Hi Tony,
>Is there any explanation for the lack of such German turrets in the book?
It's actually more like a magazine - it's a "Waffen Revue" volume, if you're familiar with them. (The author of the "Waffenstände" volume is Manfred Griehl.)
It does not mention any reason for the lack of powered and manned turrets in German bombers, except for the volume poblems.
However, reading between the lines, I think the Luftwaffe generally thought the value of defensive armament to be limited, and that they had achieved a good compromise with regard to weight and survivability in their bombers. Remember that while the British were highly enthusiastic about the value of powered turrets before the war, the "Battle of Heligoland Bay" showed that their bombers were easy prey for day fighters nevertheless. The RAF withdrew their bombers to night attacks, and of course, the Luftwaffe had learned that bombers were highly vulnerable, too.
>Even the 13mm MG 131 single turret which came later was only half-powered - a simple, single-speed motor moved the turret to about the right position, after which the gunner aimed by hand. I think only the 20mm turrets were properly powered, and they saw little use.
Thanks for the clarification - Griehl had listed that point, but not explained it well enough for me to understand :-)
Anyway, it seems that the Germans mostly skipped the powered and manned turret in favour of the powered remotely-controlled turret similar to the B-29's armament. Messerschmitt, Arado and and the Luftfahrtgerätebau Berlin each developed such a system, and AEG actually built a variety of different systems for the task. However, all of these systems seem to have had problems with accuracy, and they weren't ready for production before the German bomber programs were cancelled.
The reason for skipping the manned power turret probably was the 1939's "Bomber B" specification which called for a medium bomber with a pressure cabin. As with the B-29, remotely controlled turrets were the only way to achieve reliable pressurization, so they were in the specification, too. The Bomber B programme lead to the Ju 288 (found to be superior to the competing Do 317 and Fw 191), but all three Bomber B aircraft were to utilize the Jumo 222 which was a failure, and so the entire programme was cancelled in early 1944.
The He 177, the moderately successful Bomber A, was canceled in July 1944, too, pretty much eliminating the need for bomber armament that way. All future plans for bombers were based on jet engines and using high speed as their primary defense so that comparatively light armament would have sufficed. The Ju 287 for example was to be armed with a remotely controlled twin turret only.
Regards,
Henning (HoHun)
