TRANSCRIBER'S NOTE
Italic text is denoted by _underscores_.
Bold text is denoted by =equal signs=.
The oe ligature has been replaced by 'oe'.
Obvious typographical and punctuation errors have been corrected
after careful comparison with other occurrences within the text and
consultation of external sources.
More detail can be found at the end of the book.
THE SUBMARINE IN WAR AND PEACE
[Illustration: (Frontispiece; Simon Lake)]
THE SUBMARINE IN WAR AND PEACE
ITS DEVELOPMENTS AND ITS POSSIBILITIES
BY
SIMON LAKE, M.I.N.A.
_WITH 71 ILLUSTRATIONS
AND A CHART_
PHILADELPHIA AND LONDON
J. B. LIPPINCOTT COMPANY
1918
COPYRIGHT, 1918, BY J. B. LIPPINCOTT COMPANY
PRINTED BY J. B. LIPPINCOTT COMPANY
AT THE WASHINGTON SQUARE PRESS
PHILADELPHIA, U. S. A.
DEDICATED
TO
LEBBEUS B. MILLER
OF ELIZABETH, NEW JERSEY
An honest and patriotic man, who took up a poor young man, and
who, through his thorough grasp of things mechanical, was among
the first to see practical possibilities in the dreams of a young
inventor. With his financial means he was able to assist materially
in the development and perfection of an important weapon for the
defence of his country, thus rendering a valuable service to the
nation.
Without his assistance much of the development work described in
this volume would have been impossible of accomplishment.
No greater tribute can be paid to him than to remark of him that
he is one--and there are but few of whom this may be said--who has
steadfastly refused to take advantage of conditions which offered
him the opportunity to increase his personal fortune at the expense
of other individuals or of the welfare of his country.
FOREWORD
Some twenty years ago the author began to collect data with the idea
of publishing a book on the submarine at a future time. There was very
little information concerning submarines available at that date, as the
early experiments in this field of navigation were generally conducted
in secrecy. There had been constructed, up to that time, no submarine
vessel which was entirely successful, and for this reason inventors and
designers were disinclined to reveal the features of the vessels upon
which they were experimenting.
Since then there has been considerable dissemination of facts about
the submarine; much of this knowledge has found its way into print,
some in short historical sketches published by the author and other
designers. However, most of the publications on this subject have come
from the hands of professional writers and newspaper men, some of whom
have not had the engineering knowledge to sift the practical from the
impractical, and who have not had any actual first-hand acquaintance
with the facts. They have not understood the mechanical details of the
submarine and the principles governing its operation well enough to
comprehend or to elucidate the various phases of the development of
this type of vessel. The result has been that many inaccuracies have
been published, both in respect to the history of the development of
the submarine and in regard to the practical operation of such vessels.
There have been published one or two good works dealing with this
subject in a very complete and intelligible manner, but intended for
those engaged in engineering pursuits. One of the best of these was
"The Evolution of the Submarine Boat, Mine and Torpedo, from the
Sixteenth Century to the Present Time," by Commander Murray F. Sueter,
of the Royal British Navy, published in 1907.
When this book first appeared the present writer felt that the subject
had been so fully covered that there was no need for him to publish
his own information. However, since the beginning of the world-war
the prominent part played by the submarine has led to a demand for
more knowledge about the workings of this weapon of mystery, and for
information concerning its future possibilities.
The aim of this work, therefore, is to present to the reader in a
simple, interesting way the facts relating to the submarine; its
mechanical principles; the history of its development; its actual
operation; the difficulty of combating it; and its industrial
possibilities. These facts are presented, together with descriptions of
the experience of the author and other inventors, in order to clarify
in the reader's mind the difficulties, the trials and tribulations
of both the submarine operator and the inventor. Furthermore, the
narrative is not restricted to a discussion of the submarine question
from a mechanical standpoint. The submarine to-day is a factor in the
political and industrial life of the world. The submarine problem
transcends a mere matter of mechanical detail, and a book upon this
topic must, of necessity, deal with it in its broadest aspects.
SIMON LAKE
CONTENTS
CHAPTER PAGE
I. WHAT THE MODERN SUBMARINE IS 6
II. COMEDY AND TRAGEDY IN SUBMARINE DEVELOPMENT 36
III. EXPERIENCES OF PIONEER INVENTORS OF THE SUBMARINE 77
IV. THE EVOLUTION OF THE SUBMARINE 149
V. USE OF THE SUBMARINE IN WAR 196
VI. THE POSSIBILITY OF DEFEATING THE SUBMARINE 228
VII. THE SUBMARINE IN TIMES OF PEACE 259
VIII. THE DESTINY OF THE SUBMARINE 289
ILLUSTRATIONS
DOUBLETONES
PAGE
Simon Lake _Frontispiece_
The Pigmy Conquerer of the Sea 2
Storage Battery Cell 14
A Submarine Cell Completely Assembled Ready for Installation 14
On Picket Duty 20
The Lower Portion of Galileo Periscope 22
The Voice and Ear of the Submarine 26
Torpedo Tubes Assembled Ready for Installation in a Submarine Boat 27
A Whitehead Torpedo 28
Rear End of the Whitehead Torpedo 29
Rapid-firing Guns 30
A Modern Submarine Cruiser, or Fleet Submarine (Lake Type) 32
The Launching of the "Protector" 62
The "Delphine" 66
The "Fenian Ram" 96
"Argonaut, Jr.," 1894 128
Sketch of the Confederate Submarine "Hunley" 150
The New Orleans Submarine 152
The "Intelligent Whale" 153
"Argonaut" as Originally Built. Launched in August, 1897 176
Submarine with Cushioned Bottom Wheels 178
The "Argonaut" after being Lengthened and Rebuilt, in 1898,
Showing Ship-shaped, Watertight, Buoyant Superstructure 182
The "Holland" Running on the Surface 190
"Amphibious" Submarine 202
The "Protector" (Lake Type, 1901-1902) 210
Official Drawing of the Captured German Mine-planting Submarine,
U C-5 214
A Bottom-Creeping Submarine Passing Through a Mine Field 216
A Mine and Net Evading Submarine Under-running a Net 217
Mines Placed Under Ships at Anchor 220
Submarine Supply Station 221
Submarine "Seal"--Lake Type U.S. 226
British Submarine B-1 (Holland type) 227
British Submarine C-2 Arriving at Portsmouth in a Gale 230
Germany's U-9 and Some of Her Sister Submarines.--Aeroplane
and Submarine 234
Russian Cruiser-Lake Type Submarine in Shed Built by Peter
the Great--1905 236
A Group of German U-boats 238
Russian-Lake Type Cruising Submarine "Kaiman" making a Surface
Run in Rough Weather in the Gulf of Finland 239
The U-65 242
Russian-Lake Type 243
C-1, One of the Later Type French Submarines 248
Cargo-Carrying Submarines of the Author's Design 249
The "Deutschland" 252
Torpedo being Fired from the Deck Tubes of the Submarine "Seal" 256
British Submarine No. 3 Passing Nelson's Old Flagship "Victory" 257
Under-ice Navigation 260
A Submarine Garden at the Bottom of the Sea 266
Submarines for Hydrographic Work and Wreck Finding 267
The "Argonaut" Submerged 276
Experimental Cargo-Recovering Submarine 278
Sketch Drawing Illustrating a Method of Transferring Cargoes from
Sunken Vessels to Submerged Freight Cargo-Carrying Submarines 278
Semi-submergible Wrecking Apparatus 280
Submarine Oyster-Gathering Vessel 286
The "Argosy and Argonaut III" 290
Diagram of the "Argosy and Argonaut III" 291
LINE CUTS
Method of Control in Diving Type Boats 17
Method of Controlling Hydroplane Boats 18
How Hydroplanes Control Depth of Submersion 19
Showing Various Conditions in Which a Submarine of the Level Keel
Type Fitted with Bottom Wheels, May Navigate 21
The Periscope is the Eye of the Submarine 23
Diving Compartment 31
Bushnell's Submarine, the "American Turtle" 79
Robert Fulton's Submarine 82
Tuck's "Peacemaker" 84
Longitudinal Section of the French Submarine "Le Plongeur" 153
The "Plunger" (Holland Type Submarine), Launched in August, 1897 167
Lake Design as Submitted to the U. S. Navy Department in 1893 170
The "Argonaut" after Lengthening and Addition of Buoyant,
Ship-shaped Superstructure, Increasing the Surface Buoyancy
over 40 Per Cent 178
The "Holland" 190
Various Types of Modern Foreign Submarines 194
An Amphibious Submarine being Hauled out of the Water 204
The "Caviar Map" of Shipping's Greatest Grave-yard 283
CHART
Diagram to Illustrate the Comparative Visibility and Consequently
the Comparative Safety of Surface Ships and Cargo-Carrying
Submarines 254
THE SUBMARINE IN WAR AND PEACE
INTRODUCTION
Jules Verne, in 1898, cabled to a New York publication: "While my book,
'Twenty Thousand Leagues Under the Sea,' is entirely a work of the
imagination, my conviction is that all I said in it will come to pass.
