NavList:

Ronald

The production tables of the MHR-1 reproduced in your article imply (to me, anyway) that there were many, many more MHR-1's than Kriegsmarine ships plus U-boats, combined.  (Yes, some of the slide rules were destined for the Luftwaffe.)

Frankly, the surface fleet of the Kriegsmarine was more a fleet in being, rather than an active maneuvering fleet.  Beyond the handful of ships supporting the U boat fleet and some others like the Merchant Raider ships, the Kriegsmarine generally stayed in port.  Being tied up to a wharf makes position finding easy!!

The U boat fleet, on the other hand, was actively involved in chasing convoys at the direction of HQ.  There was active maneuvering and obviously, celestial navigation.

Your post states that the slide rule was issued only to submarines that could stay on the surface for only a short time.  Yet that is a general description of U boat fleet activities once Allied air power forced the U boat fleet under water to avoid detection.  Perhaps during the so-called 'Happy Time' U boats weren't forced under however,  that period did not last in the face of mounting Allied pressure.  Further, the U boat fleet during the Happy Time was rather small compared to later years.  It would have been easy to supply all U boat ships during the Happy Time, due to low requirements.

Is it your contention that the U boat fleet was NOT supplied with the MHR-1 (and MHR-2)? 

Is it your contention that even though the U boat fleet was supplied with the MHR-1, that they used the F-Taffel in its place (instead of the MHR-1)?

This thread is U boat celestial navigation in WWII.  It is not Kriegsmarine celestial navigation in WWII.  Nor is it German Merchant Marine Celestial Navigation in WWII.  Moreover, not Luftwaffe celestial navigation. 

U boats were supplied with an MHR-1.  Why would they bother with a cumbersome and creaky F-Taffel when the slide rule was fast and easy?

Brad