SHIPPING: WAR LOSSES OF. The outstanding fea tures of the attack upon merchant shipping in the World War were (I) the enormous preponderance of the British losses, ( 2 ) a neu tral nation—Norway—suffered the second largest losses, (3) two allied nations, the United States and Japan, owned more shipping at the end of the war than at the beginning, every other nation possessing less, (4) submarines accounted for 87% of the losses, (5) nearly one-half of the losses occurred in the 12 months Nov. 1916 to Oct. 1917, (6) marine losses of British ships were nearly 5o% greater in 1918 than in 1913, (7) one commerce raider, "Mi5we" accounted for more than double the number of ships sunk by any other individual surface craft, (8) on an average approximately i,000,000 tons of shipping was continuously under repair, (9) the current losses were greater than the output of new shipping until the last nine months of the war.
The enemy conducted his campaign by submarine, by surface craft and by mine, five vessels only being sunk by aircraft. To losses directly due to enemy action must be added the losses due to marine risks which were greatly increased by strandings and collisions, resulting from the unlighted coasts, concentrated ship ping, etc. There was also a diminution of effective tonnage on account of damage to vessels which ultimately reached port. The campaign falls into three periods, the first extending until Aug. 1916, when the enemy began an intensified effort. This continued until the "sink-at-sight" campaign began in Feb. 1917. For this last period, much more detailed information was obtained regard ing the circumstances of each attack, and this part of the cam paign can be studied from every possible standpoint. Comparison cannot be made, however, with the earlier periods owing to the lack of the earlier statistics, particularly in regard to foreign tonnage. In the case of British tonnage, the losses do not include merchant ships which were fitted out as armed escorts or as mer chant cruisers for the protection of shipping routes, etc.
Excluding fishing vessels, the total war losses of the allies and neutrals were in part made good by new construction (10,849,00o tons) and by 2,411,000 tons captured from the enemy, the total pre-war tonnage of 34,825,00o being reduced to 33,041,000 tons. There were net gains to the United States of 4,196,00o tons (128% over 1914) and to Japan of 677,000 tons (67%), while the largest net losses were to United Kingdom 3,084,00o tons (17%) and to Norway 1,260,000 tons (48%).
Submarine Attacks During the Unrestricted Campaign. —During the 21 months, 3,672 vessels were reported attacked, of which 2,93o were by torpedo and 742 by gun-fire. Of those at tacked, 2,262 were sunk, 345 damaged and 1,065 escaped. Of the 2,93o attacked by torpedo, 1,949 were British (28% escaped) and 981 foreign (18% escaped). Of the 742 attacked by gun-fire 368 were British (71% escaped) and 374 foreign (21% escaped).
A comparison between the 9 months Feb.–Oct. 1917 with the same period in 1918 gives the following interesting figures:— Losses by Surface Craft.—Of the 191 vessels (562,900 tons) lost throughout the war, cruisers accounted for 48, raiders 61, armed merchant cruisers 27, and torpedo boats, etc. 55; 117 were British (averaging 3,80o tons) 43 allies (1,90o tons) and 31 neu trals (1,20o tons). The most successful enemy vessel was the raider "Mowe," which in the 15 months from Jan. 1916 sank 38 vessels (33 British). The cruisers Emden and Karlsruhe in the first four months of the war had 17 and 16 to their credit, all except one being British vessels averaging 4,00o tons. Two other raiders "Seeadler" and "Wolf" operating 2 and 6 months in 1917 accounted for 12 and io, each sinking 6 British vessels. The armed merchantmen Kronprinz Wilhelm sank 9 British and 5 others and the Prinz Eitel Friedrich 5 British and 6 others, before being interned in March and Feb. 1915 respectively. The 16 British vessels sunk by torpedo boats and by unidentified vessels averaged 1,275 tons and the 39 others were about the same size.