A thousand-mile voyage in the Baltimore submarine boat (the _Argonaut_)
is evidence of this. This conspicuous success of submarine navigation
in the United States will push on under-water navigation all over the
world. If such a successful test had come a few months earlier it might
have played a great part in the war just closed (Spanish-American war).
The next war may be largely a contest between submarine boats. Before
the United States gains her full development she is likely to have
mighty navies, not only on the bosom of the Atlantic and Pacific, but
in the upper air and beneath the waters of the surface."
The fantasy of Verne is the fact of to-day.
Admiral Farragut, in 1864, entered Mobile Bay while saying: "Damn the
torpedoes--four bells; Captain Drayton, go ahead; Jouett, full speed!"
An admiral, in 1917, damns the torpedoes and orders full speed ahead,
but _not_ toward those points guarded by submarine torpedo boats.
While the British Admiralty once held that the submarine "is the weapon
of the weaker power and not our concern," to-day the British naval
officers in the North Sea operations somewhat discredit the former
official Admiralty stand that "we know all about submarines; they are
weapons of the weaker power; they are very poor fighting machines and
can be of no possible use to the mistress of the seas."
Even as late as 1904 the submarine was not considered by naval
authorities as a weapon of much value. A British admiral expressed his
views on the submarine at that time in these words: "In my opinion,
the British Admiralty is doing the right thing in building submarines,
as in habituating our men and officers to them we shall more clearly
realize their weaknesses when used against us. Even the weapon they
carry (the Whitehead torpedo) is, to all intents and purposes, of
unknown value for sea fighting."
However, from the very outbreak of the war now being carried on in
Europe, the submarine has made its presence felt as a most effective
weapon. German submarines have translated into actuality the prophecies
of Verne, and have altered the views not only of the English but of the
world as to the efficacy of the submarine as a naval weapon.
[Illustration: THE PIGMY CONQUERER OF THE SEA.
A drawing made by the author in 1893 to illustrate the possibilities of
his submarine boat, and called "The Pigmy Conquerer of the Sea."]
On March 10, 1915, a former chief constructor in the French Navy,
M. Lauboeuf, stated: "An English fleet blockades the German coast,
but at such a distance that a German division was able to go out and
bombard Scarborough. When the English tried a close blockade at the
beginning of the war, the German submarines made them pay dearly
by torpedoing the _Pathfinder_, _Cressy_, _Hogue_, and _Aboukir_.
Similarly the French fleet in the Adriatic was compelled to
blockade Austrian ports from a great distance, and the battleships
_Jules Ferry_, _Waldeck Rousseau_, and _Jean Bart_ had fortunate
escapes from the Austrian fleet."
As I write, the submarines of Germany are holding the navies of the
Allied Powers in check. The British fleet dares not invade German
waters or attempt a close blockade of German ports. In spite of the
mighty English navy, the German U-boats--the invisible destroyers--are
venturing forth daily into the open Atlantic and are raising such havoc
with merchant shipping that the world is terrified at the prospect.
It is the German U-boat which to-day encourages the Central Powers to
battle almost single-handedly against the rest of the world's great
nations.
So it is in this surprising manner that the submarine torpedo boat has
emerged from its swaddling clothes and has begun to speak for itself.
Its progress and development have been retarded for many years by the
lack of appreciation of its possibilities on the part of those who have
had the planning of naval programs. These have been, for the most part,
men of ripe years and experience, and perhaps because of these years of
experience they have become ultra-conservative and have been inclined
to scoff and doubt the capabilities of any new device until it has been
tried out by the fire of actual experience. Notwithstanding the fact
that the problem of submarine navigation has been successfully solved
for the past fifteen years, it has been only within the past four years
that any great naval authority has unqualifiedly endorsed submarines as
being of paramount importance in naval affairs.
Admiral Sir Percy Scott, in a strong letter to the _London Times_
shortly previous to the beginning of the present war, stated: "The
introduction of the vessels that swim under water has, in my opinion,
entirely done away with the utility of the ships that swim on top of
the water."
He stated further: "If we go to war with a country that is within
striking distance of submarines, I am of the opinion that the country
will at once lock up their dreadnoughts in some safe harbor and we
shall do the same. I do not think the importance of submarines has
been fully recognized, neither do I think that it has been realized
how completely their advent has revolutionized naval warfare. In my
opinion, as the motor has driven the horse from the road, so the
submarine has driven the battleship from the sea."
Sir Percy Scott, however, is an inventor, being the man who devised the
"spot" method of gun firing, and has, therefore, the type of mind which
is able to foresee and to grasp the value of new devices.
Sir A. Conan Doyle, another man of great vision and imagination, was
so impressed with the potentialities of the submarine that he wrote a
story which prophesied, with such accuracy as to make his tale almost
uncanny, the events which are actually taking place to-day around the
coast of England in the prosecution of Germany's submarine blockade.
