Chapter IV: The Evolution of the Submarine (1)

Among the many submarines which were built previous to the beginning of the present century, very few taught lessons of positive value, for the great majority of these experimental craft were total failures. Knowledge of the causes of their failures is important, however, because it teaches us what errors in construction to avoid. Practically all of these early submarines were built secretly; when failures resulted the vessels were abandoned and the results of such trials were not published, consequently the succeeding designers were very apt to make the same mistakes.

It was not until the past decade that any general description of many of the early submarines was published and made available to students of this problem. In looking over the published plans and descriptions of a number of those early submarines, I have been convinced that many lives and much capital could have been saved had the results of the various experiments been openly disclosed for the guidance of later designers.

The desire to navigate in the depths of the sea has possessed the minds of many men since the beginning of history, and even at very early times several crude submarines were devised in the attempt to solve the problem. But, as I have related in the preceding chapter, it was not until the period of the war between England and her American colonists that any important progress was made. Bushnell's little submarine, called the _American Turtle_, was built at that time. It took its name from its shape, which resembled the back shells of two turtles joined together.

From the rather complete description of this vessel contained in one of Dr. Bushnell's letters, it appears to have been propelled by a screw propeller to obtain forward or reverse motion. It was ballasted in such a manner as to give the vessel great inherent stability. It had water ballast tanks which could be filled to give the vessel negative buoyancy, if desired, or to reduce the positive buoyancy so much that the vessel could be readily drawn under water by another screw propeller which was operated by a vertical shaft extending through a stuffing box into the vessel. This submarine carried a mine on its back, and provision was made to enable the operator inside the submarine to attach the mine to the bottom of a ship at anchor. This vessel was regulated in such a way that the mine could be exploded by a clockwork mechanism after the submarine had reached a safe distance from the vessel.

With this submarine a mine was placed under the bottom of the English frigate _Eagle_, anchored in New York Bay, but the mine drifted clear before the clockwork mechanism caused it to explode, otherwise the frigate would undoubtedly have been destroyed. General Washington complimented Dr. Bushnell on having so nearly succeeded in his attempt to sink the ship.

Made after she was recovered and hoisted on the dock years after the war.

(Drawing by R. S. Skerrett.)]

This submarine was unquestionably a successful model. It had one important feature that many designers have failed to appreciate, and that was great inherent stability. Great stability in a submarine means the carrying out of the now popular maxim "Safety First." Sufficient static stability is a guarantee that during all the manoeuvring evolutions of a submarine she will always remain right side up and not dive into the bottom unless the hull is punctured or flooded at one end or the other.

Bushnell's model was not suited to high speed, but high speed was not essential in the days of the sailing ship. If this design had been developed further, so that several men could have been used to operate the propeller, it should have given a good account of itself.

Robert Fulton's boat, to which I also have made reference in the foregoing chapter, differed from Bushnell's in its method of submerged control, which was by vertical and horizontal rudders at the stern. It also carried a collapsible mast on which a sail could be spread for surface navigation.

A Bavarian by the name of Bauer built a submarine in 1850. Its method of control was by shifting a weight forward to dive and aft to rise. It was a flat-sided and flat-decked vessel with comparatively thin plating and entirely unsuited to resist the pressure of the water at any considerable depth. It collapsed in the harbor of Kiel during one of its trial trips. Bauer kept his presence of mind, however, and when sufficient water had entered and raised the trapped air pressure inside of the boat equal to the pressure outside, he opened the hatch and swam to the surface. This vessel remained partly buried in the mud into which it had sunk until 1887, when it was located during the deepening of Kiel harbor and taken to Berlin, where it is now kept in the Museum of Oceanography as an exhibit of Germany's first submarine.

No further important advance was made in the art of submarine navigation until the period of the Civil War, when the Confederates built several small submarines, called "Davids." One of these was called the _Hunley_, after her designer. During her brief career she suffocated or drowned thirty-two men, including her designer.

During my early experiments with the _Argonaut_ in 1898 I received a visit from Col. Charles H. Hasker, of Richmond, Virginia, who explained in detail the method of operating the _Hunley_. She was a cylindrical-shaped craft, about thirty feet long and six feet in diameter, with both bow and stern flattened to form a stem and stern-post, respectively. Water-ballast compartments were located in either end of the vessel. She was propelled by eight men, who turned the cranked propeller shaft by hand. These men sat on benches on either side of the shaft. She had the usual vertically hung rudder aft, and a diving rudder forward to incline her bow down for diving, or to raise her bow to bring her to the surface (see page 150). Unfortunately she lacked longitudinal stability, and during her experimental trials twice dove head first into the bottom. Of her experience I have given an account elsewhere.

The lesson to be learned from the disastrous trials of this vessel was that sufficient statical stability should always be secured to prevent the vessel taking on an excessive inclination due to shifting of water ballast or movement of crew.

Built by the Confederates during the Civil War.]

Another submarine built by the Confederates shows a much safer design. It is shown as the New Orleans submarine. According to the story told by a native of New Orleans, this vessel was built during the Civil War to destroy the Northern ships. The story of her launching has been given in a foregoing chapter.

