[Transcriber's note: Chart B is a navigational map of the waters southwest of Ireland, with approach routes marked.]

The idea was that the traffic in, say, Approach Route B, should, commencing on a certain date, be ordered by the Routeing Officer to pass along the line Alpha. Traffic would continue along the line for a certain period, which was fixed at five days, when it would be automatically diverted to another line, say Gamma, but the traffic along Gamma would not commence until a period of 24 hours had elapsed since discontinuance of the use of the line Alpha. This was necessary in order to give time for the patrol craft to change from one line to the other. During this period of 24 hours the arrangement for routeing at the ports of departure ensured that no traffic would reach the outer end of any of the approach lines, and consequently that traffic would cease on line Alpha 24 hours before it commenced on line Gamma. After a further period of five days the line would again change automatically.

It was necessary that Shipping Intelligence Officers should have in their possession the orders for directing traffic on to the various lines for some considerable time ahead, and the masters of ships which were likely to be for some time at sea were informed of the dates between which the various lines were to be used, up to a date sufficient to cover the end of their voyage. There was, therefore, some danger of this information reaching the enemy if a vessel were captured by a submarine and the master failed to destroy his instructions in time. There was also some danger in giving the information to neutrals.

However, the system, which was adopted, did result in a reduction of losses during the comparatively short time that it was in use, and the knowledge that patrol craft on the line would be much closer together than they would be in an approach area certainly gave confidence to the personnel of the merchant ships, and those who had been forced to abandon their ship by taking to the boats were afforded a better chance of being picked up.

Various arrangements were in existence for effecting rapidly a diversion of shipping from one route to another in the event of submarines being located in any particular position, and a continual change of the signals for this purpose was necessary to guard against the possibility of the code being compromised by having fallen into enemy hands, an event which, unfortunately, was not infrequent.

Elaborate orders were necessary to regulate coastal traffic, and fresh directions were continually being issued as danger, especially danger from mines, was located. Generally speaking, the traffic in home waters was directed to hug the coast as closely as safe navigation permitted. Two reasons existed for this, (a) in water of a depth of less than about eight fathoms German submarines did not care to operate, and (b) under the procedure indicated danger from submarine attack was only likely on the side remote from the coast.

Here is an example of the instructions for passing up Channel:

From Falmouth to Portland Bill.—Hug the coast, following round the bays, except when passing Torbay. (Directions followed as to the procedure here.)

From Portland Bill to St. Catherines.—Pass close south of the Shambles and steer for Anvil Point, thence hug the coast, following round the bays.

And so on.

As it was not safe navigationally to follow round the bays during darkness, the instructions directed that ships were to leave the daylight route at dusk and to join the dark period route, showing dimmed bow lights whilst doing so.

Two "dark period routes" were laid down, one for vessels bound up Channel, and another for vessels bound down Channel, and these routes were some five miles apart in order to minimize the danger of collision, ships being directed not to use their navigation lights except for certain portions of the route, during which they crossed the route of transports and store ships bound between certain southern British ports (Portsmouth, Southampton and Devonport) and French ports.

Routes were similarly laid down for ships to follow when navigating to or from the Bristol Channel, and for ships navigating the Irish Sea.

Any system of convoy was at this time out of the question, as neither the cruisers to marshal the convoy to the submarine area, nor the destroyers to screen it when there, were available.

There was one very important factor in the situation, viz., the comparative rate at which the Germans could produce submarines and at which we could build vessels suitable for anti-submarine warfare and for defence of commerce. The varying estimates gave cause for grave anxiety. Our average output of destroyers was four to five per month. Indeed, this is putting the figure high; and, of course, we suffered losses. The French and Italians were not producing any vessels of this type, whilst the Japanese were, in the early part of 1917, not able to spare any for work in European waters, although later in the year they lent twelve destroyers, which gave valuable assistance in the Mediterranean. The United States of America were not then in the war. Consequently measures for the defence of the Allied trade against the new menace depended on our own production.

Our submarines were being produced at an average rate of about two per month only, and—apart from motor launches, which were only of use in the finest weather and near the coast—the only other vessels suitable for anti-submarine work that were building at the time, besides some sloops and P-boats, were trawlers, which, whilst useful for protection patrol, were too slow for most of the escort work or for offensive duties. The Germans' estimate of their own submarine production was about twelve per month, although this figure was never realized, the average being nearer eight. But each submarine was capable of sinking many merchant ships, thus necessitating the employment of a very large number of our destroyers; and therein lay the gravity of the situation, as we realized at the Admiralty early in 1917 that no effort of ours could increase the output of destroyers for at least fifteen months, the shortest time then taken to build a destroyer in this country.

And here it is interesting to compare the time occupied in the production of small craft in Great Britain and in Germany during the war.

In pre-war days we rarely built a destroyer in less than twenty-four months, although shortly before the war efforts were made to reduce the time to something like eighteen to twenty months. Submarines occupied two years in construction.

In starting the great building programme of destroyers and submarines at the end of 1914, Lord Fisher increased very largely the number of firms engaged in constructing vessels of both types. Hopes were held out of the construction both of destroyers and of submarines in about twelve months; but labour and other difficulties intervened, and although some firms did complete craft of both classes during 1915 in less than twelve months, by 1916 and 1917 destroyers averaged about eighteen months and submarines even longer for completion.

The Germans had always built their small craft rapidly, although their heavy ships were longer in construction than our own. Their destroyers were completed in a little over twelve months from the official date of order in pre-war days. During the early years of the war it would seem that they maintained this figure, and they succeeded in building their smaller submarines of the U.B. and U.C. types in some six to eight months, as U.B. and U.C. boats began to be delivered as early as April, 1915, and it is certain that they were not ordered before August, 1914.

The time taken by the Germans to build submarines of the U type was estimated by us at twelve months, and that of submarine cruisers at eighteen months. German submarine officers gave the time as eight to ten months for a U-boat and eighteen months for a submarine cruiser.

(It is to be observed that Captain Persius in a recent article gives a much longer period for the construction of the German submarines. It is not stated whether he had access to official figures, and his statement is not in agreement with the figures given by German submarine officers.)

It is of interest to note here the rate of ship production attained by some firms in the United States of America during the war.

As I mention later (Vide Chapter vi, p. 157), the Bethlehem Steel Company, under Mr. Schwab's guidance, produced ten submarines for us in five months from the date of the order. Mr. Schwab himself informed me that towards the end of the war he was turning out large destroyers in six weeks. The Ford Company, as is well known, produced submarine chasers of the "Eagle" type in even a shorter period, but these vessels were of special design and construction.

I have dealt so far with the question of anti-submarine measures involving only the use of destroyers and other small surface craft. There were, of course, other methods both in use and under consideration early in 1917 when we took stock of the situation.

For some time we had been using Decoy vessels, and with some success; it was possible to increase the number of these ships at the cost of taking merchant ships off the trade routes or by building. A very considerable increase was arranged.

The use of our own submarines offensively against enemy submarines had also been tried, and had met with occasional success, but our numbers were very limited (the total in December, 1916, fit for oversea or anti-submarine work was about forty). They were much needed for reconnaissance and offensive work against surface men-of-war in enemy waters, and only a few were at the time available for anti-submarine operations, and then only at the cost of other important services.

The hydrophone had been in the experimental stage and under trial for a considerable period, but it had not so far developed into an effective instrument for locating submarines, and although trials of the different patterns which had been devised were pushed forward with energy, many months elapsed before it became a practicable proposition.

One of the best offensive measures against the enemy submarines, it was realized, was the mine, if laid in sufficiently large numbers. Unfortunately, in January, 1917, we did not possess a mine that was satisfactory against submarines.

Our deficiency in this respect was clearly shown in the course of some trials which I ordered, when one of our own submarines was run against a number of our mines, with the result that only about 33 per cent. of the mines (fitted, of course, only with small charges) exploded. The Germans were well aware that our mines were not very effective against submarines.

We possessed at the time mines of two patterns, and whilst proving unsatisfactory against submarines, they were also found to be somewhat unreliable when laid in minefields designed to catch surface vessels, owing to a defect in the mooring apparatus. This defect was remedied, but valuable time was lost whilst the necessary alterations were being carried out, and although we possessed in April, 1917, a stock of some 20,000 mines, only 1,500 of them were then fit for laying. The position, therefore, was that our mines were not a satisfactory anti-submarine weapon.

A new pattern mine, which had been designed on the model of the German mine during Sir Henry Jackson's term of office as First Sea Lord in 1916, was experimented with at the commencement of 1917, and as soon as drawings could be prepared orders for upwards of 100,000 were placed in anticipation of its success. There were some initial difficulties before all the details were satisfactory, and, in spite of the greatest pressure on manufacturers, it was not until November, 1917, that mines of this pattern were being delivered in large numbers. The earliest minefields laid in the Heligoland Bight in September and October, 1917, with mines of the new pattern met with immediate success against enemy submarines, as did the minefields composed of the same type of mine, the laying of which commenced in November, 1917, in the Straits of Dover.