In these pages, therefore, I may make claims for submarines which have
not yet been publicly proved by actual performance, and such claims
may impress many as being as visionary as the destructive capabilities
of submarines appeared to be until Lieutenant Weddingen, of the German
Navy, shocked the conservatives and put the submarine on the map as a
naval weapon by sinking, single-handed, three cruisers within one hour
of each other.
I shall be careful, however, not to make any claim for submarines which
is not warranted by experiments actually made during my twenty-two
years' continual study and experience in designing and building
submarine boats and submarine appliances in the United States and
abroad.
To men of imagination and of inventive faculties these claims will not
appear preposterous. The achievements of the submarine, in the face
of all the ridicule, scepticism, and opposition which surrounded its
development, will, I hope, commend these advanced ideas of mine to the
attention, if not the respect, of the more conservative.
CHAPTER I
WHAT THE MODERN SUBMARINE IS
What is a modern submarine boat? A modern submarine vessel is a complex
mechanism capable of being navigated on the surface of the water just
as is any boat, but with the added faculty of disappearing at will
beneath the surface, and of being operated beneath the surface in
any desired direction at any desired depth. Some submarines are able
to wheel along the bottom itself, and are also provided with diving
compartments from which members of the crew, encased in diving suits,
may readily leave and re-enter the vessel during its submergence.
The principal use to which the submarine vessel has thus far been
turned has been that of a naval weapon, for scouting and for firing
explosive automobile torpedoes, either for defensive or offensive
purposes. Its full capacity has by no means been realized up to the
present time.
All submarines, regardless of their design, have certain essential
features which will be described in the order of their importance.
=The Hull.=--This must be watertight and capable of withstanding a
pressure corresponding to the depth at which the vessel is designed
to operate. The hull in most submarines is circular in cross-section;
the circular form is best adapted for withstanding pressure. In some
cases this circular hull is surrounded by another hull or is fitted
with other appendages which will both increase the stability and
seaworthiness of the submarine and add to its speed.
=Superstructure.=--Most of the early military submarines built for
the French, Spanish, United States, and English governments were
circular in cross-section and of cigar-or spindle-shaped form in their
longitudinal profile view. It is difficult, in vessels of this form,
to secure sufficient stability to make them seaworthy. They are apt to
roll like a barrel when light, due to a diminishing water plane, and
when under way the water is forced up over their bows, making a large
"bow wave" which absorbs power and causes such vessels to dive at times
when least expected. In some instances this tendency to dive has caused
loss of the vessel, and, in some cases, of the lives of the crew as
well.
They are also very wet for surface navigation, as the seas break over
their inclined sides like breakers on a beach. These difficulties
led to the invention of the buoyant superstructure, first used on
the _Argonaut_. This is a watertight structure built of light-weight
plating--in some cases it has been built of wood--with valves which
admit free water to the interior of the superstructure before
submerging.
By the admission of the water, danger of collapse is prevented. By this
expedient the pressure upon these light plates is equalized when the
vessel is submerged. This combination of a circular pressure-resisting
inner structure, surmounted by a non-pressure-resisting outer structure
of ship-shaped form, is now common to all modern submarines of all
navies of the world. This superstructure adds to the seaworthiness and
habitability of submarine vessels and increases their speed, both in
the light and submerged conditions, as it admits of better stream lines.
=Stability.=--The stability of a vessel refers to its ability to
keep upright and on a level keel. It is desirable to have great
stability in a submarine in order that it may not assume excessive
angles when submerged. The measure of stability is expressed in
inches of metacentric height. The metacentric height of a vessel when
submerged is the distance between the centre of buoyancy--or submerged
volume--of the vessel and the centre of all the weights of hull,
machinery, stores, and equipment contained within the vessel. This
distance between the centre of buoyancy and the centre of gravity must
be determined very accurately in order to obtain conditions of ideal
stability in a submarine.
The metacentric height of a vessel is a term used in naval architecture
to express the stability of the ship. In surface ships the term may
be used to express either the longitudinal or transverse stability of
the vessel, and varies according to the load line and trim or heel of
the ship. On the other hand, in submarine boats _when submerged_ the
metacentric height is constant and expresses the distance between the
centre of gravity and the centre of buoyancy of the vessel, and is the
same either in the transverse or longitudinal plane of the vessel. In
other words, the centre of buoyancy of the vessel when submerged must
be directly over the centre of gravity of the vessel to cause her to
submerge on a level keel.
We then get the effect of a pendulum, the length of the pendulum arm
being the distance between the two points, and the weight of the
pendulum equalling the weight of the ship. Therefore, if a submarine
has a submerged displacement of five hundred tons, with a metacentric
height of twelve inches, her stability, or ability to remain upright,
is equal to a pendulum of five hundred tons hung by an arm twelve
inches long, and it would require the same force to incline the ship
as it would to incline the pendulum. Therefore it is evident that the
greater the metacentric height the more stable the ship, and the less
likely she is to make eccentric dives to the bottom or "broach" to the
surface.
=Ballast Tanks.=--All submarines are fitted with tanks which may be
filled with water so that the vessel will submerge; these are called
ballast tanks. When the vessel is navigating on the surface she has
what is called "reserve of buoyancy," the same as any surface vessel.
It is this reserve of buoyancy which causes the vessel to rise with the
seas in rough weather. It means the volume of the watertight portion
of the vessel above the water line. In surface cruising a vessel with
great buoyancy will rise to the seas, while if the "reserve" is small
the vessel is termed "loggy" and will not rise to the sea. In the
latter case the seas will break over the vessel just as they break over
a partially submerged rock in a storm. On such a vessel the men cannot
go on deck in a storm; in a sea-going submarine a large reserve of
buoyancy is therefore essential.
Now in a modern submarine, of five hundred tons submerged displacement,
for instance, this reserve should be about one hundred and twenty-five
tons, according to the best practice. This means that before the vessel
could sink beneath the surface the ballast tanks must be filled with
one hundred and twenty-five tons of water. On the surface these tanks
are filled with air. The water is permitted to enter by the opening of
valves for that purpose. These ballast tanks are located within the
main hull and in the superstructure.
=Propelling Machinery.=--When on the surface the submarine may be
propelled by steam, internal-combustion engines, or any other kind
of motive power adapted to the propulsion of surface ships. For
propulsion when submerged many types of engine have been tried:
compressed air engines; steam engines drawing the steam from boilers
in which water has been stored at high temperatures; carbonic acid
gas engines, and the internal-combustion engines receiving their
air supply from compressed-air tanks. Most modern submarines use
internal-combustion engines for surface navigation and storage
batteries delivering current to electric motors for submerged
propulsion. The internal-combustion engine is best suited for surface
work because it can be started or stopped instantly, which is a
desirable feature in submarine work. It is not fitted for submerged
operation because of its great noisiness, and also because its spent
gases must be discharged from the boat, in which case these gases
ascend to the surface in the form of bubbles and thus betray the
presence and position of the submarine. The storage battery, on the
contrary, permits the use of practically noiseless machinery and does
not require any outboard discharge of gases, as the battery gives off
no material quantity of gases when delivering its stored-up power.
