Convoy OB 318
Encyclopedia
OB 318 was a North Atlantic convoy
which ran during the Battle of the Atlantic in World War II
. It saw the capture of U-110 and a wealth of signals intelligence, which led to the Allied breakthough
into cracking the German naval Enigma
code.
on 2 May 1941 bound for ports in North America
. The convoy commodore was R.Adm. WB MacKenzie in SS Colonial.
It was escorted by 7 EG, an escort group led by HMS Westcott (Cdr. Bockett-Pugh) and comprising ten warships; these were joined in md-ocean by 3 EG, a force of eight warships led by HMS Bulldog (Cdr J Baker-Cresswell). Opposing them was a force of nineteen U-boats, though in the event only six were in a postion to pose a threat.
) alerted other U-boats in the area.
There were six U-boats witin striking distance, and these were ordered to close with U-94's position.
Meanwhile during 7 May the escort force was joined by five ships from Iceland
and the destroyers of 3 EG, which were to take over escort duties from the Western Approaches
to a dispersal point at 34 West, a location south of Greenland
. Three ships and the destroyers of 7 EG left for Iceland during 7 May, leaving the escort force still at ten warships.
At nightfall on 7 May U-94 attacked the convoy, sinking two ships. Her skipper, Herbert Kuppisch, was able to enter the convoy by submerging ahead of the convoy and letting the lead escorts pass. he was then able to fire at close range on the ships in the centre of the convoy, hitting Ixion and Eastern Star. However U-94 was found by the sloop
Rochester and counter-attacked by her, Bulldog and Amazon
for four hours. U-94 was damaged and forced to retire, though she was able to effect repairs later and continue her patrol.
On 8 May the remaining vessels of 3 EG, three corvette
s and two trawlers
, with the Armed Merchant Cruiser Ranpura in company, joined the convoy, and the remaining ships of 7 EG departed.
On the evening of 8 May U-110 and U-201 also made contact, tracking the convoy until morning. In an unusual move, the two skippers made rendezvous in order to co-ordinate their attack; Fritz-Julius Lemp
in U-110 would make a submerged attack from ahead, while Adalbert Schnee
in U-201 would do the same from the rear. It was expected that the escort would have departed by this time, leaving the convoy vulnerable to their assault.
During the morning of 9 May U-110 moved into position and commenced her attack. Lemp was surprised to encounter the escort still in place, but succeeded in penetrating the convoy, sinking two ships.
U-110 was also vigorously counter-attacked, by Aubretia, Bulldog and Broadway. She was forced to the surface and abandoned. U-110 was still afloat and was captured by the three warships, which dropped out of the convoy to secure their prize.
Meanwhile Schnee in U-210 made his attack, sinking one ship and damaging another. He was also counter-attacked, by Amazon, Nigella and St Apollo, and forced to retire, damaged.
In the ealy hours of 10 May OB 318 was found by U-556 which attacked immediately, resulting in one ship damaged. As OB 318 was at its dispersal point, the convoy separated during the night, while the escorts departed to meet their next charge.
However U-556 was able to keep in touch with a group of ships heading south-west, and during the day sank two more.
Over the next two weeks the remaining 36 ships from OB 318 made landfall at various ports around the Atlantic, although three, including the convoy commodore's ship Colonial, were sunk before arriving by U-boats patrolling near their destinations.
However outweighing the material losses in this action was the capture, intact, of U-110 and her signal equipment, including an Enigma coding machine, current rotors and code-books. Though U-110 was subsequently lost, sinking while under tow, the signals intelligence was invaluable to the Allied code-breakers at Bletchley Park
, and led to a lasting break-through in reading German naval traffic (with some interruptions) throughout the rest of the Atlantic campaign.
Convoy
A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support, though it may also be used in a non-military sense, for example when driving through remote areas.-Age of Sail:Naval...
which ran during the Battle of the Atlantic in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. It saw the capture of U-110 and a wealth of signals intelligence, which led to the Allied breakthough
Cryptanalysis of the Enigma
Cryptanalysis of the Enigma enabled the western Allies in World War II to read substantial amounts of secret Morse-coded radio communications of the Axis powers that had been enciphered using Enigma machines. This yielded military intelligence which, along with that from other decrypted Axis radio...
into cracking the German naval Enigma
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
code.
