Submarine Warfare of To-day Part 4

MOTOR LAUNCHES

About the now famous motor launches, or "movies," as they are called in the Service, much will be said in later pages. They numbered over 500, and, with but few exceptions, were a h.o.m.ogeneous flotilla of fast sea-going patrol boats, heavily armed for their size. Some idea of their appearance under varying conditions will be gained from a study of the ill.u.s.trations.

They were all commanded by R.N.V.R. officers, whose training on H.M.S.

_Hermione_ and elsewhere has been described in an earlier chapter. They carried a crew of nine men and two officers, and their zones of operations extended from the icy seas which wash the Orkneys and Shetlands to the West Indies and the Suez Ca.n.a.l.

It may be of interest to give here an extract from the American journal, _Rudder_, showing how these vessels came into being.[3] Although the hulls were constructed in Canada, and much of the a.s.sembling was also carried out on the banks of the St Lawrence, the engines came from the United States. It was to the organising ability of Mr Henry R. Sutphen, of the Electric Boat Company, New York, that the delivery of over 500 of these wonderful little craft in less than a year was due. Here is that gentleman's story of the "M.L." contract:

"It was in February, 1915, that we had our initial negotiations with the British Naval authorities. A well-known English shipbuilder and ordnance expert was in this country, presumably on secret business for the Admiralty, and I met him one afternoon at his hotel. Naturally the menace of the German submarine warfare came into discussion; we both agreed that the danger was a real one, and that steps should be taken to meet it.

"I suggested the use of a number of small, speedy gasolene boats for use in attacking and destroying submarines. My idea was to have a mosquito fleet big enough to thoroughly patrol the coastal waters of Great Britain, each of them carrying a 13-lb.

rapid-fire gun.

[Ill.u.s.tration: FIG. 1.--Diagram showing princ.i.p.al characteristics of an armed motor launch. _A._ Wheel-house. _B._ Searchlight. _C._ Chart-room.

_D._ Navigation lights. _E._ 3 or 13 pounder quick-firing gun. _F._ Wheel and indicators in wheel-house. _H._ Hand pumps supplementing power pumps in engine-room. _I._ Hatchway leading to engine-room. _J._ Hatchway leading to wardroom. _K._ Life-boat. _L._ Officers' cabins.

_M._ Hatchway leading to officers' cabins. _N._ Depth charges (2 or 4).

_O._ Deck box containing life-belts. _P._ Stern petrol tanks (2). _Q._ Officers' sleeping cabin. _R._ Officers' mess-room. _S._ Galley. _T._ Engine-room. _U._ Main petrol engines (2). _V._ Reservoirs of compressed air for starting main engines. _W._ Foreward petrol tanks. _X._ Forecastle and men's quarters. _Y._ Men's lavatory. _Z._ Forepeak.]

"I explained that I had in mind two distinct types. The first would have an over-all length of about 50 feet, and would be fitted with high-speed engines; such a boat would show a maximum of 25 knots. The alternative would be something around 80 feet in length, with slow turning engines and a speed of 19 knots. I added that my preference was for the larger and slower type.

"He asked how many units of that cla.s.s we could build in a year's time, and I told him that I could guarantee fifty. He said that he would think the matter over, and we parted.

"A few days later I had another interview and was told that the British Government was ready to give us a contract for fifty vessels of the larger type, the whole lot to be delivered within a year's time.

"On April 9th, 1915, the contract for fifty 'chasers' was signed.

"The _Lusitania_ sailed on her last voyage May 1st, 1915, and a week later her torpedoing by a German U-boat was reported. My English friend was sailing that same day from New York, and we were giving him a farewell luncheon at Delmonico's.

When the appalling news was communicated to him he appeared much depressed, as indeed was natural enough, and also very thoughtful. Before he said good-bye he intimated to me that he intended advising the Admiralty to increase the number of 'Chasers'; he asked me if I thought I could take care of a bigger order. I told him that I could guarantee to build a boat a day for so long a period as the Admiralty might care to name.

"After he reached England we shortly received a cablegram ordering five hundred additional 'Sutphens,' our code word for submarine 'Chaser'; in other words we were now asked to build five hundred and fifty of these boats and deliver them in complete running order by November 15th, 1915."

[Ill.u.s.tration: FIG. 2.--Plan of armed motor launch, showing internal arrangements. _A._ Officers' sleeping cabin. _B.B._ Bunks. _C._ Cupboard. _D._ Lavatory. _E.E._ Stern petrol tanks. _F._ Wardroom. _G._ Table. _H._ Settee. _I._ Galley. _J._ Petrol stove. _K._ Engine-room.

_L.L._ Main engines. _M._ Compressed air reservoirs. _N._ Auxiliary petrol engine driving dynamo, bilge pumps, fire pumps and air compressor. _O._ Electric storage batteries, switchboard and electrical starting arrangements for auxiliary engine. _P._ Chart-room with petrol tanks below. _Q._ Magazine. _R._ Fresh-water tanks. _S._ Forecastle.

_T._ Bunks for crew. _U._ Forecastle lavatory. _V._ Watertight forepeak.]