I was the first to use successfully an internal-combustion engine in
a submarine boat, the _Argonaut_. This first engine was a heavy-duty
engine of rugged construction, and gave but little trouble. This
type of engine, with but slight modifications, was installed in six
other boats built subsequent to the _Argonaut_. They also worked
satisfactorily for several years, and so long as I had knowledge of
them they always gave satisfactory and reliable service.
The first gasolene (petrol) internal-combustion engines installed in
the Holland boats were also of rugged construction, and I have been
informed by various officers in our submarine service that they were
reliable and gave but little trouble. It is known that, after twelve
years' service, some of them are still doing good work. The boats in
which these engines were installed were slow-speed boats, making only
from eight to nine knots on the surface.
A natural desire on the part of the governments of various nations was
to secure increased speed. They sent out requirements to submarine boat
builders calling for increased speeds within certain limits of cost.
The submarine boat builders said: "Certainly we can give you increased
speed if the engine builders can give us engines of the necessary
power to go into the available space, and within a certain weight, to
thus enable us to get the power plant within a certain size vessel
possessing the fine lines necessary to give the required speed." The
engine builders said _they could do it_.
The first, as I remember, to break away from the slow-speed, heavy-duty
type was a celebrated Italian firm. Then two large and well-known
German firms followed; then a celebrated English firm, and certain
American firms claimed that they could build reliable, compact,
high-speed engines on very much less weight than we had been using.
I remember one American firm which offered engines as low in weight
as twenty pounds per horsepower. Fortunately, we had sense enough to
refuse to accept an engine so light as that, but we, as well as all
other submarine boat builders both in this country and abroad, did
accept contracts which required engines very much less in weight than
the old, slow, heavy-duty type first used, and there has been "wailing
and gnashing of teeth" both by the submarine boat builders and by the
engine-room forces in the world's submarine navies ever since.
The first light-weight engines built by the Italian firm "smashed
up" in short order. The German engines followed suit, and the losses
to this firm, or to the shipbuilders, must have been enormous, as a
large number of engines were built by them before a set was tested
out in actual service. The test of an engine in the shop, on a heavy
foundation, open to inspection on all sides, and with expert mechanics
in constant touch with the engine, does not mean that this same
engine will prove satisfactory in the restricted space available in a
submarine boat when run by other than expert engine-building mechanics.
I was present at a shop test of one of the German engines referred to,
and under shop conditions it appeared to work very well--so well, in
fact, that I took an option for my firm to build from the same designs
in America. When the engine was tried out, however, in one of the
German submarines it rapidly deteriorated and pounded itself into junk
in a few weeks. Cylinders and cylinder heads cracked, bed-plates were
broken, and crank-shafts twisted or broken. It was evident that the
design was too light all the way through.
There are some destructive actions in connection with large,
high-speed, light-weight internal-combustion engines which practically
all designing engineers have failed to grasp. Otherwise, engineers of
all nationalities would not have failed to the extent they have; and I
do not believe that there is a submarine engine in service to-day which
has fully met the expectations of its designers and builders.
It is unfortunate for the engineering profession that government policy
will not permit of a full disclosure of the defects of engines and
other equipment in government-owned vessels. Were a frank disclosure
made, other inventors and engineers would, in all probability, take up
the problems and they might the sooner be solved.
All the earlier submarines were equipped with engines which used
gasolene (petrol) as a fuel, but the gas from this fuel, when mixed
with a proper proportion of air, is highly explosive. A number of
serious explosions occurred in submarines due to this gas escaping from
leaky tanks, pipings, or valves. Some of them were accompanied by loss
of life. The most disastrous was that on board the Italian submarine
_Foca_, in which it is reported that twenty-three men were killed.
Therefore, several years ago, all governments demanded the installation
of engines using a non-explosive fuel; and builders then turned to the
"Diesel" engine as offering a solution of the problem.
As early as 1905 I had anticipated that such a demand would ultimately
be made, so during that year I built, in Berlin, Germany, an
experimental double-acting heavy-oil engine; but unfortunately the
engineer in charge of the work was taken ill and eventually died. This
engine was later completed and showed great flexibility in its control
and in reversing. It, however, has never been put on a manufacturing
basis.
In the meantime, others took up the work of developing the heavy oil
Diesel engine for submarines. The first of the Diesel type engines to
be installed in a submarine were built by a well-known French firm of
engine builders. As we were then in the market for heavy-oil submarine
engines, plans of these engines were submitted to me, but I found it
impossible to install them in any boat we then had under construction,
owing to their size and weight. I have been advised that engines of
this design were installed in some of the French submarine boats. I
have also been informed that the shock and vibrations produced by them
were such as to cause the rivets in the boats to loosen, and this
started the vessels to leaking so badly that it was found necessary to
take them out. These engines differed only slightly from the vertical
Diesel land engine.
The engine is the most important element in the submarine. Without this
it is impossible to make long surface runs, and in the event of its
disablement it is impossible to charge the storage batteries to enable
the submarine to function submerged, which is, of course, what she is
built for doing.
I think the demand for increased speed has come too rapidly. It is
more important to have reliability than speed. The criticisms which
have been made regarding United States submarines, if traced to
their source, may be found to be justified so far as they apply to
the engines, but the Navy Department cannot be held responsible, and
neither can the designers of submarines. They have both searched the
world's markets and secured the best that could be purchased. All naval
departments were undoubtedly right when they decided to abandon the
gasolene (petrol) engine and substitute therefor the heavy-oil engine.
Eventually a successful heavy-oil engine will be produced.
[Illustration: STORAGE BATTERY CELL]
[Illustration: A SUBMARINE CELL COMPLETELY ASSEMBLED READY FOR
INSTALLATION
Storage batteries as used in modern submarines have been especially
developed to meet the special needs of submarine-boat service. The
requirements for this service are much more severe than those for
any other service to which the storage battery has been applied. The
batteries as first introduced in submarines were entirely too frail to
stand up to their work, and the gases given off from them while being
charged were the cause of much distress and danger to the crew, and
have been in some cases responsible for the loss of both vessel and
crew.]
The Diesel engine, weighing practically five hundred pounds or more
per horsepower, has functioned satisfactorily in land installations
and has come into very general use, especially in Germany, but when
the attempt was made to change this slow-speed engine of five hundred
pounds per horsepower into high-speed engines of approximately
fifty pounds per horsepower, all designers "fell down." It was but
natural that naval authorities throughout the world should call for
increased speed; they cannot be criticised for that, as it is a
desirable thing, but experience has shown that they called for it too
early in the game.
The expense of the development of a new type of motive power, such as
the high-speed, heavy-oil-burning engine, for use in vessels whose
prime purpose is to preserve the autonomy of the country, should
be borne by the government rather than by individuals or private
corporations. Millions of dollars have been expended in the development
work of engines, but, although vast improvements are now in progress,
the successful engine is not yet on the market.
Dr. Diesel has stated that he worked seven years before he succeeded in
getting his first engine to make one complete revolution. Governments
and the people must therefore content themselves to accept what they
can get in a heavy-oil engine, imperfect though it may be, until such
time as a satisfactory engine is evolved, built, and tested out under
service conditions.
