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 ...
of
Nazi Germany
Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
.
Her keel was
laid down
Laying the keel or laying down is the formal recognition of the start of a ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship.
Keel laying is one o ...
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 ...
Kapitänleutnant
''Kapitänleutnant'', short: KptLt/in lists: KL, ( en, captain lieutenant) is an officer grade of the captains' military hierarchy group () of the German Bundeswehr. The rank is rated OF-2 in NATO, and equivalent to Hauptmann in the Heer an ...
'' (''Kptlt.'') Hans-Wilhelm von Dresky took over on 29 October 1938 and commanded the boat until her loss.
Rotor
Rotor may refer to:
Science and technology
Engineering
* Rotor (electric), the non-stationary part of an alternator or electric motor, operating with a stationary element so called the stator
*Helicopter rotor, the rotary wing(s) of a rotorcraft ...
s from ''Kriegsmarine''s Enigma machine were captured from the survivors, the wiring of which was unknown at that time to
British
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies.
** Britishness, the British identity and common culture
* British English, ...
codebreakers at
Bletchley Park
Bletchley Park is an English country house and estate in Bletchley, Milton Keynes ( Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years followin ...
.
Design
As one of the first ten German Type VII submarines later designated as Type VIIA submarines, ''U-33'' had a displacement of when at the surface and while submerged. She had a total length of , a
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 ...
length of , a beam of , a height of , and a draught of . The submarine was powered by two
MAN
A man is an adult male human. Prior to adulthood, a male human is referred to as a boy (a male child or adolescent). Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromo ...
M 6 V 40/46 four-stroke, six-cylinder
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 producing a total of for use while surfaced, two BBC GG UB 720/8double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . ''U-33'' was fitted with five
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 (four fitted at the bow and one at the stern), eleven
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, one SK C/35 naval gun, 220 rounds, and an anti-aircraft gun. The boat had a
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 ...
of between forty-four and sixty.
Service history
''U-33'' took part in
Operation Ursula
German involvement in the Spanish Civil War commenced with the Spanish Civil War, outbreak of war in July 1936, with Adolf Hitler immediately sending in powerful air and armored units to assist General Francisco Franco and his National faction ...
— the German submarine operation in support of Franco's naval forces during the
Spanish Civil War
The Spanish Civil War ( es, Guerra Civil Española)) or The Revolution ( es, La Revolución, link=no) among Nationalists, the Fourth Carlist War ( es, Cuarta Guerra Carlista, link=no) among Carlists, and The Rebellion ( es, La Rebelión, link ...
from November 1936.
During World War II, ''U-33'' sank 10 ships for a total of in just three war patrols.
On Monday, 20 November 1939 she sank three British steam trawlers. At 10:30 am, ''Thomas Hankins'' 14 miles north-west of
On Tuesday, 21 November 1939 at 08:30 in rough seas, the trawler FD87 ''Sulby'' (from
Fleetwood
Fleetwood is a coastal town in the Borough of Wyre in Lancashire, England, at the northwest corner of the Fylde. It had a population of 25,939 at the 2011 census.
Fleetwood acquired its modern character in the 1830s, when the principal lando ...
), was sunk by gunfire from ''U-33'' 75–80 miles north-west of Rathlin Island. The crew had just managed to launch and push off the two lifeboats as the submarine fired two shells into the trawler amidships and she sank within two minutes. The U-boat commander pointed at the crew as they rowed from their ship and laughed. One of the lifeboats, whose occupants were Harold Blackburn, James Hay, James William Geddes (of Buckie, Banffshire, Scotland), Fred Brunt, Augustus Lewis, Sydney Mellish and Jack Threlfall were picked up the following day by the Tobermory lifeboat. The other lifeboat was lost with five men including the Skipper, Clarence Hudson; Mate John Michael (Jack) Dawson; and deck hands Raymond Randles, James Wood and R.A. Lister.
An hour or so later at the same location, ''U-33'' sank another trawler, ''William Humphries''. The entire crew of 13 men were lost. Two of them were buried in the graveyard of Cill Chriosd on the Isle of Skye.
Fate
In February 1940, ''U-33'', then captained by Hans-Wilhelm von Dresky, had been ordered to lay mines in the
Firth of Clyde
The Firth of Clyde is the mouth of the River Clyde. It is located on the west coast of Scotland and constitutes the deepest coastal waters in the British Isles (it is 164 metres deep at its deepest). The firth is sheltered from the Atlantic ...
, in Scotland. However, the
minesweeper
A minesweeper is a small warship designed to remove or detonate naval mines. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping.
History
The earliest known usage of ...
, captained by Lieutenant-Commander Hugh Price, detected the U-boat on the 12th and dropped depth charges over a period of several hours. Eventually, the damaged ''U-33'' was forced to surface and the crew abandoned the boat, which sank soon afterward. 25 men died while 17 survived. Before the boat was abandoned, the U-boat's secret
Enigma rotor
This article contains technical details about the rotors of the Enigma machine. Understanding the way the machine encrypts requires taking into account the current position of each rotor, the ring setting and its internal wiring.
Physical desi ...
s were distributed amongst a few of the crew, who were instructed to release them into the sea to avoid capture. This was not done, however, and as a result the British captured three rotors, including two (VI and VII), that were only used by the ''Kriegsmarine'' and for which the wiring was previously unknown.
Summary of raiding history
References
Bibliography
*
*
*
*
* David Kahn, ''Seizing the Enigma'', 1991, pp. 104–112.
*
* Hugh Sebag-Montefiore, ''Enigma: The Battle for the Code'', 2000, pp. 67–77,
* ''Sulby'' sinking information from Statements to the Secretary of the Fleetwood Steam Trawlers Association Limited and a newspaper cutting from the time.