CHAPTER XV

THE NORDENFELT SUBMARINES

About the year 1878 a gentleman in holy orders, Mr. Garrett by name, designed a submarine boat, which was built by Messrs. Cochrane, of Liverpool. It was 45 feet long, of the shape of two cones, with a central cylindrical portion. This vessel, to which the name of _Resurgam_ was given, was tried in the Birkenhead Float in 1879. It descended by means of pistons which varied the displacement of the boat by being drawn in and pushed out, as well as by central rudders which steered it up and down. Compressed-air tanks were provided, and chemicals were stored to purify the air after use.

Soon after a larger boat was constructed in which steam replaced manual labour as the motive power; when about to sink the chimney was removed and an air-tight stopper fitted on the opening to the up-take; the furnace mouths were similarly closed by doors, like those of a gas retort, and the boat sank. Power was supplied on Lamm’s system by the hot water in the boiler. After a number of experiments she was finally lost off the Welsh coast.

The attention of Mr. Thorsten Nordenfelt (the inventor of the gun which bears his name) was directed to Mr. Garrett’s design, and the result was that he decided to build a submarine vessel himself. He acknowledged that the negative experience gained during the trials of the Garrett boat had been of advantage to him in avoiding the faults which made that boat unsuccessful.

[Sidenote: Nordenfelt I.]

Mr. Nordenfelt’s first submarine boat was built at Stockholm, and was tried in the Sound of Landskrova, in Sweden, in September, 1885, in the presence of delegates from most of the leading Governments.

Its dimensions and details were as follows: Length 64 feet, beam 9 feet (over sponsons 12 feet), draught 11 feet, displacement 60 tons; speed on measured mile 9 knots; distance travelled without re-coaling 150 miles; depth to which safe descent was possible, about 50 feet. Engines, surface condensing compound type, with two cylinders and cranks at 90°; at pressure of 100 lbs. to square inch, indicating 100 horse-power. Boiler of ordinary marine return tube type, having one furnace, and about 200 square feet of heating surface; two hot-water cisterns, rhomboidal in body with spherical ends. The boilers and cisterns contained about eight tons of water. Both boilers and cisterns were made for a working pressure of 150 lbs. to square inch. One fish torpedo, 14 feet long, was carried outside on the bow and discharged mechanically. The sinking apparatus consisted of two vertical propellers driven by a 6–h.p. double-cylinder engine, and placed in sponsons on each side of the boat. The revolution of these caused the boat to descend horizontally when its buoyancy had been sufficiently diminished. There was one cold-water tank in the centre of boat, holding about four tons of water, for regulating buoyancy. This tank was used as coal bunker when doing long surface runs. In the stern was a four-bladed propeller 5 feet in diameter, and the rudder for port and starboard steering was placed aft of this propeller.

In the bow on either side were balanced rudders on one and the same axle, always maintained in the horizontal position. The crew consisted of three men, and when the boat was closed up there was sufficient air to supply three men for six hours without causing discomfort, and this was not supplemented by any storage of compressed air or restorative chemicals. The depth below the surface at which the boat travelled could be varied in two ways; either by varying the speed of the vertical propellers, or by reducing the speed of the engines driving them by an automatic valve controlling the steam supply. On the surface the boat was driven by working the boiler in the usual manner, and the temperature of the water in the cisterns was kept up to a degree corresponding to a steam pressure of 150 lbs. When it was desired to descend, the ashpit and fire door were closed, as also the funnel inside the boat, and the vertical propellers were started. For sub-surface travelling there was available, as propelling power, the steam given off by the heated water (about eight tons), and this was found sufficient for a distance of 14 knots; on one occasion, when the boat was opened up, there was still over 20 lbs. pressure in the boiler.

[Sidenote: Nordenfelt II.]

Mr. Nordenfelt recognised that for the defence of open coasts and for operations where it might be necessary to keep the sea for days together without being able to seek the shelter of inlets or the mouths of rivers, other and larger proportions than those of his first 64 foot-boat would be desirable.