Prelude
OB 318 was a west-bound convoy of 38 ships, either in ballast or carrying trade goods, and sailed from LiverpoolLiverpool
Liverpool is a city and metropolitan borough of Merseyside, England, along the eastern side of the Mersey Estuary. It was founded as a borough in 1207 and was granted city status in 1880...
on 2 May 1941 bound for ports in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. The convoy commodore was R.Adm. WB MacKenzie in SS Colonial.
It was escorted by 7 EG, an escort group led by HMS Westcott (Cdr. Bockett-Pugh) and comprising ten warships; these were joined in md-ocean by 3 EG, a force of eight warships led by HMS Bulldog (Cdr J Baker-Cresswell). Opposing them was a force of nineteen U-boats, though in the event only six were in a postion to pose a threat.
Action
OB 318 was sighted on 7 May 1941 by U-94, which reported its position and commenced shadowing while U-boat Command (BdUBDU
The abbreviation BDU may refer to:*Battle Dress Uniform, United States' combat uniforms.*Befehlshaber der U-Boote , commander-in-chief of Germany's submarine fleets in WW-II.*FAA location identifier for Boulder Municipal Airport...
) alerted other U-boats in the area.
There were six U-boats witin striking distance, and these were ordered to close with U-94's position.
Meanwhile during 7 May the escort force was joined by five ships from Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
and the destroyers of 3 EG, which were to take over escort duties from the Western Approaches
Western Approaches
The Western Approaches is a rectangular area of the Atlantic ocean lying on the western coast of Great Britain. The rectangle is higher than it is wide, the north and south boundaries defined by the north and south ends of the British Isles, the eastern boundary lying on the western coast, and the...
to a dispersal point at 34 West, a location south of Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
. Three ships and the destroyers of 7 EG left for Iceland during 7 May, leaving the escort force still at ten warships.
At nightfall on 7 May U-94 attacked the convoy, sinking two ships. Her skipper, Herbert Kuppisch, was able to enter the convoy by submerging ahead of the convoy and letting the lead escorts pass. he was then able to fire at close range on the ships in the centre of the convoy, hitting Ixion and Eastern Star. However U-94 was found by the sloop
Sloop-of-war
In the 18th and most of the 19th centuries, a sloop-of-war was a warship with a single gun deck that carried up to eighteen guns. As the rating system covered all vessels with 20 guns and above, this meant that the term sloop-of-war actually encompassed all the unrated combat vessels including the...
Rochester and counter-attacked by her, Bulldog and Amazon
HMS Amazon (D39)
HMS Amazon was a prototype design of destroyer ordered for the Royal Navy in 1924. She was designed and built by Thornycroft in response to an admiralty request for a new design of destroyer incorporating the lessons and technological advances of the First World War...
for four hours. U-94 was damaged and forced to retire, though she was able to effect repairs later and continue her patrol.
On 8 May the remaining vessels of 3 EG, three corvette
Corvette
A corvette is a small, maneuverable, lightly armed warship, originally smaller than a frigate and larger than a coastal patrol craft or fast attack craft , although many recent designs resemble frigates in size and role...
s and two trawlers
Naval trawler
A naval trawler is a vessel built along the lines of a fishing trawler but fitted out for naval purposes. Naval trawlers were widely used during the First and Second world wars. Fishing trawlers were particularly suited for many naval requirements because they were robust boats designed to work...
, with the Armed Merchant Cruiser Ranpura in company, joined the convoy, and the remaining ships of 7 EG departed.
On the evening of 8 May U-110 and U-201 also made contact, tracking the convoy until morning. In an unusual move, the two skippers made rendezvous in order to co-ordinate their attack; Fritz-Julius Lemp
Fritz-Julius Lemp
Fritz-Julius Lemp was a Kapitänleutnant with the Kriegsmarine during World War II and commander of , and . He was also a recipient of the Knight's Cross of the Iron Cross...
in U-110 would make a submerged attack from ahead, while Adalbert Schnee
Adalbert Schnee
Lieutenant Commander Adalbert Schnee was a Korvettenkapitän with the Kriegsmarine during World War II. He commanded the U-boats , , , and , sinking twenty-one merchant ships on twelve patrols, for a total of of Allied shipping, and received the Knight's Cross with Oak Leaves...
in U-201 would do the same from the rear. It was expected that the escort would have departed by this time, leaving the convoy vulnerable to their assault.
During the morning of 9 May U-110 moved into position and commenced her attack. Lemp was surprised to encounter the escort still in place, but succeeded in penetrating the convoy, sinking two ships.