It is evident that the designer of this vessel miscalculated and made his boat so much overweight that she could not be given sufficient buoyancy to bring her to the surface by the means provided. From a study of the form of this vessel, she should have been very stable, and I am of the opinion that she could have been successfully navigated submerged had she been properly ballasted.

Built by O. S. Halstead of Newark, N. J., and sold to the U. S. Government in 1870, now in Brooklyn Navy Yard.]

During the years 1863 and 1864, Messrs. Bourgois and Brun brought out for the French Navy the largest and, in some respects, the most completely equipped submarine that was produced during the nineteenth century. This was _Le Plongeur_, a vessel about one hundred and forty feet long, ten feet depth, and twenty feet beam, with a displacement of over four hundred tons. Her motive power consisted of compressed-air engines of eighty horsepower. The compressed air was carried in air tanks at a pressure of one hundred and eighty pounds per square inch. It is reported that the capacity of the air tanks exceeded one hundred and forty cubic metres.

This vessel was built by Messrs. Bourgois and Brun in 1864 and was backed by the French Government. She was the largest and the most costly vessel built in the attempt to solve the problem of successful submarine navigation up to about the beginning of the 20th century. (See text.)]

Her submerged control system consisted of the usual water-ballast tanks for reducing the vessel's surface buoyancy preparatory to submerging. The final adjustment of displacement was to be effected by means of cylinders which could be forced out through stuffing boxes to increase her displacement or withdrawn to reduce her displacement. It was hoped that by manipulating these cylinders she could be put in equilibrium with the water she displaced, and that she could then be steered in any desired direction by the vertical and horizontal rudders placed at her stern.

Theoretically this is an ideal method for submerged control, but in practice it works out badly, especially when a vessel has little stability, for the reason that there are so many disturbing influences to cause the vessel to take on dangerous angles in diving. If free surfaces exist in the water-ballast tanks, the slightest change from a level keel causes the water to flow to the lower end of the ballast tank. This is apt to augment the inclination still further, and cause the vessel to dive, or, _vice versa_, to broach. The density of the water also varies, especially where freshwater rivers empty into salt water. At times quite different densities are found at various depths. The fresh water and salt water, instead of rapidly mixing, seem to have a tendency to remain in strata which extend, in some cases, considerable distances off shore. Therefore it is practically impossible to secure and maintain a vessel in perfect equilibrium. The movement of the crew forward and aft, or the effect of the sea, which imparts a vertical motion to the water beneath the surface, all tend to destroy both trim and equilibrium to such an extent that many failures have resulted in vessels of this type.

_Le Plongeur_ was no exception to this rule, because it was found impossible to control her depth when running submerged, and she would either dive into the bottom or broach to the surface. One report stated that even in depths of thirty feet she would make progress "by alternately striking the bottom and then rebound to the surface like an elastic india-rubber ball."

One other novel feature introduced in _Le Plongeur_ was an "escape boat," which was carried on top of the main hull, to which it was secured by bolts. A double hatch connected the submarine and the escape boat together. In case the submarine became disabled or entangled in wreckage and could not be brought to the surface, the crew could enter through double hatches into the escape boat, secure the bottom hatch, and by turning the securing bolts from the interior release the escape boat and ascend to the surface.

Mr. O. S. Halstead, of Newark, New Jersey, completed, in 1866, a submarine vessel on which the United States Government made a partial payment. This vessel is known as the _Intelligent Whale_, and is now installed as a permanent exhibit on the Green at the Brooklyn Navy Yard, New York. The vessel had a vertical and horizontal rudder at the stern for submerged control. According to official reports, she must have functioned fairly well when submerged.

One of the features of this vessel consisted in its ability to be converted into a diving bell when resting on the bottom. A large trap-door was arranged in the bottom of the vessel. After filling the whole interior of the vessel with compressed air equal in pressure to the pressure of the water at the bottom of the vessel, the trap-door could be opened and the air pressure would keep the water from rising, the same as in a diving bell.

A study of this vessel shows that she must have been a very stable craft and not likely to dive at an excessive angle or to stand on end, as was the tendency of many of the early diving boats. A report signed by Gen. T. W. Sweeny, U. S. A., and Col. John Michal, Col. T. R. Tresilian, and Major R. C. Bocking, engineers, strongly endorsed this vessel.

On the strength of the above-mentioned reports and endorsements, the government, through the Navy Department, appointed a commission composed of Commodore C. M. Smith, Commodore Augustus L. Chase, Chief of Bureau of Ordnance, and Edward O. Mathews, Chief of the Torpedo Board, "to examine, inspect, and report on the merit of said boat." As the report of this commission confirmed the capacity and efficiency of the boat for submarine purposes, the government made a contract for her purchase for the sum of $50,000 (£10,250).

The contract specified certain conditions which were to be fulfilled before the final payment was made, one of which was that Halstead should "write out fully and describe, without reservation, all the inventions, secrets, and contrivances necessary to enable any competent person or persons to operate and manage said boat as contemplated, desired, or designed, more especially the methods of furnishing, managing, controlling, purifying, and renewing the air when and in quantity as needed, so as to enable those in the boat to descend and ascend or remain under water any reasonable length of time; also, to open the doors in the bottom of the boat and keep the water from coming therein at any reasonable and regulated depth." For this information Halstead was to receive such further sum as a board of officers might grant. Halstead was to have the further right to apply to Congress for additional compensation.