The armament of a motor launch consisted of a 13-pounder quick-firing high-angle gun, capable of throwing a lyddite sh.e.l.l for over four miles, and was as useful against aircraft as it was against submarines. In addition to this heavy gun for small craft they carried about 1200 lb.

of high explosive in the form of depth charges for bombing under-water craft, a Lewis machine gun, rifles and revolvers.

These vessels were driven by twin screws connected to twin engines of about 500 h.p. They possessed, in addition, an auxiliary petrol engine of about 60 h.p. for compressing the air required to start the main engines, for working the fire and bilge pumps, and for driving a dynamo to recharge the electric storage batteries. The triple tanks carried over 3000 gallons of petrol, and the consumption, when travelling at full speed, was a gallon a minute.

Many were fitted with wireless, and all of them had on board the most approved pattern of hydrophone, with which to listen below the surface for the movements of hostile submarines. They had electric light in the cabins and for navigation, fighting and mast-head signalling purposes. A moderately powerful searchlight, fitted with a Morse signalling shutter, was also part of their equipment.

These little miniature warships possessed a small wardroom and sleeping cabin for the officers, a galley with petrol range for cooking, an engine-room, magazine for the ammunition, chart-room, and ample forecastle accommodation for the crew of nine men. All parts of the ship were connected with the bridge by speaking-tubes and electric bells, and the aft deck accommodated a steel life-boat.

The duties of these craft varied considerably. For over three years they maintained a constant patrol in the North Sea, Atlantic, English Channel, Irish Sea, Mediterranean, Adriatic, Suez Ca.n.a.l, Straits of Gibraltar, and in West Indian waters. Only one who knows by experience can fully appreciate what work in these northern seas, with their winter snows and Arctic winds, and their chilly summer fogs, really means to a mere thirty tons of nautical humanity in as many square leagues of storm-swept sea infested with mines and hostile submarines. But when this book has been finished the reader will be in a position to judge for himself.

The losses of motor launches were not heavy considering the dangerous nature of their cargoes (3000 gallons of petrol within a few feet of 1500 lb. of high explosive in a wooden hull) and the duties they were called upon to perform in all weathers short of heavy gales. Several were blown up with terrible results to those aboard. Others caught fire and were burned--allowing only just sufficient time to sink the explosives aboard. A few were smashed to pieces on exposed coasts after struggling for hours amid heavy seas. One struck a mine off Ostend.

Another was destroyed by sh.e.l.l-fire in the Mediterranean, and the part they played in the raids on Zeebrugge and Ostend, in which two were lost and a V.C. gained, is now world famous.

COASTAL MOTOR BOATS

There was, besides M.L.'s, another smaller but faster type of submarine chaser. These little vessels, of which there were about 80 actually in commission, possessed no cabin or other accommodation for long cruises.

They were simply thin grey hulls with powerful high-speed engines. They were known as C.M.B.'s, or, to give them their full t.i.tle, Coastal Motor Boats. The purpose for which they were constructed was to operate from coastal bases, and to be launched from ocean-going ships to chase a hostile submarine which had been located by seaplanes and reported by wireless in a given locality. This, however, was what they were _intended_ for, but bore little relation to the work they actually accomplished. Their nickname was "Scooters," and they certainly did "scoot" over the sea.

[Ill.u.s.tration: FIG. 3.--Diagram showing princ.i.p.al characteristics of a coastal motor boat (C.M.B.). Speed 50 miles per hour. _A._ Hydroplane hull, so constructed as to rise on to surface when travelling at full speed. _B._ Covered wheel-house. _C._ Navigating well. _D._ Wireless aerials. _E._ Depth charges (2 small size). _F._ Manhole to engine-room.]

There were three types of C.M.B.'s. One had a length of only 44 feet, and was intended for carriage on the decks of light cruisers or other moderate-sized surface ships. The armament was a Lewis machine gun and two depth charges for anti-submarine warfare. The next cla.s.s were 55 feet in length and operated from coast bases. These were fitted with one or more Whitehead torpedoes, launched by an ingenious contrivance from the stern. Cla.s.s III. were 70 feet in length, and were commissioned just before the signing of the Armistice. They were fitted for mine-laying close up to enemy harbours.

[Ill.u.s.tration: FIG. 4.--Plan of coastal motor boat, showing torpedo in cleft stern. _A._ Whale-back or arched deck. _B._ Wheel-house. _C._ Navigating well. _D._ Engine-room. _E._ Foreward petrol tanks. _F._ Forepeak. _G._ Depth charges. _H._ Cleft stern with torpedo ready for launching. _I._ Whitehead torpedo, launched stern first.]

The maximum speed of the 55-feet C.M.B.'s, which were the most numerous, was 40 knots, or nearly a mile a minute. They were driven by twin screws coupled to twin engines of 350 h.p. each--working at 1350 revolutions per minute. Being of very shallow draught, some 26 inches, these little vessels could skim, hydroplane fashion, over any ordinary mine-field, and a torpedo fired at them would merely pa.s.s under their keel. The risk of destruction from sh.e.l.l-fire was also reduced to a minimum by their small size and great speed. Their princ.i.p.al enemies were, however, seaplanes armed with machine guns.

