The Crisis of the Naval War

by John Rushworth Jellicoe

CHAPTER II

THE SUBMARINE CAMPAIGN IN THE EARLY PART OF 1917

The struggle against the depredations of the enemy submarines during the year 1917 was two-fold; offensive in the direction of anti-submarine measures (this was partly the business of the Anti-Submarine Division of the Naval Staff and partly that of the Operations Division); defensive in the direction of protective measures for trade, whether carried in our own ships or in ships belonging to our Allies or to neutrals, this being the business of the Trade and Mercantile Movements Divisions.

Prior to the formation of the Mercantile Movements Division the whole direction of trade was in the hands of the Trade Division of the Staff.

The difficulty with which we were constantly faced in the early part of 1917, when the effective means of fighting the submarine were very largely confined to the employment of surface vessels, was that of providing a sufficient number of such vessels for offensive operations without incurring too heavy risks for our trade by the withdrawal of vessels engaged in what might be termed defensive work. There was always great doubt whether any particular offensive operation undertaken by small craft would produce any result, particularly as the numbers necessary for success were not available, whilst there was the practical certainty that withdrawal of defensive vessels would increase our losses; the situation was so serious in the spring of 1917 that we could not carry out experiments involving grave risk of considerably increased losses.

On the other hand, the sinking of one enemy submarine meant the possible saving of a considerable number of merchant ships. It was difficult to draw the line between the two classes of operations.

The desire of the Anti-Submarine Division to obtain destroyers for offensive use in hunting flotillas in the North Sea and English Channel led to continual requests being made to me to provide vessels for the purpose. I was, of course, anxious to institute offensive operations, but in the early days of 1917 we could not rely much on depth-charge attack, owing to our small stock of these charges, and my experience in the Grand Fleet had convinced me that for success in the alternative of hunting submarines for a period which would exhaust their batteries and so force them to come to the surface, a large number of destroyers was required, unless the destroyers were provided with some apparatus which would, by sound or otherwise, locate the submarine. This will be realized when the fact is recalled that a German submarine could remain submerged at slow speed for a period which would enable her to travel a distance of some 80 miles. As this distance could be covered in any direction in open waters such as the North Sea, it is obvious that only a very numerous force of destroyers steaming at high speed could cover the great area in which the submarine might come to the surface. She would, naturally, select the dark hours for emergence, as being the period of very limited range of vision for those searching for her. In confined waters such as those in the eastern portion of the English Channel the problem became simpler. Requests for destroyers constantly came from every quarter, such as the Commanders-in-Chief at Portsmouth and Devonport, the Senior Naval Officer at Gibraltar, the Vice-Admiral, Dover, the Rear-Admiral Commanding East Coast, and the Admiral at Queenstown. The vessels they wanted did not, however, exist.

Eventually, with great difficulty, a force of six destroyers was collected from various sources in the spring of 1917, and used in the Channel solely for hunting submarines; this number was really quite inadequate, and it was not long before they had to be taken for convoy work.

Evidence of the difficulty of successfully hunting submarines was often furnished by the experiences of our own vessels of this type, sometimes when hunted by the enemy, sometimes when hunted in error by our own craft. Many of our submarines went through some decidedly unpleasant experiences at the hands of our own surface vessels and occasionally at the hands of vessels belonging to our Allies. On several such occasions the submarine was frequently reported as having been sunk, whereas she had escaped.

As an example of a submarine that succeeded not only in evading destruction, but in getting at least even with the enemy, the case of one of our vessels of the "E" class, on patrol in the Heligoland Bight, may be cited. This submarine ran into a heavy anti-submarine net, and was dragged, nose first, to the bottom. After half an hour's effort, during which bombs were exploding in her vicinity, the submarine was brought to the surface by her own crew by the discharge of a great deal of water from her forward ballast tanks. It was found, however, that the net was still foul of her, and that a Zeppelin was overhead, evidently attracted by the disturbance in the water due to the discharge of air and water from the submarine. She went to the bottom again, and after half an hour succeeded in getting clear of the net. Meanwhile the Zeppelin had collected a force of trawlers and destroyers, and the submarine was hunted for fourteen hours by this force, assisted by the airship. During this period she succeeded in sinking one of the German destroyers, and was eventually left unmolested.