THE MODERN SUBMARINE
Holland and Lake must be considered the fathers of the modern
submarine. This claim is not made in a spirit of patriotic
boastfulness, though, of course it is true that the latter was an
American by birth, and the former by choice, and that, therefore,
we, as a nation, have a right to be proud of the accomplishments of
these two fellow-citizens of ours. Without wishing to detract
anything from the value of the work done by many men in many
countries towards the development of the submarine after and
contemporaneously with Holland and Lake, it still remains true that
the work which these two did formed the foundation on which all
others built. To-day, no submarine worthy of the name, no matter
where it has been built and no matter where and how it is used, is
without some features which are typical of either the Holland or
Lake type. In many instances, and this is true especially of
submarines of the highest type and the greatest development, the
most significant characteristics of the Holland and Lake boats have
been combined.
During the years that followed the small beginnings of Holland and
Lake, vast and highly efficient organizations have been built up to
continue and elaborate their work. Death claimed Mr. Holland shortly
after the outbreak of the great war, on August 12, 1914. Mr. Lake in
1917 was still personally connected with and the guiding spirit of
the extensive industrial establishments which have been created at
Bridgeport, Conn., as a result of his inventions. He, too,
surrounded himself with a corps of experts who in co-operation with
him have brought the Lake submarines to a point of perfection which
at the time of the _Argonaut's_ first trip would have appeared all
but impossible.
Roughly speaking, the beginning of the twentieth century may be called
the turning point in the history of submarine invention and the
beginning of the modern submarine. Although, as we have heard, various
governments, especially those of France and the United States,
interested themselves in the submarine question and appropriated
small sums of money towards its solution previous to 1900, it was only
after that year that governmental interest and influence were set to
work with determination and purpose on behalf of submarine inventors.
Quite naturally this resulted in increased popular interest.
Experimental work on and with submarines no longer had to rely
exclusively on private capital, frequently inconveniently timid and
limited, but could count now on the vast financial resources of all
the great nations of the world. This also made available the unlimited
intellectual resources of serious scientists in every part of the
universe. Mechanical and electrical engineers, naval designers and
constructors, active men of finance and business, and quiet thinkers
and investigators in laboratories began to interest themselves in the
further development of the submarine.
The United States for a number of years after its adoption of the
Holland type remained true to its first choice. Between 1900, when
the first Holland boat was bought by the United States Government,
and 1911 all the United States submarine, boats were of the Holland
type. In the latter year, however, it was decided to give the Lake
boat a trial and since that time a number of boats of this type have
been built. In all essential features both the Holland and Lake
boats of later days were very similar to the original boats of these
two types. In all the details, however, immense progress was made.
Each new boat thus became greatly superior to its predecessors. This
was especially true in regard to size and speed and the improvements
made in these two respects naturally resulted in a corresponding
increase in radius of activity. The passing years also brought a
wonderful refinement of all the technical details of the submarine
boats. Practically every feature was developed to a remarkable
degree. There is, indeed, a great difference between the submarine
boats of the early twentieth century which had to rely on their
conning-tower for steering, and more recent boats with their
wonderful periscopes and gyro compasses. Similar progress was made
in the development of the means of propulsion. The engines used for
surface travelling became more powerful and efficient. This was also
true of the electric motors, batteries, and accumulators employed
in the submerged state. The problem of ventilation likewise has been
worked out to such an extent that in the most modern submarines most
of the inconveniences experienced by the crews of earlier boats have
been removed. This perfection of technical details which was thus
gradually approached also permitted a very considerable increase in
the fighting power of submarine boats. The number of torpedo tubes
was increased and it became possible to carry a larger reserve stock
of torpedoes. Submarines of to-day furthermore carry guns varying in
calibre, attaining in some instances four inches, and when in later
years it became evident that one of the most dangerous enemies of
the submarine was the airplane, some of the boats were equipped even
with anti-aircraft guns.
[Illustration: Copyright by Munn & Co., Inc. From the _Scientific
American_.
_Modern German Airplane Types._]
In the United States Navy the submarine has never been popular.
