Part 9 (1/2)
The laying of the North Sea mine barrage was not accomplished without very considerable delay, and many difficulties were encountered. It was originally antic.i.p.ated 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 pa.s.s. 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 inst.i.tuted near the North Channel between Ireland and Scotland. The next step was the withdrawal of some ”C” Cla.s.s submarines from coastal work on our east coast to work in the area between England and Holland near the North Hinder Lights.h.i.+p, a locality much frequented by enemy submarines on pa.s.sage. 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 pa.s.s, 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 s.h.i.+ps 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 s.h.i.+ps.
(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 a.s.sisting officers to handle their s.h.i.+ps in the manner best calculated to save them from submarine attack so great, that the Admiralty was continually being pressed by s.h.i.+powners 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 princ.i.p.al difficulty being to provide officers capable of giving the instruction required.
(3) The provision of wireless plant and operators to the Mercantile Marine. This was another matter taken up with energy during 1917, and with excellent results.
(4) The drilling of guns crews for the merchant s.h.i.+ps. Men were invited to go through a course of drill, and large numbers responded and were instructed at the Royal Naval Depot at the Crystal Palace.
All these matters were additional to the important work upon which the Trade Division was constantly employed, which included all blockade questions, the routeing of merchant s.h.i.+ps, examination of s.h.i.+ps, etc.
In addition to the instructional anti-submarine course for masters and officers, gunnery courses for cadets and apprentices were started at Portsmouth, Chatham and Devonport. A system of visits to s.h.i.+ps by officer instructors for the purpose of affording instruction and for inspection, as well as for the purpose of lecturing, was inst.i.tuted, and arrangements were made for giving instruction in signalling. Some idea of the work carried out will be gathered from the following figures showing the instructional work carried out during the year 1917:
Masters 1,929 Officers 2,149 Number of cadets and apprentices pa.s.sed through the gunnery course 543 Number of merchant seamen trained in gunnery at the Crystal Palace 3,964 Number of s.h.i.+ps visited by officer instructors 6,927 Numbers attending these lectures: Masters 1,361 Officers 5,921 Number of officers and men instructed in signalling 10,487 The keenness shown by officers and men of the merchant service contributed in a marked degree to the success of the courses inst.i.tuted; just one example may be given. I visited the Royal Naval Depot at the Crystal Palace early in 1918, and amongst other most interesting scenes witnessed a large number of men of the merchant service at gun drill. I questioned several of them as to their experiences, and many of the men had had their s.h.i.+ps torpedoed under them three, four or five times. Amongst the gun crews was a steward who had been through this experience four times. On my asking why he, as a steward, should be going through the gunnery course, he replied that he hoped that by so doing he might stand a chance of getting his own back by a.s.sisting to sink a submarine.
The knowledge which I possessed of the measures introduced during the year 1917 to combat the German submarine warfare, and the continual increase in the efficiency of the anti-submarine work which I knew would result from increased production of anti-submarine vessels and weapons, led me in February, 1918, to state that in my opinion the submarine menace would be ”held” by the autumn of the year 1918. The remark, which was made at what I understood to be a private gathering, was given very wide publicity, and was criticized at the time, but it was fulfilled, as the figures will indicate.
CHAPTER IV
THE INTRODUCTION OF THE CONVOY SYSTEM The question of the introduction of convoys for the protection of merchant s.h.i.+ps was under consideration at various times during the war. The system had been employed during the old wars and had proved its value in the case of attack by vessels on the surface, and it was natural that thoughts should be directed towards its reintroduction when the submarine campaign developed. There is one inherent disadvantage in this system which cannot be overcome, although it can be mitigated by careful organization, viz. the delay involved. Delay means, of course, a loss of carrying-power, and when tonnage is already short any proposal which must reduce its efficiency has to be very carefully examined. The delay of the convoy system is due to two causes, (a) because the speed of the convoy must necessarily be fixed by the speed of the slowest s.h.i.+p, and (b) the fact that the arrival of a large number of s.h.i.+ps at one time may cause congestion and consequent delay at the port of unloading. However, if additional safety is given there is compensation for this delay when the risk is great. One danger of a convoy system under modern conditions should be mentioned, viz. the increased risk from attack by mines. If s.h.i.+ps are sailing singly a minefield will in all probability sink only one vessel-the first s.h.i.+p entering it. The fate of that s.h.i.+p reveals the presence of the field, and with adequate organization it is improbable that other vessels will be sunk in the same field. In the case of a convoy encountering a minefield, as in the case of a fleet, several s.h.i.+ps may be sunk practically simultaneously.