In carrying out the provisions of the contract, the government, on May 27, 1870, took over the _Intelligent Whale_ and then paid $12,050 (£2,470) on account of the contract. Shortly after this Halstead was instantly killed. Differences then arose between Halstead's heirs and others who claimed an interest in the contract. It does not appear that anything further was ever done with the boat to carry out the terms of the contract. She lay neglected for years on the old "Cob dock" in the Brooklyn Navy Yard, but was recently erected as an exhibit on the Green.

Some years later that famous inventor, Mr. J. P. Holland, brought out a submarine vessel called the _Fenian Ram_. This vessel was about thirty feet long and six feet in diameter. She was navigated, when submerged, by the use of vertical and horizontal rudders located at the stern. The novel feature introduced in the vessel was an under-water air-gun which was designed to fire a shell under water.

Mr. Holland was originally a school teacher in Ireland, from which country he was exiled because of his political beliefs. On coming to the United States he became affiliated with the Fenian movement. Previous to his construction of the _Fenian Ram_ Mr. Holland built experimentally a small one-man boat. The money to build the _Fenian Ram_ was subscribed by the "Clan-na-Gael" and other Irish patriotic societies, and an associate of Mr. Holland recently informed me that over $200,000 (£41,000) was subscribed to enable Mr. Holland to carry on his experiments. After the collapse of the Fenian movement the _Fenian Ram_ was towed up to New Haven, Connecticut, and hauled out on the banks of the Mill River, where it has lain ever since, hidden under a pile of lumber.

One of the former leaders of the Fenians informed me that the scheme was to build a number of submarines of about the size of the _Ram_. They were to have been carried across the Atlantic in a special ship with water-tight compartments extending below the water line, into which the submarines were to have been floated and a sea door closed. On arrival on the English coast, this special ship, which was apparently a harmless merchantman, was to locate the British war vessels in some one of the harbors, sail in and anchor near them; then the little submarines were to be released from their mother ship and proceed to sink as many of the British ships as they could by firing explosive shells into them below the water line. The novelty of such an attack was relied upon to spread consternation among the British fleet and thus enable the submarines to escape.

In 1878 Mr. G. W. Garrett, of Liverpool, took out a patent and constructed a small boat whose equilibrium was to have been maintained by the admission of water into a cylinder and forcing it out by a piston. In 1879, Mr. Garrett brought out a larger vessel, called the _Resurgam_, in which his means of control were forward diving rudders similar to those of the Confederate _Hunley_. The novel feature of this vessel was the installation of a very large steam boiler in which sufficient heat could be stored to enable the vessel to make a submerged run of several miles after the fires were shut down. This vessel was lost during her experimental trials.

Mr. Garrett then interested Mr. Nordenfelt, the inventor of the celebrated Nordenfelt gun, in his boat. Mr. Nordenfelt improved upon Garrett's boat and built vessels for Greece, Turkey, and Russia. His first boat was sixty-four feet in length by nine feet beam, with a displacement of about sixty tons. The method of submerged control, which he devised, consisted of the use of two downhaul screws located in sponsons on either side of the vessel. These screws were operated by bevel gears and were run at sufficient speed to overcome the reserve of buoyancy. The vessel was intended to be always operated with a reserve of buoyancy. To submerge, therefore, it was necessary to run the propellers at a speed sufficient to exert a thrust to overcome this buoyancy and pull her bodily under water. After reaching the desired depth, forward motion was then to be given by the usual screw propeller, and she was expected to make progress on a level keel and in a horizontal plane. The level keel was to have been maintained by the use of a horizontal rudder placed in the bow.

This method of submerged control for submarine vessels of moderate speed seems to me to be an excellent one in principle. I have been surprised that further development has not been made along these lines. I think the final abandonment of the Nordenfelt type of vessel was due to failure in carrying out the details of design rather than to faulty basic principles. A former chief engineer of Mr. Nordenfelt informed me that the heat from the large amount of hot water stored up in the reservoirs--for submerged power--made the interior of the vessels almost unbearable for the crew when the hatches were shut down, and that he did not believe the submarines ever made any submerged runs after being delivered. I also judge, from his description of his experiences with the vessels, that they lacked longitudinal stability and were difficult to hold in the horizontal position, which Mr. Nordenfelt claimed was a _sine qua non_ for a submarine boat. I concur in this claim.

In an article on his boats, Mr. Nordenfelt stated that they were very sensitive, and that he had purposely made them so in order that the horizontal rudder might easily maintain the boat in a horizontal position. My experience has led me to prefer great statical stability rather than sensitiveness.

Mr. Nordenfelt's boats had means for discharging the smoke from the fires under the water. This was done so as not to betray the submarine's position to surface vessels. He also seems to have been the first to incorporate torpedo tubes within his hull for the discharge of the Whitehead torpedo.

The Spanish Lieut. Isaac Peral built, in 1887, a vessel in which the motive power was supplied from electric accumulators. It was operated by the usual vertical and horizontal rudders. Its submerged control was bad, but its electric propulsive system worked well.