Indeed it is by no means certain that in comparison with other
navies of the world the United States was not better off in
underwater boats in 1911 than she was three years later when the
warcloud broke. The bulk of our naval opinion has always been for
the dreadnoughts. A change of political administration at Washington
in 1912 gave a temporary setback to naval development, and the
submarines, being still a matter of controversy, languished. Few
were built and of those few many showed such structural weakness
that the reports of their manoeuvres were either suppressed, or
issued in terms of such broad generality that the public could by no
possibility suspect, what all the Navy knew to be the fact, that the
submarine flotilla of the United States was weak to the point of
impotence.
Happily we had nearly three years in which to observe the progress
of the war before becoming ourselves embroiled in it. During this
period our submarine fleet was somewhat increased, and upon our
actual entrance upon the struggle a feverish race was begun to put
us on an equality with other nations in underwater boats. It would
have been too late had any emergency arisen. But Germany had no
ships afloat to be attacked by our submarines had we possessed them.
Her own warfare upon our merchant shipping could not be met in kind,
for submarines cannot fight submarines. We have, therefore, up to
the present time, not suffered from the perilous neglect with which
we long treated this form of naval weapon.
Indeed the submarine fleet of the United States Navy at the
beginning of the war was so inconsiderable that foreign writers on
the subject ignored it. In 1900 we had purchased nine of the type of
submarines then put out by the Holland Company. One of these, the
first in actual service, known as the "Baby" Holland was kept in
commission ten years and upon becoming obsolete was honoured by
being taken in state to the Naval Academy at Annapolis and there
mounted on a pedestal for the admiration of all comers. She was 59
feet long and would make a striking exhibit placed next to one of
the new German submersible cruisers which exceed 300 feet and have a
displacement of 5000 tons. These first Holland ships which long
constituted the entire underwater force of the United States were
but trivial affairs compared with the modern vessel. Their
displacement was but 122 tons, their engines for surface navigation
were of 160 horse-power, gasoline, and for underwater navigation 70
horse-power, electric. They carried but one torpedo tube and two
extra torpedoes and had a radius of action of but 300 miles. At that
time in fact the naval theory was that submarines were coast defence
vessels altogether. After this war they are likely to form part of
the first battle line of every navy. Yet these pioneer vessels
established their seaworthiness well in 1911, when four of them
accompanied by a parent ship to supply them with fresh stocks of
fuel and to render assistance in case of need, crossed the Pacific
Ocean under their own power to the Philippines. This exploit tended
to popularize these craft in the Navy Department, and soon after
larger vessels known as the "Viper" class were ordered. One of these
was called the _Octopus_, the first submarine to be fitted with twin
screws. In many ways she represented a distinct advance in the art
of submarine construction. She was in fact the first vessel built
with the distinct idea of being a cruising, as well as a harbour
defence ship. Her type proved successful in this respect. The
_Octopus_ further established a record for deep sea submergence in
1907 when she descended to a depth of 205 feet off Boston, returning
to the surface in entire safety.
The ability to withstand the pressure of the water at great depths
is a vital quality of a successful submarine. One American submarine
narrowly escaped destruction because of structural weakness in this
respect. She had by accident descended a few feet below the normal
depth at which such boats navigate. The water pressure affected the
valves which refused to work and the vessel slowly sank deeper and
deeper. At a recorded depth of 123 feet the sinking of the vessel
became so much more rapid that the crew with frantic endeavours
sought at once to stop the leaks and pump out the water which had
entered. At that depth there was a pressure of 153-1/2 pounds upon
every square inch of the surface of the submarine. This the workers
at the one hand pump had to overcome. It was a savage and a
desperate struggle but the men finally won and the vessel regained
the surface. As a result of this experience every navy prescribed
submergence tests for its submarines before putting them into
commission. How to make these tests was perplexing at first. A
government did not want to send men down in a steel casket to see
just how far they could go before it collapsed. But if no observer
accompanied the ship it would be impossible to tell at what depth
leakage and other signs of weakness became apparent. An Italian
naval architect, Major Laurenti, whose submarines are now found in
every navy of the world, invented a dock in which these tests can be
made up to any desired pressure while the observers inside the
submarine are in communication with those without and the pressure
can be instantly removed if signs of danger appear. In the United
States Navy boats to be accepted must stand a pressure equivalent to
that encountered at 200 feet. In the German navy the depth
prescribed is 170 feet. Under normal conditions submarines seldom
travel at a depth of more than 100 feet although the "F-1" of the
United States Navy accomplished the remarkable feat of making a
six-hour cruise in San Francisco Bay at a depth of 283 feet. At this
depth the skin of the ship has to withstand a pressure of no less
than 123 pounds per square inch.