[Ill.u.s.tration: A 40-FT. COASTAL MOTOR BOAT TRAVELLING AT FULL SPEED

_Th.o.r.n.ycroft & Co., Ltd._]

[Ill.u.s.tration: A 40-FT. COASTAL MOTOR BOAT TRAVELLING AT FULL SPEED

_Th.o.r.n.ycroft & Co., Ltd._]

It is not difficult to imagine a fight between a C.M.B. travelling at 40 knots, firing with its little Lewis gun at a big seaplane swooping down from the clouds at the rate of 70 miles an hour, and splashing the water around the frail little grey-hulled scooter with bullets from its machine gun. This actually occurred many times off the Belgian coast, and is a typical picture of guerrilla war at sea in the twentieth century.

[Ill.u.s.tration: FIG. 5.--Diagram ill.u.s.trating method of attack by C.M.B.

on surface ship (or submarine on surface). _A._ Object of attack travelling in direction indicated by arrow _E._ _B._ The position of the C.M.B. after delivering the attack. _C._ The torpedo, released by the C.M.B. at point _D_, travelling on course ending at _F_, which, allowing for movement of ship _A_, is the place where the torpedo should strike its object of attack. From this it will be seen that the torpedo, when released, actually follows the ship from which it is fired until the latter swerves from the straight course, when the torpedo continues until it strikes or misses the object of attack, the speed of the torpedo being about the same or a little less than that of the C.M.B.

The total time occupied in such an attack over a course of two miles would be about 2 1/2 minutes before the torpedo struck its object.]

The C.M.B. was a purely British design, and the firm largely responsible for the success achieved was Messrs John J. Th.o.r.n.ycroft & Company Limited. There were bases for these sea-gnats at Portsmouth, Dover, Dunkirk, and in the Thames Estuary at Osea Island. From all of these points mid-Channel could be reached in less than thirty minutes.

Although useless in rough weather, a trip in a C.M.B., even on a calm day, was sufficiently exciting. The roar of the engines made speech impossible, and vision when sitting in the little gla.s.s-screened well, or conning-tower, was limited by the great waves of greenish-white water which curved upwards from either bow, and rolled astern in a welter of foam. There was an awe-inspiring fury in the thunder of the 700 h.p.

engines revolving at 1350 per minute, and a feeling of ecstasy in the stiff breeze of pa.s.sage and the atomised spray. When waves came the slap-slap-slap of the water as the sharp bows cleft through the crest and the little vessel was for a brief moment poised dizzily on the bosom of the swell caused tremors to pa.s.s through the thin grey hull, and, to complete the review of sensation, there may be added the human thrill of battle and the indescribable feeling of controlled power beneath one's feet.

The C.M.B.'s record of service, although short, is nevertheless a brilliant one. Towards the close of the year 1916 four of these little vessels coming from the base at Dunkirk intercepted five German destroyers returning from a Channel raid. The scooters raced towards the enemy in a smother of foam. Every quick-firing gun on the German ships spouted sh.e.l.ls at the mysterious white streaks approaching them with the speed of lightning. So close did these plucky little ships go to their giant adversaries that the blast of the German guns was felt aboard, but no sh.e.l.ls struck them. Then the line of C.M.B.'s swerved and their torpedoes were launched at close range. One of the enemy destroyers was. .h.i.t and badly damaged, while two others had narrow shaves.

There was no time for German retaliation. For a brief few minutes the sea around the scooters was ploughed up by the sh.e.l.ls from the Hun artillery, then the four little attacking craft were five miles distant from the scene of their victory, and presented almost invisible white specks to the enemy gunners.

At Zeebrugge these craft ran close in under the guns of the sh.o.r.e fortifications, and covered the approach of the landing parties and block-ships with a screen of artificial smoke. At Ostend they entered the harbour under heavy fire and ignited flares to enable the block-ships to navigate in the darkness. Others, in the same operations, torpedoed the piers and silenced the guns mounted thereon.

Their exploits savour of old-time sea romance, as, for example, when the little _Condor_ ran in under the guns of the fortress of Alexandria, or further back in our naval history, when sail and round shot took the place of petrol and torpedoes.

For anti-submarine work these wonderfully fast little chasers were used in small flotillas. They were fitted with short-range wireless sets, and when the message came stating that a vessel was being attacked in a certain position, perhaps twenty miles from the coast, a number were instantly released from the leash, and in a fraction of the time taken by larger vessels they were on the scene with torpedoes and Lewis guns for surface attack and depth charges for submerged bombing.

They were commanded, in many instances, by R.N.V.R. officers of the auxiliary service, and carried two engineers. No crew was necessary, nor was s.p.a.ce available for them. The plucky dash of these vessels into the harbours of Zeebrugge and Ostend, their subsequent operations on the Belgian coast, and their losses in the action at the entrance to the Heligoland Bight in 1918, when they were launched from a big ship, have earned for them high renown in naval history.

BOOM DEFENCE SHIPS