When it became possible to adopt the system of bringing merchant ships in convoys through the submarine zone under the escort of a screen of destroyers, this system became in itself, to a certain extent, an offensive operation, since it necessarily forced the enemy submarines desirous of obtaining results into positions in which they themselves were open to violent attack by depth charges dropped by destroyers.

During the greater part of the year 1917, however, it was only possible to supply destroyers with a small number of depth charges, which was their principal anti-submarine weapon; as it became feasible to increase largely the supply of these charges to destroyers, so the violence of the attack on the submarines increased, and their losses became heavier.

The position then, as it existed in the early days of the year 1917, is described in the foregoing remarks.

The result measured in loss of shipping (British, Allied, and neutral) from submarine and mine attack in the first half of the year was as follows in gross tonnage:

January - 324,016 February - 500,573 March - 555,991 April - 870,359 May - 589,754 June - 675,154

Because of the time required for production, it was a sheer impossibility to put into effect any fresh devices that might be adopted for dealing with submarine warfare for many months, and all that could be done was to try new methods of approach to the coast and, as the number of small craft suitable for escort duty increased, to extend gradually the convoy system already in force to a certain extent for the French coal trade and the Scandinavian trade.

In the chapters which follow the further steps which were taken to deal with the problem, and the degree of success which attended them, will be described.



CHAPTER III

ANTI-SUBMARINE OPERATIONS

The previous chapters have dealt with the changes in organization carried out at the Admiralty during the year 1917 largely with the object of being able to deal more effectively with the submarine warfare against merchant ships. Mention has also been made of the submarine problem with which the Navy had to deal; particulars of the anti-submarine and other work carried out will now be examined.

A very large proportion of the successful anti-submarine devices brought into use during 1917, and continued throughout the year 1918, were the outcome of the work of the Anti-Submarine Division of the Naval Staff, and it is but just that the high value of this work should be recognized when the history of the war comes to be written by future historians. As has been stated in Chapter I, Rear-Admiral A.C. Duff, C.B., was the original head of the division, with Captain F.C. Dreyer, C.B., Commander Yeats Brown, and Commander Reginald Henderson as his immediate assistants. Captain H.T. Walwyn took the place of Captain Dreyer on March 1, 1917, when the latter officer became Director of Naval Ordnance. When Admiral Duff was appointed Assistant Chief of the Naval Staff, with a seat on the Board, in May, 1917, Captain W.W. Fisher, C.B., became head of the division, which still remained one of the divisions of the Staff working immediately under the A.C.N.S. It is to these officers, with their most zealous, clever and efficient staff, that the institution of many of the successful anti-submarine measures is largely due. They were indefatigable in their search for new methods and in working out and perfecting fresh schemes, and they kept their minds open to new ideas. They received much valuable assistance from the great civilian scientists who gave such ready help during the war, the function of the naval officers working with the scientists being to see that the effort was being directed along practical lines. They were also greatly indebted to Captain Ryan, R.N., for the exceedingly valuable work carried out by him at the experimental establishment at Hawkcraig. Many brilliant ideas were due to Captain Ryan's clever brain.

I doubt whether the debt due to Admiral Duff and Captain Fisher and their staff for their great work can ever be thoroughly appreciated, but it is certainly my duty to mention it here since I am better able to speak of it than any other person. In saying this I do not wish to detract in the least from the value of the part performed by those to whose lot it fell to put the actual schemes into operation. Without them, of course, nothing could have been accomplished.

When the Anti-Submarine Division started in December, 1916, the earlier devices to which attention was devoted were:

(1) The design and manufacture of howitzers firing shell fitted to explode some 40 to 60 feet under water with which to attack submarines when submerged.

(2) The introduction of a more suitable projectile for use against submarines than that supplied at the time to the guns of destroyers and patrol craft.

(3) The improvement of and great increase in the supply of smoke apparatus for the screening of merchant ships from submarines attacking by gunfire.

(4) A great increase in the number of depth charges supplied to destroyers and other small craft.

(5) The development of the hydrophone for anti-submarine work, both from ships and from shore stations.

(6) The introduction of the "Otter" for the protection of merchant ships against mines.

(7) A very great improvement in the rapidity of arming merchant ships defensively.

(8) The extended and organized use of air craft for anti-submarine work.

(9) A great development of the special service or decoy ship.

(10) The introduction of a form of net protection for merchant ships against torpedo fire.

Other devices followed, many of which were the outcome of work in other Admiralty Departments, particularly the Departments of the Director of Naval Ordnance and the Director of Torpedoes and Mines, working in conjunction with the Anti-Submarine or the Operations Division of the Naval Staff. Some of the new features were the development of depth-charge throwers, the manufacture and use of fast coastal motor-boats for anti-submarine work, the production of mines of an improved type for use especially against submarines, very considerable developments in the use of minefields, especially deep minefields, including persistent mining in the Heligoland Bight and the laying of a complete minefield at varying depths in the Straits of Dover; also, after the United States entered the war, the laying of a very extensive minefield right across the northern part of the North Sea. The provision of "flares" for illuminating minefields at night, and a system of submarine detection by the use of electrical apparatus were also matters which were taken up and pressed forward during 1917. During the year the system of dazzle painting for merchant ships was brought into general use.

On the operational side of the Naval Staff the work of dealing with enemy submarines before they passed out of the North Sea was taken in hand by organized hunting operations by destroyers and other patrol craft, and by the more extended use offensively of our own submarines, as vessels became available.

Considerable developments were effected in the matter of the control of mercantile traffic, and much was done to train the personnel of the mercantile marine in matters relating to submarine warfare.

Taking these subjects in detail, it will be of interest to examine the progress made during the year.

HOWITZERS

The howitzer as a weapon for use against the submarine when submerged was almost non-existent at the beginning of 1917, only thirty bomb-throwers, on the lines of trench-mortars, being on order. By April of that year designs for seven different kinds of bomb-throwers and howitzers had been prepared and approved, and orders placed for 1,006 weapons, of which number the first 41 were due for delivery in May. By the end of May the number of bomb-throwers and howitzers on order had been increased to 2,056, of eight different patterns. Over 1,000 of these weapons fired a bomb or shell carrying a burster exceeding 90 lbs. in weight, and with a range varying between 1,200 and 2,600 yards. Later in the war, as we gained experience of the value of this form of attack, heavier bombs were introduced for use in the existing bomb-throwers and howitzers. The howitzer as an anti-submarine weapon was handicapped by the comparatively small weight of the bursting charge of its shell. This applied more particularly to the earlier patterns, and to inflict fatal injury it was necessary to burst the shell in close proximity to the submerged submarine. This weapon, although not very popular at first, soon, however, proved its value, when employed both from patrol craft and from merchant ships.

One curious instance occurred on March 28, 1918, of a merchant ship being saved by a 7.5-inch howitzer. A torpedo was seen approaching at a distance of some 600 yards, and it appeared certain to hit the ship. A projectile fired from the howitzer exploded under water close to the torpedo, deflected it from its course, and caused it to come to the surface some 60 yards from the ship; a second projectile caused it to stop, and apparently damaged the torpedo, which when picked up by an escorting vessel was found to be minus its head.

Delivery of howitzers commenced in June, 1917, and continued as follows:

Total completed, No. of Howitzers including those Date. actually issued. under proof.

July 24, 1917 35 48 October 1, 1917 92 167 December 10, 1917 377 422

The slow rate of delivery, in spite of constant pressure, which is shown by these figures gives some idea of the time required to bring new devices into existence.

PROJECTILE FOR USE AGAINST SUBMARINES

In January, 1917, the Director of Naval Ordnance was requested by the Anti-Submarine Division of the Naval Staff to carry out trials against a target representing the hull of a German submarine, so far as the details were known to us, to ascertain the most suitable type of projectile amongst those then in existence for the attack of submarines by guns of 4.7-inch calibre and below.

The results were published to the Fleet in March, 1917. They afforded some useful knowledge and demonstrated the ineffectiveness of some of the shells and fuses commonly in use against submarines from 12-pounder guns, the weapon with which so many of our patrol craft were armed. The target at which the shell was fired did not, however, fully represent a German submarine under the conditions of service. The trials were therefore continued, and as a result, in June, 1917, a further order was issued to the Fleet, giving directions as to the type of projectile to be used against submarines from all natures of guns, pending the introduction of delay action fuses for the smaller guns; this was the temporary solution of the difficulty until a new type of shell evolved from the experience gained at the trials could be produced and issued. The trials, which were exhaustive, were pressed forward vigorously and continuously throughout the year 1917, and meanwhile more accurate information as to the exact form of the hull and the thickness of the plating of German submarines became available. Early in 1918 the first supplies of the new fuses were ready for issue.

SMOKE APPARATUS

The earlier smoke apparatus for supply to merchant ships was designed towards the end of 1916.