Specific information as to the nature of submarine construction in
the United States since the beginning of the war in 1914 is
jealously guarded by the Navy Department. In broad general terms the
number of ships under construction is revealed to the public, but
all information as to the size of individual vessels, their armour
or the qualities of novelty with which every one hopes and believes
American inventive genius has invested them, are kept secret. The
_Navy Year Book of 1916_ summarized our submarine strength at that
time as follows:
_Displacement_
Submarines fit for action 42 15,722 Tons
" under construction 33 21,093 "
" authorized and appropriated
for 30 22,590 "
--- ------
Total 105 59,405 "
In addition thirty-seven more had been authorized by Congress
without the appropriation of money for them. By this time however
these appropriations have been made together with further heavy
ones. While figures are refused at the Navy Department, it is
declared that while the United States in 1914 was the last of the
great powers in respect to submarine strength provided for, it is
now well up to the foremost, even to Germany.
Great Britain like the United States continued for many years to
build submarines of the Holland type. Naturally all the recent
improvements were incorporated in the British boats. Very little,
however, is known concerning the details of the more recent
additions to the British submarine flotilla because of the secrecy
maintained by the British authorities in war time.
At the beginning of the present war, the British navy possessed 82
active submarines of 5 different classes. They were all of the
Holland type, but in each class there were incorporated vast
improvements over the preceding class. Displacement, size, motive
power, speed, radius of action, and armament were gradually
increased until the "E" class contained boats possessing the
following features: Submerged displacement, 800 tons; length 176
feet; beam 22-1/2 feet; heavy oil engines of 2000 H.-P.; electric
engines of 800 H.-P.; surface speed 16 knots; submerged speed 10
knots; cruising range 5000 miles; armament: 4 torpedo tubes, space
for 6 torpedoes, and two 3-inch quick-firing, high-angle,
disappearing guns; armoured conning-towers and decks; wireless
equipment; 3 panoramic periscopes.
At the same time 22 other submarines were said to be in course of
construction. Some of these were of the "F" class (Holland type),
similar to the "E" class except that every single characteristic had
been greatly increased, in many instances even doubled. In addition
to the "F" class Holland-type boats, there were also under
construction a number of boats of different types designated
respectively as "V," "W," and "S" class. The "V" class were of the
Lake type, the "W" of the French "Laubeuf" type, and the "S" class
of the Italian "F. I. A. T." or Laurenti type; both of the last
named were adaptations of the Lake type.
France, which was for many years the prodigal of the nations when it
came to submarine building has continued this tendency. In a way
this liberal expenditure of money did not pay particularly well.
For, although it resulted in the creation of a comparatively large
submarine fleet, this fleet contained boats of every kind and
description. Quite a number of the boats were little more than
experiments and possessed not a great deal of practical value. The
manning and efficient handling of a fleet having so little
homogeneity naturally was a difficult matter and seriously
restricted its fighting efficiency.
At the outbreak of the war France had 92 submarines in active
service, belonging to 12 different classes. In addition there had
also been built at various times 5 experimental boats which had been
named: _Argonaute_, _Amiral Bourgeoise_, _Archimède_, _Mariotte_,
and _Charles Brun_. The majority of the boats belonging to the
various classes were of the Laubeuf type, an adaptation of the Lake
type made for the French navy by M. Laubeuf, a marine engineer. In
their various details these boats vary considerably. Their
displacement ranges from 67 tons to 1000 tons, their length from 100
feet to 240 feet, their beam from 12 feet to 20 feet, their surface
speed from 8-1/2 knots to 17 1/2 knots, their submerged speed from 5
knots to 12 knots, the horse-power of their heavy oil engines from
1300 to 2000 and that of their electric motors from 350 to 900. Some
of the boats, however, have steam engines, others gasoline motors,
and still others steam turbines. The cruising range of the biggest
and newest boats is 4000 miles. Armament varies with size, of
course, the latest boats carrying 4 torpedo tubes for eight 18-inch
torpedoes and two 14-pdr. quick-firing, high angle, disappearing
guns.
