Ocean boarding vessel

from Wikipedia, the free encyclopedia

During the Second World War, the Ocean Boarding Vessel (OBV) was the name for converted and makeshift armed British merchant ships, which, although mostly in service with civil shipping companies , were subordinate to the Royal Navy and used to monitor sea routes and to search for blockade breakers and supply ships of the Axis powers were used. If possible, the enemy ships should be captured and brought into an Allied port as prizes , which is why the Ocean Boarding Vessels could certainly be compared with auxiliary cruisers , although they were mostly not as heavily armed as these. Furthermore, the OBVs were used to search ships of neutral states for contraband and also served as lead ships in convoy operations. Between 1940 and 1941 a total of at least 20 British or captured former enemy merchant ships were converted to OBVs.

OBV Largs from 1941 (photo from 1942); The 15.2 cm gun on the forecastle is clearly visible.
The former OBV Hilary after being converted into a landing ship (photo from 1943).
The OBV Cavina in December 1941, the two 15.2 cm guns are clearly visible fore and aft.

Technical details and armament

Since all Ocean Boarding Vessels are civil cargo ships selected at random , there is no uniform technical data. For the most part, however, the ships were measured at around 4,000 to 7,000 GRT and had a maximum speed of between 14 and 18 knots . The largest OBV was the HMS Lady Somers with 8,194 GRT , which was commissioned in October 1940 . There were also big differences with regard to the propulsion systems, for example older ships with composite steam engines as well as more modern turbine ships were found among the units . The armament of these ships often varied, but mostly there were at least two 15.2 cm Mark XII guns and one 7.6 cm cannon, as well as four to six lighter anti-aircraft guns of 2 cm and 4 cm caliber on board. The crew was between 140 and 180 seamen.

Some OBVs were converted into CAM ships after a relatively short period of use and received a makeshift catapult from which Hawker Hurricane or Fairey Fulmar fighter aircraft could be launched.

List of all ocean boarding vessels (in alphabetical order)