He accordingly constructed a boat on such larger lines, the details of which are as follows:—

Length 100 feet, beam 12 feet, displacement 160 tons, speed on measured mile 12 knots, distance travelled without re-coaling 900 miles, depth to which descent could safely be made, about 50 feet. Engines, surface condensing compound type, with two cylinders, and cranks at 90°, and at a pressure of 100 lbs. of steam indicating 250 h.p. Boiler, of the ordinary marine return tube type, having two furnaces; about 750 square feet of heating surface. Hot-water cistern, rhomboidal in body with spherical ends. Both boiler and cistern made for a working pressure of 150 lbs. per square inch. Armament, two fish torpedoes, 14 feet long, carried outside on the bow and discharged mechanically. Two Nordenfelt quick-firing machine guns consisting of 1–inch calibre. Sinking apparatus, two _vertical_ propellers, driven by two engines, each indicating 6 h.p.; these propellers were placed in the fore and aft line. This was an improvement on the earlier boat whose screws were fitted in side sponsons. The mere arrest of these propellers sufficed to bring the boat to the surface, as it had a reserve buoyancy. Bow fins, whose action was both automatic and controllable, maintained the boat in the horizontal position. The main propeller was placed abaft the rudder. Two main cold-water cisterns placed at each end, and containing 15 tons of water each, also one in centre of boat for regulating buoyancy containing 7 tons; coal bunkers on the side of boiler; 8 tons of coal carried at the side of hot-water cistern and in middle of boat. Crew, three men in a watch: two watches carried. With coal in the bunkers only, this boat could keep the sea for five days or more. No attempt was made to purify the air when submerged. When descending, the boat was perfectly horizontal, and was invariably kept so when moving under water by means of the bow rudders operated by a plumb weight.

Nordenfelt II. had two distinct conditions of existence as a torpedo craft—that of a surface boat and a submarine one. The sinking operations were as follows: the furnaces were hermetically closed, upon which combustion was soon brought to an end. The piece of funnel connecting the boiler with the outward portion was then removed and the doors placed in position. Whilst these changes were being effected, water was allowed to run into the ballast tanks to reduce the buoyancy to its proper limit, and this arrived at, nothing remained but to close up the conning tower and to set in motion the vertically acting screws to place the boat quite out of sight.

In a paper which he read before the Royal United Service Institution, on February 5, 1886, Major-General Sir Andrew Clarke in the chair, Mr. Nordenfelt after mentioning previous under-water vessels, gave his views as to the reason of their failure.

First of all he said they were always built too small and too weak. The longest was 45 feet, and their small dimensions and weak plates made them useless in bad weather and dangerous for submersion; the small air space available forced the crew to use chemical means to obtain pure air. Secondly, they were never made for firing a fish torpedo; consequently they had to endeavour to fix a mine to the bottom of a vessel, a feat which Mr. Nordenfelt considered impracticable, owing to the risk of contact with the vessel, which, especially if it were pitching or moving, might easily destroy the boat. Thirdly, in all the early boats, the mines were charged with only black powder, the effect of which was less destructive than that of the gun-cotton or dynamite in the fish torpedoes. The effect of the explosion, again, against a wooden ship, was nothing like as serious as against the thin bottom plates of an ironclad. Fourthly, all the boats hitherto in use were propelled by hand power; this gave too much hard work to the crew, who could not take the boat any distance on the surface previous to the actual attack, and made it quite impossible for it to face any rough weather. In the Nordenfelt boat the use of steam diminished the number of men, and they had so little to do when below the surface that the temperature, lower than in modern stokeholes, was no detriment. Fifthly, all previous boats had most unreliable means of descending and ascending. The descent by steering downwards in the American boats of the Civil War period was quite as dangerous as the attempts before and after that time to lower and raise the boats and to keep them steady at any desired depth, by means of increasing and decreasing the weight of the boats by more or less water-ballast or by altering their displacement.

None of these boats used the principle which Mr. Nordenfelt applied to pull his boat down by mechanical means, while relying upon its always retained buoyancy for rising; so that if the mechanical apparatus failed the boat rose at once to the surface. Again, they did not have the tendency to steadiness given by the two forces of constant pulling down by the vertical screws, acting all the time, whether still or moving, against the pulling upwards caused by the buoyancy.