One description of smoke apparatus consisted of an arrangement for burning phosphorus at the stern of a ship; in other cases firework composition and other chemicals were used. A dense smoke cloud was thus formed, and, with the wind in a suitable direction, a vessel could hide her movements from an enemy submarine or other vessel, and thus screen herself from accurate shell fire.

In another form the apparatus was thrown overboard and formed a smoke cloud on the water.

The rate of supply of sets of the smoke apparatus to ships is shown by the following figures:

April 1, 1917 - 1,372 sets July 3, 1917 - 2,563 sets October 5, 1917 - 3,445 sets November 26, 1917 - 3,976 sets

DEPTH CHARGES

Depth charges, as supplied to ships in 1917, were of two patterns: one, Type D, contained a charge of 300 lb. of T.N.T., and the other, Type D*, carried 120 lb. of T.N.T. At the commencement of 1917 the allowance to ships was two of Type D and two of Type D*, and the supply was insufficient at that time to keep up the stock required to maintain on board four per destroyer, the number for which they were fitted, or to supply all trawlers and other patrol craft with their allowance. The great value of the depth charge as a weapon against submarines, and the large number that were required for successful attack, became apparent early in 1917, and the allowance was increased. Difficulty was experienced throughout the year in maintaining adequate stocks owing to the shortage of labour and the many demands on our industries made by the war, but the improvement is shown by the fact that while the average output per week of depth charges was only 140 in July, it had become over 500 by October, and that by the end of December it was raised to over 800, and was still increasing very rapidly. As a consequence, early in 1918 it was found possible to increase the supply very largely, as many as 30 to 40 per destroyer being carried.

Improvements in the details of depth charges were effected during 1917. One such improvement was the introduction of a pistol capable of firing at much greater depths than had been in use before. The result was that all vessels, whether fast or slow, could safely use the 300-lb. depth charge if set to a sufficient depth. This led to the abolition of the Type D* charges and the universal supply of Type D.

In spite of the difficulties of dropping depth charges so close to submarines as to damage them sufficiently to cause them to come to the surface, very good results were obtained from their use when destroyers carried enough to form, so to speak, a ring round the assumed position at which the submarine had dived. In order to encourage scientific attack on submarines, a system of depth charge "Battle Practice" was introduced towards the end of 1917.

It is as well to correct a common misapprehension as to the value of depth charges in destroying submarines.

Many people held very exaggerated ideas on this subject, even to the extent of supposing that a depth charge would destroy a submarine if dropped within several hundred yards of her. This is, unfortunately, very far indeed from being the case; it is, on the contrary, necessary to explode the charge near the submarine in order to effect destruction. Taking the depth charge with 300 lb. weight of explosive, ordinarily supplied to destroyers in 1917, it was necessary to explode it within fourteen feet of a submarine to ensure destruction; at distances up to about twenty-eight feet from the hull the depth charge might be expected to disable a submarine to the extent of forcing her to the surface, when she could be sunk by gun-fire or rammed, and at distances up to sixty feet the moral effect on the crew would be considerable and might force the submarine to the surface.

A consideration of these figures will show that it was necessary for a vessel attacking a submarine with depth charges to drop them in very close proximity, and the first obvious difficulty was to ascertain the position of a submarine that had dived and was out of sight.

Unless, therefore, the attacking vessel was fairly close to the submarine at the moment of the latter diving there was but little chance of the attack being successful.

HYDROPHONES

The Hydrophone, for use in locating submerged submarines, although first evolved in 1915, was in its infancy, so far as supply to ships was concerned, at the commencement of 1917. Experiments were being carried out by the Board of Invention and Research at Harwich, and by Captain Ryan, R.N., at Hawkcraig, and although very useful results had been obtained and a considerable number of shore stations as well as some patrol vessels had been fitted with hydrophones, which had a listening range of one or two miles, all the devices for use afloat suffered from the disadvantage that it was not possible to use them whilst the ship carrying them was moving, since the noise of the vessel's own machinery and of the water passing along the side prevented the noise made by other vessels being located. What was required was a listening instrument that could be used by a ship moving at least at slow speed, otherwise the ship carrying the hydrophone was herself, when stopped, an easy target for the submarine's torpedo. It was also essential, before an attack could be delivered, to be able to locate the direction of the enemy submarine, and prior to 1917 all that these instruments showed was the presence of a submarine somewhere in the vicinity.

Much research and experimental work was carried out during the year 1917 under the encouragement and supervision of the Anti-Submarine Division of the Naval Staff. Two hydrophones were invented in the early part of 1917, one by Captain Ryan, R.N., and one by the Board of Invention and Research, which could be used from ships at very slow speed and which gave some indication of the direction of the sound; finally, in the summer of 1917, the ability and patience of one inventor, Mr. Nash, were rewarded, and an instrument was devised termed the "fish" hydrophone which to a considerable extent fulfilled the required conditions. Mr. Nash, whose invention had been considered but not adopted by the Board of Invention and Research before he brought it to the Anti-Submarine Division of the Naval Staff, laboured under many difficulties with the greatest energy and perseverance; various modifications in the design were effected until, in October, 1917, the instrument was pronounced satisfactory and supplies were put in hand.

The next step was to fit the "fish" hydrophone in certain auxiliary patrol vessels as well as some destroyers, "P" boats and motor launches, to enter and train men to work it, and finally to organize these vessels into "submarine hunting flotillas," drill them, and then set them to their task.

This work, which occupied some time, was carried out at Portland, where a regular establishment was set up for developing the "fish" hydrophone and for organizing and training the "hunting flotillas" in its use. A considerable amount of training in the use of the hydrophone was required before men became efficient, and only those with a very keen sense of hearing were suited to the work. The chances of the success of the hunting flotillas had been promising in the early experiments, and the fitting out of patrol craft and organizing and drilling them, proceeded as rapidly as the vessels could be obtained, but largely owing to the slow production of trawlers it was not until November that the first hunting flotilla fitted with the "fish" hydrophone was actually at work. The progress made after this date is illustrated by the fact that in December, 1917, a division of drifters, with a "P" boat, fitted with this "fish" hydrophone hunted an enemy submarine for seven hours during darkness, covering a distance of fifty miles, kept touch with her by sound throughout this period, and finished by dropping depth charges in apparently the correct position, since a strong smell of oil fuel resulted and nothing further could be heard of the submarine, although the drifters listened for several hours. On another occasion in the same month a division of drifters hunted a submarine for five hours. The number of hydrophones was increased as rapidly as possible until by the end of the year the system was in full operation within a limited area, and only required expansion to work, as was intended, on a large scale in the North Sea and the English Channel.

Meanwhile during 1917 directional hydrophones, which had been successfully produced both by Captain Ryan and by the Board of Invention and Research, had been fitted to patrol craft in large numbers, and "hunting flotillas" were operating in many areas. A good example of the working of one of these flotillas occurred off Dartmouth in the summer of 1918, when a division of motor launches fitted with the Mark II hydrophone, under the general guidance of a destroyer, carried out a successful attack on a German submarine. Early in the afternoon one of the motor launches dropped a depth charge on an oil patch, and shortly afterwards one of the hydrophones picked up the sound of an internal combustion engine; a line of depth charges was run on the bearing indicated by the hydrophone. The motor launches and the destroyer remained listening, until at about 6.0 P.M. a submarine came to the surface not far from Motor Launch No. 135, which fired two rounds at the submarine before the latter submerged. Other motor launches closed in, and depth charges were dropped by them in close proximity to the wash of the submarine. Oil came to the surface, and more depth charges were dropped in large numbers on the spot for the ensuing forty-eight hours. Eventually objects came to the surface clearly indicating the presence of a submarine. Further charges were dropped, and an obstruction on the bottom was located by means of a sweep. This engagement held peculiar interest for me, since during my visit to Canada in the winter of 1919 the honour fell to me of presenting to a Canadian—Lieutenant G.L. Cassady, R.N.V.R.—at Vancouver the Distinguished Service Cross awarded him by His Majesty for his work in Motor Launch No. 135 on this occasion.

Motor Launches were organized into submarine hunting flotillas during the year 1917. These vessels were equipped with the directional hydrophone as soon as its utility was established, and were supplied with depth charges. In the summer of 1917 four such hunting flotillas were busy in the Channel; the work of one of these I have described already, and they certainly contributed towards making the Channel an uneasy place for submarine operations.

These results were, of course, greatly improved on in 1918, as the numbers of ships fitted with the "fish" and other hydrophones increased and further experience was gained.

The progress in supply of hydrophones is shown by the following table:

Supply of Directional Date General Service Mark I and Shark Fin Fish 1917. Portable Type. Mark II. Type. Type.

Jul 31 2,750 500 - - Aug 31 2,750 700 - - Sep 30 2,750 850 - - Oct 31 3,500 1,000 - - Dec 31 3,680 1,950 870 37

HYDROPHONE STATIONS AND TRAINING SCHOOLS

At the beginning of 1917 four shore hydrophone stations were in use. During the year eight additional stations were completed and several more were nearing completion. The first step necessary was a considerable increase in the instructional facilities for training listeners both for the increased number of shore stations and for the large number of vessels that were fitted for hydrophone work during the year.

