Submarines and their Weapons - Aircraft of World War II

TYPE XVIIB
Type: Coastal submarine
Displacement: 317 tonnes (312 tons) surfaced;
363 tonnes (357 tons) submerged
Length: 41.50m (136.17ft)
Submerged speed: 21.5 knots
equipped Mark 27 torpedo in 1944, and in the last
years of the war, 106 were fired in combat, scoring 33
hits (31 per cent).
Another approach was to fit a form of automatic
pilot, which caused the torpedo to make a series of
pre-programmed turns after it had run a preset distance,
in the hope that a torpedo fired in the general
direction of a convoy would turn and hit a ship purely
by chance. Neither the success rate of the
Federapparat-Torpedo, nor that of its more sophisticated
successor, the Lagcnunabhangiger-Torpedo
(which could be fired from depths of up to 50m;
164ft), seems to have been recorded. Later U-boats
had their six forward-facing torpedo tubes organised
into an array which covered 10 degrees of arc; firing
all six in a salvo gave a much-improved chance of hitting
the target. It is obvious that the same guidance
system which was applied to the glider bombs and the
guided missiles could also have been applied to torpedoes,
even though keeping a precise track of the
missile's course would naturally have been more difficult.
It is inconceivable that an experimental programme,
at least, was not initiated. Certainly, one of
the Kriegsmarine's original submarine warfare
instructors, Werner Fürbringer, suggested it.
A viable alternative to the torpedo was to lay mines
in the path of the oncoming enemy (particularly if this
was a slow-moving convoy), and a variety of submarine-launched
mines were developed. The Torpedo-
Ankertaumine (TMA) had a 215kg (4751b) explosive
charge, and was attached to an anchor which allowed
it to float at a predetermined height, while the
Torpedo-Grundminen lay on the seabed in shallower
water. They came in two sizes: the 500kg (llOOlb)
TMB and the 1000kg (22001b) TMC. All three mines
were dimensioned to allow them to be deployed
SUBMARINES AND THEIR WEAPONS
Submerged range: 210km (130 miles)
Armament: 2 x 533mm (21 in) torpedo tubes
Crew: 1,9
Above: The Type XVII boats had both conventional diesel
engines and a single Walter closed-cycle engine. They
were designed for coastal operations.
through a standard 533mm (21in) torpedo tube and
could be fitted with a variety of remotely actuated detonators,
magnetic or acoustic.
THE NEW GENERATION OF SUBMARINES
There was little development of the basic submarine
in the inter-war period, except that the once-popular
saddle-tank design, in which the buoyancy chambers
were located outside the pressure hull, gave way more
and more to the double hull, in which they enclosed it
almost completely and were themselves contained
within a light enclosure which could be shaped to
improve sea-keeping and performance. In Germany,
developments in the late 1930s were aimed only at
increasing the size and endurance of existing types,
not making any radical changes to their design.
However, by 1941, experimental boats with a new
type of powerplant which did not need atmospheric
oxygen had been produced, and were proving to be
quite remarkable. The powerplant in question was,
once again, the creation of the prolific Professor
Hellmuth Walter, whom we have already met.
Walter had constructed a small experimental boat,
the V30, launched on 19 January 1940, which displaced
just 73.8 tonnes (75 tons) submerged. He
equipped it with a steam turbine, fed by a variant of
the liquid-fuel motors which were to power the VI
flying bomb's launch catapult, producing their steam
by the chemical reaction of hydrogen peroxide with a
catalyst. Walter soon discovered that his submarine
could make almost 30 knots submerged - around
three times the submerged speed of any conventional
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