Mons. Goubet built several small boats during the period from 1885 to 1890 with a propeller which worked on a universal joint so arranged that the direction of thrust could be changed to drive the boat under water or to bring her to the surface when submerged. This propeller took the place of the usual vertical and horizontal rudders.

Prof. Josiah L. Tuck built, in 1885, a vessel called the _Peacemaker_, the novel feature of which consisted of a "caustic soda" boiler for generating steam for submerged work.

In 1886 a Mr. Waddington, of England, brought out a small electric accumulator boat with downhaul screws arranged in vertical tubes. He also used side rudders to assist in control of depth. It is reported that this vessel functioned quite successfully, but she was abandoned, and Mr. Waddington does not seem to have developed anything further.

In 1892 George H. Baker brought out an egg-shaped vessel which he ran submerged by the use of side propellers driven by bevel gears. These propellers were carried in frames so that they could be inclined to exert a thrust downward or upward, or at any desired angle so as to pull the boat downward and drive her forward at the same time. This was an improvement over Nordenfelt's side propellers, which ran on fixed vertical shafts. This vessel functioned fairly satisfactorily at slow speeds, but neither the form nor driving mechanism was suitable for the higher speeds required by modern practice.

A number of other boats were built, but there does not appear to be anything new in principle in them.

This brings us up to 1893, when the United States Government made an appropriation of $200,000 (£41,000) for a submarine boat and advertised for inventors to submit designs. This was the first time that it was officially recognized in this country that there _might_ be possibilities in this type of boat. Most of the naval officers, however, were very sceptical of the practicability of such craft, and, from the conservative point of view, they were perhaps justified, as no satisfactory boat had been built up to that time.

A program of requirements, which undoubtedly would produce a weapon valuable for defence, was made up by the Navy Department, and these requirements were designated in the following order of importance:

1. Safety.
2. Facility and certainty of action when submerged.
3. Speed when running on the surface.
4. Speed when submerged.
5. Endurance, both submerged and on the surface.
6. Offensive power.
7. Stability.
8. Visibility of object to be attacked.

This standard of accomplishments is as important to-day as when it was first promulgated.

This first appropriation was brought about by a recommendation to Congress, made by Commander Folger, Chief of Ordnance, who had been much impressed with the possibilities of submarines after witnessing a test of the Baker boat in Lake Michigan. Commander G. A. Converse, president of the Torpedo Board, also made a report certifying that it was his belief that a larger vessel operating on the Baker principles would, with some modifications, prove valuable for defensive and offensive purposes.

France at this date was the only other country which was giving official encouragement to the development of the submarine. She was conducting experiments with the _Gymnote_, a small vessel of the diving type, and had under construction a much larger vessel to be operated on the same principle. This vessel was afterward called the _Gustave Zédé_, but she did not go into commission for some time, as her submerged control was found to be bad. One report of her trials states that, "with the committee of engineers on board, her performance in attempting to keep an even depth line was most erratic, and frequently a thirty-degree inclination was reached before the boat could be brought up. On one occasion she hit the bottom in ten fathoms with sufficient force to unseat the engineering experts."

The _Gymnote_ was five feet ten inches in diameter amidships and fifty-nine feet ten inches in length. The _Gustave Zédé_ was ten feet nine inches in diameter and one hundred forty-eight feet long. It is very difficult to secure sufficient metacentric height in a boat of the above proportions, which probably accounted largely for their erratic behavior when submerged.

In response to the United States Government's advertisement for designs of submarine boats, only three inventors submitted plans and specifications. These were Mr. George C. Baker, Mr. J. P. Holland, and myself. Mr. Baker submitted designs of a boat sixty feet in length and of about one hundred and twenty tons displacement. This vessel was expected to have a speed of about eight miles per hour. The method of submerged control and known characteristics were the same as have already been described in connection with his boat as built in 1892. Mr. Holland proposed to build a vessel eighty-five feet in length, eleven and one-half feet in diameter, of one hundred and sixty-eight tons submerged displacement, and of one hundred and fifty-four tons light displacement. This gave a surface "reserve of buoyancy" of only fourteen tons, or less than ten per cent. The method of control was by the use of vertical and horizontal rudders on the same principle as was used in his _Fenian Ram_, described above.

In 1897 Mr. Holland published in _Cassier's Magazine_ an article on submarine navigation, giving some of his experiences with the _Fenian Ram_. This article explains very well the state of the art of submarine navigation in 1893. One of the early difficulties encountered was how to know the direction one was going when submerged. Referring to his experience in the _Fenian Ram_, Mr. Holland said:

"Experience with submarine boats had been so very limited up to
1881 that more difficulty in steering a straight course by compass
while submerged than while moving on the surface was scarcely
expected. The writer had no suspicion that his boat could not be
steered perfectly until he had tried it after making about half a
dozen preliminary dives to adjust the automatic apparatus. Having
become doubtful of the reliability of the compass, he had it
carefully compensated, and then made a trial submerged run in New
York Harbor, heading the vessel toward a point which he knew was
about twelve minutes' run distant.

