Forces from Harwich also succeeded in capturing or sinking twenty-four merchant ships trading between Antwerp and Dutch ports and Germany during the year, but the main result of the operations of this force was shown in the refusal of the enemy to risk his vessels except under cover of darkness in the area in which the Harwich force worked.

The duty of protecting the Dutch convoy imposed a heavy strain upon the Harwich force.  During the year 1917, 520 eastbound and 511 westbound vessels were convoyed between Dutch and British ports with the loss of only four ships by submarine attack, one by destroyer attack, and one by mine.  The price paid by the force for this success was the loss of four destroyers by mines, and one by collision, and the damage of three destroyers by mine or torpedo, and of five destroyers and one light cruiser by collision.  The frequent collisions were due to the conditions under which the traffic was carried out at night without lights, and to the prevalence of fogs.  The procedure adopted by the force was frequently changed as it necessarily became known to the Germans.

The extraordinarily small losses in the convoys were a very great tribute to the handling of the protecting force and to the organization in Holland for arranging sailings, when it is borne in mind that it was almost impossible to prevent leakage of information to German agents once the time of sailing was given out, and that the convoys were open to attack from destroyers and submarines operating either from Zeebrugge or from the Ems or other German ports.  The orders of course emanated from the Admiralty, and of all the great work achieved by Vice-Admiral Sir Henry Oliver, the Deputy Chief of the Naval Staff, during his service at the Admiralty in the year 1917 and indeed in the two preceding years, the success attending the work of this convoy was certainly not the least.

It is difficult to put into words the great admiration which I felt for Sir Henry Oliver’s work throughout the war.  Our association commenced during my command of the Grand Fleet, but became of course much closer at the Admiralty, and during my service there his assistance was of immense help to me and of incalculable value to the nation.

It was fortunate indeed for the Allied cause that he held such important Staff appointments during the most critical periods of the war.

CHAPTER IX

THE SEQUEL

The foregoing chapters have been devoted to describing the measures that were devised or put into force or that were in course of preparation during the year 1917 to deal with the unrestricted submarine warfare against merchant shipping adopted by Germany and Austria in February of that year.  It now remains to state, so far as my information admits, the effect of those measures.