Type VII submarine

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Type VII U-boats were the workhorses of the German World War II U-boot-waffe that was based on a E-2 type, developed by Deschimag company for the Soviet Navy (produced in USSR as IX series). Type VII boats were the most widely used submarines of the war and were built in the biggest series in the world -- up to 700 units. The type had several modifications.

U-995 Type VIIC at the German navy memorial at Laboe

Type VIIA

The Type VIIA boats were designed in 1933 until 1934 as the first of a new generation of attack U-boats. They were popular with their crews and much more powerful than the smaller Type II U-boats they replaced, with four bow and one stern torpedo tubes. Usually carrying 11 torpedoes onboard, they were very agile on the surface and mounted the 88 mm fast-firing deck gun with about 160 rounds.

Ten Type VIIA boats were built between 1935 and 1937. All but two (U-29 and U-30, both scuttled in Kupfermühlen Bay on May 4, 1945) Type VIIA U-boats were sunk during World War II.

General characteristics:

  • Displacement: surfaced 626 tons, submerged 745 tons
  • Length: overall 64.5 m, pressure hull 45.5 m
  • Beam: overall 5.85 m, pressure hull 4.7 m
  • Draft: 4.4 m
  • Height: 9.5 m
  • Power: surfaced 2310 hp (1,700 kW), submerged 750 hp (560 kW)
  • Speed: surfaced 17 knot (31 km/h), submerged 8 knot (15 km/h)
  • Range: surfaced 11,470 km (6200 miles) at 10 knots (19 km/h), submerged 175 km (94 miles) at 4 knots (7 km/h)
  • Torpedo tubes: 4 bow, 1 stern (11 torpedoes)
  • Deck gun: 88 mm/45 with 220 rounds
  • Crew: 42-46 officers & ratings
  • Max depth: 220 m (722 ft)
  • Crush depth: 230-250 m (754-820 ft)

Type VIIB

Prien's U-47 (model)
Prien's U-47 (model)

The only significant drawback of the VIIA was the limited fuel capacity, so 24 Type VIIB boats were built between 1936 and 1940 with an additional 33 tons of fuel in external saddle tanks which added another 2500 miles (4625 km) of range at 10 knots (19 km/h) surfaced. They were slightly faster than the VIIA, and had two rudders for even greater agility. They had the same armament as the VIIA (except U-83, which lacked a stern tube), but could carry three additional torpedoes.

Type VIIB included many of the most famous U-boats of World War II, including U-48 (the most successful), Prien's U-47, Kretschmer's U-99, and Schepke's U-100.

General characteristics:

  • Displacement: surfaced 753 tons, submerged 857 tons
  • Length: overall 66.5 m, pressure hull 48.8 m
  • Beam: overall 6.2 m, pressure hull 4.7 m
  • Draft: 4.74 m
  • Height: 9.5 m
  • Power: surfaced 3200 hp (2,400 kW), submerged 750 hp (560 kW)
  • Speed: surfaced 17.9 knots (33 km/h), submerged 8 knot (15 km/h)
  • Range: surfaced 16,095 km (8700 miles) at 10 knots 19 km/h), submerged 175 km (94 miles) at 4 knots (7 km/h)
  • Torpedo tubes: 4 bow, 1 stern (14 torpedoes)
  • Deck gun: 88 mm/45 with 220 rounds
  • Crew: 44-48 officers & men
  • Max depth: 220 m (722 ft)
  • Crush depth: 230-250 m (754-820 ft)

Type VIIC

A cross-section of a Type VIIC U-boat.
miniature model of a Type VIIC.

The Type VIIC was the workhorse of the German U-boat force, with 568 commissioned from 1940 to 1945. Boats of this type were built throughout the war. The first VIIC boat commissioned was the U-69 in 1940. The Type VIIC was an effective fighting machine and was seen almost everywhere U-boats operated, although their range was not as great as that of the larger Type IX. The VIIC came into service as the "Happy Time" at the beginning of World War II were almost over, and it was this boat that saw the final defeat by the Allied anti-submarine campaign in late 1943 and 1944.

Type VIIC was a slightly modified version of the successful VIIB. They had very similar engines and power, but were larger and heavier which made them slightly slower than the VIIB. Many of these boats were fitted with the Schnorchel in 1944 and 1945.