"The boat dived at an inclination of about fifteen degrees, and
it was noticed that when she again reached a horizontal position
the compass needle swung around a complete circle and vibrated a
good deal before coming to rest. The boat was then discovered to
be about ninety degrees off her course. It was steered again in
the proper direction, and then inclined upward at a sharp angle to
find whether the action of the compass would be as erratic while
rising as while running downward. One end of the needle dipped to
the bottom of the cup when beginning the ascent, and remained there
during the rise. When the boat approached a horizontal position, a
few feet below the surface, the needle swung around as violently as
it had done during the boat's descent, and then came to rest again
at a point that indicated the boat to be far off the true course.

"As it appeared quite clear that the run was not made in the
direction intended, and that about one mile must have been covered
from the start, ten minutes having already passed, the boat was
brought to the surface of the water just in time to prevent her
from running on rocks that lay about twenty yards straight ahead
and sixty yards down from the starting point.

"The boat had been started to run over one mile up stream, and
the mile-run ended sixty yards down stream, with the boat heading
exactly opposite to her original direction. This erratic action
of the compass was discovered to be due to heeling, or inclining
from the horizontal position, and that it could not be corrected in
that boat on account of the near proximity to the compass needle of
considerable masses of iron that were liable to have their position
changed while the vessel was submerged."

To overcome the above-mentioned difficulties, Mr. Holland invented a device and was granted a patent (No. 492,960) for a triangular drag, which was expected to keep the vessel on a true course when under water. This triangular drag was the novel feature of Mr. Holland's 1893 design, and was intended automatically to steer the vessel on a straight course when submerged. It was intended to operate on the following ingenious principle:

While the vessel was running on the surface the steering gear was under the control of the steersman. In this condition the compass could be adjusted, as the vessel was on a substantially level keel and the masses of metal remained fixed in their relation to the compass, but when the vessel was caused to dive the masses of metal changed their relation to the adjusting magnets and the compass was thrown out of true. Therefore, on beginning a dive the vessel was first started on the surface on the course it was intended to follow submerged until the triangular drag, being drawn through the water, assumed a direction parallel to the axial line of the boat by reason of the rush of water against said drag, and especially against the rib thereon. As soon as the boat was on her course the steersman was expected to disconnect his hand steering gear and allow the drag to control the rudder to hold her to her original course. Mr. Holland maintained that any departure from a straight line would cause the drag to produce swinging motion of a lever, which was expected to throw the rudder in a reverse direction, thus returning the ship to her original course.

Another automatic steering device operated by the pressure of the water was expected to automatically control the depth of submergence, it being only necessary, theoretically, to move a control lever to a point on a dial corresponding to the desired or predetermined depth of submergence, and the horizontal diving rudder would then be automatically manipulated to incline the bow of the boat down so as to dive until the desired depth was reached and then to be manipulated to throw the bow up or down to maintain that depth.

In further describing his 1893 design for the _Plunger_, for which he received the award based on a guarantee of performance, Mr. Holland describes her as follows:

"The boat now being built for the United States Government satisfies
all the requirements detailed earlier in this article. It will have
a length over all of eighty-five feet, and diameter of eleven and
one-half feet; total displacement, one hundred and sixty-eight tons,
and a light displacement of one hundred and fifty-four tons. The
guaranteed speed on the surface will be fifteen knots, the speed awash
fourteen knots, and submerged eight knots. At full speed the boat
will have an endurance of twelve hours and a radius of action of one
thousand miles at slower speed. The endurance, when submerged, will be
ten hours at a speed of six knots. The boat will be propelled by triple
screws, operated by three independent sets of triple-expansion steam
engines, capable of developing 1625 indicated horsepower. There will
also be electric storage batteries and a motor of 70 horsepower for
submerged running. The armament will consist of two expulsion tubes and
five Whitehead torpedoes.

Machinery not drawn to scale. The engines of 1,600 horse-power,
with the necessary auxiliaries, nearly filled the after portion of
the vessel.]

"Steering on the horizontal plane while submerged is accomplished
by an automatic apparatus that performed very well in one of the
boat's predecessors. Steering in the vertical plane is also done
automatically, and with considerable exactness, while submerged.
Steering in both planes can also, at the same time, be controlled
manually. There will be a steel armored turret, four feet high, to
protect the pilot and smokestack, and the hull will be covered by
three feet of water while the vessel runs awash to attack.