The greater part of this training took place at the establishment at Hawkcraig, near Rosyth, at which Captain Ryan, R.N., carried out so much exceedingly valuable work during the war. I am not able to give exact figures of the number of officers and men who were instructed in hydrophone work either at Hawkcraig or at other stations by instructors sent from Hawkcraig, but the total was certainly upwards of 1,000 officers and 2,000 men. In addition to this extensive instructional work the development of the whole system of detecting the presence of submarines by sound is very largely due to the work originally carried out at Hawkcraig by Captain Ryan.

The first hydrophone station which was established in the spring of 1915 was from Oxcars Lighthouse in the Firth of Forth; it was later in the year transferred to Inchcolm. Experimental work under Captain Ryan continued at Hawkcraig during 1915, and in 1916 a section of the Board of Invention and Research went to Hawkcraig to work in conjunction with him. This station produced the Mark II directional hydrophone of which large numbers were ordered in 1917 for use in patrol craft. It was a great improvement on any hydrophone instrument previously in use. Hawkcraig also produced the directional plates fitted to our submarines, as well as many other inventions used in detecting the presence of submarines.

In addition to the work at Hawkcraig an experimental station under the Board of Invention and Research was established near Harwich in January, 1917. The Mark I directional hydrophone was designed at this establishment in 1917, and other exceedingly valuable work was carried out there connected with the detection of submarines.

At Malta an experimental station, with a hydrophone training school, was started in the autumn of 1917, and good work was done both there and at a hydrophone station established to the southward of Otranto at about the same time, as well as at a hydrophone training school started at Gallipoli at the end of the year.

"OTTERS" AND PARAVANES

The "Otter" system of defence of merchant ships against mines was devised by Lieutenant Dennis Burney, D.S.O., R.N. (a son of Admiral Sir Cecil Burney), and was on similar lines to his valuable invention for the protection of warships. The latter system had been introduced into the Grand Fleet in 1916, although for a long period considerable opposition existed against its general adoption, partly on account of the difficulties experienced in its early days of development, and partly owing to the extensive outlay involved in fitting all ships. However, this opposition was eventually overcome, and before the end of the war the system had very amply justified itself by saving a large number of warships from destruction by mines. It was computed that there were at least fifty cases during the war in which paravanes fitted to warships had cut the moorings of mines, thus possibly saving the ships. It must also be borne in mind that the cutting of the moorings of a mine and the bringing of it to the surface may disclose the presence of an hitherto unknown minefield, and thus save other ships.

Similarly, the "Otter" defence in its early stages was not introduced without opposition, but again all difficulties were overcome, and the rate of progress in its use is shown in the following statement giving the number of British merchant ships fitted with it at different periods of 1917:

By July 1, 95 ships had been fitted. By September 1, 294 ships had been fitted. By December 1, 900 ships had been fitted.

The system was also extended to foreign merchant ships, and supplies of "Otters" were sent abroad for this purpose.

A considerable number of merchant ships were known to have been saved from destruction by mine by the use of this system.

DEFENSIVE ARMING OF MERCHANT SHIPS

The defensive arming of merchant ships was a matter which was pressed forward with great energy and rapidity during the year 1917. The matter was taken up with the Cabinet immediately on the formation of the Board of Admiralty presided over by Sir Edward Carson, and arrangements made for obtaining a considerable number of guns from the War Office, from Japan, and from France, besides surrendering some guns from the secondary and anti-torpedo boat armament of our own men-of-war, principally those of the older type, pending the manufacture of large numbers of guns for the purpose. Orders for some 4,200 guns were placed by Captain Dreyer, the Director of Naval Ordnance, with our own gun makers in March, April and May, 1917, in addition to nearly 3,000 guns already on order for this purpose; 400 90-m.m. guns were obtained from France, the mountings being made in England. Special arrangements were also made by Captain Dreyer for the rapid manufacture of all guns, including the provision of the material and of extra manufacturing plant.

These orders for 4,200 guns and the orders for 2,026 howitzers placed at the same time brought the total number of guns and howitzers under manufacture in England for naval and merchant service purposes in May, 1917, up to the high figure of 10,761.

At the end of the year 1916 the total number of merchant ships that had been armed since the commencement of the war (excluding those which were working under the White Ensign and which had received offensive armaments) was 1,420. Of this number, 83 had been lost.

During the first six months of 1917 armaments were provided for an additional 1,581 ships, and during the last six months of that year a further total of 1,406 ships were provided with guns, an aggregate number of 2,987 ships being thus furnished with armaments during the year. This total was exclusive of howitzers.

The progress of the work is shown by the following figures:

Number or guns that had been Date. provided for British Merchant Ships excluding Howitzers.

January 1, 1917 1,420 April 1, 1917 2,181 July 1, 1917 3,001 October 1, 1917 3,763 January 1, 1918 4,407

The figures given include the guns mounted in ships that were lost through enemy action or from marine risks.

It should be stated that the large majority of the guns manufactured during 1917 were 12-pounders or larger guns, as experience had shown that smaller weapons were usually outranged by those carried in submarines, and the projectiles of even the 12-pounder were smaller than was desirable. Of the 2,987 new guns mounted in merchant ships during the year 1917 only 190 were smaller than 12-pounders.

AIRCRAFT FOR ANTI-SUBMARINE WORK

Anti-submarine work by aircraft was already in operation round our coasts by the beginning of 1917, and during the year the increase in numbers and improvement in types of machines rendered possible considerable expansion of the work. Closer co-operation between surface vessels and aircraft was also secured, and as the convoy system was extended aircraft were used both for escort and observation work, as well as for attack on submarines. For actual escort work airships were superior to heavier-than-air machines owing to their greater radius of action, whilst for offensive work against a submarine that had been sighted the high speed of the seaplane or aeroplane was of great value.

In 1916 and the early part of 1917 we were but ill provided with aircraft suitable for anti-submarine operations at any considerable distance from the coast, and such aircraft as we possessed did not carry sufficiently powerful bombs to be very effective in attacking submarines, although they were of use in forcing these vessels to submerge and occasionally in bringing our surface craft to the spot to press home the attack.

The Royal Naval Air Service, under Commodore Godfrey Paine, devoted much energy to the provision of suitable aircraft, and the anti-submarine side of the Naval Staff co-operated in the matter of their organization; with the advent of the large "America" type of seaplane and the Handley-Page type of aeroplane, both of which carried heavy bombs, successful attacks on enemy submarines became more frequent. They were assisted by the airships, particularly those of the larger type.

Improvements which were effected in signalling arrangements between ships and aircraft were instrumental in adding greatly to their efficiency, and by the early summer of 1917 aircraft had commenced to play an important part in the war against submarines and in the protection of trade.

Thereafter progress became rapid, as the following figures show:

In June, 1917, aeroplanes and seaplanes patrolling for anti-submarine operations covered 75,000 miles, sighted 17 submarines, and were able to attack 7 of them.

In September, 1917, the distance covered by anti-submarine patrols of aeroplanes and seaplanes was 91,000 miles, 25 submarines were sighted, of which 18 were attacked.

In the four weeks ending December 8, 1917, in spite of the much shorter days and the far less favourable flying weather experienced, the mileage covered was again 91,000 miles; 17 submarines were sighted, of which 11 were attacked during this period.

As regards airships the figures again show the increased anti-submarine work carried out:

In June, 1917, airships engaged in anti-submarine patrol covered 53,000 miles, sighted and attacked 1 submarine.

In September, 1917, they covered 83,000 miles, and sighted 8 submarines, of which 5 were attacked.

In the four weeks ending December 8, 1917, they covered 50,000 miles, sighted 6 submarines, and attacked 5 of them.

The airships were more affected by short days, and particularly by bad weather, than the heavier than air craft, and the fact that they covered practically the same mileage in the winter days of December as in the summer days of June shows clearly the development that took place in the interval.

During the whole of 1917 it was estimated that our heavier than air craft sighted 135 submarines and attacked 85 of them, and our lighter than air craft sighted 26 and attacked 15. The figures given in Chapter IX of the number of submarines sunk during the war by aircraft (viz. 7 as a minimum), when compared with the number of attacks during 1917 alone suggest the difficulties of successful attack.

In September, 1917, as extensive a programme as was consistent with manufacturing capabilities, in view of the enormous demands of the Army, was drawn up by the Naval Staff for the development of aircraft for anti-submarine operations during 1918.

The main developments were in machines of the large "America" type and heavy bombing machines for attacking enemy bases, as well as other anti-submarine machines and aircraft for use with the Grand Fleet.

Included in the anti-submarine operations of aircraft during 1917 were the bombing attacks on Bruges, since the German submarines and the shelters in which they took refuge were part of the objective.

