Use search function please. All the info found with Ł - refers to this site
GORDON WILLIAMSON, illustrated by IAN PALMER
A design project only, this version was to have been fitted with a new type of two-stroke V12 lightweight diesel engine made by the Deutz firm. The project was abandoned before any could be built.
The Type VIIF was a modification of the basic Type VII design similar to that of the VIID, in that a 10.5 m additional length of hull was inserted just abaft the control room. This allowed an extra 24 torpedoes to be carried, as well as additional refrigerated food storage and two extra crew members. The VIIF was to act as a resupply boat, carrying additional torpedoes to front-line boats that had expended their ammunition.
U-431, a newly launched Type VIIC, shows to good advantage the hull shape of the Type VII with its narrow foredeck, widening around the conning tower, to narrow again towards the stern and the bulge of the saddle tanks. The demarcation between the light grey upper works and the dark grey scheme below the waterline is also clearly visible.
Only four of this type were eventually built (U-1059 to U-1062), all produced by Germaniawerft.
Length - 77.6 m
Beam - 7.3 m
Draft - 4.9 m
Displacement - 1,084 tons surfaced, 1,181 tons submerged
Speed - 16.9 knots surfaced, 7.9 knots submerged
Endurance - 9,500 nautical miles surfaced, 75 nautical miles submerged
Powerplant - 2 × 1.400 bhp diesels coupled with 2 × 375 bhp electric motors
Armament - 5 torpedo tubes (4 bow, 1 stern), 1 × 8.8 cm gun, 1 × 2 cm gun
Crew - 46
Of all of the Type VII models, none saw as much modification and improvement to the basic design as did the most common model of all, the Type VIIC. The variants mentioned above relate principally to internal modifications, which would not be obvious from photographs of the boats themselves. However, one major series of modifications that became necessary during the course of the war, and which drastically altered the appearance of each type, was made to the conning tower.
As Allied anti-submarine measures improved, the use of aircraft against U-boats took on a considerable significance and it quickly became apparent that the single 2 cm anti-aircraft gun carried on the basic Type VII was woefully inadequate. In fact, no matter how much the flak armament was beefed up, few U-boats would risk taking on enemy aircraft (although in several recorded cases, when left with no option but to remain on the surface, U-boats did take on enemy aircraft, and succeeded in shooting them down).
The various conning tower configurations, beginning with the basic circular platform to the rear of the tower, with its single 2 cm flak gun, were given numeric codes, the basic configuration being known as Turin 0.
The first major attempt to beef up flak defences was to widen the platform somewhat, and replace the single 2 cm flak gun with two twin 2 cm machine gun mounts.
Turm 1. This design was to see a second, lower, platform fitted to the rear of the conning tower (generally known to U-boat men as the 'Wintergarden') on which would be fitted a twin 2 cm flak. This design was approved in June 1942.
U-377, a Type VIIC, seen here after her bridge conversion. The armoured shelters, intended to give bridge crew some protection against enemy fire, can be seen welded to either side of the forward part of the tower. The deck gun has been removed and an extended 'wintergarden' platform fitted to the rear of the tower to take the upgraded flak armament. (Jak P. Mallmann-Showell)
Turm 2. Due to problems with the supply of the new weapons required for the Turm 1 design, a second new tower configuration was introduced in which the original round upper platform was joined by a similar lower platform, both of which were fitted with a single 2 cm flak gun. Installation of this type commenced in December 1942.
Turm 3. This little-used configuration saw two single 2 cm flak guns mounted side by side on the upper platform and was used only on the Type VIII).
Turm 4. This, destined to become the most common configuration, had two twin 2 cm guns fitted on a widened upper platform, and a single four-barrelled 2 cm flak gun, the Flakvierling, on the lower. The Flakvierling was gradually replaced by a single-barrelled 3.7 cm flak gun.
Turm 5. An experimental model, fitted to only one U-boat (U-362), this configuration had two twin 2 cm flak guns on the upper platform, a single twin 2 cm flak gun on the lower, and a fourth twin 2 cm gun on a special platform built on to the front of the tower.
Turm 6. Another little-used model, only two boats received this modification. This configuration had a single-barrelled 3.7 cm flak gun on the lower platform, two twin 2 cm flak guns on the upper, and a single twin 2 cm in front of the tower on a separate pedestal. Only L-673 and U-973 were so converted.
Turm 7. A 'concept' only and never actually built, this tower would have seen twin 3.7 cm flak guns on platforms both to the rear and in front of the tower.
Flak Boats. A small number of boats (seven only) were ordered to be converted into Flak Boats, and given heavy anti-aircraft armament to allow them to take on enemy aircraft on relatively even terms. U-441 was given a Flakvierling on a mount in front of the tower, another on the upper platform at the rear of the tower, as well as a 3.7 cm flak the rear lower platform. Although U-441 succeeded in shooting down a Sunderland flying boat, the adverse effect of the new bridge structure on diving times and handling, combined with the heavy armament now being installed on standard boats, saw the order cancelled with all Flak Boats to be reconverted back to Turm 4 configuration.
/ page 7 from 19 /
mobile version of the page