They had the same torpedo tube arrangement as their predecessors, except for U-72, U-78, U-80, U-554, and U-555, which had only two bow tubes, and for U-203, U-331, U-351, U-401, U-431, and U-651, which had no stern tube.

Perhaps the most famous VIIC boat was U-96, featured in the movie "Das Boot".

General characteristics:

  • Displacement: surfaced 769 tons, submerged 871 tons
  • Length: overall 67.1 m, pressure hull 50.5 m
  • Beam: overall 6.2 m, pressure hull 4.7 m
  • Draft: 4.74 m
  • Height: 9.6 m
  • Power: surfaced 3200 hp (2,400 kW), submerged 750 hp (560 kW)
  • Speed: surfaced 17.7 knot (33 km/h), submerged 7.6 knot (14 km/h)
  • Range: surfaced 15170 km (8200 miles) at 10 knots (19 km/h), submerged 150 km (80 miles) at 4 knots (7 km/h)
  • Torpedo tubes: 4 bow, 1 stern (14 torpedoes)
  • Deck gun: 88 mm/45 with 220 rounds
  • Crew: 44-52 officers & men
  • Max depth: 230 m (754 ft)
  • Crush depth: 250-295 m (820-967 ft)

U-flak

The "U-flak" boats were four VIIC boats (U-441, U-256, U-621, and U-951) modified to be surface escorts for the attack U-boats operating from the French Atlantic bases. They had greatly increased anti-aircraft fire-power.

Conversion began on three others (U-211, U-263, and U-271) but none were completed, and they were eventually returned to duty as traditional VIIC attack boats.

The modified boats became operational in June of 1943 and at first appeared to be successful against the surprised RAF. Seeing their potential, Dönitz ordered the boats to cross the Bay of Biscay in groups at maximum speed. The effort earned the Germans about two more months of still-limited freedom, until the RAF developed counter-measures. When the RAF began calling in surface hunters to assist the aircraft, the U-flak boats were withdrawn and converted back into fighting vessels.

The concept of the U-flak began the year before, on August 31, 1942, when U-256 was seriously damaged by aircraft. Rather than scrap the boat, it was decided to refit her as a heavily-armed anti-aircraft boat intended to stop the losses in the Bay of Biscay inflicted by Allied aircraft.

Two 20 mm quadruple Flakvierling mounts and the experimental 37 mm automatic gun were installed on the U-flaks' decks. A battery of 86 mm line-carrying antiaircraft rockets was tested, but this idea proved unworkable. At times, two additional single 20 mm guns were also mounted. The submarines' fuel capacities were limited to Bay of Biscay operations only. Only five torpedoes were carried, preloaded in the tubes, to free the space needed for the additional gunners.

In November 1943 -- less than six months after the experiment began -- all U-flaks were converted back to normal attack boats, fitted with Turm 4. The standard anti-aircraft armament for U-boats was no longer much inferior to U-flaks, and the U-flaks had not been particularly successful. Even with massive anti-aircraft firepower, a U-boat was still vulnerable to having her pressure hull punctured; her best bet when encountering aircraft was simply to dive. According to German sources only two aircraft had been shot down by U-flaks in six missions (three by U-441, one each by U-256, U-621, and U-953).

Type VIIC/41

Type VIIC/41 U-995

Type VIIC/41 was a slightly modified version of the successful VIIC and had the same armament and engines. The difference was a stronger pressure hull and lighter machinery to compensate for the added steel in the hull, making them actually slightly lighter than the VIIC. A total of 91 were built; all of them from U-1271 onwards lacked the fittings to handle mines.

Today one Type VIIC/41 still exists: U-995 is on display at Laboe (north of Kiel), the only surviving Type VII in the world.

General characteristics:

  • Displacement: surfaced 769 tons, submerged 871 tons
  • Length: overall 67.1 m, pressure hull 50.5 m
  • Beam: overall 6.2 m, pressure hull 4.7 m
  • Draft: 4.74 m
  • Height: 9.6 m
  • Power: surfaced 3200 hp (2,400 kW), submerged 750 hp (560 kW)
  • Speed: surfaced 17.7 knots (33 km/h), submerged 7.6 knots (14 km/h)
  • Range: surfaced 15,725 km (8500 miles) at 10 knots (19 km/h), submerged 150 km (80 mile) at 4 knots (7 km/h)
  • Torpedo tubes: 4 bow, 1 stern (14 torpedoes)
  • Deck gun: 88 mm/45 with 220 rounds
  • Crew: 44-52 officers & men
  • Max depth: 250 m (820 ft)
  • Crush depth: 275-325 m (902-1066 ft)

Type VIIC/42

The Type VIIC/42 was designed in 1942 and 1943 to replace the aging Type VIIC. It would have had a much stronger pressure hull, with skin thickness up to 28 mm, and would have dived twice as deep as the previous VIICs. These boats would have been very similar in external appearance to the VIIC/41 but with two periscopes in the tower and would have carried two more torpedoes.