Nine more submarines were in course of construction at the outbreak
of war, most of which were of the improved "Gustave Zédé" class.
During the war French shipyards were chiefly occupied with capital
navy ships and it is not thought the submarine strength has been
much increased.
Of the great naval powers, Germany was, strangely enough, the last to
become interested in the building of a submarine fleet. This, however,
was not due to any neglect on the part of the German naval
authorities. It is quite evident from the few official records which
are available that they watched and studied very carefully the
development of the submarine and growth of the various submarine
fleets. During the early years of the twentieth century, however, the
Germans seemed to think that most of the boats that were being built
then had not yet passed through the experimental stage and they also
apparently decided that it would be just as well to wait until other
nations had spent their money and efforts on these quasi experimental
boats. Not until submarines had been built in the United States,
England, and France which had proved beyond all doubt that they were
practicable vessels of definite accomplishments, did the Germans
seriously concern themselves with the creation of a German submarine
fleet. When this period had been reached they went ahead with full
power, and with the usual German thoroughness they adopted the best
points from each of the various types developed by that time. The
result of this attitude was a submarine boat built at first
exclusively by Krupp and known as the "Germania" type. It was this
type which formed the basis of the German submarine which has become
known so extensively and disastrously during recent years. In most
respects this type is perhaps more similar to the Lake type than to
any other, although some features of the Holland type have been
incorporated as well.
At the beginning of the war Germany was credited with only thirty
submarines. Six more were then rapidly approaching completion and
the German naval law passed some time before provided for the
building of seventy-two submarines by the end of 1917. It is
believed in fact that by that time the Germans had not less than two
hundred _Unterseeboots_.
From the very beginning the Germans have designated their submarines
by the letter "U" (standing for _Unterseeboot_) followed by numbers.
The first boat was built in 1905 and was named "U-1." It was a
comparatively small boat of 236 tons displacement. The motive power
on the surface was a heavy-oil engine of 250 H.-P. Under water the
boat was driven by electric motors of a little more than 100 H.-P.
Submerged the "U-1" was capable of a speed of 7 knots only, which on
the surface of the water could be increased to 10. Her radius of
action was about 750 miles. Only one torpedo tube had been provided.
[Illustration: © U. & U.
_German Submarine Mine-Layer Captured by the British._]
From this boat to the modern German submarine was indeed a long step
taken in a comparatively short time. Not very much is known
regarding modern German submarines, but the latest boats completed
before the war were vessels of 900 tons displacement with heavy-oil
engines of 2000 H.-P. and electric motors of 900 H.-P., possessing a
surface and submerged speed of 18 and 10 knots respectively and a
cruising radius of 4000 miles. They had four torpedo tubes for eight
torpedoes, two 14-pdr. quick-firing guns, and two 1-pdr. high-angle
anti-aircraft guns. Naturally they were also equipped with all the
latest improvements, such as wireless apparatus, panoramic
periscopes, armoured conning-towers, and decks. Since the outbreak
of the war the Germans have built even more powerful submarine boats
whose perfections in regard to speed, radius of action and armament
became known through their accomplishments. Of these we will hear
more in a later chapter.
At just what period of the war the Germans woke up to the vital
importance to them of an enormous submarine fleet is not known. It
may have been immediately upon the amazing exploit of Captain
Weddigen in the North Sea. At any rate the war had not long
progressed before the destruction caused by German submarine attacks
began to awaken the apprehension of the Allies and neutral nations.
Retaliation in kind was impossible. The Germans had neither
merchant nor naval ships at sea to be sunk. The rapidity with which
the volume of the loss inflicted upon merchant shipping grew
indicated an equally rapid increase in the size of the German
underwater fleet. Neutrals were enraged by the extension by the
Germans of the areas of sea in which they claimed the right to sink
neutral ships, and their growing disregard for the restraining
principles of international law. How greatly they developed the
submarine idea was shown by their construction in 1916 of vessels
with a displacement of 2400 tons; a length of 279 feet, and a beam
of 26 feet; a surface speed of 22 knots, cruising radius of 6500
miles, mounting 4 to 8 guns and carrying a crew of from 40 to 60.