"When engaged in harbor defence duty its position will be outside
the outer line of harbor defences; that is, beyond the reach of the
guns defending the entrance. While performing this duty it will lie
awash; that is, with only the top of its turret over the surface
of the water. On the approach of an enemy's vessel the smokestack
will be shipped and the aperture on top of the turret through which
it passed will be quickly closed watertight. She will then run in
a direction to intercept the enemy's ship, still remaining in the
awash condition, until she comes near enough to be discovered by
the lookouts on the ship, when she will go from the awash to the
entirely submerged condition. The distance from the ship at which
she will dive will depend upon the weather. In rough weather she
can come quite close without being observed. Having come within a
distance that the operator estimates at two or three hundred yards
from the ship, the diving rudders are manipulated so as to cause
the top of the turret to come for a few seconds above the surface
of the water. During this short exposure of the turret--much too
short to give the enemy a chance to find its distance and train a
gun on it capable of inflicting any injury--the pilot ascertains
the bearing of the enemy's ship, alters his course or makes another
dive if necessary. If he finds that the submarine boat is within
safe striking distance, say one hundred yards, a Whitehead torpedo
is discharged at the ship. A heavy explosion within six seconds
after the torpedo is expelled will notify the operator that his
attack has been successful, and he may then devote his attention
to the next enemy's ship that may be within reach. When the boat
is running on the surface of the water, with full steam power, and
it becomes necessary to dive quickly, the pilot gives the order,
'Prepare to dive.' The oil fuel is instantly shut off from the
furnace, the valves are opened to admit water to the water-ballast
tanks, an electric engine draws down the smokestack and air-shaft
into the superstructure, and moves a large, massive sliding valve
over the aperture on the turret through which the smokestack
passes. These operations will be completed in about thirty seconds,
when the boat is in the awash condition and prepared to dive. In
twenty seconds more it will be running horizontally at a depth of
twenty feet below the surface of the water and quite beyond reach
of the enemy's projectiles."

I submitted designs of a twin-screw vessel eighty feet long, ten feet beam, and one hundred fifteen tons displacement, with 400-horsepower steam engines for surface propulsion and 70-horsepower motors for submerged work. This design introduced several new and striking features into the art of submarine navigation which have been the cause of considerable scientific discussion. The design called for a _double hull_ vessel, the spaces between the inner and outer hulls forming water-ballast tanks; the design also called for twin screws and four torpedo tubes, two firing forward and two aft.

Novel features consisted in: (A) wheels for running on the bottom; (B) rudder forming also a steering wheel when navigating on the bottom; (C-C) propellers for holding vessel to depth when not under way; (D-D) depth regulating vanes or hydroplanes for causing vessel to change depth while under way and to accomplish the changes of depth on an even keel; (E-E) horizontal rudders or "leveling vanes" designed to automatically hold the vessel on a level keel when under way; (F) a weight automatically controlled by a pendulum; (P) mechanism to correct trim; (G) gun arranged in watertight revolving turret for defense purposes or attack on unarmored surface craft; (L) propeller in tube for swinging vessel at rest to facilitate "pointing" her torpedoes; (M) conning tower; (N) telescoping smokestack; (O) observing instrument arranged to turn down on deck when under way; (T-T) torpedo tubes, two firing forward and two aft; (W-W) anchoring weights to hold the vessel at rest at any desired depth between the surface and bottom; (X) an "emergency keel" which would be automatically released if the vessel reached an unsafe depth. She was a double-hull vessel, water being admitted to the space between the inner and outer hulls and in trim tanks forward and aft to effect submergence. A diving compartment was also provided to enable the crew to leave or enter the vessel while submerged.]

The novel feature which attracted the most attention and scepticism regarding this design was--so I was later informed by a member of the Board--in the claim made that the vessel could readily navigate over the water-bed itself and that while navigating on the water-bed a door could be opened in the bottom of a compartment and the water kept from entering the vessel by means of compressed air, and that the crew could, by donning diving suits, readily leave and enter the vessel while submerged. Another novel feature was in the method of controlling the depth of submergence when navigating between the surface and the water-bed. The vessel was designed always to submerge and navigate on a level keel rather than to be inclined down or up by the bow to dive or rise. This maintenance of a level keel while submerged was provided for by the installation of four depth-regulating vanes, which I later termed "hydroplanes" to distinguish them from the forward and aft levelling vanes or horizontal rudders. These hydroplanes were located at equal distances forward and aft of the centre of gravity and buoyancy of the vessel when in the submerged condition, so as not to disturb the trim of the vessel when the planes were inclined down or up to cause the vessel to submerge or rise when under way. I also used, in conjunction with the hydroplanes, horizontal rudders, which I called "levelling vanes," as their purpose was just the opposite from that of the horizontal rudder used in the diving type of vessel. They were operated by a pendulum-controlling device to be inclined so as always to maintain the vessel on a level keel rather than cause her to depart therefrom. When I came to try this combination out in practice I found hand control of the horizontal rudders was sufficient. If vessels with this system of control have a sufficient amount of stability, they will run for hours and _automatically maintain both a constant depth and a level keel_, without the depth-control man touching either the hydroplane or horizontal rudder control gear. This automatic maintenance of depth without manipulating the hydroplanes or rudders was a performance not anticipated or claimed in my original patent on the above-mentioned combination, and what caused these vessels to function in this manner remained a mystery, which was left unsolved until I built a model tank in 1905, in Berlin, Germany, and conducted a series of experiments on models of submarines. I then learned that the down pull of a hydroplane with a given degree of inclination varied according to its depth of submergence, and the deeper the submergence the less down pull. This works out to give automatic maintenance of depth so long as the vessel is kept at a constant trim on a substantially level keel, and I have known of vessels running for a period of over two hours without variation of depth of one foot and without once changing the inclination of either the hydroplanes or the horizontal rudder.

The capability of this arrangement of hydroplanes and horizontal rudders to control the depth of submergence was questioned and doubted for many years. As late as 1902, nearly ten years after I first submitted this method of control to the United States Navy Department, Naval Constructor L. Y. Spear, U. S. N., testifying before the Committee of Naval Affairs, House of Representatives, in reference to the "Lake even-keel boat" and my use of hydroplanes, said, "As an expert I do not think he will make his hydroplanes work"; and strongly contended that submergence by inclining the vessel itself was the proper method.

