BETASOM


BETASOM was a submarine base established at Bordeaux, France by the Italian Regia Marina Italiana during World War II. From this base, Italian submarines participated in the Battle of the Atlantic from 1940 to 1943 as part of the Axis anti-shipping campaign against the Allies.

Establishment

naval co-operation started after the signing of the Pact of Steel in June 1939 with meetings in Friedrichshafen, Germany, and an agreement to exchange technical information. After the Italian entry into the war and the Fall of France, the Italian Royal Navy established a submarine base at Bordeaux, which was within the German occupation zone. The Italians were allocated a sector of the Atlantic south of Lisbon to patrol. The base was opened in August 1940, and in 1941 the captured French passenger ship was used as a depot ship before being returned to the Vichy French Government in June 1942. Admiral Angelo Parona commanded the submarines at BETASOM under the operational control of Konteradmiral Karl Dönitz. Dönitz was the "Commander of the Submarines" for the German Kriegsmarine. About 1,600 men were based at BETASOM.
The base could house up to thirty submarines, and it had dry docks and two basins connected by locks. Shore barracks accommodated a security guard of 250 men of the San Marco Regiment.
A second base was established at La Pallice in La Rochelle, France. This second base allowed submerged training which was not possible at Bordeaux.

Operational detail

From June 1940, three Italian submarines patrolled off the Canary Islands and Madeira, followed by three more off the Azores. When these patrols were completed, the six boats returned to their new base at Bordeaux. Their initial patrol area was the Northwestern Approaches. Dönitz was pragmatic about the Italians, seeing them as inexperienced, but useful for reconnaissance and likely to gain expertise.
In November 1940 there were 26 Italian boats at Bordeaux. Initially, their activity did not meet much success; unacquainted with Atlantic weather conditions, Italian submarines sighted convoys but lost contact and failed to make effective reports. As co-operation between the two navies was not working well, Dönitz decided to reassign the Italian boats to the southern area where they could act independently. In this way, about thirty Italian boats achieved more success, though without much impact on the most critical areas of the campaign.
Dönitz considered the Italians as displaying "great dash and daring in battle, often exceeding that of Germans", but less toughness, endurance and tenacity. By 30 November 1940, Italian submarines in the Atlantic each sank an average of 200 gross tons per day, while German U-boats each averaged 1,115 gross tons per day during the same period. Italian submarines, however, had only been in the Atlantic for a few months at this time, and had not had yet the time to adapt to the new operational conditions, whereas the U-boats had already been operating there for more than a year.
In an attempt to improve the performance of the Italian submarines, several measures were taken: taking cue from the Kriegsmarine, older Italian submarine commanders were replaced with younger officers, who possessed more aggressiveness and stamina; a "submarine school" was created in Gotenhafen, where commanders, officers and bridge crews of the BETASOM submarines were trained according to the German model. Italian submarines also underwent improvement work, such as the reshaping of their excessively large conning towers.
These measures significantly improved the performance of the remaining Italian submarines ; the average tonnage sunk by BETASOM submarines rose from 3,844 Gross Register Tons in 1940 to 27,335 GRT in 1942. The tonnage sunk for every lost submarine was 32,672 GRT in 1940, 20,432 GRT in 1941, 136,674 GRT in 1942 and 13,498 GRT in 1943.
Between February and March 1942, five BETASOM submarines took part in Operation Neuland, sinking 15 of the 45 Allied merchant ships destroyed during this operation.
The top scoring BETASOM aces, Gianfranco Gazzana-Priaroggia and Carlo Fecia di Cossato, were among the few Italian recipients of the Knight's Cross of the Iron Cross. Gazzana-Priaroggia's boat, Leonardo da Vinci, was the top-scoring non-German submarine of World War II, with 17 ships sunk totalling 120,243 GRT.
Italian naval historian Giorgio Giorgerini writes that Italian submarines did not perform as well as the U-boats, but achieved good results considering the deficiencies of their boats. Comparing the respective tonnages sunk by U-boats compared to the Italian submarines and their respective losses, the respective "exchange rates" were respectively 40.591 t for the German units and 34.512 t for the Italian ones. The strategic significance of Italy's participation in the Battle of the Atlantic was however small, as the number of Italian submarines that operated in the Atlantic was 30 at its peak, whereas the Kriegsmarine committed over 1,000 submarines to the battle of the Atlantic between 1939 and 1945.
Overall, Italian submarines operating in the Atlantic sank 109 allied merchant ships totalling 601,425 tons, and lost 16 boats.

German U-boat activities

Admiral Dönitz decided in mid-1941 to build protective U-boat pens in Bordeaux. Construction began in September 1941. Constructed of reinforced concrete, wide, deep, and high, with a roof above the pens thick, and thick above the rear servicing area.
On 15 October 1942, the 12th U-boat Flotilla was formed at Bordeaux by the Kriegsmarine under the command of Korvettenkapitän Klaus Scholtz. The first U-boat to use the bunker was on 17 January 1943.

End of operations

The base was bombed by the British on several occasions, especially in 1940 and 1941, but no significant damage was suffered, except for the sinking of the barracks ship Usaramo. The base was indirectly attacked by Operation Josephine B in June 1941, a raid to destroy the electricity substation that served the base.
The remaining BETASOM boats ended their last offensive patrol in 1943, after which seven BETASOM submarines were adapted to carry critical matériel from the Far East. Two of these were sunk by the Allies, two were captured in the Far East by the Germans after the Italian surrender in the Armistice of Cassibile of September 1943, and used by them, and a fifth was captured in Bordeaux by the Germans, but not used.
After the Armistice of Cassibile the base was seized by the Germans. Some of the Italian personnel joined the Germans independently of the Italian Social Republic. During this period the Italian postage stamps on hand were overprinted to show loyalty to Mussolini's rump state.
The last two remaining U-boats left Bordeaux in August 1944, three days before the Allies occupied the base on 25 August. The last remaining German naval personnel attempted to march back to Germany but were captured by US forces on 11 September 1944.