These attacks were carried out from the aerodrome established by the Royal Naval Air Service at Dunkirk. During 1917 the Naval Air Forces of the Dover Command, which included the squadrons at Dunkirk, were under the command of Captain C.L. Lambe, R.N., and the operations of this force were of a very strenuous character and of the utmost value.

Bombing operations prior to the year of 1917 had been carried out by various types of machines, but the introduction of the Handley-Page aeroplanes in the spring of 1917 enabled a much greater weight of bombs—viz. some 1,500 lbs.—to be carried than had hitherto been possible. These machines were generally used for night bombing, and the weight of bombs dropped on the enemy bases in Belgium rose with great rapidity as machines of the Handley-Page type were delivered, as did the number of nights on which attacks were made. It was no uncommon occurrence during the autumn of 1917 for six to eight tons of bombs to be dropped in one night. I have not the figures for 1918, but feel no doubt that with the great increase in aircraft that became possible during that year this performance was constantly exceeded.

SPECIAL SERVICE OR DECOY SHIPS

The story of the work of these vessels constitutes a record of gallantry, endurance and discipline which has never been surpassed afloat or ashore. The earliest vessels were fitted out during the year 1915 at Scapa, Rosyth, Queenstown and other ports, and from the very first it was apparent that they would win for themselves a place in history. The earliest success against an enemy submarine by one of these vessels was achieved by the Prince Charles, fitted out at Scapa, and commanded by Lieutenant Mark-Wardlaw, an officer on the Staff of Admiral Sir Stanley Colville, then Admiral Commanding the Orkneys and Shetlands. In the early months of 1917 it was decided to augment greatly the force of these special service vessels, and steps were taken to organize a separate Admiralty Department for the work. Special experience was needed, both for the selection of suitable ships and for fitting them out, and care was taken to select officers who had been personally connected with the work during the war; the advice of successful commanders of decoy ships was also utilized. At the head was Captain Alexander Farrington, under whose directions several ships had been fitted out at Scapa with great ingenuity and success. Every class of ship was brought into the service: steam cargo vessels, trawlers, drifters, sailing ships, ketches, and sloops specially designed to have the appearance of cargo ships. These latter vessels were known as "convoy sloops" to distinguish them from the ordinary sloop. Their design, which was very clever, had been prepared in 1916 by Sir Eustace T. D'Eyncourt, the Director of Naval Construction. The enemy submarine commanders, however, became so wary owing to the successes of decoy ships that they would not come to the surface until they had inspected ships very closely in the submerged condition, and the fine lines of the convoy sloops gave them away under close inspection.

In the early spring of 1917 the Director of Naval Construction was asked whether the "P" class of patrol boats then under construction could be altered to work as decoy vessels, as owing to their light draught they would be almost immune from torpedo attack.

A very good design was produced, and some of the later patrol boats were converted and called "P Q's." These vessels had the appearance of small merchant ships at a cursory glance. They would not, however, stand close examination owing, again, to their fine lines, but being better sea boats than the "P's," by reason of their greater freeboard, the design was continued, and they met with considerable success against submarines (especially in the Irish Sea) by ramming and depth charge tactics, the submarines when submerged probably not realizing when observing the "P Q.'s" through a periscope the speed of which they were capable.

During 1917, when the unrestricted submarine warfare was in progress, many of the decoy vessels were fitted with torpedo tubes, either above water or submerged, since, as the submarine commanders became more wary, they showed great dislike to coming to the surface sufficiently close to merchant ships to admit of the gun armament being used with certainty of success. A torpedo, on the other hand, could, of course, be used effectively against a submarine whilst still submerged. The use also became general of casks or cargoes of wood to give additional flotation to decoy ships after being torpedoed, so as to prolong their life in case the submarine should close near enough to allow of effective gunfire.

Another ruse adopted was that of changing the disguise of a decoy ship during the night, so that she could not be identified by a submarine which had previously made an attack upon her. In all cases of disguise or of changing disguise it was essential that the decoy ship should assume the identity of some class of vessel likely to be met with in the particular area in which she was working, and obviously the courses steered were chosen with that object in view.

Again, since for success it was essential to induce the submarine to come within close range so that the decoy ship's gunfire should be immediately effective, it was necessary that her disguise should stand the closest possible examination through the periscope of a submarine. German submarine commanders, after a short experience of decoy ships, were most careful not to bring their vessels to the surface in proximity to craft that were apparently merchant ships until they had subjected them to the sharpest scrutiny at short range through the periscope, and the usual practice of an experienced submarine commander was to steer round the ship, keeping submerged all the time.

Not only was it essential that there should be no sign of an armament in the decoy ship, or a man-of-war-like appearance in any respect, but when the "panic" signal was made to lead the submarine commander to think that his attack had succeeded, precautions had to be taken against the presence of more than the ordinary number of men in the boats lowered and sent away with the supposed whole ship's company; also the sight of any men left on board would at once betray the real character of the decoy ship and result in the disappearance of the submarine and the probable sinking of the disguised craft by torpedo fire.

During the late summer of 1917 it became evident that the submarine commanders had become so suspicious of decoy craft that the chances of success by the larger cargo vessels were not sufficient to justify any further addition to existing numbers in view of the increasing shortage of shipping; a considerable fleet of steamers building for this purpose was therefore diverted to trade purposes. The number of smaller vessels, particularly sailing craft, was, however, increased especially in Mediterranean waters where they had not been previously operating on an extensive scale.

It is impossible to close these remarks on this class of vessel without testifying once more to the splendid gallantry, self-sacrifice, skilful resource and magnificent discipline shown by those on board. This is illustrated by descriptions of a few typical actions fought during 1917.

The first which I relate took place on February 17, 1917, when a decoy vessel, a steamship armed with five 12-pounder guns, commanded by that most gallant officer, Captain Gordon Campbell, R.N., was torpedoed by a submarine in a position Lat. 51.34 N., Long. 11.23 W.

Captain Campbell saw the torpedo coming and manoeuvred to try and avoid being hit in the engine-room, but as he purposely always selected a very slow ship for decoy work his attempt was only partially successful and the engine-room began to fill. No signal for assistance was made, however, as Captain Campbell feared that such a signal might bring another vessel on the scene and this would naturally scare the submarine away. The usual procedure of abandoning the ship in the boats with every appearance of haste was carried out, only sufficient hands remaining hidden on board to work the guns. The periscope of the submarine was next sighted on the quarter within 200 or 300 yards, and she came slowly past the ship still submerged and evidently examining the vessel closely through the periscope. She passed within a few yards of the ship, then crossed the bow and came to the surface about 200 yards off and passed down the port side again close to. Captain Campbell waited until every gun would bear before giving the signal for "action." The decoy ship's true character was then revealed; concealed gunports were thrown open; colours were hoisted, and a hot fire opened from all guns. The submarine was hit at once and continued to be hit so rapidly that it was evidently impossible for her to submerge. She sank in a very short time. One officer and one man were picked up. A signal was then made for assistance and help arrived within a couple of hours. The decoy ship was rapidly filling, but efforts were made to tow her into port, and with the greatest difficulty, and entirely owing to the splendid manner in which all hands stuck to the work, she was brought into Berehaven with her stern under water thirty-six hours later and beached. The great restraint shown by Captain Campbell, in withholding fire as the submarine passed her in a submerged condition, and the truly wonderful discipline and steadiness and ingenuity which baffled so close an examination of the ship were the outstanding features of this great exploit.

On April 22, 1917, a decoy ship known as "Q22," a small sailing vessel with auxiliary power, armed with two 12-pounder guns, and commanded by Lieutenant Irvine, R.N.R., while in a position about fifty miles south of Kinsale Head, sighted a submarine on the surface which opened fire immediately at a range of about 4,000 yards. The fire was accurate and the decoy ship was hit frequently, two men being killed and four wounded in a few minutes and the vessel considerably damaged. As further concealment appeared useless the guns were then unmasked and the fire returned with apparently good results, several hits being claimed. The enemy's fire then fell off in accuracy and she increased the range, and after about one and a half hours' fighting the light became too bad to continue the action. It was thought that the submarine was sunk, but there was no positive evidence of sinking.

On April 30, 1917, a decoy ship—H.M.S. Prize—a small schooner with auxiliary power, armed with two 12-pounder guns and commanded by Lieutenant W.E. Sanders, R.N.R., a New Zealand officer, sighted, when in position Lat. 49.44 N., Long. 11.42 W., a submarine about two miles away on the port beam at 8.30 P.M. At 8.45 P.M. the submarine opened fire on the Prize and the "abandon ship" party left in a small boat. The submarine gradually approached, continuing to pour in a heavy fire and making two hits on the Prize which put the motor out of action, wrecked the wireless office, and caused much internal damage besides letting a great deal of water into the ship.

