[RFB Team]

Originally Posted by Capt Jack Harkness

Okay, well in my original post I was referring to shaft speeds. The diesels did run around 750 RPM but they were only connected to the props (direct-drive) on the S boats. All of the later classes were diesel-electric so the motors ran around 330 RPM at flank speed on the surface while the engines turned generators to power them at 750 RPM.

If you can point me to a source that shows what type of RPM ratings the fleet boat motors ran at, I'd be glad to adjust these values. I've not been able to find a source that shows how many RPM the motors were capable of generating, other than what you've listed above. If you can, could you quote the passage from "Wahoo" that mentions the 330 RPM value?

EDIT: from Fincuan's link:

For surface operation, using the various combinations of armatures and taking power from the main generators, the motors develop power ranging from 20 hp to 2,700 hp per propeller shaft at speeds ranging from approximately 67 rpm to 282 rpm.

For submerged operation, using various combinations of armatures and taking power from the batteries, the motors will develop power ranging from 30 hp to 1,719 hp per propeller shaft, and will give a speed range from 42 to 219 rpm.