=Storage Batteries.=--It is impossible in a book of this character to
go into much detail regarding the development of the storage battery.
There have been two types in general use. They are both lead batteries,
one known as the Planté type, in which metallic lead is used to form
both the positive and negative plates. The other type employs what
is commonly known as pasted plates, in which various compositions of
materials are worked up into a paste and forced into metallic grids to
form the positive and negative plates. The pasted type has greater
capacity per pound of material used, but much shorter life.
In both of these batteries sulphuric acid solutions are used as the
excitant between the elements. In charging, hydrogen gas is given off
in the form of bubbles, the skin of the bubbles being composed of
sulphuric acid solution. These bubbles, when taken in one's lungs, are
very irritating, and if they collect in any quantity, or break up and
allow the hydrogen gas to mix with the air, there is always danger of
creating an explosive mixture within the hull of the vessel or in the
battery tanks, which a spark would set off at any time.
The best method of installing batteries on a submarine boat is to
have them isolated from the living quarters of the vessel in separate
watertight compartments. The elements of the battery should be
contained in non-metallic containers and sealed to prevent spilling
of the electrolyte under excessive rolling or pitching of the vessel.
Means should be provided to discharge the hydrogen gases from the boat
as rapidly as formed. Special care should be taken to prevent leakages
between the adjacent cells. Circulation of air to keep the cells dry is
the best means of preventing this.
Mr. Edison has been working for a number of years on a storage battery
suitable for submarine work, and it has recently been stated that he
has finally solved the problem of producing a battery that will stand
up longer than the lead type of battery, and that it has the further
advantage in that it will not give off chlorine gas in case salt water
should get into the cells. It should, however, be contained in a
separate compartment, which should be ventilated during the charging
period, as I understand the Edison battery gives off hydrogen gas the
same as the lead batteries. Chlorine gas, as given off from the lead
battery when salt water has got into it, has undoubtedly caused the
loss of some lives. Mr. Edison claims that his battery, when immersed,
will not give off poisonous gases of any kind.
[Illustration: METHOD OF CONTROL IN DIVING TYPE BOATS
Horizontal rudder set down aft inclines the vessel down by the bow,
in which condition, with only a small reserve of buoyancy, she will
"dive." When she reaches the desired depth a lesser inclination of
the diving rudder is supposed to reduce her angle of inclination
sufficiently so that the pressure on the top of her hull will offset
the tendency to rise due to her positive buoyancy. To be successful
there must be no movable ballast, and variable stream line effect
requires expert manipulation of the diving rudder.]
=Depth Control.=--Practically all modern submarines use hydroplanes
with a horizontal rudder for the control of depth when under way.
Hydroplanes might be said to correspond to the side fins of a fish.
They are substantially flat vanes that extend from either side of
the vessel. They are set on shafts that may be partially rotated by
mechanism in control of a man within the vessel. They readily control
the depth of the vessel with a certain amount of either positive or
negative buoyancy. For instance, submarines are usually submerged
with a small amount of positive buoyancy. If a vessel has positive
buoyancy she will float. We have seen that in a surface condition the
five-hundred-ton submarine has about one hundred and twenty-five tons
of positive buoyancy.
[Illustration: METHOD OF CONTROLLING HYDROPLANE BOATS
Showing a proper arrangement of hydroplanes and horizontal rudders. C
B represents the centre of buoyancy of the vessel when submerged. G
represents centre of gravity, which lies directly beneath centre of
buoyancy. Now if hydroplanes are located at equal distances fore and
aft their up or down pull is always balanced and does not cause the
vessel to dive or broach, but holds her to a level keel. If stream line
pull tends to upset this level keel, horizontal rudders may be used to
correct it.]
Now to prepare the vessel for a submerged run, we admit, say, one
hundred and twenty-four tons of water; the positive buoyancy is then
reduced to one ton. Now if the forward edges of the hydroplanes are
inclined downward (see diagram), and the vessel is given headway, the
pressure of the water on top of the inclined hydroplanes, combined
with the tendency for a vacuum to form under the planes, will overcome
the one ton of positive buoyancy and will pull the vessel bodily under
the water. When the desired depth is reached the operator sets the
inclination of the hydroplanes so as to just balance the upward pull
of the one ton of positive buoyancy, and the vessel proceeds at the
desired depth. On modern boats the control of depth is most remarkable;
it is very common for submarines to make continuous runs of several
hours' duration without varying their depth more than a couple of feet.
When the headway or motive force of the submarine is stopped, if she
has reserved some positive buoyancy she will come to the surface. If
she has negative buoyancy she will sink, but while under way with as
much as a ton of positive or negative buoyancy the hydroplanes will
absolutely control the depth of the vessel.
[Illustration: HOW HYDROPLANES CONTROL DEPTH OF SUBMERSION
The vessel being "under way" in the course of the arrow, the water
contacting against the upper surface of the hydroplanes, as in the
upper view, its course is thus diverted and adds weight to the upper
surface of the planes. There is also a tendency to form a vacuum under
the plane. Both these forces tend to overcome the positive buoyancy of
the boat and force her under water and on a level keel if these forces
are properly distributed fore and aft of the centre of buoyancy and
gravity of the vessel.]
=Action of the Hydroplanes=.--The diagrams are intended to demonstrate
how it is that the Lake and other hydroplane boats can be so easily
held at a predetermined depth and controlled vertically on an even
keel.
The hydroplanes are symmetrically disposed on two sides of the vessel.
They should be equal distance forward and aft of amidships. This
symmetrical disposition, with equal forces acting on each hydroplane,
compels the boat either to rise or sink on an even keel, depending upon
which face of the hydroplanes is presented to the passing water during
the boat's progress.
In the upper diagram the entering edges of the hydroplanes are inclined
downward, and the force of the passing stream lines strikes upon the
upper face of the blades. This exerts a downward force which causes the
boat to sink, as indicated by the arrows marked "A, A." The opposite
of this takes place when the forward ends of the hydroplanes are
lifted. This brings the force of the stream lines against the under
side of the hydroplanes, and the resultant is a lifting impulse in the
direction of the line of least resistance, which is here indicated by
the arrows marked "B, B." It is the lifting force so applied that makes
it possible to raise hydroplane boats from the bottom even when having
considerable negative buoyancy.
[Illustration: ON PICKET DUTY
This is a field of service to which the anchoring weights and the
diving compartment of the Lake boats lend themselves conjointly with
especial fitness. The illustration represents a submarine doing picket
duty on an offshore station. A junction box is placed in a known
locality with telephone or telegraph cables leading therefrom to the
shore. The submarine, having taken her position on the surface, lowers
her anchoring weights, reduces her reserve buoyancy to the desired
extent, and then draws herself down to the bottom by winding in again
on the cables connecting with the anchoring weights. Having reached the
bottom, the diving door is opened and a diver passes out and makes the
necessary connections between that junction box and the instruments in
the boat.]