The crew of the Prize remained quietly hidden at their concealed guns throughout this punishment, which continued for forty minutes as the submarine closed, coming up from right astern, a position no doubt which she considered one of safety. When close to she sheered off and passed to the port beam at a distance of about one hundred yards. At this moment Lieutenant Sanders gave the order for "action." The guns were exposed and a devastating fire opened at point blank range, but not before the submarine had fired both her guns, obtaining two more hits, and wounding several of the crew of the Prize. The first shell fired from the Prize hit the foremost gun of the submarine and blew it overboard, and a later shot knocked away the conning tower. The submarine went ahead and the Prize tried to follow, but the damage to her motor prevented much movement. The firing continued as the submarine moved away, and after an interval she appeared to be on fire and to sink. This occurred shortly after 9.0 P.M., when it was nearly dark. The Prize sent her boats to pick up survivors, three being taken out of the water, including the commander and one other officer. The prisoners on coming on board expressed their willingness to assist in taking the Prize into port. It did not at this time seem likely that she would long remain afloat, but by great exertion and good seamanship the leaks were got under to a sufficient extent to allow of the ship being kept afloat by pumping. The prisoners gave considerable help, especially when the ship caught fire whilst starting the motor again. On May 2 she met a motor launch off the coast of Ireland and was towed into port. In spite of the undoubted great damage to the submarine, damage confirmed by the survivors, who were apparently blown overboard with the conning tower, and who had no thought other than that she had been sunk, later intelligence showed that she succeeded in reaching Germany in a very disabled condition. This incident accentuated still further the recurrent difficulty of making definite statements as to the fate of enemy submarines, for the evidence in this case seemed absolutely conclusive. The commander of the submarine was so impressed with the conduct of the crew of the Prize that when examined subsequently in London he stated that he did not consider it any disgrace to have been beaten by her, as he could not have believed it possible for any ship's company belonging to any nation in the world to have been imbued with such discipline as to stand the shelling to which he subjected the Prize without any sign being made which would give away her true character.

Lieut.-Commander Sanders was awarded the Victoria Cross for his action and many decorations were given to the officers and ship's company for their conduct in the action. It was sad that so fine a commander and so splendid a ship's company should have been lost a little later in action with another submarine which she engaged unsuccessfully during daylight, and which followed her in a submerged condition until nightfall and then torpedoed her, all hands being lost.

It was my privilege during my visit to New Zealand in 1919 to unveil a memorial to the gallant Sanders which was placed in his old school at Takapuna, near Auckland.

On June 7, 1917, a decoy ship, the S.S. Pargust, armed with one 4-inch gun, four 12-pounder guns and two torpedo tubes, commanded by Captain Gordon Campbell, R.N., who had meanwhile been awarded the Victoria Cross, was in a position Lat. 51.50 N., Long. 11.50 W., when a torpedo hit the ship abreast the engine-room and in detonating made a hole through which water poured, filling both engine-room and boiler-room. The explosion of the torpedo also blew one of the boats to pieces. The usual procedure of abandoning ship was carried out, and shortly after the boats had left, the periscope of a submarine was sighted steering for the port side. The submarine passed close under the stern, steered to the starboard side, then recrossed the stern to the port side, and when she was some fifty yards off on the port beam her conning tower appeared on the surface and she steered to pass round the stern again and towards one of the ship's boats on the starboard beam. She then came completely to the surface within one hundred yards, and Captain Campbell disclosed his true character, opened fire with all guns, hitting the submarine at once and continuing to hit her until she sank. One officer and one man were saved. The decoy ship lost one man killed, and one officer was wounded by the explosion of the torpedo.

As in the case of the action on February 17 the distinguishing feature of this exploit was the great restraint shown by Captain Campbell in withholding his fire although his ship was so seriously damaged. The gallantry and fine discipline of the ship's company, their good shooting and splendid drill, contributed largely to the success. The decoy ship, although seriously damaged, reached harbour.

On July 10, 1917, a decoy ship, H.M.S. Glen, a small schooner with auxiliary power and armed with one 12-pounder and one 6-pounder gun, commanded by Sub-Lieutenant K. Morris, R.N.R., was in a position about forty miles south-west of Weymouth when a submarine was sighted on the surface some three miles away. She closed to within two miles and opened fire on the Glen. The usual practice of abandoning ship was followed, the submarine closing during this operation to within half a mile and remaining at that distance examining the Glen for some time. After about half an hour she went ahead and submerged, and then passed round the ship at about 200 yards distance, examining her through the periscope, finally coming to the surface about 50 yards off on the port quarter. Almost immediately she again started to submerge, and fire was at once opened. The submarine was hit three or four times before she turned over on her side and disappeared. There was every reason to believe that she had sunk, although no one was on deck when she disappeared. No survivors were rescued.

The feature of this action was again the restraint shown by the commanding officer of the Glen and the excellent discipline of the crew.

On August 8, 1917, the decoy ship H.M.S. Dunraven, in Lat. 48.0 N., Long. 7.37 W., armed with one 4-inch and four 12-pounder guns and two torpedo tubes, commanded by Captain Gordon Campbell, V.C., R.N., sighted a submarine on the surface some distance off. The submarine steered towards the ship and submerged, and soon afterwards came to the surface some two miles off and opened fire. The Dunraven, in her character of a merchant ship, replied with an after gun, firing intentionally short, made a smoke screen, and reduced speed slightly to allow the submarine to close.

When the shells from the submarine began to fall close to the ship the order to abandon her was given, and, as usual with the splendidly trained ship's company working under Captain Campbell, the operation was carried out with every appearance of disorder, one of the boats being purposely left hanging vertical with only one end lowered. Meanwhile the submarine closed. Several shells from her gun hit the after part of the Dunraven, causing a depth charge to explode and setting her on fire aft, blowing the officer in charge of the after gun out of his control station, and wounding severely the seaman stationed at the depth charges. The situation now was that the submarine was passing from the port to the starboard quarter, and at any moment the 4-inch magazine and the remaining depth charges in the after part of the Dunraven might be expected to explode. The 4-inch gun's crew aft knew the imminence of this danger, but not a man moved although the deck beneath them was rapidly becoming red hot; and Captain Campbell was so certain of the magnificent discipline and gallantry of his crew that he still held on so that the submarine might come clearly into view on the starboard side clear of the smoke of the fire aft. In a few minutes the anticipated explosion occurred. The 4-inch gun and gun's crew were blown into the air just too soon for the submarine to be in the best position for being engaged. The explosion itself caused the electrical apparatus to make the "open fire" signal, whereupon the White Ensign was hoisted and the only gun bearing commenced firing; but the submarine submerged at once.

Fifteen minutes later a torpedo hit the ship, and Captain Campbell again ordered "abandon ship" and sent away a second party of men to give the impression that the ship had now been finally abandoned although her true character had been revealed. Meanwhile he had made a wireless signal to other ships to keep away as he still hoped to get the submarine, which, now keeping submerged, moved round the ship for three quarters of an hour, during which period the fire gained on the Dunraven and frequent explosions of ammunition took place.

The submarine then came to the surface right astern where no guns could bear on her, and recommenced her shellfire on the ship, hitting her frequently. During this period the officers and men still remaining on board gave no sign of their presence, Captain Campbell, by his example, imbuing this remnant of his splendid ship's company with his own indomitable spirit of endurance. The submarine submerged again soon afterwards, and as she passed the ship Captain Campbell from his submerged tube fired a torpedo at her, which just missed. Probably the range was too short to allow the torpedo to gain its correct depth. She went right round the ship, and a second torpedo was fired from the other tube, which again missed. This torpedo was evidently seen from the submarine, as she submerged at once. The ship was sinking, and it was obviously of no use to continue the deception, which could only lead to a useless sacrifice of life; wireless signals for assistance were therefore made, and the arrival of some destroyers brought the action to a conclusion. The wounded were transferred to the destroyers and the ship taken in tow, but she sank whilst in tow forty-eight hours later.

This action was perhaps the finest feat amongst the very many gallant deeds performed by decoy ships during the war. It displayed to the full the qualities of grim determination, gallantry, patience and resource, the splendid training and high standard of discipline, which were necessary to success in this form of warfare. Lieutenant Charles G. Bonner, R.N.R., and Petty-Officer Ernest Pitcher, R.N., were awarded the V.C. for their services in this action, and many medals for conspicuous gallantry were also given to the splendid ship's company.

Captain Campbell, as will be readily realized, met with great success in his work, and he was the first to acknowledge how this success was due to those who worked so magnificently under his command, and he also realized the magnitude of the work performed by other decoy ships in all areas, since he knew better than most people the difficulties of enticing a submarine to her doom.

On September 17, 1917, in position Lat. 49.42 N., Long. 13.18 W., the decoy ship Stonecrop, a small steamer commanded by Commander M. Blackwood, R.N., armed with one 4-inch, one 6-pounder gun and some stick-bomb throwers and carrying four torpedo tubes, sighted a submarine, which opened fire on her at long range, the fire being returned by the 6-pounder mounted aft. After the shelling had continued for some time the usual order was given to "abandon ship," and a little later the periscope of the submarine was sighted some distance away. The submarine gradually closed, keeping submerged, until within about a quarter of a mile, when she passed slowly round the ship, and finally came to the surface at a distance of about 500 yards on the starboard quarter. She did not close nearer, so the order was given to open fire, and hitting started after the third round had been fired and continued until the submarine sank stern first. No survivors were picked up, but all the indications pointed to the certainty of the destruction of the submarine.

