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 ships 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 ship, and (b) the fact that the arrival of a large number of ships 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 ships are sailing singly a minefield will in all probability sink only one vessel—­the first ship entering it.  The fate of that ship 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 ships 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 ships 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 shipping.