Several years later, in 1908, in Paris, I met Captain Lauboeuf, the celebrated French naval constructor, who has perhaps done more toward perfecting the French submarines than any other designer, and he informed me that after the French Government had its sad experience in the loss of the _Lutine_ and _Farfadet_ with their crews, it had changed all their diving boats into even-keel boats and was now using substantially my method of even-keel submergence with hydroplane control. He also informed me that it had, at that time, thirty-five new boats under construction to operate on the even-keel principle, eighteen of which were of five hundred and fifty tons displacement. Captain Lauboeuf was kind enough to compliment me as having been the first to introduce this method of submerged control.

Commander Murray F. Sueter, Royal British Navy, in his most complete work on "The Evolution of the Submarine Boat, Mine and Torpedo, from the Sixteenth Century to the Present Time," published in 1907, said:

"After scrutinizing all the information available, I am certain
that several features of the 'Lake' design will be embodied by most
nations in the construction of future boats, the chief of which,
perhaps, are 'the even-keel method of submergence' in preference to
the 'dynamical dive' of the Holland boats; also the provision of a
safety keel and diving compartment. This latter forms a ready means
of communicating with the surface should the boat, through some
small mishap, find herself on the bottom and unable to rise."

Sir Trevor Dawson, formerly (R. N.) manager of "Vickers," in discussing submarine boats before the Institution of Naval Architects in 1907, said:

"Mr. Lake mentioned the question of the importance of horizontal
stability and the use of hydroplanes. I think these have been
used by the Holland Company in America in connection with the
experiments they made for the American Government. In one of
the boats I saw they gave me particulars of such experiments.
I know, too, that they have been used considerably in France
with satisfactory results, and I think his contention as to the
importance of horizontal stability, as things exist to-day, is
fully justified."

Captain Edgar Lees (R. N.), who was the officer in charge of the British submarines, said:

"I may say, with regard to the features that Mr. Lake has brought
to our notice--the hydroplane, for instance, and getting good
freeboard and seaworthy boats--the mere fact that they have been
largely copied and that most nations build these submarine boats
is, as Mr. Lake contends, a conclusive proof that he has been
for years on the right tack. Well, I do not think at the present
moment submarine boats are being built in any country without
hydroplanes, in order to dive, if desired, almost horizontally."

One of the latest contract requirements of the United States Government, specifying the characteristics of the new boats to be built under the appropriation for submarines for the year 1915, stated:

"The vessel shall make also the necessary trials to demonstrate her ability to effect initial submergence, to maintain submergence under way, and to change depths without exceeding an angle of inclination of one degree." This, in substance, calls for "even-keel submergence" when one considers that it was common for early boats of the diving type to take on an inclination of fifteen to twenty degrees, and inclinations of as much as forty-five degrees were not unknown.

All governments and submarine builders have at present in their latest boats adopted the method of even-keel submergence by the use of hydroplanes, and I am gratified that this method of control has been finally adopted as the standard, as I believe none of the latest modern submarine boats will make the uncontrollable dives to the bottom common in the boats of the diving type, which have been accompanied in many cases by the loss of their crews.

I did not make a proposal to build a boat from my designs as submitted in 1893, but offered to coöperate with the government in developing submarines under my patents, which were then pending, on such terms as the government might desire. Not being fortunate enough, however, to secure the financial assistance of the government in developing my inventions for the protection of our country, I turned my attention for a time to applying my inventions to commercial purposes and to prove the practicability of navigating on the bottom.

For this purpose I built, in 1894, the _Argonaut, Jr._, which I mentioned in the preceding chapter, and will now describe more fully. This vessel was provided with three wheels, two on either side forward and one aft, the latter acting as a steering wheel. When on the bottom the wheels were rotated by hand by one or two men inside the boat. Her displacement was about seven tons, yet she could be propelled at a moderate walking gait when on the bottom. She was also fitted with an air-lock and diver's compartment, so arranged that by putting an air pressure on the diver's compartment equal to the water pressure outside a bottom door could be opened and no water could come into the vessel. Then by putting on a pair of rubber boots the operator could walk around on the sea bottom and push the boat along with him and pick up objects, such as clams, oysters, etc., from the sea bottom.

Experiments with this vessel on the bottom of Sandy Hook Bay convinced a sufficient number of people who were permitted to witness the experiments that submarine navigation in this manner was practicable, and I succeeded in raising sufficient capital to build a larger vessel to continue my experiments on a broader scale. Therefore, in 1895, I designed the _Argonaut_.

Built to further demonstrate the possibility of navigation over the waterbed of seas or the ocean. She covered thousands of miles in her experimental work, testing out the practicability of the submarine for various kinds of commercial work.]

At this time I was living in Baltimore, Md., so I made a contract with the Columbian Iron Works and Dry Dock Company, of that city, for her construction. This company was also building for the Holland Torpedo Boat Company the _Plunger_, which was being constructed for the government under the 1893 appropriation. Both vessels were completed about the same time. They were launched in August, 1897, and went into dry dock together.