But it was reported that two vessels designed primarily for surface
cruising, but nevertheless submersible at will, had been laid down
of 5000 tons, a length of 414 feet, and a radius of 18,000 to 20,000
miles. These "submersible cruisers" as they were called, mounted 6
to 8 guns, 30 torpedo tubes, and carried 90 torpedoes. What part
vessels of this type shall play in war is still to be determined.
Of the smaller naval powers, Italy comparatively early had become
interested in the building of submarines. Most of her boats are of
the Laurenti type--which is a very close adaptation of the Lake
type. Russia and Japan, especially the latter, built up fairly
efficient underwater fleets. The lesser countries, like Austria,
Holland, Sweden, Denmark, Norway, and Spain have concerned
themselves seriously with the creation of submarine fleets. The
submarine boats of all of these countries in most instances were
either of the Lake or Holland type though frequently they were built
from plans of English, French or German adaptations rather than in
accordance with the original American plans.
The exact number of submarines possessed now by the various navies
of the world is a matter of rather indefinite knowledge. Great
secrecy has been maintained by every country in this respect. From a
variety of sources, however, it has been possible to compile the
following list which at least gives an approximate idea of the
respective strength of the various submarine fleets at the beginning
of the war. The numbers assigned to each country are only
approximate, however, and include both boats then in existence or
ordered built: United States 57; Great Britain 104; France 92;
Germany 36; Italy 28; Russia 40; Japan 15; Austria 12; Holland 13;
Denmark 15; Sweden 13; Norway 4; Greece 2; Turkey 2; Brazil 3; Peru
2.
Having traced the development of the submarine from its earliest
beginnings to recent times we are naturally now confronted with the
question "What are the principal requirements and characteristics of
the modern submarine?"
The submarine boat of to-day, in order to do its work promptly and
efficiently, must first of all possess seaworthiness. This means
that no matter whether the sea is quiet or rough the submarine must
be able to execute its operations with a fair degree of accuracy and
promptness and must also be capable of making continuous headway.
Surface and underwater navigation must be possible with equal
facility and it is necessary that a state of submergence can be
reached without loss of time and without any degree of danger to the
boat's safety. At all times, travelling above water or below, the
submarine must possess mechanical means which will make it possible
to control its evolutions under all conditions. Furthermore, the
ability of the submarine to find and to observe objects in its
vicinity must not be greatly reduced when it is in a submerged
position. In the latter it also becomes of extreme importance that
the provisions for ventilation are such that the crew of the
submarine should lose as little as possible in its efficiency and
comfort. A fair amount of speed both on and below the surface of the
water is essential and the maintenance of the speed for a fairly
long period of time must be assured.
In regard to their general outward appearance, submarines of various
types to-day vary comparatively little. In many respects they
resemble closely in shape, torpedo boats--the earlier submarines
particularly. In size, of course, they differ in accordance with the
purposes for which they have been designed. As compared with earlier
submarines the most notable difference is that modern submarines
possess more of a superstructure. Almost all of them are built now
with double hulls. The space between the outer and the inner hull is
utilized primarily for ballast tanks by means of which submergence
is accomplished and stability maintained and regulated. Some of
these tanks, however, are not used to carry water ballast, but serve
as reservoirs for the fuel needed by the engines. The stability of
the submarine and the facility with which it can submerge also
depend greatly on the distribution of weight of its various parts.
This problem has been worked out in such a way that to-day there is
little room for improvement. Its details, however, are of too
technical a nature to permit discussion in this place.