   Ship (surveying)      Shipyard      Launch      Commissioning as OBV Notes and whereabouts
HMS Ariguani (6,746 GRT ) Alexander Stephen and Sons , Linthouse , United Kingdom October 20, 1925 October 1940 The ship was 129.61 m long and had two triple expansion engines . The armament consisted of two 15.2 cm guns. Converted to a CAM ship in early 1941 . Damaged by submarine torpedo in October 1941. After the end of the war, she was back in service as a civilian ship. Canceled around 1956.
HMS Camito (6,833 GRT) Alexander Stephen and Sons , Linthouse , United Kingdom April 17, 1915 September 26, 1940 Coal firing; Driven by two triple expansion machines. Torpedoed and sunk by a German submarine in May 1941 (28 dead).
HMS Cavina (6,907 GRT) Alexander Stephen and Sons, Linthouse, United Kingdom March 20, 1924 October 15, 1940 Former Fyffes Line reefer ship . Demilitarized at the beginning of April 1942 and in service as a civil refrigerated ship until 1946 (in this case, however, subject to the Ministry of War Transport ). In service again with the Fyffes Line from 1946 until at least 1957. Scrapped in Hong Kong around 1958 .
HMS Corinthian (3,151 GRT) William Gray & Company , Stockton-on-Tees , United Kingdom May 3, 1938 September 1940 Former Ellerman Lines cargo ship . Armed with two 6-inch guns and a 3-inch cannon. Operated as OBV until July 1944, then converted into a training ship for landing maneuvers. Assisted in the recovery of survivors of the passenger ship RMS Laconia, which was sunk by a submarine in 1942 .
HMS Crispin (5,051 GRT) Cammell, Laird & Company , Birkenhead , United Kingdom December 7, 1934 August 1940 On February 3, 1941, as part of the securing of convoy OB-280, about 450 nautical miles south of Iceland, torpedoed and sunk by the German submarine U 107 (20 dead).
HMS Empire Audacity (5,537 GRT) Vegesacker shipyard , Bremen , German Empire March 29, 1939 November 1940 Former Kühlschiff Hannover of the North German Lloyd , which had been applied by British naval forces in March 1940th The ship was equipped as an OBV, but after only two months it was decommissioned and converted into an escort aircraft carrier. Commissioned as such in June 1941 under the name Audacity . Sunk in December 1941 by a German submarine.
HMS Hilary (7,403 GRT) Cammell, Laird & Company , Birkenhead , United Kingdom April 17, 1931 January 21, 1941 In service as an Ocean Boarding Vessel until July 1942, then dismantled as a civilian cargo ship. From March 1943 used as an attack landing ship and command ship. After 1945 back in service as a cargo ship. Demolition from September 1959.
HMS Inanda (5,985 GRT) Swan Hunter , Wallsend , United Kingdom February 24, 1925 - The ship was sunk while still being equipped in a German air raid on London on September 9, 1940. Lifted in October 1940, the ship was later used as a cargo ship under the new name Empire Explorer . On July 9, 1942, west of Tobago, torpedoed and sunk by the German submarine U 575 (three dead).
HMS Inkosi (6,618 GRT) Swan Hunter , Wallsend , United Kingdom February 25, 1937 - The ship was sunk while still being equipped in a German air raid on Liverpool on September 7, 1940. Lifted in October 1940, repaired and in service as the Empire Chivalry freighter until the end of the war. Canceled around 1958.
HMS Jamaica Producer (5,464 GRT) Lithgows , Glasgow , United Kingdom April 4, 1934 August 1940 Demilitarized again in October 1941 and used as a cargo ship. Badly damaged by submarine torpedoes in the North Atlantic in March 1943. Repair until June 1943. Wrecked around 1962.
HMS Lady Somers (8,194 GRT) Cammell, Laird & Company , Birkenhead , United Kingdom November 13, 1928 October 1940 Largest of all ocean boarding vessels. Turbine ship. On July 15, 1941 from the Italian submarine R. Smg. Francesco Morosini was torpedoed and sunk in the Atlantic, the entire crew survived.
HMS Largs (4,504 GRT) Chantiers et Ateliers de Provence, Port-de-Bouc , France October 1938 May 1941 Former Vichy-French reefer ship Charles Plumier of the Compagnie Générale Transatlantique , which was converted into an auxiliary cruiser in 1939 . The ship was seized by the Royal Navy in Gibraltar in October 1940 , renamed Largs in May 1941 and used as an OBV. From October 1942 it was used as a landing transporter. Returned to France after the end of the war and used as a cargo ship until 1964. Wrecked around 1968 in Greece .
HMS Malvernian (3,133 GRT) William Gray & Company , Stockton-on-Tees , United Kingdom February 25, 1937 September 1940 Former Ellerman Lines cargo ship . On July 1, 1941 in the North Atlantic while securing convoy OG-66, it was bombed and badly damaged by a German long-range bomber Focke-Wulf Fw 200 . After lengthy rescue attempts, the ship was abandoned on July 7, 1941 and sank. The entire crew (164 men) survived.
HMS Manistee (5,368 GRT) Cammell, Laird & Company , Birkenhead , United Kingdom October 28, 1920 December 1940 On February 24, 1941, while the convoy OB-288 was being secured, it was torpedoed and sunk in the North Atlantic by the German submarine U 107 . The entire crew (141 men) was killed.
HMS Maplin (5,824 GRT) Workman, Clark , Belfast , United Kingdom April 5, 1932 September 1940 In service until January 1941 under the name Erin , then conversion to a CAM ship until March 1941. Demilitarized in July 1942 and again in service as a civilian cargo ship.
HMS Maron (6,487 GRT) Caledon Shipbuilding and Engineering , Dundee , United Kingdom December 17, 1929 August 7, 1940 The ship was disarmed on April 7, 1942, returned to the previous owner, the Blue Funnel Line , and used again as a cargo ship. On 13 November 1942, the German submarine sank U 81 , the Maron in the Mediterranean north-west of Oran . The crew survived.
HMS Marsdale (4,890 GRT) Lithgows , Glasgow , United Kingdom December 13, 1939 September 1940 Demilitarized in June 1942 and back in service as a cargo ship. 1957 as Volta River to the Black Star Line , 1965 to Greek owners and renamed Psara , from May 24th 1967 scrapped at Lotti in La Spezia.
HMS Patia (5,355 GRT) Cammell, Laird & Company , Birkenhead , United Kingdom January 14, 1922 December 1940 Conversion to a CAM ship in March 1941. On April 27, 1941, the single-moving ship was bombed and sunk by a German He 111 bomber off the coast of Northumbria (39 dead). Today the wreck is about 60 m deep.
HMS Registan (5,886 GRT) John Redhead & Sons , South Shields , United Kingdom January 30, 1930 October 1940 On May 27, 1941, the Registan near Cape Cornwall was badly damaged in a German air raid, killing 63 sailors. The ship was towed to Falmouth and repaired by November 1941. The Registan then went back as a cargo ship. On September 29, 1942, the German submarine U 332 sank the steamer about 140 nautical miles east of Barbados by a torpedo hit, killing 16 sailors.
HMS Tortuguero (5,285 GRT) Alexander Stephen and Sons , Linthouse , United Kingdom April 19, 1921 January 1941 Former reefer ship. Demilitarized in June 1942 and returned to freight service. Canceled in Ghent from December 1958 .

