Немецкая подводная лодка "Бобёр" времён Второй мировой войны.

Type of midget submarine

Biber (German for "beaver") was a German midget submarine of the Second World War. Armed with two externally mounted torpedoes or mines, they were intended to attack coastal shipping. They were among the smallest submarines in the Kriegsmarine. The Biber was hastily developed to help meet the threat of an Allied invasion of Europe. This resulted in basic technical flaws that, combined with the inadequate training of their operators, meant they never posed a real threat to Allied shipping, despite 324 submarines being delivered. One of the class's few successes was the sinking of the cargo ship Alan A Dale. Several survive in museums, including one in operational condition.

Originally proposed by Kapitänleutnant Bartels in 1942, but not acted on until the need for coastal defence in the event of an invasion became paramount. Construction of the first prototype began in February 1944, at the Flender shipyard in Lübeck, and was completed in less than 6 weeks.

The hull was built in three sections composed of thick steel with an aluminium alloy conning tower bolted to the top. The torpedoes or mines were accommodated in semi circular recesses in the side of the hull. These reduced the overall width of the loaded craft, making land transport easier and also reduced drag in the water, but at the cost of weakening the hull. The Biber was powered on the surface by a Otto Blitz petrol engine, which was used despite concerns about the risks posed by the carbon monoxide the engine gave off.

Biber operations were carried out under the auspices of the K Verband, a German naval unit which operated a mixture of midget submarines and explosive speedboats. The training of Biber operators was originally planned to take eight weeks, but the initial group of pilots was rushed through in just three weeks. Operations generally lasted from one to two days with pilots either using a drug known as D IX to stay awake on longer missions or caffeine laced chocolate.

In December 1944 it was decided to deploy Bibers against traffic to Antwerp in the Scheldt Estuary. Reinforcements allowed operations to continue until April 1945 but no successes were achieved and the Biber flotillas continued to take a very high rate of losses. The last Biber mission was an attempt at mine laying and took place on the night of 26 April.

In January 1945 an attempt was made to mount an attack on Vaenga Bay in the Kola Inlet.