Hydroplanes both fore and aft are now generally used to assist in
regulating and controlling stability in the submerged state. The
motive power of the modern submarine is invariably of a two-fold
type. For travelling on the surface internal combustion engines are
used. The gasoline engine of former years has been displaced by
Diesel motors or adaptations of them. Although these represent a
wonderful advance over the engines used in the past there is still a
great deal of room for improvement. The opinions of engineers in
this respect vary greatly, American opinion being generally
unfavourable to the Diesel type, and whether the final solution of
this problem will lie in the direction of a more highly developed
motor of Diesel type, of an improved gasoline engine, or of some
other engine not yet developed, only the future can tell. Simplicity
of construction and reliability of operation are the two essential
features which must be possessed by every part of the power plant of
a submarine. For underwater travel electric motors and storage
batteries are employed exclusively. These vary, of course, in
detail. In principle, however, they are very much alike. Although
this combination of electric and oil power is largely responsible
for having made the submarine what it is to-day, it is far from
perfect. Mechanical complications of many kinds and difficulties of
varying degrees result from it. Up to comparatively recently these
were considered insurmountable obstacles. But engineers all over the
world are giving their most serious attention to the problem of
devising a way to remove these obstacles and continuous progress is
made by them.
As an immediate result of the development of motive power in the
submarine its speed both on and below the surface of the water as
well as its radius of action has been materially increased. To-day
submarines travel on the water with a speed which even a few years
ago would have been thought quite respectable for the most powerful
battleships or the swiftest passenger liners. And even under water,
submarines attain a velocity which is far superior to that of which
earlier submarines were capable on the surface of the water. How
immensely extended the radius of action of the submarine has become
in recent years, has impressed itself on the world especially in the
last few years. Both English and French submarines have travelled
without making any stops from their home ports to the Dardanelles
and back again. And used to, and satiated as we are with mechanical
wonders of all kinds the whole world was amazed when in 1916 German
submarines made successful trips from their home ports to ports in
the United States and returned with equal success. This meant a
minimum radius of action of 3500 miles. In the case of the German
U-boat which in 1916 appeared at Newport for a few hours, then
attacked and sank some merchantmen off the United States coast and
later was reported as having arrived safely in a German port, it has
never been established whether the boat renewed its supplies of food
and fuel on the way or carried enough to make the trip of some 7000
miles.
One other important feature without which submarines would have
found it impossible to score such accomplishments is the periscope.
In the beginning periscopes were rather crude appliances. They were
very weak and sprung leaks frequently. Moisture, formed by
condensation, made them practically useless. In certain positions
the image of the object picked up by the periscope became inverted.
Their radius of vision was limited, and in every way they proved
unreliable and unsatisfactory. But, just as almost every feature of
submarine construction was gradually developed and most every
technical obstacle overcome, experts gradually concentrated their
efforts on the improvement of periscopes. Modern periscopes are
complicated optical instruments which have been developed to a very
high point of efficiency. A combination of prisms and lenses makes
it possible now to see true images clearly. Appliances have been
developed to make the rotation of the periscope safe, prompt, and
easy so that the horizon can be swept readily in every direction.
Magnification can be established at will by special devices easily
connected or disconnected with the regular instrument. The range of
vision of the modern periscope is as remarkable as its other
characteristics. It differs, of course, in proportion to the height
to which the periscope is elevated above the surface of the water.
In clear weather a submarine, having elevated its periscope to a
height of 20 feet can pick up a large battleship at as great a
distance as 6 miles, while observers on the latter, even if equipped
with the most powerful optical instruments, are absolutely unable to
detect the submarine. This great distance is reduced to about 4000
yards if the periscope is only 3 feet above the surface of the water
and to about 2200 yards if the elevation of the periscope is 1 foot.
But even the highly developed periscope of to-day, usually called
"panoramic periscope," has its limitations. The strain on the
observer's eyes is very severe and can be borne only for short
periods. In dirty weather the objectives become cloudy and the
images are rendered obscure and indefinite, although this trouble
has been corrected, at least in part, by forcing a strong blast
through the rim surrounding the observation glass. At night, of
course, the periscope is practically useless. Formerly a shot which
cut off the periscope near the water's edge might sink the boat.
This has been guarded against by cutting off the tube with a heavy
plate of transparent glass which does not obstruct vision but shuts
off the entrance of water.
Important as the periscope is both as a means of observing the
surroundings of the submarine and as a guide in steering it, it is
not the only means of accomplishing the latter purpose. To-day every
submarine possesses the most reliable type of compass available. At
night when the periscope is practically useless or in very rough
weather, or in case the periscope has been damaged or destroyed,
steering is done exclusively by means of the compass. The latest
type in use now on submarines is called the gyroscope compass which
is a highly efficient and reliable instrument.
