[Footnote 2: World's Work, Sept., 1919.]
| Vessels sunk per submarine destroyed | Total No. sunk | ||
| Aug. 1, 1914- Feb., 1915 | 10.4 | 69 ships sunk, almost entirely by surface cruisers. | |
| Feb. 1, 1915- Feb. 1, 1917 | 48 | 544 (two years) | Half by torpedo; 148 without warning; 3,066 lives lost. |
| Feb. 1, 1917- Sept. 1, 1917 | 67 | 736 (7 months) | 572 by torpedo; 595 (69%) with out warning. |
| Sept. 1, 1917- April 1, 1918 | 20.2 | 548 (7 months) | 448 (82%) without warning. |
| April 1, 1918- Nov. 1, 1918 | 12 | 252 (7 months) | 239 (91%) without warning. |
From July 26, 1917, to October 26, 1918, 90,000 vessels were convoyed, with a total loss from the convoys of 436, or less than half of one per cent. The convoy system forced submarines to expose themselves to the attacks of destroyer escorts, or else to work close in shore to set upon vessels after the dispersion of the convoy. But when working close to the coast they were exposed to Allied patrols and submarines.
Testifying before a German investigation committee, Captain Bartenbach, of the V-boat section of the German Admiralty, gave the chief perils encountered by his boats as follows: (1) mines, (2) Allied submarines, which "destroyed a whole series of our boats," (3) aircraft of all types, (4) armed merchantmen, (5) hydrophones and listening devices. Admiral Capelle in his testimony referred to the weakening of their efforts due to "indifferent material and second-rate crews."
Transport Work
Dependent in large measure upon the anti-submarine campaign for its safety and success, yet in itself an immense achievement, the transport of over 2,000,000 American troops to France must be regarded as one of the major naval operations of the war. Of these forces 48% were carried in British, and 43% in American transports. About 83% of the convoy work was under the protection of American naval vessels.
The transportation work of the British navy, covering a longer period, was, of course, on a far greater scale. Speaking in Parliament on October 29, 1917, Premier Lloyd George indicated the extent of this service as follows: "Since the beginning of the war the navy has insured the safe transportation to the British and Allied armies of 13,000,000 men, 12,000,000 horses, 25,000,000 tons of explosives and supplies, and 51,000,000 tons of coal and oil. The loss of men out of the whole 13,000,000 was 3500, of which only 2700 were lost through the action of the enemy. Altogether 130,000,000 tons have been transported by British ships." These figures, covering but three years of the war, are of significance chiefly as indicating the immense transportation problems of the British and Allied navies and the use made of sea communications.
These three main Allied naval operations—the blockade of Germany, the anti-submarine campaign, and the transportation of American troops to France—were unquestionably decisive factors in the war. Failure in any one of them would have meant victory for Germany. The peace of Europe, it is true, could be achieved only by overcoming Germany's military power on land. A breakdown there, with German domination of the Continent, would have created a situation which it is difficult to envisage, and which very probably would have meant a peace of compromise and humiliation for England and America. It is obvious, however, that, but for the blockade, Germany could have prolonged the war; but for American reënforcements, France would have been overrun; but for the conquest of the submarine, Great Britain would have been forced to surrender.
In the spring of 1918 Germany massed her troops on the western front and began her final effort to break the Allied lines and force a decision. With supreme command for the first time completely centralized under Marshal Foch, and with the support of American armies, the Allies were able to hold up the enemy drives, and on July 18 begin the forward movement which pushed the Germans back upon their frontiers. Yet when the armistice was signed on November 11, the German armies still maintained cohesion, with an unbroken line on foreign soil. Surrender was made inevitable by internal breakdown and revolution, the first open manifestations of which appeared among the sailors of the idle High Seas Fleet at Kiel.
On November 21, 1918, this fleet, designed as the great instrument for conquest of world empire, and in its prime perhaps as efficient a war force as was ever set afloat, steamed silently through two long lines of British and Allied battleships assembled off the Firth of Forth, and the German flags at the mainmasts went down at sunset for the last time.