PATROL GUNBOATS

Mention may here be made of another vessel of a special class designed in 1917. In the early summer, in consequence of the shortage of destroyers, of the delays in the production of new ones, and the great need for more small craft suitable for escorting merchant ships through the submarine zone, arrangements were made to build a larger and faster class of trawler which would be suitable for convoy work under favourable conditions, and which to a certain extent would take the place of destroyers. Trawlers could be built with much greater rapidity than destroyers, and trawler builders who could not build destroyers could be employed for the work, thus supplementing the activities of the yards which could turn out the bigger craft.

Accordingly a 13-knot trawler was designed, and a large number ordered. Great delays occurred, however, in their construction, as in that of all other classes of vessel owing to the pressure of various kinds of war work and other causes, and only one was delivered during 1917 instead of the twenty or so which had been promised, whilst I believe that by July, 1918, not more than fourteen had been completed instead of the anticipated number of forty. I was informed that they proved to be a most useful type of vessel for the slower convoys, were excellent sea boats, with a large radius of action, were a great relief to the destroyers, and even to light cruisers, for convoy work. It is understood that some fifty were completed by the end of the war.

NET PROTECTION FOR MERCHANT SHIPS

This idea originated in 1915 or 1916 with Captain Edward C. Villiers, of the Actaeon Torpedo School ship. Experiments were carried out by a battleship at Rosyth, in the first instance, and later at Scapa. They were at that time unsuccessful.

At the end of 1916 I gave directions for a reconsideration of the matter, and fresh trials were made; but early in 1917 there seemed to be no prospect of success, and the trials were again abandoned. However, Captain Villiers displayed great confidence in the idea, and he introduced modifications, with the result that later in the year 1917 directions were given for fresh trials to be undertaken. At the end of the year success was first obtained, and this was confirmed early in 1918, and the device finally adopted. A curious experience during the trials was that the vessel carrying them out was actually fired at by a German submarine, with the result that the net protection saved the ship from being torpedoed. It is not often that an inventor receives such a good advertisement.

DEPTH CHARGE THROWERS

The first proposal for this device came from Portsmouth, where the Commander-in-Chief, Admiral the Hon. Sir Stanley Colville, was indefatigable in his efforts to combat the submarine; throwers manufactured by Messrs. Thornycroft, of Southampton, were tried and gave good results. The arrangement was one by which depth charges could be projected to a distance of 40 yards from a vessel, and the throwers were usually fitted one on each quarter so that the charges could be thrown out on the quarter whilst others were being dropped over the stern, and the chances of damaging or sinking the submarine attacked were thus greatly increased.

As soon as the earliest machines had been tried orders were placed for large numbers and the supplies obtained were as follows:

Deliveries commenced in July, 1917. By September 1, 30 had been delivered. By October 1, 97 had been delivered. By December 1, 238 had been delivered.

COASTAL MOTOR BOATS

At the end of 1916 we possessed 13 fast coastal motor boats, carrying torpedoes, and having a speed of some 36 knots. They had been built to carry out certain operations in the Heligoland Bight, working from Harwich, but the preliminary air reconnaissance which it had been decided was necessary had not been effected by the end of 1916 owing to bad weather and the lack of suitable machines.

When winter set in it became impossible, with the type of aircraft then existing, to carry out the intended reconnaissance, and early in 1917 I abandoned the idea of the operations for the winter and sent the boats to the Dover Command for Sir R. Bacon to use from Dunkirk in operations against enemy vessels operating from Ostend and Zeebrugge. They quickly proved their value, and it became evident that they would also be useful for anti-submarine work. A large number were ordered, some for anti-submarine work and some for certain contemplated operations in enemy waters, including a night attack on the enemy's light cruisers known to lie occasionally in the Ems River, an operation that it was intended to carry out in the spring of 1918. A daylight operation in this neighbourhood, which was carried out during 1918, did not, from the published reports, meet with success, the coastal motor boats being attacked by aircraft, vessels against which they were defenceless. The new boats were of an improved and larger type than the original 40-feet boats. Delays occurred in construction owing principally to the difficulty in obtaining engines by reason of the great demand for engines for aircraft, and but few of the new boats were delivered during the year 1917.

MINING OPERATIONS

The policy which was carried out during 1917 in this respect, so far as the supply of mines admitted, aimed at preventing the exit of submarines from enemy ports. Incidentally, the fact that we laid large numbers of mines in the Heligoland Bight rendered necessary such extensive sweeping operations before any portion of the High Sea Fleet could put to sea as to be very useful in giving us some indication of any movement that might be intended. In view of the distance of the Grand Fleet from German bases and the short time available in which to intercept the High Sea Fleet if it came out for such a purpose as a raid on our coasts, or on convoys, the information thus gathered would have proved of great value.

In planning mining operations in the Heligoland Bight, it was necessary to take into consideration certain facts. The first was the knowledge that the Germans themselves had laid minefields in some portions of the Bight, and it was necessary for our minelayers to give such suspected areas a wide berth. Secondly, it was obvious that we could not lay minefields in areas very near those which we ourselves had already mined, since we should run the risk of blowing up our own ships with our own mines.

Mining operations had necessarily to be carried out at night, and as there were no navigational aids in the way of lights, etc., in the Heligoland Bight, the position in which our mines were laid was never known with absolute accuracy. Consequently an area in which we had directed mines to be laid, and to which a minelayer had been sent, could not safely be approached within a distance of some five miles on a subsequent occasion.

The use in mining operations of the device known as "taut wire" gear, introduced by Vice-Admiral Sir Henry Oliver, was of great help in ensuring accuracy in laying minefields and consequently in reducing the danger distance surrounding our own minefields.

As our mining operations increased in number we were driven farther and farther out from the German ports for subsequent operations. This naturally increased the area to be mined as the Heligoland Bight is bell-mouthed in shape, but it had the advantage of making the operations of German minesweepers and mine-bumpers more difficult and hazardous as they had to work farther out, thus giving our light forces better chances of catching them at work and engaging them. Such actions as that on November 17, 1917, between our light forces and the German light cruisers and minesweepers were the result. We did not, of course, lay mines in either the Danish or Dutch territorial waters, and these waters consequently afforded an exit for German vessels as our minefields became most distant from German bases.

Broadly speaking, the policy was to lay mines so thoroughly in the Heligoland Bight as to force enemy submarines and other vessels to make their exits along the Danish or Dutch coasts in territorial waters.

At the end of the exit we stationed submarines to signal enemy movements and to attack enemy vessels. We knew, of course, that the enemy would sweep other channels for his ships, but as soon as we discovered the position of these channels, which was not a very difficult matter, more mines were laid at the end. In order to give neutrals fair warning, certain areas which included the Heligoland Bight were proclaimed dangerous. In this respect German and British methods may be contrasted: We never laid a minefield which could possibly have been dangerous to neutrals without issuing a warning stating that a certain area (which included the minefield) was dangerous. The Germans never issued such a warning unless the proclamation stating that half the Atlantic Ocean, most of the North Sea, and nine-tenths of the Mediterranean were dangerous could be considered as such. It was also intended, as mines became available, to lay more deep minefields in positions near our own coast in which enemy submarines were known to work; these minefields would be safe for the passage of surface vessels, but our patrol craft would force the submarines to dive into them. This system to a certain extent had already been in use during 1915 and 1916.

Schemes were also being devised by Admiral of the Fleet Sir Arthur Wilson, who devoted much of his time to mining devices, by which mines some distance below the surface would be exploded by an enemy submarine even if navigating on the surface.

Such was the policy. Its execution was difficult.

The first difficulty lay in the fact that we did not possess a thoroughly satisfactory mine. A percentage only of our mines exploded when hit by a submarine, and they failed sometimes to take up their intended depth when laid, betraying their presence by appearing on the surface.

Energetic measures were adopted to overcome this latter defect, but it took time and but few mines were available for laying in the early months of 1917.

The result of our minelaying efforts is shown in the following table:

Mines laid Deep mines laid Year. in the Heligoland off our own coasts Bight. to catch submarines.

1915 4,498 983 1916 1,679 2,573 First quarter of 1917 4,865 ) Second quarter of 1917 6,386 ) 3,843 Third quarter of 1917 3,510 )

In the Straits of Dover, Thames Estuary and off the Belgian coast we laid 2,664 mines in 1914, 6,337 in 1915, 9,685 in 1916, and 4,669 in the first three quarters of 1917.

These last mines were laid as fast as the alterations, made with a view to increasing their efficiency, could be carried out.