Ocean Boarding Vessels Achievements

Relatively few successes have been achieved in relation to the number of OBVs taken into service. The following is a list of ships that were hijacked or stopped by OBVs (the completeness is not guaranteed):

  • December 25, 1940: The Vichy-French fishing liner Senateur Duhamel (928 GRT) was seized by OBV Camito northwest of Casablanca . The cutter was later used as a submarine trawler by the Royal Navy and was lost in a collision in 1942.
  • January 10, 1941: The Vichy-French cargo ship Cantal (3,178 GRT), on its way from Fort-de-France to Casablanca, was seized by OBV Maron . The steamer was lost in May 1941 during a German air raid on Liverpool .
  • March 5, 1941: The small Vichy French fish steamer Bijou Bihon (112 GRT) is seized by the OBV Corinthian . The trawler was later used as an auxiliary submarine hunter .
  • May 1, 1941: The Italian tanker and blockade breaker Sangro (6,466 GRT) was seized by OBV Cavina on the way from Tenerife to France . The captured tanker was torpedoed and sunk on May 6, 1941 by the German submarine U 97 .
  • May 1, 1941: The Vichy-French sailing ship Martin Pecheuer (350 GRT) was seized by the OBV Corinthian . The sailor was completely destroyed by a fire on board (caused by an accident) on May 10, 1941.
  • May 3, 1941: The Italian tanker and blockade breaker Recco (5,595 GRT) near Tenerife by the OBV Hilary . The tanker sank itself when the OBV approached .
  • May 10, 1941: The Italian tanker and blockade breaker Gianna M. (5,719 GRT) about 325 nautical miles north of the Azores by OBV Hilary . The ship later sailed under the British flag, survived the war and was scrapped in 1953.
  • June 4, 1941: The OBV Marsdale seized the German tanker and submarine supplier Gedania (8,966 GRT) about 400 nautical miles northwest of the Azores. The crew left the ship in a panic without destroying the secret documents, which is why the British side was able to steal important documents on board the ship. Among other things , the Royal Navy learned the exact locations of the German weather ships and gained insight into the routes of the German blockade breakers and suppliers. The losses of the German supply ship Egerland (9,798 GRT) and the tanker Esso Hamburg (9,849 GRT) just one day later west of Freetown , both ships were surprised by British naval forces and had to sink themselves, were very likely due to the capture of the Gedania traced the captured secret documents. Because of the failure to submerge themselves , the crew of the Gedania was later suspected of treason by the German side , but this could not be proven. The Gedania sailed under the British flag until the end of the war and under the new name Empire Garden . The ship was scrapped in 1960.
  • June 23, 1941: The OBV Marsdale seized the German blockade breaker and supplier Alstertor (3,039 GRT) about 200 nautical miles west of Cape Finisterre . The ship sank itself when the OBV approached, the crew was rescued by the British.
  • June 28, 1941: The German weather observation ship Lauenburg (344 GRT) was seized by the British light cruiser HMS Nigeria , OBV Malvernian and three destroyers about 300 nautical miles east of Jan Mayen . On board, the British Navy found details about the plug connections and the internal setting of the Enigma machine . This made it possible to decode the radio messages of the German Navy during almost the entire month of July 1941. The capture of the Lauenburg may also be related to the capture of the Gedania .
    Sinking of the German weather observation ship Lauenburg on June 28, 1941.
  • 4th August 1941: The OBV Cavina seized the German blockade breaker Frankfurt (5,522 GRT) from Rio de Janeiro west of the Azores . The freighter sank itself when the OBV approached.