[Illustration: Permission of _Scientific American_.
_The Exterior of First German Submarine._]
In the matter of ventilation the modern submarine also has reached a
high state of perfection. The fresh air supply is provided and
regulated in such a manner that most of the discomforts suffered by
submarine crews in times past have been eliminated. The grave danger
which formerly existed as a result of the poisonous fumes, emanating
from the storage batteries and accumulators, has been reduced to a
minimum. In every respect, except that of space, conditions of life
in a submarine have been brought to a point where they can be
favourably compared with those of boats navigated on the surface of
the water. Of course, even at the best, living quarters in a
submarine will always be cramped. However, it is so important that
submarine crews should be continuously kept on a high plane of
efficiency that they are supplied with every conceivable comfort
permitted by the natural limitations of submarine construction.
[Illustration: Permission of _Scientific American_.
_The Interior of First German Submarine. Showing Appliances for
Man-Power._]
Submarine boats so far have been used almost exclusively as
instruments of warfare. One of their most important features,
therefore, naturally is their armament. We have already heard
something about the use of torpedoes by submarines. The early
submarines had as a rule only one torpedo tube and were incapable of
carrying more than two or three torpedoes. Gradually, however, both
the number of torpedo tubes and of torpedoes was increased. The
latest types have as many as eight or ten tubes and carry enough
torpedoes to permit them to stay away from their base for several
weeks. In recent years submarines have also been armed with guns.
Naturally these have to be of light weight and small calibre. They
are usually mounted so that they can be used at a high angle. This
is done in order to make it possible for submarines to defend
themselves against attacks from airships. The mountings of these
guns are constructed in such a way that the guns themselves
disappear immediately after discharge and are not visible while not
in use. Though mounted on deck they are aimed and fired from below.
As part of the armament of the submarine we must also consider the
additional protection which they receive from having certain
essential parts protected by armour plate.
All these features have increased the safety of submarine navigation
to a great extent. In spite of the popular impression that submarine
navigation entailed a greater number of danger factors than
navigation on the surface of the water, this is not altogether so.
If we stop to consider this subject we can readily see why rather
the opposite should be true. Navigation under the surface of the
water greatly reduces the possibility of collision and also the
dangers arising from rough weather. For the results of the latter
are felt to a much lesser degree below than on the surface of the
water. Many other factors are responsible for the comparatively high
degree of safety inherent in submarines. Up to the outbreak of the
present war only about two hundred and fifty lives had been lost as
a result to accidents to modern submarines. Considering that up to
1910 a great deal of submarine navigation was more or less
experimental this is a record which can bear favourable comparison
with similar records established by overwater navigation or by
navigation in the air.
To the average man the thought of imprisonment in a steel tube
beneath the surface of the sea, and being suddenly deprived of all
means of bringing it up to air and light is a terrifying and nerve
shattering thing. It is probably the first consideration which
suggests itself to one asked to make a submarine trip. Always the
newspaper headlines dealing with a submarine disaster speak of those
lost as "drowned like rats in a trap." Men will admit that the
progress of invention has greatly lessened the danger of accident to
submarines, but nevertheless sturdily insist that when the accident
does happen the men inside have no chance of escape.
As a matter of fact many devices have been applied to the modern
submarine to meet exactly this contingency. Perhaps nothing is more
effective than the so-called telephone buoy installed in our Navy
and in some of those of Europe. This is a buoy lightly attached to
the outer surface of the boat, containing a telephone transmitter
and receiver connected by wire with a telephone within. In the event
of an accident this buoy is released and rises at once to the
surface. A flag attached attracts the attention of any craft that
may be in the neighbourhood and makes immediate communication with
those below possible. Arrangements can then be made for raising the
boat or towing her to some point at which salvage is possible. An
instance of the value of this device was given by the disaster to
the German submarine "U-3" which was sunk at Kiel in 1910. Through
the telephone the imprisoned crew notified those at the other end
that they had oxygen enough for forty-eight hours but that the work
of rescue must be completed in that time. A powerful floating
derrick grappled the sunken submarine and lifted its bow above
water. Twenty-seven of the imprisoned crew crept out through the
torpedo tubes. The captain and two lieutenants conceived it their
duty to stay with the ship until she was actually saved. In the
course of the operations one of the ventilators was broken, the
water rushed in and all three were drowned.
