Hi All,

Let’s not forget that Germany was restricted as to the size of her U-boats by treaty to a percentage of the British fleet, i.e., a maximum total tonnage for all U-boats. Germany had to choose between a small number of large U-boats or a larger number of small U-boats. As a result they compromised with some of both and in both cases they had to sacrifice crew comforts for fighting capabilities to produce the most boats within the treaty limitations. The environment they were designed for called for a high surface speed, good maneuverability and a fast diving time (getting below the surface) to avoid enemy planes and escorts and size was a major factor in all three.

Once the treaty was no longer a factor they had limited resources to contend with and proven designs that worked so they continued with those designs. Hitler also forbid certain research projects that weren’t going to be completed within the time frame he had decided the war was going to take and this delayed the design of the Walter boat and that led to the belated design of the Type XXI.

The Type XXI was a new design and it did have more crew comforts than the Type VII & Type IX. It also had a different environment to survive and fight in – an underwater environment. That environment required a high underwater speed instead of a high surface speed and good maneuverability and a fast diving time were less important so the boats could be bigger. The allies had control of the air and large numbers of aircraft and surface escorts plus airborne centimeteric radar forcing the U-boats to contend with long patrols completely underwater which were much harder on the crew than the type of patrol the previous designs were intended for so more crew comforts were also called for.

Regards,

Ken Dunn