The _Argonaut_, as originally built, was thirty-six feet long and nine feet in diameter. She was the first submarine to be operated successfully with an internal-combustion engine. She was propelled with a thirty-horsepower gasolene (petrol) engine driving a single-screw propeller. She was fitted with two toothed driving wheels forward, which were revolved by suitable gearing when navigating on the water-bed. They could be disconnected from this gearing and permitted to revolve freely, propulsion being secured by the screw propeller. A wheel in the rudder enabled her to be steered in any direction when on the bottom. She also had a divers' compartment to enable divers to leave or enter the vessel when submerged, so as to operate on wrecks or to permit inspection of the bottom or to recover shellfish. She also had a lookout compartment in the extreme bow, with a powerful searchlight to light up a pathway in front of her as she moved along over the water-bed. This searchlight I later found of little value except for night work in clear water. In clear water the sunlight would permit of as good vision without the use of the light as with it; while, if the water was not clear, no amount of light would permit of vision through it for any considerable distance.

As the _Argonaut_ was principally built in order to further test out the possibility of navigating on the water-bed in exploration and commercial work, she was propelled, both when on the surface and submerged, by her gasolene (petrol) engines. Storage batteries were carried only for lighting purposes. The air to run her engines was first drawn into the vessel through a hose extending to a buoy floating on the surface. Later she was fitted with pipe masts, which enabled her to navigate on the bottom in depths up to fifty feet. She functioned satisfactorily from the start. We found we could readily navigate over any kind of bottom, soft or hard, by regulating her buoyancy to suit, and she would, due to her buoyancy, readily climb over any obstruction that did not reach higher than her forefoot.

Showing how such a vessel will surmount a steep declivity while a boat of the diving type (D) will likely "bury her nose" into it or strike with sufficient force to disarrange her machinery. If the submarine has sufficient statical stability she will maintain substantially a level keel even when riding over a steep declivity.]

There were three things which caused us to delay her departure on a submarine exploration trip for a few weeks. The first was the escape of gasolene (petrol) fumes in the boat. When first built, fuel tanks were built in the hull itself and formed an integral part of the vessel. Special care was given to make these fuel tanks tight. They were tested under hydraulic pressure and found to be tight, but the fumes from gasolene (petrol) are very searching, and, after filling the fuel tanks and keeping them filled over night, gasolene fumes were found to exist in the boat the next morning to such an extent that I would not venture to make a start until a fuel tank had been built outside of the vessel, where any escape of fumes would not form an explosive mixture. I followed this practice in all our later gasolene-engined boats, which largely eliminated the danger from carrying gasolene as a fuel. A number of explosions have occurred in other types of gasolene-propelled boats, in some cases with fatal results, from gasolene fuel being carried in built-up tanks within the hull itself.

The next cause of delay was due to the escape of and collection of carbon monoxide within the vessel. This developed on our first submarine run. After we had been down about two hours some of us commenced to experience a dull pain at the base of the brain and a decided feeling of lassitude. On coming to the surface a couple of our men collapsed completely, and one was very sick all night. I could not understand the cause of this, as nothing of the kind had occurred in my previous hand-propelled vessel, so we made another submerged run the following day, and after about the same period of time the pain in the head and weariness came on again. I then discovered that the engine would occasionally backfire out into the boat and that gas was escaping past the piston rings into the base of the engine and from there into the boat. To overcome this difficulty I installed what I called an induction tank, which was piped up to the air intake of the engine and also the engine base. A check valve admitted air into this induction tank. When the engine was started the check valve was automatically lifted and induced a flow of air through the tank, in which a slight vacuum was maintained, which also served to draw the gases out from the engine base. In case of a backfire, the check valve automatically closed and the gases from the backfire were caught in the induction tank, from which they were drawn out on the next stroke of the engine. This solved the difficulty, and thereafter the air was always fresh and pure when running submerged even after a submergence of several hours' duration.

Like Mr. Holland, I also had difficulty on our first submergence in always knowing where we were going. Our compass was first installed in the boat itself, where it was surrounded by steel. The compass adjuster had searched for and found what he considered the most _neutral_ place in the ship to install the compass, and had adjusted it by magnets in the usual manner, but it was too "loggy" for correct navigation and we were forced finally to install it in a bronze binnacle directly over the conning tower, where it could be viewed by mirrors from the steersman's station. This cut out most of the adjusting magnets, and the compass was nearly accurate on all courses. Submarine navigation thus became reliable.

On the completion of these changes the _Argonaut_ was taken down the Chesapeake Bay to Hampton Roads, where several months were spent in examining the bottom conditions in the bay and out on the ocean, and in locating and picking up cables and in examining wrecks. The Spanish-American War was on at this time, and an effort was made to interest the government officials in charge of the mines at Fortress Monroe. I tried to get some of the officers to go down in the _Argonaut_ and see how easily observation mine cables could be located and cut if desired, as I was making almost daily submerged runs in their vicinity. Finally I received peremptory orders not to submerge within a mile of the mine fields, as I might accidentally sever one of the cables, and then, as the officer in charge said, "There would be the devil to pay in Washington."