In some of the Holland ships of late construction there is an
ingenious, indeed an almost incredible device by which the ship
takes charge of herself if the operators or crew are incapacitated.
It has happened that the shock of a collision has so stunned the men
cooped up in the narrow quarters of a submarine that they are for
quite an appreciable time unable to attend to their duties. Such a
collision would naturally cause the boat to leak and to sink. In
these newer Holland ships an automatic device causes the ship, when
she has sunk to a certain depth, registered of course by automatic
machinery, to start certain apparatus which empties the ballast
tanks and starts the pumps which will empty the interior of the ship
if it has become flooded. The result is that after a few minutes of
this automatic work, whether the crew has sufficiently recovered to
take part in it or not, the boat will rise to the surface.
This extraordinary invention is curiously reminiscent of the fact
chronicled in earlier chapters of this book that the most modern
airplanes are so built that should the aviator become insensible or
incapacitated for his work, if he will but drop the controls, the
machine will adjust itself and make its own landing in safety.
Unaided the airplane drops lightly to earth; unaided the submarine
rises buoyantly to the air.
In recent years there have been developed special ships for the
salvage of damaged or sunk submarines. At the same time the navies
of the world have also produced special submarine tenders or mother
ships. The purpose of these is to supply a base which can keep on
the move with the same degree of facility which the submarine itself
possesses. These tenders are equipped with air compressors by means
of which the air tanks of submarines can be refilled. Electric
generators make it possible to replenish the submarine storage
batteries. Mechanical equipment permits the execution of repairs to
the submarine's machinery and equipment. Extra fuel, substitute
parts for the machinery, spare torpedoes are carried by these
tenders. The most modern of them are even supplied with dry dock
facilities, powerful cranes, and sufficiently strong armament to
repel attacks from boats of the type most frequently encountered by
submarines.
There are, of course, many other special appliances which make up
the sum total of a modern submarine's equipment. Electricity is used
for illuminating all parts of the boat. Heat is supplied in the same
manner; this is a very essential feature because the temperature of
a submarine, after a certain period of submergence, becomes
uncomfortably low. Electricity is also used for cooking purposes.
Every submarine boat built to-day is equipped with wireless
apparatus. Naturally it is only of limited range varying from one
hundred and twenty to one hundred and eighty miles, but even at that
it is possible for a submarine to send messages to its base or some
other given point from a considerable distance by relay. If the
submarine is running on the surface of the water the usual means of
naval communication-flag signals, wig-wagging or the semaphore, can
be employed. The submarine bell is another means for signalling. It
is really a wireless telephone, operating through the water instead
of the air. Up to the present, however, it has not been sufficiently
developed to permit its use for any great distance. It is so
constructed that it can also be used as a sound detector.
Some submarines, besides being equipped with torpedo tubes, carry
other tubes for laying mines. In most instances this is only a
secondary function of the submarine. There are, however, special
mine-laying submarines. Others, especially of the Lake type, have
diving compartments which permit the employment of divers for the
purpose of planting or taking up mines.
Disappearing anchors, operated by electricity from within the boat,
are carried. They are used for steadying the boat if it is desired
to keep it for any length of time on the bottom of the sea in a
current.
From this necessarily brief description it can be seen readily that
the modern submarine boat is a highly developed, but very
complicated mechanism. Naturally it requires a highly trained,
extremely efficient crew. The commanding officers must be men of
strong personality, keen intellect, high mechanical efficiency, and
quick judgment. The gradual increase in size has brought a
corresponding increase in the number of a submarine's crew. A decade
ago from 8 to 10 officers and men were sufficient but to-day we hear
of submarine crews that number anywhere from 25 to 40.
In spite of the marvellous advances which have been made in the
construction, equipment, and handling of the submarine during the
last ten years, perfection in many directions is still a long way
off. How soon it will be reached, if ever, and by what means, are,
of course, questions which only the future can answer.