=Holding Depth When Not Under Way.=--If it is desired to bring the
boat to rest while submerged, but when no motive force is being used,
other methods must be used than that just described. One method is to
have an anchor or anchors to hold the vessel at the desired depth.
If it is desired to lie at rest off the entrance of the enemy's
harbor to wait for her ships to come out, the submarine proceeds to
her station submerged with a small amount of buoyancy,--which is
the usual method of navigating submerged. When she arrives at the
desired station the speed is reduced and an additional amount of
water is gradually admitted to give her a small amount of negative
buoyancy. At the same time her anchoring weights are paid out until
they touch bottom. As soon as they do so water is forced out of the
ballast tanks by compressed air until positive buoyancy is restored
and the vessel stops sinking and remains at rest anchored between the
surface and the bottom, like an anchored buoyant mine. By winding in
on the anchor cables a submarine may then be hauled down nearer the
bottom, and by paying out the cables she may rise nearer the surface.
On picket duty off harbor entrances she remains sufficiently near the
surface to project her telescoping periscope occasionally above the
crest of the waves to keep watch and see that an enemy ship does not
enter or clear. In this condition there is no necessity to have any
machinery running on board the submarine, therefore she can remain
for weeks at a time on station without exhausting her fuel supply.
It is only necessary for her to renew the air supply now and then,
which can be done at night. Another method for holding a vessel at
rest is by taking in and forcing out alternately small quantities of
water so as to keep her in equilibrium between positive and negative
buoyancy. Another method is to use vertical propellers operating in
wells extended from the sides, and by running these it is possible
to exert an upward or downward pressure and so hold her at a depth.
Neither of these methods is as satisfactory, however, as the anchor
weights, because the vessel will not hold a definite position on
station, but will drift off with the current. They also make a drain
on the storage battery and require constant attention on the part of
the members of the crew. By the anchor weights scheme the vessel may
stay on station as long as the food and fuel supply holds out.
[Illustration: SHOWING VARIOUS CONDITIONS IN WHICH A SUBMARINE OF THE
LEVEL KEEL TYPE FITTED WITH BOTTOM WHEELS, MAY NAVIGATE
1, running light on surface; 2, awash, ready for submergence; 3,
submerged, depth controlled by hydroplanes; 4, running on bottom.]
The above facts set forth simply the outstanding mechanical principles
upon which the operation of the submarine is based. The submarine of
to-day, however, has many auxiliaries, to describe which in detail
would require several volumes of technical description.
I will briefly enumerate a few of the more important of these devices
and describe their function as applied to the war submarine.
[Illustration: THE LOWER PORTION OF GALILEO PERISCOPE]
[Illustration: THE PERISCOPE IS THE EYE OF THE SUBMARINE.
(See description.)]
=The Periscope.=--The periscope is the eye of the submarine. In its
simpler form it consists of a stiff metallic tube, from fifteen to
twenty feet in length and about four inches in diameter. Referring to
Figure 1, on page 23, it is made up of an object glass, _A_, which
"views" or takes an impression of all objects within its range or
field of vision, and transmits an image of such object through the
right-angle prism, _B_, which turns the image so that it appears some
distance down the tube, say, for purposes of description, at _C_. If
a piece of ground glass were held at the focus of the objective lens
at _C_, the image could be seen. The lens _D_, located farther down
the tube, in turn now "views" the image and transmits it still
farther down the tube, where it is turned through the right-angle
prism, _E_, and where the image is again turned into an erect
position. A piece of ground glass located at _F_ would show the
image in the same manner as an image is shown on the ground glass of
a camera. The magnifying eyepiece _G_ magnifies the image so that
distant objects appear of natural size.
Other figures show a periscope as made by the Officina Galileo in
Florence, Italy. This firm makes periscopes with binocular eyepieces.
The success of any periscope depends upon the character of the material
used in the lenses and prisms and the accuracy of the workmanship.
This firm, which is probably the oldest optical manufacturing house
in the world, said to have been founded by Galileo himself, turns
out instruments of the most beautiful workmanship. The flange of
the instrument is bolted to the top of the conning tower, or deck,
and a gate valve is arranged between the deck and the eyepiece so
that in case the tube should be carried away the gate valve can be
closed and thus prevent water from entering the vessel. A hand wheel
arranged below the binocular eyepiece permits of easy rotation of the
instrument. Provision is made for introducing dry air; this prevents
condensation forming on the lenses or prisms within the tube.
Owing to the fact that there is a certain loss of light in transmitting
the image through the various prisms and lenses, it is customary to
magnify the image so that it appears to be about one-quarter larger
than when viewed by the natural eye. This has been found by experience
to give, when viewed through the periscope alone from a submerged
vessel, the impression of correct distance.
Previous to 1900 there was no instrument which would give through a
long tube normal vision and a correct idea as to distance. At this
time I took up with various opticians the question of producing such
an instrument. They all contended that it was impossible to produce
an instrument that would give through a long tube a field of vision
equal to the natural eye or that would convey a correct idea as to
the distance of an object when viewed through a long tube. The camera
lucida which Mr. Holland and others had used in the earlier submarines
simply threw a picture of the object on a bit of white paper, usually
located on a table. This did not give to the observer any more idea of
the correct distance of an object than a photograph would. Believing,
however, that a solution could be found, I then purchased a variety of
lenses and started making experiments.
Without any special knowledge of optical science, one day quite by
accident I secured the desired result and found that it was possible
to secure practically normal vision through a tube of considerable
length. About the same time, Sir Howard Grubb, of England, brought
out an instrument in which he accomplished the same result. I then
continued in my experimental work and brought out an instrument which
was designed to give a simultaneous view of the entire horizon.
This instrument was called an "omniscope." It was first called a
"skalomniscope," which was a word coined with the idea of describing
the function of the instrument and which, translated, means "to view
and measure everything." A scale was used in connection with this
instrument which would convert it into a range finder by measuring the
image of an abject of known dimensions, such as the length of a ship or
the height of its smokestack, and give simultaneous reading as to its
distance.
For a time it was necessary for us to manufacture our own sighting
instruments, but later, when the optical houses understood the
principle of the periscope, they took up the matter of manufacture
and have so greatly improved them that it is now possible to secure
instruments of great accuracy and fine definition.
The periscope, however, is faulty, in that it is only an instrument for
day use. As soon as dusk comes on the periscope becomes useless. The
passing of the image down the tube and through the various lenses and
prisms reduces the brilliancy of the image to such an extent that, even
though it is finally magnified to above normal, the image is so thin
at night that it cannot be seen. This forces the submarine to become
vulnerable in making an attack at night, as it is necessary for the
conning tower to be brought a sufficient distance above the surface of
the water to permit the commanding officer to secure natural vision.
With the powerful searchlights and rapid-fire guns, the submarine would
have little opportunity to approach a surface war vessel at night
without great danger of being discovered and destroyed.
[Illustration: THE VOICE AND EAR OF THE SUBMARINE
A Fessenden oscillator, before being installed. The flange of the
oscillator is riveted to the shell of the ship and its diaphragm is
caused to vibrate by the sound waves, which pass through water more
distinctly than they do through the air. To send out signals it is
caused to vibrate mechanically by electrical apparatus.]