Mr. Nordenfelt considered it most dangerous to rely upon a detachable weight in case of emergency, as the apparatus for detaching it would be always liable to fail. He confessed that he could not imagine how the longitudinal instability of a submerged boat could possibly have been satisfactorily controlled by any of the means applied to the previous boats. Even Goubet’s system of moving water or weights fore and aft inside the boat must act more slowly and cause more diving and oscillation than his rudders which always remained in the horizontal, and thus controlled the slightest tendency of the boat to get out of the longitudinally horizontal position. He considered it absolutely essential to keep the boat horizontal when moving, as he believed that any inclination downwards with the impetus of a heavy boat would almost to a certainty carry the boat below its safe depth before it could be effectually counteracted by shifting weights.

The reason which led Mr. Nordenfelt to construct his submarine boats was the almost insuperable difficulty in carrying the Whitehead and Schwarzkopf fish torpedoes with any degree of certainty up to the short distance at which they could be considered infallibly effective. It seemed to him that a much greater chance would be given for carrying the torpedoes within striking distance, if, instead of trying to rush the distance by many boats, all the time exposed to the destructive fire from machine guns, he could carry the torpedo secretly up to this distance without the probability of being seen at all, and without any probability of being struck by the enemy’s shot even if seen.

The tactics to be adopted by his submarines in action were thus laid down by Mr. Nordenfelt. Out of sight of the enemy the vessel ran on the surface with its cupola and about three feet of its turtle back out of water, but by forced draught, blowing out its smoke under the surface. When she arrived within such distance of the enemy that she might be discovered, she descended into the water so far that the cupola alone appeared above the waves, this was done by taking in water into the cold-water tanks sufficient to reduce the floatability to what the horizontal screws were capable of overpowering. The “reduced floatability” was never done away with, but the descent from the “awash” position was effected by starting the vertical screws, thus overcoming mechanically the buoyancy of the boat, which was pulled down to a less or greater depth depending upon the speed given to the screws.

The three main points in Mr. Nordenfelt’s system on which he laid special stress were these:

1. That by using water as the means of storing up energy he was in possession of a reservoir which could never get out of order, and which could be replaced at any hour in any part of the world, and without any extraneous assistance from shore or other ships. The reason of all others which at once decided him to adopt the hot-water system was the enormous factor of safety obtained by his being able to blow out, by steam pressure without the use of machinery, large weights of water which would lighten the boat and counteract any leak likely to occur. Mr. Nordenfelt had little faith in electricity as a motive power, which is not surprising considering the accumulators then in use.

2. The submerging the boat by mechanical means: Mr. Nordenfelt was convinced that previous attempts had proved unsuccessful, mainly because either they depended upon varying the displacement of the boat by taking in water to submerge her and to regulate the depth at which they desired to operate, or they descended by steering downwards. His objection to the first-named method of descending, by taking in water and thus increasing the specific gravity of the boat, was that practically there was no difference in the specific gravity of water on the surface or at 50 feet depth; thus when the boat had lost its buoyancy at the surface it had also no buoyancy at any given depth, and the risk was thus very great of suddenly descending beyond a safe depth.

3. The horizontal position Mr. Nordenfelt found to be a _sine qua non_ for a submarine boat.

When Mr. Nordenfelt built his boats electric accumulators were very much inferior to those of to-day; no designer of an under-water vessel would think nowadays of using the steam given off by heated water for under-water propulsion. As to his theory that a submarine boat must always descend on an even keel, this has since proved to be entirely erroneous; the modern diving torpedo boat goes down at an angle and is brought to the horizontal position at the required depth either automatically or by hand-worked mechanism.

During her trials _Nordenfelt I._ hardly did herself justice, but nevertheless in the beginning of 1886, she was bought by the Greek Government, and in April, 1886, trials took place in the Bay of Salamis, when Mr. Nordenfelt’s agent carried out the various conditions imposed.

Shortly after the first boat had been bought by Greece, Turkey ordered two submarine boats (_Nordenfelt II._ and _III._) from the inventor. Both boats were sent to Turkey in sections, but only one was assembled and tested. In 1887 it underwent trials at Constantinople, which were witnessed by the Sultan himself, who expressed himself highly satisfied with the performance of the boat.

[Sidenote: Nordenfelt IV.]

