Hello to all. I am a writer working to complete my father's (Louis L'Amour) last few novels. A couple of years ago I finished his first (circa 1940) novel, No Traveller Returns, a book that contained a good deal of technical maritime detail. The current project is a thriller that deals with certain elements of WWII technology. It is a work of fiction but, of course, I'm trying to be as accurate as I can while still being appropriately entertaining.

In searching for information I have tried contacting both the Museum of Science and Industry in Chicago and the Bremerhaven Maritime Museum but have had no luck getting any useful response. I suspect that Covid has seriously disrupted their operations. Some of the Chicago people appear to have gone on to other jobs.

I'm now turning to you here at uboat.net to see if you can help me discover the answers to a number of questions:

1) On the Type XXI, was there an equivalent to the Salvage Air System found on US Submarines? If so, where would the connection manifold be found? Is there any place I could look for documentation?

2) Was a Salvage Air System found on other German submarines? I believe I saw a report somewhere that suggested it was included in some designs yet was not always installed on the completed boat.

3) I suspect that a number of Uboats were briefly sunk in port or not far out of port due to air raids and the like. If Salvage Air Systems were not common, or not common after a certain era, does anyone know any details of how these subs were raised during wartime conditions and put back in commission?

I'd be incredibly grateful for any help I can receive!