back to Sea Transportation

More than a dozen submarines of this class are built for the Kriegsmarine during 1935, numbered U-7 to U-18 (more were built later). The construction of these vessels is kept a secret until the signing of the Anglo-German Naval Treaty of 1935.

Length 140', beam 14', displacement (surfaced) 279 tons.

Surface speed 13 kts, submerged 7 kts; range 3900 nautical miles at 8 kts, 1050 nautical miles at 12 kts, submerged 43 nautical miles at 4 kts, 71 nautical miles at 2 kts; max designed depth 500'.

Armament: 3 bow tubes; 6 torpedoes carried (that is, 1 reload for each tube); also 12 mines, and a twin 20mm AA gun.

Crew: 25 (including 3 officers).

The Type IIB is a lengthened version of the Type IIA. Three additional compartments were inserted amidships which are fitted with additional diesel tanks beneath the control room, thus increasing the range. Diving time was also improved to 30 seconds; they are considered very maneuverable and durable by their crews. There are seven compartments - torpedo room, bow quarters, radio room, control room, diesel engine room, electric engine room, and stern quarters. Provisions for up to 4 weeks are carried.

• The G7a torpedo has a range of 6 km at 44 kts (or 8 km at 40 kts, or 14 km at 30 kts); as a "compressed air" torpedo it leaves a visible trail of bubbles on the way to the target. Warhead, 616 pounds; cost 20,000 marks (about $7500 in 1934).

• The TMA is a moored mine, which means that it is secured by a heavy anchor and a cable attached to the mine. The mine floats at the surface, while the anchor secures its position in the sea (maximum 885'). Two can be loaded in each torpedo tube. Warhead, 473 pounds.