Mr. Nordenfelt’s fourth vessel was built by the Barrow Ship Building Company, the machinery being supplied by Messrs. Plenty & Sons, Newbury.

The principal dimensions were: Length, 125 feet; diameter, 12 feet; displacement fully immersed, 245 tons; in light surface condition, 160 tons. The engines turning the main propeller were especially designed for using steam at varying pressures, and indicated 1,000 h.p. when working with steam at a pressure of 150 lbs. At that power her estimated speed was 15 knots. Submerged, her speed was 5 knots. Fourteen auxiliary engines were carried for driving air circulating and feed pumps for steering and sinking. In the middle was the entrance to the stokehole through a scuttle 4 feet in diameter. Fore and aft of this scuttle were two funnels, and about 30 feet from the stem and stern of the boat were the conning towers, 2 feet high and of the same diameter. They were of 1–inch steel and were considered perfectly impervious to any shot which in warfare would ever be directed against them. In the forward tower were placed at the hands of a commander means of controlling every motion of the vessel. The boat was divided into five compartments: (1) The torpedo chamber containing two tubes; (2) Quarters for four officers; (3) The boiler room; (4) The engine room; (5) The men’s quarters, cooking galley, stoves, &c. The crew consisted of nine men all told; 35 tons of cold water were carried in the tanks; and 27 tons of hot water in the boilers. These latter were expected to store sufficient heat for a run of 20 knots under water. The coal bunkers held stores of coal which, at a speed of 8–9 knots, could drive the boat a distance of 1,000 miles. Should it be necessary to transport her to a greater distance, her water tanks could be filled with coal, enabling her to steam 2,500 miles. Two vertical propellers, one forward and one aft, kept the vessel submerged and overcame the retained force of buoyancy (500 lbs.). The boat was lighted by candles; without any special provision of air it contained enough for a crew of nine men for about six hours.

_Nordenfelt IV._ made her passage from Barrow-in-Furness to Southampton through some heavy seas, and during the voyage she was tested by her commander in every wind and every condition of wave and sea, and she proved that she was capable of being manœuvred in any weather, however bad.

On the 26th of May, 1887, she underwent her first examination before a body of critics, composed for the most part of skilled, experienced scientific officers of both branches of the Service. She was first run with nothing above water save the two conning towers and a few inches of her back, at the rate of about six miles an hour. The time occupied by the trial in the awash condition was 1½ hours, and at the end of the time a sufficiency of steam was stored up in the boilers to drive her a distance of about 24 miles. On the pumps being put in motion, some 20 tons of water were pumped out in eight minutes. The funnels were then fixed, the fires relighted, and the _Nordenfelt_ was soon making 15 knots on the surface.

On December 19, 1887, a semi-official trial of the _Nordenfelt_ took place, when she manœuvred successfully both on the surface and submerged, but no attempt was made to fire the torpedoes.

“The neutral tint she was painted,” wrote the special correspondent of the _Engineer_, “rendered her almost invisible at the distance of even a few hundred yards, while as a target she presented nothing to attack save the two conning towers and a few inches of her turtle back, and as these were of great strength and rendered still more invulnerable by their shape, it is all but certain that no gun carried on any other torpedo boat would ever do her the slightest injury, while she at the same time possesses the enormous advantage of being able to attack without smoke, or fire, or noise. Indeed, given these advantages of a minimum of target and a total absence of noise and smoke, we fail to see what more could be desired in any vessel of war.”

In a leading article in the issue of December 23, 1887, the _Engineer_ said: “We may—we hope we shall—have quite a little fleet of _Nordenfelts_ when Christmas comes round again. When once Columbus had shown the way to America, the water was freely traversed.”

The correspondent of the _Army and Navy Gazette_ said that the _Nordenfelt_ had a great and assured future before it, that with a gun or two on her turtle back, and working as an above-water torpedo boat, she certainly possessed many advantages over the ordinary first-class torpedo boat, and that her powers of submersing should make her the more valuable craft, the cost being the same. “It is not likely or advisable that a number of such boats should be at once built, but the country which can give £100,000 for a Brennan torpedo would do well to further, in every possible manner, trials and experiments with a boat so simple, yet possessing such possibilities in the future.”

