
and in the near future it will become available for
issue to all submarines (figs. 135, 136, and 137).
The garment is a zippered coverall made of waterproofed nylon fabric, in a dull olive green color.
The hood and vest have been combined into a
unit, made of the same material as the suit and
colored yellow. The face opening of the hood is
lined with sponge rubber and the vest secured
with one strap around the waist. The mittens are
Figure 135.-Submarine cold weather gear-component parts laid out.
Figure 136.-Submarine cold weather gear as worn-
Figure 137.-Submarine cold weather gear as worn-
of the ambidexterous, single fingered type, made
of rubber and designed to be worn over standard
woolen mittens, and long enough to be pulled over
a rubber ring in the suit's cuff to establish a waterproof seal at this point. The short boots with
improved traction treads are of the vapor barrier
type constructed with a flexible steel ring at the
top which provides the tension for watertight
seal with the rubber bottoms of the suit leg. They
are designed to be worn without shoes and with a
single pair of light socks. This submarine exposure
suit has received enthusiastic reception by those
using it during cold weather operations. It is
apparent, however, that the gloves need further
improvement in order to be entirely satisfactory.
The boots receive the greatest praise of all in that
one can stand a long watch and maintain complete
foot comfort throughout the watch.
18a. ComOpDevFor: Habitability in the U. S. Navy; 12
18b. DUFF, IVAN F., A Medical Study of the Experiences of
Submarines as Recorded in 1,471 Submarine Patrol
Reports in World War II, BuMed (confidential).
18c. Nay Med P-126 (Rev 1949): Manual of Naval Hygiene
and Sanitation, Vol. 1, Chapters 1, 3, and 6.
18d. National Research Council, Committee on Undersea
Warfare: Human Factors in Undersea Warfare,
18e. Medical Research Laboratory, New London: Report
No. 131, HARRIS, J. D. and STOVER, A. D.: Noise
Levels Aboard a Fleet Submarine, 1948.
18f. MRL Report No. 181, SCHAEFER, K. E.: Studies of
Carbon Dioxide Toxicity: (1) Chronic CO2 Toxicity
in Submarine Medicine, 10: 156-76, 1951.
18g. MRL Report No. 197, KINSEY, JACK L.: Observations
on the Habitability of Submarines in Northern
Waters, 11: No. 14, 1952.
18h. MRL Report No. 209, FARNSWORTH, DEAN: Developments in Submarine and Small Vessel Lighting, 11:
No. 26, 1952.
18i. YAGLOU, C. P., Thermal Standards in Industry Year
Book, Part 2, Amer. J. of Public Health 40: 131,
18j. BuShips Manual, Chap. 38: Ventilation and Heating.
18k. USN Electronics Laboratory, San Diego, Human
Engineering Guide for Equipment Designers, Human
Factors Division, Human Engineering Section,
18l. NavPers 16160: The Fleet Type Submarine, 1946.
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