During the early part of the year 1917 the new pattern of mine, known as the "H" Type, evolved in 1916, had been tried, and although not perfectly satisfactory at the first trials, the success was sufficient to warrant the placing of orders for 100,000 mines and in making arrangements for the quickest possible manufacture. This was done by the Director of Torpedoes and Mines, Rear-Admiral the Hon. Edward Fitzherbert, under the direction of the then Fourth Sea Lord, Rear-Admiral Lionel Halsey.

Deliveries commenced in the summer of 1917, but by the end of September only a little over 1,500 were ready for laying. Some 500 of these were laid in September in the Heligoland Bight and were immediately successful against enemy submarines. More were laid in the Bight during October, November and December, and the remainder, as they were produced, were prepared for laying in the new minefield in the Straits of Dover. In the fourth quarter of the year a total of 10,389 mines was laid in the Heligoland Bight and in the Straits of Dover.

During this last quarter delivery of "H" pattern mines was as follows: In October 2,350, November 5,300, December 4,800; total 12,450. So that it will be seen that the mines were laid as fast as delivery was made.

The great increase in projected minelaying operations during the year 1917 made it necessary also to add considerably to the number of minelaying vessels.

In January, 1917, the only vessels equipped for this service were four merchant ships and the Flotilla Leader Abdiel, with a total minelaying capacity of some 1,200 mines per trip. It was not advisable to carry out minelaying operations in enemy waters during the period near full moon owing to the liability of the minelayers being seen by patrol craft. Under such conditions the position of the minefield would be known to the enemy. As the operation of placing the mines on board occupied several days, it was not passible to depend on an average of more than three operations per ship per month from the larger minelayers. Consequently, with the intended policy in view, it was obvious that more minelayers must be provided.

It was inadvisable to use merchant ships, since every vessel was urgently required for trade or transport purposes, and the alternative was to fit men-of-war for minelaying. The only old vessels of this type suitable for mining in enemy waters were ships of the "Ariadne" class, and although their machinery was not too reliable, two of these vessels that were seaworthy were converted to minelayers. In addition a number of the older light cruisers were fitted with portable rails on which mines could be carried when minelaying operations were contemplated, in place of a portion of the armament which could be removed; a flotilla of destroyers, with some further flotilla leaders, were also fitted out as minelayers, and several additional submarines were fitted for this purpose.

For a projected special scheme of minelaying in enemy waters a number of lighters were ordered, and some of the motor launches and coastal motor boats were fitted out and utilized for mining operations on the Belgian coast towards the end of 1917.

By the end of that year 12 light cruisers, 12 destroyers and flotilla leaders and 5 submarines had been fitted for minelaying. Two old cruisers had been added to the minelaying fleet and several other vessels were in hand for the same purpose. The detailed plans of the arrangements were prepared and the work of fitting out minelayers carried out under the supervision of Admiral R.N. Ommanney, C.B., whose services in this matter were of great value. The rapidity with which ships were added to the minelaying fleet was largely due to his efforts.

On the entry of the United States of America into the war a further development of mining policy became feasible. The immense manufacturing resources of the United States rendered a large production of mines an easy matter, with the result that as soon as the United States Navy produced a reliable type of mine the idea of placing a mine barrage across the northern part of the North Sea which had been previously discussed became a matter of practical politics. With this end in view a still further addition to the minelaying fleet became necessary, and since the mining would be carried out at leisure in this case and speed was no great necessity for the minelayer owing to the distance of the minefields from enemy waters, an old battleship was put in hand for conversion.

With the enormous increase in the number of mines on order the problem of storage became of importance, including as it did the storage of the very large number, some 120,000, required for the northern barrage. The Third Sea Lord, Admiral Lionel Halsey, took this matter in hand with characteristic energy, and in conjunction with United States naval officers made all the necessary arrangements.

The United States mines were stored in the vicinity of Invergordon, and the British mines intended for use in the northern barrage were located at Grangemouth, near Leith, where Rear-Admiral Clinton Baker was in charge, as well as in other places, whilst those for use in the Heligoland Bight and Channel waters were stored at Immingham and other southern depots.

The laying of the North Sea mine barrage was not accomplished without very considerable delay, and many difficulties were encountered. It was originally anticipated that the barrage would be completed in the spring of 1918, but owing to various defects in both British and United States mines which made themselves apparent when the operations commenced, due partly to the great depth of water as well as to other causes, a delay of several months took place; and, even when near completion, the barrage was not so effective as many had hoped in spite of the great expenditure of labour and material involved. I have not the figures of the number of submarines that the barrage is thought to have accounted for, but it was known to be disappointing.

FLARES

In the late summer of 1917 flares were experimented with; they were intended to be used from kite balloons with the object of sighting submarines when on the surface at night. Previously searchlights in destroyers had been used for this purpose. The flares were not much used, however, from kite balloons owing to lack of opportunity, but trials which were carried out with flares from patrol craft, such as trawlers and drifters, demonstrated that they would be of value from these vessels, and when the Folkestone-Grisnez minefield was laid in November and December, 1917, it was apparent that the flares would be of use in forcing submarines to dive at night into the minefield to escape detection on the surface and attack by gunfire.

Manufacture on a large scale was therefore commenced, and during 1918 the flares were in constant use across the Straits of Dover.

ELECTRICAL SUBMARINE DETECTOR

The existence of this very valuable device was due to the work of certain distinguished scientists, and experiments were carried out during 1917. It was brought to perfection in the late autumn, and orders were given to fit it in certain localities. Some difficulty was experienced in obtaining the necessary material, but the work was well in hand by the end of the year, and quickly proved its value.

SUBMARINE AGAINST SUBMARINE

Prior to the year 1917 the only areas in which our own submarines operated against enemy vessels of the same type was in the North Sea, or occasionally in the vicinity of the Hebrides. Grand Fleet submarines were used in the northern areas during 1916, and Harwich submarines operated farther south, but the number of underwater craft available was insufficient for any extended method of attack. Early in 1917, when our mercantile losses were very heavy, some submarines were withdrawn from the Harwich and Humber districts and formed into a flotilla off the coast of Ireland for this form of operation. Some risk had to be accepted in thus reducing our submarine strength in southern waters. At the same time some Grand Fleet submarines were organized into a watching patrol in the area off the Shetland Islands, through which enemy submarines were expected to pass. The watch off the Horn Reef and in the Heligoland Bight, which had previously been in force, was also maintained.

A little later the submarine flotilla off the Irish coast was strengthened, and a regular patrol instituted near the North Channel between Ireland and Scotland. The next step was the withdrawal of some "C" Class submarines from coastal work on our east coast to work in the area between England and Holland near the North Hinder Lightship, a locality much frequented by enemy submarines on passage. Still later some submarines were attached to the Portsmouth Command, where, working under Sir Stanley Colville, they had some striking successes; others went to the Dover Command. The latter were fitted with occulting lights on top of the conning-tower, and were moored at night to buoys in the Dover Net Barrage, in places where enemy submarines were likely to pass, in order that they might have a chance of torpedoing them. A division of submarines was also sent to Gibraltar, to operate against enemy cruiser submarines working in that vicinity or near the Canaries. Successes against enemy submarines were also obtained in the latter locality.

Finally, the arrival of some United States submarines enabled the areas in which this form of attack was in force to be still further extended, after the American personnel had been trained to this form of warfare. There was a great increase in the number of enemy submarines sunk by this method of attack during 1917 as compared with previous years; the number of vessels sunk does not, however, convey a complete appreciation of the effect of this form of anti-submarine warfare. The great value of it lay in the feeling of insecurity that it bred in the minds of the enemy submarine commanders. The moral effect of the constant apprehension that one is being "stalked" is considerable. Indeed, the combination of our aircraft and our submarine patrols led to our vessels reporting, regretfully, that it was very seldom that German submarines were found on the surface in daylight, and towards the end of 1917 quite a large proportion of the attacks on merchant ships took place at night.

The work for our own vessels was very arduous indeed. It was only on rare occasions that it was possible to bring off a successful attack on a submarine that had been sighted, the low underwater speed of submarines making it difficult to get into position when the enemy was only sighted at short range, which was naturally usually the case.

In order to obviate this difficulty directions were given in 1917 to design a special type of submarine for this form of warfare, and I believe that the first vessel was completed by the autumn of 1918.

This account of the development of anti-submarine measures during 1917 would not be complete without mention of the work of the Trade Division of the Staff, of which Captain Richard Webb, C.B., was the Director until September.

This Division was either partly or wholly responsible for:

(1) The great increase in the rapidity of placing the armaments on board merchant ships.

(2) The establishment of schools of instruction for captains and officers of the Mercantile Marine.

This training scheme was begun at Chatham Barracks in February, 1917, by Commander E.L.B. Lockyer, acting under Captain Webb, and later was extended to Portsmouth, Cardiff and Greenock. Its success was so marked, and its benefit in assisting officers to handle their ships in the manner best calculated to save them from submarine attack so great, that the Admiralty was continually being pressed by shipowners and by the officers of the Mercantile Marine to extend the instruction to more and more ports. This was done so far as possible, our principal difficulty being to provide officers capable of giving the instruction required.