It will be very naturally wondered why, in spite of these favourable opinions, the _Nordenfelt_ was so soon forgotten. The answer may be found in some recent issues of the _Engineer_. This journal published, during the years 1886–1888, all the information that was suffered to leak out concerning the experiments with the Nordenfelt boats. In 1901, by the courtesy of Mr. P. W. D’Alton (now Chief Engineer to the Central London Railway), who was associated with Mr. Garrett and Mr. Nordenfelt, it was enabled to state much more than had hitherto been made public.

Taking first the Turkish boat, it was easily proved that as a boat working near the surface, but not wholly submerged, she was fast, manageable, and a very dangerous foe because of the difficulty of finding her, and the very small mark which she offered.

As a submarine boat, she was entirely a failure.

“She had the fault of all submarine boats, viz., a total lack of longitudinal stability. All submarines are practically devoid of weight when under water. The _Nordenfelt_, for example, weighed by a couple of hundredweights less than nothing when submerged, and had to be kept down by screw-propellers provided for the purpose. The Turkish boat was submerged by admitting water to tanks aided by horizontal propellers, and raised by blowing the ballast out again and reversing the propellers. Nothing could be imagined more unstable than this Turkish boat. The moment she left the horizontal position the water in her boiler and the tanks surged forward and backwards and increased the angle of inclination. She was perpetually working up and down like a scale beam, and no human vigilance could keep her on an even keel for half a minute at a time. Once, and we believe only once, she fired a torpedo with the result that she as nearly as possible stood up vertically on her tail and proceeded to plunge to the bottom stern first. On another occasion all hands were nearly lost. Mr. Garrett was in the little conning tower. The boat was being slowly submerged—an operation of the utmost delicacy—before a committee of Ottoman officers, when a boat came alongside without warning. Her wash sent a considerable quantity of water down the conning tower, the lid of which was not closed, and the submarine boat instantly began to sink like a stone. Fortunately Mr. Garrett got the lid closed just in time, and Mr. Lawrie, the engineer, without waiting for orders, blew some water ballast out. It was an exceedingly narrow escape. In spite of these difficulties, the Ottoman officers were so impressed that the Turkish Government bought the boat. It goes without saying that it was only with the greatest difficulty the price was extracted from the Sultan’s treasury. But no use whatever has been made of her, and she lies rotting away in Constantinople, unless, indeed, she has found her way piecemeal to the marine-store dealers. A paramount difficulty in the way of utilising her was that no engineers could be got to serve in her. If men were appointed they promptly deserted. Indeed, it may be taken as certain that not one man in five hundred is fit to take charge of any submarine boat.”

The _Engineer_ is not less severe on _Nordenfelt IV._

“To all intents and purposes the _Nordenfelt_ was a total failure as a submarine boat. She began badly. As soon as she was launched from the stocks at Barrow it was seen that a mistake had been made in calculating weight, as she was down by the stern, drawing 9 feet aft and about 4 feet 6 inches forward. This would have been partially rectified by her torpedoes, but she never had one on board. Extra ballast had to be put in forward, and it was always held, rightly or wrongly, that this made it all the more difficult to keep her on an even keel, when submerged. The extra weight carried militated greatly against her speed as a surface boat. Another mistake was that the water ballast tanks were too large, or perhaps it would be more correct to say that they were not sufficiently subdivided. When she was in just the proper condition to be manœuvred by her horizontal propellers the ballast tanks were only about three-quarters full, and the water being left free surges backwards and forwards in them. It must not be forgotten, however, that ample tank capacity was necessary because the quantity of ballast needed, depended on the number of tons of coal and stores on board. Subdivision would, however, have prevented the surging of the ballast water. If, for example, the boat was moving forward or on an even keel at, say, two knots, if a greaser walked forward a couple of feet in his engine room her head would go down a little. Then the water surged forward in the tanks, and she would proceed to plunge, unless checked, and in shallow water would touch the bottom, as she did on the Mother Bank in the Solent, or if in deep water she would run down until the pressure of water collapsed her hull. No one who has not been down in a submarine can realise their extraordinary crankness. The _Nordenfelt_ was always rising or falling, and required the greatest care in handling.”