Type XXI U-boats, also known as "Elektroboote", were the first submarines designed to operate primarily submerged, rather than as surface ships that could submerge as a means to escape detection or launch an attack.
The key improvement in the Type XXI was greatly increased battery capacity, roughly triple the Type VIIC. This gave these boats great underwater range, and dramatically reduced the time spent on or near the surface. They could travel submerged at about 5 kn (5.8 mph; 9.3 km/h) for two or three days before recharging batteries, which took less than five hours using the snorkel. The Type XXI was also far quieter than the VIIC, making it harder to detect when submerged.
Type XXI U-boats in Bergen, NorwayThe Type XXI's streamlined and hydrodynamically clean hull design allowed high submerged speed. The ability to outrun many surface ships while submerged, combined with improved dive times (also a product of the new hull form), made it far harder to chase and destroy. It also gave the boat a 'sprint ability' when positioning itself for an attack. Older boats had to surface to sprint into position. This often revealed a boat's location, especially after aircraft became available for convoy escort. The new hull design also reduced visibility via marine or airborne radar when surfaced; whether this was a goal of the design or coincidence is still debated.
They also featured a hydraulic torpedo reloading system that allowed all six bow torpedo tubes to be reloaded faster than a Type VIIC could reload one tube.[citation needed] The Type XXI could fire 18 torpedoes in under 20 minutes. The class also featured a very sensitive passive sonar for the time.
The Type XXIs also had better facilities than previous U-boat classes, including a freezer for food.
Between 1943 and 1945, 118 boats were assembled by Blohm & Voss of Hamburg, AG Weser of Bremen, and F. Schichau of Danzig. Each hull was constructed from eight prefabricated sections with final assembly at the shipyards. This new method could have pushed construction time below six months per vessel, but in practice all the assembled U-boats were plagued with severe quality problems that required extensive post-production work to fix. One of the reasons was, as a result of Albert Speer's decision, sections were made by companies having little experience in shipbuilding. As a result, of 118 Type XXIs completed, only four were fit for combat before the war ended in Europe.
It was planned that final assembly of Type XXI boats would eventually be carried out in the Valentin submarine pens, a massive, bomb�hardened concrete bunker built at the small port of Farge, near Bremen. Construction took place between 1943 and 1945, using around 10,000 concentration camp prisoners and prisoners of war as forced�labour. The facility was 90% completed when, in March 1945, it was badly damaged by Allied bunker buster bombs and abandoned. A few weeks later, the area was captured by the British Army.
Characteristics:
Displacement: 1,621 tonnes standard
2,100 tonnes full load
Length: 76.7 m (251 ft 8 in)
Beam: 8 m (26 ft 3 in)
Draught: 5.3 m (17 ft 5 in)
Propulsion: Diesel/Electric
2� MAN M6V40/46KBB supercharged 6-cylinder diesel engines, 4,000 PS (2.9 MW)
2� SSW GU365/30 double acting electric motors, 5,000 PS (3.7 MW)
2� SSW GV232/28 silent running electric motors, 226 PS (0.166 MW)
Speed: Surfaced:
15.6 kn (28.9 km/h) (diesel)
17.9 kn (33.2 km/h) (electric)
Submerged:
17.2 kn (31.9 km/h) (electric)
6.1 kn (11.3 km/h) (silent running motors)
Range: Surfaced:
15,500 nmi (28,700 km) at 10 kn (19 km/h)
Submerged:
340 nmi (630 km) at 5 kn (9.3 km/h)
Complement: 57 officers and men
Armament: 6 � 21 in (53 cm) torpedo tubes (bow), 23 torpedoes (or 17 torpedoes and 12 mines)
4 x 20 mm cannon
Source: Wikipedia
Type XXI U-boats, also known as "Elektroboote", were the first submarines designed to operate primarily submerged, rather than as surface ships that could submerge as a means to escape detection or launch an attack.
The key improvement in the Type XXI was greatly increased battery capacity, roughly triple the Type VIIC. This gave these boats great underwater range, and dramatically reduced the time spent on or near the surface. They could travel submerged at about 5 kn (5.8 mph; 9.3 km/h) for two or three days before recharging batteries, which took less than five hours using the snorkel. The Type XXI was also far quieter than the VIIC, making it harder to detect when submerged.
Type XXI U-boats in Bergen, NorwayThe Type XXI's streamlined and hydrodynamically clean hull design allowed high submerged speed. The ability to outrun many surface ships while submerged, combined with improved dive times (also a product of the new hull form), made it far harder to chase and destroy. It also gave the boat a 'sprint ability' when positioning itself for an attack. Older boats had to surface to sprint into position. This often revealed a boat's location, especially after aircraft became available for convoy escort. The new hull design also reduced visibility via marine or airborne radar when surfaced; whether this was a goal of the design or coincidence is still debated.
They also featured a hydraulic torpedo reloading system that allowed all six bow torpedo tubes to be reloaded faster than a Type VIIC could reload one tube.[citation needed] The Type XXI could fire 18 torpedoes in under 20 minutes. The class also featured a very sensitive passive sonar for the time.
The Type XXIs also had better facilities than previous U-boat classes, including a freezer for food.
Between 1943 and 1945, 118 boats were assembled by Blohm & Voss of Hamburg, AG Weser of Bremen, and F. Schichau of Danzig. Each hull was constructed from eight prefabricated sections with final assembly at the shipyards. This new method could have pushed construction time below six months per vessel, but in practice all the assembled U-boats were plagued with severe quality problems that required extensive post-production work to fix. One of the reasons was, as a result of Albert Speer's decision, sections were made by companies having little experience in shipbuilding. As a result, of 118 Type XXIs completed, only four were fit for combat before the war ended in Europe.
It was planned that final assembly of Type XXI boats would eventually be carried out in the Valentin submarine pens, a massive, bomb�hardened concrete bunker built at the small port of Farge, near Bremen. Construction took place between 1943 and 1945, using around 10,000 concentration camp prisoners and prisoners of war as forced�labour. The facility was 90% completed when, in March 1945, it was badly damaged by Allied bunker buster bombs and abandoned. A few weeks later, the area was captured by the British Army.
Characteristics:
Displacement: 1,621 tonnes standard
2,100 tonnes full load
Length: 76.7 m (251 ft 8 in)
Beam: 8 m (26 ft 3 in)
Draught: 5.3 m (17 ft 5 in)
Propulsion: Diesel/Electric
2� MAN M6V40/46KBB supercharged 6-cylinder diesel engines, 4,000 PS (2.9 MW)
2� SSW GU365/30 double acting electric motors, 5,000 PS (3.7 MW)
2� SSW GV232/28 silent running electric motors, 226 PS (0.166 MW)
Speed: Surfaced:
15.6 kn (28.9 km/h) (diesel)
17.9 kn (33.2 km/h) (electric)
Submerged:
17.2 kn (31.9 km/h) (electric)
6.1 kn (11.3 km/h) (silent running motors)
Range: Surfaced:
15,500 nmi (28,700 km) at 10 kn (19 km/h)
Submerged:
340 nmi (630 km) at 5 kn (9.3 km/h)
Complement: 57 officers and men
Armament: 6 � 21 in (53 cm) torpedo tubes (bow), 23 torpedoes (or 17 torpedoes and 12 mines)
4 x 20 mm cannon
Source: Wikipedia
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