During the year 1916, whilst I was still in command of the Grand Fleet, suggestions as to convoys had been forwarded to the Admiralty for the better protection of the ocean trade against attack by surface vessels; but it was pointed out to me that the number of cruisers available for escort work was entirely insufficient, and that, consequently, the suggestions could not be adopted. This objection was one that could only be overcome by removing some of the faster merchant s.h.i.+ps from the trade routes and arming them. To this course there was the objection that we were already-that is before the intensive campaign began-very short of s.h.i.+pping.
Shortly after my taking up the post of First Sea Lord at the Admiralty, at the end of 1916, the question was discussed once more. At that time the danger of attack by enemy raiders on s.h.i.+pping in the North Atlantic was small; the protection needed was against attack by submarines, and the dangerous area commenced some 300-400 miles from the British Islands. It was known that unrestricted submarine warfare was about to commence, and that this would mean that s.h.i.+pping would usually be subjected to torpedo attack from submarines when in a submerged condition. Against this form of attack the gun armament of cruisers or armed merchant s.h.i.+ps was practically useless, and, however powerfully armed, s.h.i.+ps of this type were themselves in peril of being torpedoed. Small vessels of shallow draught, possessing high speed, offered the only practicable form of protection. Shallow draught was necessary in order that the protecting vessels should themselves be comparatively immune from successful torpedo fire, and speed was essential for offensive operations against the submarines.
Convoy sailing was, as has been stated, the recognized method of trade protection in the old wars, and this was a strong argument in favour of its adoption in the late war. It should, however, be clearly understood that the conditions had entirely changed. Convoy sailing for the protection of merchant s.h.i.+ps against torpedo attack by submarines was quite a different matter from such a system as a preventive against attack by surface vessels and involved far greater difficulties. In the days of sailing s.h.i.+ps especially, accurate station keeping was not very necessary, and the s.h.i.+ps comprising the convoy sailed in loose order and covered a considerable area of water. On a strange vessel, also a sailing vessel, being sighted, the protecting frigate or frigates would proceed to investigate her character, whilst the s.h.i.+ps composing the convoy closed in towards one another or steered a course that would take them out of danger.
In the circ.u.mstances with which we were dealing in 1917 the requirements were quite otherwise. It was essential for the protection of the convoy that the s.h.i.+ps should keep close and accurate station and should be able to manoeuvre by signal. Close station was enjoined by the necessity of reducing the area covered by the convoy; accurate station was required to ensure safety from collision and freedom of manoeuvre. It will be realized that a convoy comprising twenty to thirty vessels occupies considerable s.p.a.ce, even when steaming in the usual formation of four, five or six columns. Since the number of destroyers or sloops that could be provided for screening the convoy from torpedo attack by submarines was bound to be very limited under any conditions, it was essential that the columns of s.h.i.+ps should be as short as possible; in other words, that the s.h.i.+ps should follow one another at close intervals, so that the destroyers on each side of the convoy should be able as far as possible to guard it from attack by submarines working from the flank, and that they should be able with great rapidity to counter-attack a submarine with depth charges should a periscope be sighted for a brief moment above the surface, or the track of a torpedo be seen. In fact, it was necessary, if the protection of a convoy was to be real protection, that the s.h.i.+ps composing the convoy should be handled in a manner that approached the handling of battles.h.i.+ps in a squadron. The diagram on p. 107 shows an ideal convoy with six destroyers protecting it, disposed in the manner ordered at the start of the convoy system.