U-110 was also vigorously counter-attacked, by Aubretia, Bulldog and Broadway. She was forced to the surface and abandoned. U-110 was still afloat and was captured by the three warships, which dropped out of the convoy to secure their prize.
Meanwhile Schnee in U-210 made his attack, sinking one ship and damaging another. He was also counter-attacked, by Amazon, Nigella and St Apollo, and forced to retire, damaged.
In the ealy hours of 10 May OB 318 was found by U-556 which attacked immediately, resulting in one ship damaged. As OB 318 was at its dispersal point, the convoy separated during the night, while the escorts departed to meet their next charge.
However U-556 was able to keep in touch with a group of ships heading south-west, and during the day sank two more.
Over the next two weeks the remaining 36 ships from OB 318 made landfall at various ports around the Atlantic, although three, including the convoy commodore's ship Colonial, were sunk before arriving by U-boats patrolling near their destinations.
Aftermath
The action around OB 318 was a qualified Allied success. Five ships were lost in attacks on the convoy,and two more shortly after dispersal. In reply, one U-boat was lost and two damaged, a poor rate of exchange and one which illustrated the growing effectiveness of the escort forces. Thirty-three ships arrived safely at their destinations.However outweighing the material losses in this action was the capture, intact, of U-110 and her signal equipment, including an Enigma coding machine, current rotors and code-books. Though U-110 was subsequently lost, sinking while under tow, the signals intelligence was invaluable to the Allied code-breakers at Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
, and led to a lasting break-through in reading German naval traffic (with some interruptions) throughout the rest of the Atlantic campaign.
Allied ships hit
| Date | Name | Nationality | Casualties | Tonnage (GRT Gross Register Tonnage Gross register tonnage a ship's total internal volume expressed in "register tons", one of which equals to a volume of . It is calculated from the total permanently enclosed capacity of the vessel. The ship's net register tonnage is obtained by reducing the volume of non-revenue-earning spaces i.e... ) |
Sunk by... |
|---|---|---|---|---|---|
| 7 May 1941 | Ixion | Br United Kingdom The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages... |
none | 10,263 | U-94 |
| 7 May 1941 | Eastern Star | Nor Norway Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million... |
none | 5,658 | U-94 |
| 9 May 1941 | Bengore Head | Br | 1 | 2,609 | U-110 |
| 9 May 1941 | Esmond | Br | none | 4,976 | U-110 |
| 9 May 1941 | Gregalia | Br | none | 5,802 | U-201 |
| 9 May 1941 | Empire Cloud SS Empire Cloud Empire Cloud was a 5,969 GRT cargo ship which was built in 1940 by William Pickersgill & Sons Ltd, Sunderland for the Ministry of War Transport . She was torpedoed on her maiden voyage, but repaired and returned to service. In 1942, she was torpedoed and sank whilst under tow to... |
Br | none | damaged | U-201 |
| 10 May 1941 | Aelybryn | Br | none | damaged | U-556 |
| 10 May 1941 | Empire Caribou SS Empire Caribou Empire Caribou was a 4,861 GRT cargo ship which was built in 1919 for the United States Shipping Board as Waterbury. She was sold in 1920 to the American Star Line and renamed Northern Star. In 1923, she was sold to American Sugar Transporters Inc and renamed Defacto... |
Br | 38 | 4,861 | U-556 |
| 10 May 1941 | Gand | Bel Belgium Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many... |
1 | 5,086 | U-556 |
U-boats hit
| Date | Number | Type | Commander | Casualties | Hit by... |
|---|---|---|---|---|---|
| 7/8 May 1941 | U-94 | VIIC | K/L H. Kuppisch Herbert Kuppisch Herbert Kuppisch was a Kapitänleutnant with the Kriegsmarine during World War II and commander of U-58, U-94, U-516 and U-847... |
? | damaged |
| 9 May 1941 | U-110 | IXB | KK. F-J Lemp Fritz-Julius Lemp Fritz-Julius Lemp was a Kapitänleutnant with the Kriegsmarine during World War II and commander of , and . He was also a recipient of the Knight's Cross of the Iron Cross... |
15 | Aubretia, Bulldog, Broadway |
| 9 May 1941 | U-201 | VIIC | O/L A. Schnee Adalbert Schnee Lieutenant Commander Adalbert Schnee was a Korvettenkapitän with the Kriegsmarine during World War II. He commanded the U-boats , , , and , sinking twenty-one merchant ships on twelve patrols, for a total of of Allied shipping, and received the Knight's Cross with Oak Leaves... |
? | damaged |