Type U 31 was a class of
U-boat
U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare ro ...
s built during World War I by the
Kaiserliche Marine
{{italic title
The adjective ''kaiserlich'' means "imperial" and was used in the German-speaking countries to refer to those institutions and establishments over which the ''Kaiser'' ("emperor") had immediate personal power of control.
The term wa ...
.
Between 1912 and 1915 eleven were built on
Germaniawerft in
Kiel
Kiel () is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 246,243 (2021).
Kiel lies approximately north of Hamburg. Due to its geographic location in the southeast of the Jutland ...
, amongst these top-three-scoring with the famous
Lothar von Arnauld de la Perière as commander, with
Walter Forstmann and with
Max Valentiner
Captain Christian August Max Ahlmann Valentiner (15 December 1883 – 19 July 1949) was a German U-boat commander during World War I. He was the third highest-scoring U-boat commander of the war, and was awarded the Pour le Mérite for his achievem ...
. Together these U-boats sunk more than .
Later
admiral and head of the
Abwehr from 1935 to 1944
Wilhelm Canaris
Wilhelm Franz Canaris (1 January 1887 – 9 April 1945) was a German admiral and the chief of the ''Abwehr'' (the German military-intelligence service) from 1935 to 1944. Canaris was initially a supporter of Adolf Hitler, and the Nazi re ...
also served as commander on two different Type U 31 U-boats. He first took over from Max Valentiner on ''U-38'' and later on .
Design
German Type U 31 submarines were
double-hulled ocean-going submarines similar to
Type 23 and
Type 27 subs in dimensions and differed only slightly in propulsion and speed. They were considered very good high sea boats with average manoeuvrability and good surface steering.
Type U-31s had an
overall length
The overall length (OAL) of an ammunition cartridge is a measurement from the base of the brass shell casing to the tip of the bullet, seated into the brass casing. Cartridge overall length, or "COL", is important to safe functioning of reloads i ...
of , their
pressure hull
A submarine hull has two major components, the ''light hull'' and the ''pressure hull''. The light hull (''casing'' in British usage) of a submarine is the outer non-watertight hull which provides a hydrodynamically efficient shape. The pressure ...
s were long. The boats'
beam was (o/a), while the pressure hull measured . Type 31s had a
draught of with a total height of . The boats
displaced a total of ; when surfaced and when submerged.
Type U-31s were fitted with two
Germania 6-cylinder two-stroke
diesel engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-ca ...
s with a total of for use on the surface and two
Siemens-Schuckert
Siemens-Schuckert (or Siemens-Schuckertwerke) was a German electrical engineering company headquartered in Berlin, Erlangen and Nuremberg that was incorporated into the Siemens AG in 1966.
Siemens Schuckert was founded in 1903 when Siemens & H ...
double-acting
electric motors
An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate forc ...
with a total of for underwater use. These engines powered two shafts each with a
propeller, which gave the boats a top surface speed of , and when submerged. Cruising range was at on the surface, and at under water. Diving depth was .
The U-boats were armed with four
torpedo tube
A torpedo tube is a cylindrical device for launching torpedoes.
There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboa ...
s, two fitted in the
bow and two in the
stern, and carried 6
torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, s ...
es. Most boats received one or two
SK L/30 deck gun
A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret.
The main deck gun was a dual-purpose ...
s, which were later replaced with
SK L/45 guns on some. The boats'
complement
A complement is something that completes something else.
Complement may refer specifically to:
The arts
* Complement (music), an interval that, when added to another, spans an octave
** Aggregate complementation, the separation of pitch-clas ...
was 4 officers and 31 enlisted.
List of Type U 31 submarines
There were eleven Type U 31 submarines
commissioned into the Kaiserliche Marine.
See also
*
References
Bibliography
*
External links
*
Submarine classes
World War I submarines of Germany
{{Germany-submarine-stub