Departure from the concept of the Ocean Boarding Vessel from 1942

Since from 1942 more and more powerful escort ships and warships were built on the Allied side and the air surveillance of the important sea and convoy routes could also be intensified, also through the appearance of the first pure escort aircraft carriers , the concept of the OBV gradually became superfluous, which is why most of them Ships were either dismantled and used again as normal merchant ships or were assigned other fields of activity (convoy command ships, training vehicles, landing ships). Another reason was that, on the one hand, the number of blockade breakers by the Axis powers fell sharply from 1942 and, on the other hand, there was no longer a permanent network of German reconnaissance and supply ships in the Atlantic (as was the case until the British Navy largely dismantled this network in mid-1941 Case). The supply of the German (and also Italian) submarines was now taken over by special supply submarines .

Ocean Boarding Vessel Losses

A total of nine OBVs were lost in the course of the war, including the largest ocean boarding vessel, the Lady Somers (8,194 GRT), which was hit by a torpedo of the Italian submarine R. Smg on July 15, 1941 in the Atlantic . Francesco Morosini fell victim. The 175-man crew was completely rescued. One of the worst losses occurred on February 24, 1941, when the OBV Manistee (5,368 GRT) belonging to convoy OB-288 was torpedoed and sunk south of Iceland by the German submarine U 107 . Due to the stormy weather, none of the 141 crew members could be rescued.

See also

Individual evidence

  1. ↑ http://uboat.net/allies/merchants/906.html
  2. ↑ http://www.uboat.net/allies/merchants/751.html
  3. ↑ http://uboat.net/allies/merchants/1911.html
  4. ↑ http://www.wlb-stuttgart.de/seekrieg/41-07.htm
  5. ↑ http://www.clydesite.co.uk/clydebuilt/viewship.asp?id=18248
  6. ↑ http://uboat.net/allies/merchants/2223.html
  7. ↑ http://www.clydesite.co.uk/clydebuilt/viewship.asp?id=3568
  8. ↑ http://uboat.net/allies/merchants/905.html
  9. ↑ http://www.wlb-stuttgart.de/seekrieg/41-06.htm
  10. ↑ Brennecke, Jochen: The turning point in the submarine war. Causes and consequences 1939–1943 . Wilhelm Heyne Publishing House. Munich 1998, p. 522.
  11. ↑ http://www.aukevisser.nl/german/id79.htm
  12. ↑ http://www.wlb-stuttgart.de/seekrieg/41-08.htm
  13. ↑ http://www.wrecksite.eu/wreck.aspx?31096
  14. ↑ http://www.uboat.net/allies/merchants/775.html

literature

  • Brennecke, Jochen: The turning point in the submarine war. Causes and consequences 1939–1943 . Wilhelm Heyne Publishing House. Munich 1998.
  • Costello, John / Hughes, Terry: Battle of the Atlantic . Bastei Lübbe. Bergisch Gladbach 1995.
  • Hewson, Robert: The World War II Warships Guide . Chartwell Books. Edison 2000.
  • Dinklage / Witthöft: Die Deutsche Handelsflotte 1939-1945, Vol. 1 + 2, Nikol Verlagsgesellschaft 2001, especially Vol. II, P. 34 ff. On OBV "Cavina" and Dampfer "Frankfurt".
  • Boie / Oesterle: Deutsche Handelschiffahrt at the outbreak of war in 1939, Elbe-Spree-Verlag 2000, especially on OBV "Cavina" and "Frankfurt" s. Pages 99 and 101

Web links