German Submarine Warfare 1914-1918 in the Eyes - British Naval ...

During the first months of 1917, the figure was 14,000 tons, and from August onwards fell to
9,000 tons per boat per trip.” 41
Table 9: Ocean-going U-boats available 1915-1918,
North-Sea and Atlantic 42
100
90
80
70
60
50
40
30
20
10
0
2
15
13%
Ocean-going uboats avail. per day
No. on merchant war per day
% usage for merchant war
39
13%
5
41 NA, HW 7/2, pp. 447, 448.
42 Numbers based on: NA, HW 7/3; on: Spindler, Handelskrieg; on: Bendler, UB- und UC-Boote.
xxiii
86
34%
29
82
35%
1915 1916 1917 1918
Tables 9 and 10 examine ocean-going submarine from U-19, UB-18 and
UC-16 onwards. Coastal boats of the type UC-I, UB-I, and U-5 to U-18 - some
forty-six units - contributed a modest 0,2M BRT to the overall total of twelve
million BRT ships sunk. Their range topped at a modest 750-2,000 nautical miles,
effectively restricting patrols to a few days and making them totally unsuited for the
Atlantic. Further, the old petroleum boats U-5 to U-18 needed long, dangerous
minutes of preparation time in the event of an emergency crash dive. Soon enough,
all were either sunk or relegated to the submarine school. The UB-I class carried
two torpedoes; the UC-Is had no torpedoes, carried mines and could man a
machine gun. Carrier pigeon was the sole means of communication. With a
maximum surface speed of six knots the type could overtake sailing ships caught in
a weak wind or in irons. Most of their sinkings were the result of luck. Their
operational area was the North Sea, the Baltic and the eastern Channel. These boats
are included in the tables that address sinkings, not in tables about ocean-going
boats.
In 1915, the number of ocean-going boats in service in the North Sea and
Atlantic throughout the year was fifteen. In the annual average there were two
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