List of submarines operating from BETASOM

In 1940, all twenty-eight Italian submarines which were to be based at BETASOM initially had to sail from bases on the Mediterranean Sea and transit the Straits of Gibraltar to reach the Atlantic Ocean. All twenty-eight did this successfully without incident.
NameArrival dateSuccessesFate/Notes
Malaspina4 Sept 19406 patrols,
3 ships sunk totalling 16,384 GRT		lost with all hands in September 1941
Barbarigo8 Sept 194011 patrols,
7 ships sunk totalling 39,300 GRT		sunk with all hands by aircraft in June 1943 after conversion into transport submarine
Dandolo10 Sept 19406 patrols,
2 ships sunk totalling 6554 GRT		returned to the Mediterranean in June–July 1941
Marconi29 Sept 19406 patrols,
7 ships sunk totalling 19,887 GRT		lost with all hands in September 1941
Finzi29 Sept 194010 patrols,
5 ships sunk totalling 30,760 GRT		converted into transport submarine and seized after the Italian armistice
Bagnolini30 Sept 194011 patrols,
2 ships sunk totalling 6926 GRT		converted into transport submarine and seized after the armistice
Emo3 Oct 19406 patrols,
2 ships sunk totalling 10,958 GRT		returned to the Mediterranean in August 1941
Tarantini5 Oct 19402 patrols,
no ships sunk		sunk by HMS Thunderbolt on 15 December 1940
Torelli5 Oct 194012 patrols,
7 ships sunk totalling 42,871 GRT		converted into transport submarine and seized after the armistice
Faà di Bruno5 Oct 19402 patrols,
no ships sunk		lost with all hands in October 1940
Otaria6 Oct 19408 patrols,
1 ship sunk of 4662 GRT		returned to the Mediterranean in September 1941
Baracca6 Oct 19406 patrols,
3 ships sunk totalling 8989 GRT		sunk by HMS Croome on 8 September 1941
Giuliani6 Oct 19403 patrols,
3 ships sunk totalling 13,603 GRT		transferred for a time to Gdynia to train Italian submariners in U-boat tactics; converted into transport submarine and seized at the armistice
Glauco22 Oct 19405 patrols,
no ships sunk		sunk by HMS Wishart on 27 June 1941
Calvi23 Oct 19408 patrols,
6 ships sunk totalling 34,193 GRT		sunk by HMS Lulworth on 15 July 1942
Tazzoli24 Oct 19409 patrols,
18 ships sunk totalling 96,650 GRT		converted into transport submarine and lost with all hands in May 1943
Argo24 Oct 19406 patrols,
1 ship sunk of 5066 GRT		returned to the Mediterranean in October 1941
Leonardo Da Vinci31 Oct 194011 patrols,
17 ships sunk totalling 120,243 GRT		lost with all hands in May 1943; the best performing non-German submarine in World War II
Veniero2 Nov 19406 patrols,
2 ships sunk for 4987 GRT		returned to the Mediterranean in August 1941
Nani4 Nov 19403 patrols,
2 ships sunk totalling 1,939 GRT		lost with all hands in January 1941
Cappellini5 Nov 194012 patrols,
5 ships sunk totalling 31,648 GRT		converted into transport submarine and seized after the armistice
Morosini28 Nov 19409 patrols,
6 ships sunk totalling 40,933 GRT		lost with all hands in August 1942
Marcello2 Dec 19403 patrols,
1 ship sunk of 1550 GRT		lost with all hands in February 1941
Bianchi18 Dec 19404 patrols,
3 ships sunk totalling 22,266 GRT		sunk with all hands by HMS Tigris on 4 July 1941
Brin18 Dec 1940 reached the base after the fall of that colony during the East African Campaign. All four had to travel around the Cape of Good Hope to get to BETASOM.
Transferred from the Red Sea Flotilla during the summer of 1941:
NameArrival dateSuccessesFate/Notes
7 May 19413 patrols, 2 ships sunk totalling 25,629 GRTsunk by planes on 15 April 1943
7 May 1941no patrols under Betasomreturned to the Mediterranean in September–October 1941
9 May 19411 patrol, no ships sunksunk by on 25 October 1941
19 May 1941coastal submarine, no patrols under Betasomreturned to the Mediterranean in September–October 1941

In 1941, it was decided to return some of the boats to the Mediterranean. Perla, Guglielmotti, Brin, Argo, Velella, Dandolo, Emo, Otaria, Mocenigo, and Veniero made the passage. Glauco also made the return voyage but was sunk by the British Royal Navy off Cape Spartel.
The submarine cruiser Cagni was dispatched from the Mediterranean to patrol off South Africa in October 1942. On completion she returned to Bordeaux, transferring to BETASOM in February 1943. She was converted there for transport to the Far East but was overtaken by the Italian Armistice in September 1943 and was interned at Durban.
NameArrival dateSuccessesFate/Notes
Cagni20 Feb 19432 ships, totalling 5,840 GRTconverted to transport submarine, interned at armistice

Post-World War II

The submarine pens have proved to be infeasible to demolish due to their massive reinforced construction which had been designed to withstand aerial bombardment., after conversion several years previously, approximately of the building are open to the public as a cultural centre for the performing arts, exhibitions, and evening events.
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