=Invisible Conning Tower.=--For night observation it has been
proposed to use transparent conning towers built of clear glass,
in which the commander takes his station and just sticks his head
above the crest of the waves in order to direct his vessel against
the enemy. This has not as yet come into general use because of the
difficulty of securing sufficiently clear glass in the desired form.
Experiments have been made, however, which show that quite a large
transparent conning tower cannot be seen on a submarine at rest even
when within a couple of hundred yards; the application of these
conning towers will greatly increase the submarine's efficiency for
night work.
=Submarine Sound Receivers.=--All modern submarines are fitted with
devices which enable the commanders of submarines to communicate with
each other when running under water even when considerable distances
apart. One of these outfits consists of a signal bell and a powerful
receiver with which sounds may be transmitted and heard. Conversations
may be carried on by the Morse and other codes for distances of ten or
twelve miles.
[Illustration: TORPEDO TUBES ASSEMBLED READY FOR INSTALLATION IN A
SUBMARINE BOAT
Left view, the breech end of the tube. Right view, the outboard doors,
which must first be opened before the torpedo is expelled from the
tube by compressed air. When the torpedo is expelled it starts a
compressed-air engine supplied with air stored at high pressure within
the torpedo, and will run several thousand yards under its own power.]
A later device, called the Fessenden oscillator, will transmit
or receive sounds a distance of twenty miles. The principle of
its operation is that of setting up wave vibrations by very large
transmitters; these vibrations are carried by the water and taken up
by receivers on other submarines. It has been found that the human
voice will set up vibrations in the Fessenden transmitter so clearly
that wireless conversation may be carried on under water for several
hundred yards. I discovered in my earlier experiments that when a
submarine was lying submerged, with all machinery shut down, the
noise of the machinery in an approaching ship could be detected quite
a distance off without the use of any special kind of receivers. In
this way the commander of a submarine can always note the approach of
an enemy simply by shutting down his own machinery. The warning thus
given him comes long before he could sight the enemy ship were he on
the surface. After a little experience one can tell the type of ship
approaching from the sound, as every type of ship has sounds peculiar
to her class. The smash of paddle wheels, the deep, slow pound of the
heavy merchant ships or battleships, the clack and the whir of the
higher speed machinery on destroyers or torpedo boats, are all easily
recognizable when one becomes familiar with them. At the present time
all the larger submarines are fitted with wireless outfits on their
decks which they may use when on the surface to communicate with other
submarines or with their base.
=Torpedo Tubes.=--These are used to start the automobile torpedo on its
course toward the enemy. In simple form they are tubes about eighteen
inches in diameter and seventeen feet long, placed in line with the
axis of the vessel. They are fitted with doors both internal and
external to the submarine. The inboard door of the tube opens into the
interior of the vessel and permits the loading of the torpedo. When the
torpedo is to be discharged the inboard door is closed and securely
fastened. The outer door is then opened, and through the operation of
quick-opening valves compressed air is admitted back of the torpedo
and the torpedo is driven out of the tube in the same manner that the
bullet is driven out of an air rifle or the cork out of a pop-gun.
Some of the larger modern submarines carry several torpedo tubes
firing in line with the axis of the vessel both forward and aft. Some
carry torpedo tubes on their decks which may be made to train to fire
broadside on either side of the vessel.
[Illustration: A WHITEHEAD TORPEDO
Courtesy of the Scientific American
The forward end of the torpedo is the war head filled with guncotton
or trinitrotoluol. A detonator is screwed into the end of the war head
to set off the main charge on contact. An air flask forms the middle
portion of the torpedo. Aft of this is the depth-control mechanism, in
which a diaphragm controls the diving rudder by the pressure of the
water against a spring set for the desired depth. A pendulum controls
the levelling mechanism and a gyroscope its direction in the horizontal
plane, tending to keep it on the course by its control of the vertical
rudder.]
[Illustration: REAR END OF THE WHITEHEAD TORPEDO
Courtesy of the Scientific American
Showing compressed air engine and twin propeller with their control
gear.]
=Automobile Torpedoes.=--These are the projectiles which are used
to destroy the enemy's ship. They are called automobile torpedoes
because they will, on being ejected from the torpedo tubes, continue
running in the direction in which they are aimed, from power and
mechanism contained within themselves. They are wonderful pieces of
mechanism and cost several thousand dollars each. They are virtually
miniature submarine boats. The essential features of the automobile
torpedo are the airflask, the warhead, the depth control, and steering
and propelling machinery. The airflask forms the central section, which
is a steel tank containing compressed air stored at high pressure;
about twenty-five hundred pounds per square inch is the present
practice. When the torpedo is expelled from the torpedo tube this
air is automatically turned on to run the engines. It passes through
reducing valves and heaters to drive either a multiple cylinder or a
turbine engine, and revolves two propellers, running one clockwise and
the other counterclockwise, set in tandem at the stern of the torpedo.
The propellers, running in opposite directions, thus enable the torpedo
to be more easily steered by the delicate automatic steering machinery.
A diaphragm operated by the pressure of the water operates control
mechanism which regulates the depth. An instrument called the "Obry
gear" steers it in the horizontal plane. The essential feature of the
"Obry gear" is a gyroscope which is started when the torpedo is ejected
from the tube. It is instantly speeded up either by a powerful spring
or an air turbine to about fifteen thousand revolutions per minute.
The peculiarity of the gyroscope is that it has a tendency to hold
the direction in which it is started. Hence, if the torpedo starts
swerving either to the right or left from the direction in which it
is aimed, the gyroscope causes certain valves to function which will
automatically set the steering rudder to bring the torpedo back into
its original course. The "Gyro" will continue this control until the
torpedo has completed its course, which in some of the latest types is
said to be about five miles.
The warhead is the forward portion of the torpedo and contains usually
wet gun-cotton, which is a safe high explosive and can be exploded
only by a detonating charge of the more sensitive explosives. This
detonating charge is placed in a tube screwed into the forward end of
the torpedo. Extending out from the forward end of the tube is a small
propeller, the purpose of which is to set the firing mechanism after
the torpedo has run a certain distance from the vessel from which it
has been fired. This is a safety device to prevent the torpedo from
being exploded near its own ship. The torpedo running through the water
causes the propeller to revolve, which turns a shaft. After the shaft
makes a certain number of revolutions it sets a firing pin, and then
if it hits an object it will explode. Many modern torpedoes are loaded
with trinitrotoluol. This is a much more powerful explosive. According
to experts, the explosion of two hundred and fifty pounds of T-N-T, as
it is called, will destroy any battleship ever built.
[Illustration: RAPID-FIRING GUNS
Courtesy of the Scientific American
Rapid-fire disappearing guns may be quickly elevated above armored
turret when the submarine rises to the surface.]
