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Re: Type XXI engines
Posted by: Patrick Meagher ()
Date: July 19, 2008 04:52PM

Question 1. Silent running motors were electric motors connected to the the propeller shafts with a V-belt drive allowing a Type XXI to make 6 knots in near silence. For previous classes to achieve this speed submerged the propulsion moters had to operate at high speed which created a lot of noise. Silent running motors V-belt drive on a type XXI had a ratio of 2.68 to 1 to the propeller shaft. USN listening tests on the U 2513 while operating on silent running motors in 1946 found that she could not be reliably tracked on passive sonar even at a distance of 220 meters. Source: Kohl and Rossler, The type XXI U-Boat, 1991.

Question 2. Huh???

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Subject Written By Posted
Type XXI engines Martin 06/29/2008 10:56PM
Re: Type XXI engines Patrick Meagher 07/19/2008 04:52PM


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