Contracts were signed for 164 boats and a few boats were laid down, but all were cancelled on September 30, 1943 in favor of the new Type XXI, and none were advanced enough in construction to be launched.

General characteristics:

  • Displacement: surfaced 999 tons, submerged 1099 tons
  • Length: overall 68.7 m, pressure hull 50.9 m
  • Beam: overall 6.85 m, pressure hull 5 m
  • Draft: 5 m
  • Height: 10 m
  • Power: surfaced 4400 hp (3,300 kW), submerged 750 hp (560 kW)
  • Speed: surfaced 18.6 knots (34 km/h), submerged 7.6 knots (14 km/h)
  • Range: surfaced 23,310 km (12,600 mile) at 10 knots (19 km/h), submerged 150 km (80 mile) at 4 knots (7 km/h)
  • Torpedo tubes: 4 bow, 1 stern (16 torpedoes)
  • Deck gun: none
  • Crew: 44-52 offiers & men
  • Max depth: 270 m (890 ft)
  • Crush depth: 350-400 m (1148-1312 ft)

Type VIID

The type VIID boats, designed in 1939 and 1940, were a longer version of the VIIC with three banks of five vertical tubes just aft of the conning tower, rather like a modern ballistic missile submarine, except that these tubes ejected mines rather than missiles.

These boats did not fare well: only one survived the war; the other five all went down with all hands.

U-213 -- U-214 -- U-215 -- U-216 -- U-217 -- U-218

General characteristics:

  • Displacement: surfaced 965 tons, submerged 1080 tons
  • Length: overall 76.9 m, pressure hull 59.8 m
  • Beam: overall 6.4 m, pressure hull 4.7 m
  • Draft: 5 m
  • Height: 9.7 m
  • Power: surfaced 3200 hp (2,400 kW), submerged 750 hp (560 kW)
  • Speed: surfaced 16.7 knots (31 km/h), submerged 7.3 knots (14 km/h)
  • Range: surfaced 20,720 km (11,200 miles) at 10 knots (19 km/h), submerged 130 km (70 miles) at 4 knots (7 km/h)
  • Torpedo tubes: 4 bow, 1 stern (12 torpedoes)
  • Mine chutes: 15 mines
  • Deck gun: none
  • Crew: 46-52 officers & men
  • Max depth: 200 m (660 ft)
  • Crush depth: 220-240 m (721-787 ft)

Type VIIF

The Type VIIF boats, designed in 1941, were primarily built as torpedo transports. They were the largest and heaviest type VII boats built. They were armed identically with the other Type VIIs except that they could have up to 39 torpedoes onboard and had no deck guns.

Only four Type VIIFs were built. Two of them, U-1062 and U-1059, were sent to support the Monsun U-boats in the Far East; U-1060 and U-1061 remained in the Atlantic.

General characteristics:

  • Displacement: surfaced 1084 tons, submerged 1181 tons
  • Length: overall 77.6 m, pressure hull 60.4 m
  • Beam: overall 7.3 m, pressure hull 4.7 m
  • Draft: 4.9 m
  • Height: 9.6 m
  • Power: surfaced 3200 hp (2,400 kW), submerged 750 hp (560 kW)
  • Speed: surfaced 17.6 knots (33 km/h), submerged 7.9 knots (15 km/h)
  • Range: surfaced 27,195 km (14,700 miles) at 10 knots (19 km/h), submerged 140 km (75 miles) at 4 knots (7 km/h)
  • Torpedo tubes: 4 bow, 1 stern (39 torpedoes)
  • Deck gun: none
  • Crew: 46-52 officers & men
  • Max depth: 200 m (650 ft)
  • Crush depth: 220-240 m (721-787 ft)

References

  • Stern, Robert C. (1991). Type VII U-boats. Annapolis, Maryland (USA): Naval Institute Press. ISBN 1-55750-828-3.