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

CHAPTER I
GERMAN SUBMARINES, THEIR FLOTILLAS,
AND THEIR SCHOOL
The Submarines 1
Types
German submarines were of the three main types: U-boats, UB-boats, and
UC-boats. The U-boats were large double hull ocean-going boats. The UBs were
small boats built originally for coastal work; the UC-boats were minelayers. A
fourth class named UF-boats were under construction at the time of the Armistice
and were said to be of a small improved coastal type, but none of these were
completed during the war.
U-boats
The U-boats constitute the principal type. At the outbreak of war Germany
possessed 28 submarines, all of the U-class. Of these the first 18 were fitted with
Körting paraffin engines but all submarines from U-19 upwards were driven by
heavy oil Diesel engines. The submarines were built in series which at first
consisted of three to five boats, but later when greater standardization was
introduced for the sake of accelerating output, the U-boat series sometimes
contained as many as ten boats, while UB- and UC-type series were far larger. Each
series, with a few exceptions, showed a slight increase in size over the proceeding
one.
U-1, which was launched in 1906, was 138 feet long with a surface
displacement of 235 tons and a submerged of 280 tons. In the series U-19 to
U-22, which were the first boats to undertake long-distance trips, the displacement
had risen to 640/825 tons.
From this series to that of U-105 to U-114 the boats show generally a steady
increase in size, the last named boats having a displacement of 820/1,015 tons.
The average large U-boat was 210-225 feet long, 20-22 feet in breadth and in
surface trim drew 12 to 13.25 feet. A few series may be selected as containing
noteworthy points.
U-71 to U-80. These boats were fitted as minelayers carrying 34-36 mines.
They only had a single hull and were very slow, cruising generally at about 6 knots.
They were not successful as a class and were liable at all times to develop engine
defects.
1 NA, HW 7/3, chapter V, pp. 127 passim.
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