YOYA KAWAMUA (1739-LIFE-1991) tells us that, according to records, U-511 (TYPE IX-C) was presented to Japan as a gift & became Ro 500 not I-500. The Japanese Navy classified submarines under 1,000 tons as Ro Boats and those over 1,000 tons as I-Boats.

HARRY’S NOTE

Since a TYPE IX-C is more than 1,000 tons, you may wonder why it was classed as an Ro Boat. During the pre-war military build-up, Germany was allowed certain tonnage in submarine building, per her treaty with England. Germany thought correctly, that a large number of smaller tonnage boats would make a pretty fine submarine navy. They took this logic one step further, and did not give the correct tonnage for these boats.

The TYPE VII-C was the workhorse of the Kriegsmarine and they made up about 75% of the strength of the U-Bootwaffe. They were known as ‘500 ton’ U-Boats when they were in fact 769 tons surfaced and 871 tons submerged. Later models, TYPE VII-C42 for instance, displaced as much as 999 tons surfaced and 1,050 tons submerged yet they were called ‘500 ton’ U-Boats.

The standard long-range U-Boat was the TYPE IX with its various mods. They were known as ‘760 ton’ U-Boats but in fact, they were well beyond that. The first, TYPE IX-A displaced 1,032 tons surfaced and 1,153 tons submerged. Later models, such as the TYPE IX-C40 displaced 1,144 tons surfaced and 1,247 tons submerged yet they were called ‘760 ton’ U-Boats.

U-511 was the first submarine ever to fire rockets while submerged. Her Skipper at that time was KPLT Fritz Steinhoff. HEINZ REHSE (254-1987) was Engineering Petty Officer on the boat when it made its voyage to Japan under command of Schneewind.