Hi folks, let's take a look at some far fetched ideas and concepts for alternatives to OTL German submarine developments, with a focus on things outside the box.
Everything should be up for discussion, and some things should end up moved into their own threads, so that posts about specific ideas will not get lost in one giant thread will a dozen different ideas and concepts going on all at once.
We know that the Germans will be developing standard commerce raiding combat submarines and doctrine for the next war, and while that portion should be discussed here as well, let's look mainly at what differences could be made. Some things I would like to throw out there would be:
1) The Germans (NOT just the Nazi Germans), should be looking at getting around any and all ToV restrictions on their military, right off the bat. Not able to openly ignore such restrictions, they should be finding ways to get around them much more than in OTL. As pertains to submarine developments, this needs to take in German designers working in foreign lands. What lands might be open to German submarine designers after WWI, and before WWII? Obviously there will be some in Europe (Holland, for instance), but what about further abroad? Might the USA be willing to do some co-development of submarines with German companies? How about the Russian/Soviets? After the end of the Anglo-Japanese alliance, will Japan be interested in working on submarines, in concert with German companies? What other countries would/might be possible? Italy has her own submarine program, so under the right conditions, might they too climb aboard? What about Turkey, Spain, Argentina?
2) The Germans should be looking at lessons learned from WWI, and both the distant blockade, and trade submarines to partially counter such, should be on the minds of German planners, and while merchant submarines will never come close to being able to feed the German people in any meaningful way, they can feed German industry some of the most difficult to obtain rare materials. Thinking outside the box, and looking to develop viable submarine merchant shipping, I would think that the only obvious options where submarines would offer anything like an advantage over the far cheaper surface merchantmen, would be trans-polar shipping. Without Nuclear Power, is it even remotely possible to construct a submarine vessel that could transit the north polar cap submerged? Obviously not anything we saw developed in OTL, but something else? The OTL I-400 class submarines were an interesting idea, and solve the range problem very nicely, however, they don't include the submerged duration within their design to make such a voyage all the way under the polar ice cap, IIUC. The only thing that a submarine of the times could have as an option that might suffice, would have to be a propulsion method that would function without surfacing for prolonged times. The two most likely prospects for this that I can think of off the top of my head, would be the Walter submarines, or a submarine with enough battery capacity to power their engines for the entire time, and with a safety margin built in to avoid tragedy as part of such a requirement, this would have to be a very large capacity indeed. This idea obviously needs it's own thread, as it is going to be focused on non-combat, trans-polar, submerged commerce, and the needs and justifications for such as well as the engineering challenges that will have to be overcome. And of course, being me, I have to wonder just what technologies, ostensibly
under development for this goal, might just find themselves useful in a non-peaceful context.
3) Let's also look at the weapons historically used, both by and against, the submarines of the times, and see if we cannot come up with some interesting possibilities of our own. There will likely need to be some separation here as well, as discussions about SW/USW/ASW in the open oceans of the world will have little in common with midget submarines attempting to infiltrate a harbor/naval base.
4) Let's look, too, at ATL equipment and technologies that never were, and see what all folks can come up with.