=Divers' Compartment.=--Some submarines are fitted with a divers'
compartment, from which compartment mines may be planted, either when
on the surface or when submerged. This compartment is fitted with a
door which opens outwardly in the bottom of the boat. It is shut off
from the living and machinery rooms of the vessel by an air lock and
heavy pressure-resisting doors. The divers' door may be opened when the
vessel is submerged and navigating on the bottom, and _no water will
come into the vessel when the door is opened_. This is accomplished in
the following manner: The members of the crew who wish to go outside
the vessel first go into the diving compartment. They close the door
which shuts them off from other parts of the vessel. They then turn
compressed air gradually into the compartment until the air pressure
in the compartment equals the water pressure outside. If the depth is
one hundred feet the air pressure in the compartment would need to be
43.4 pounds per square inch; if the depth is two hundred feet, twice
that, or 86.8 pounds per square inch, etc. When the air pressure in the
compartment equals the water pressure outside, at any depth, the door
in the bottom may be opened and the water will not rise up into the
compartment, because the air pressure keeps it out. Tests have been
made which show that it is safe for divers to go out from compartments
of this kind in depths up to two hundred and seventy-five feet.
[Illustration: DIVING COMPARTMENT
This view shows the diving compartment being used for the purpose of
grappling for the electric cables controlling fields of submarine
mines. Operating in this manner, the diving compartment becomes a
veritable travelling diving-bell, and when the air pressure in the
diving chamber is made to balance with the water pressure outside the
diving door may be opened and yet the water will not enter the working
chamber.]
=Dangers.=--Years of painstaking development work have eliminated most
of the dangers connected with the operation of submarines in times of
peace. The experienced designers have learned the importance of having
great submerged stability, so that no modern craft is likely to make
an unexpected headfirst dive into the mud, hard sand, or rocks on
the bottom. This was a common occurrence not many years ago. Another
danger to be avoided is that of asphyxiation by the escape of noxious
gases from the engines. The blowing up of the vessel by the ignition
of hydrogen fumes from the battery is another risk to be guarded
against. In the latest vessels the noxious gases from the engine are
not permitted to escape into the engine-room; gasolene is rapidly
giving place to heavy-oil engines which do not use an explosive fuel,
and the hydrogen gas given off during the charging of batteries is
pumped overboard as rapidly as it is generated. Consequently modern
submarines, when navigating on the surface, are as safe as any surface
ship. In fact, they are safer, from the fact that they are so much
more strongly built and that they are divided into compartments. Any
one of these compartments could be filled by water in an accident and
the remaining compartments would keep the ship afloat. In submerged
peace-time navigation the dangers are those of collisions with surface
vessels, uncharted rocks, or sunken ships. The danger of collisions
with surface ships may be avoided by keeping below the depth of keel
of the deepest draft surface ship, when long under-water runs are being
made, and always stopping machinery to listen for the sound of surface
ships before rising to the surface. If running near the surface where
periscopic vision is possible, constant vigilance must be maintained,
as there are no rules of the road or right of way which may be claimed
by the submarine commander, owing to the fact that the lookout on the
surface craft, in all probability, cannot see his little periscope in
time to avoid collision.
[Illustration: A MODERN SUBMARINE CRUISER, OR FLEET SUBMARINE (LAKE
TYPE)
The parts indicated by numbers in this illustration are as follows:
1, main ballast tanks; 2, fuel tanks; 3, keel; 4, safety drop keel;
5, habitable superstructure; 6, escape and safety chambers; 7,
disappearing anti-aircraft guns; 8, rapid-fire gun; 9, torpedo tubes;
10 torpedoes; 11, twin deck torpedo tubes; 12, torpedo firing tank;
13, anchor; 14, periscopes; 15, wireless; 16, crew's quarters; 17,
officers' quarters; 18, warhead stowage; 19, torpedo hatch; 20, diving
chamber; 21, electric storage battery; 22, galley; 23, steering gear;
24, binnacle; 25, searchlight; 26, conning tower; 27, diving station;
28, control tank; 29, compressed-air flasks; 30, forward engine
room and engines; 31, after engine room and engines; 32, central
control compartment; 33, torpedo room; 34, electric motor room; 35,
switchboard; 36, ballast pump; 37, auxiliary machinery room; 38,
hydroplane; 39, vertical rudders; 40, signal masts.]
=How the Submarine Works.=--Reference to the diagrammatic view of a
modern submarine will probably make clear the following explanation of
the operation of a submarine. We will assume that our submarine leaves
her own harbor with fuel, stores, and torpedoes on board, wireless
and signal masts erected. She is bound to a station farther down the
coast, but receives word by wireless that an enemy fleet has been seen
approaching the coast in such a direction as to indicate an attack on
New York. She receives instructions to return and take up a station
fifteen miles off Sandy Hook, the entrance to New York Harbor, and also
that she is to coöperate with the smaller harbor-defense submarines
that are permanently located in New York. She therefore puts back to
the station designated. All deck fittings and lines are stowed except
the ventilators and the deck wireless outfit; the latter is left
standing so as to keep in touch with the scout ships and destroyers
which are reporting the approach of the enemy. Shortly after arriving
at her station, the commander notes smoke on the horizon and orders are
given to "prepare to submerge." Each member of the crew then proceeds
to his particular task; the wireless masts and ventilators are quickly
housed, and all hatches are closed and secured. The quartermaster
and submerged-control man who controls the steering and hydroplane
operating gear take their stations in the control department. The
engines are uncoupled by means of the rapid operating clutch, the
electric motor is coupled, the hydroplanes are unfolded, the valves
are opened, and the word is passed to the commander, "All ready for
submergence!" All this is done in a modern vessel in less than two
minutes.
The command is then given: "Fill main ballast!" Quick-opening
valves are opened and the water rushes into the ballast tanks and
superstructure at the rate of fifty or sixty tons per minute. The
order is then given: "Trim for submergence!" Sufficient water is then
admitted into the final adjustment and trim tank to give the desired
buoyancy and trim, and the vessel is now ready to submerge on signal
from the commander, who now takes his station at the periscope. The
gunners have also taken their stations at the torpedo tubes to prepare
to load the tubes as soon as the torpedoes already in the tubes are
discharged. The whole time consumed from the time word to "prepare to
submerge" until the vessel is running under water has probably not been
over two or three minutes. In the meantime the enemy has been rapidly
approaching and her superstructure is already above the horizon. The
commander of the submarine notes that if the enemy holds its course it
will be advantageous to change his position to intercept the oncoming
fleet. He therefore gives word to submerge to the desired depth and
gives the quartermaster the course, and the vessel proceeds, entirely
submerged, to get nearer the enemy's line of approach. The commander
then brings his submarine to rest before extending his periscope above
the surface. As soon as the enemy is found to be coming within range he
manoeuvres his ship so that his torpedoes will bear the proper distance
in advance of the ship he selects to destroy. To make a hit it is
necessary to fire in advance of the oncoming ship to allow for the time
the torpedo takes to reach the point where the enemy will be. Range
finders, torpedo directors, and rapid calculators enable the commander
to calculate this to a nicety. If the distance is only a thousand or
fifteen hundred yards, a hit is pretty certain to be made, but the
greater the distance the less the chance of success and the greater the
opportunity for error.