While I have to dig up the bulk of the relevant information, It is at least reasonable to begin this thread, because others may wish to add their knowledge to an arcane but nonetheless tangentially interesting topic.
The British K boats were decidedly odd even in an era where Naval Architecture (today, we’d call it Marine Engineering) was itself at times eccentric.
Imagine if you will, a submarine nearly the size of a WW2 Type XXI.
Imagine further, that this vessel was intended to operate both as a submarine, and a Fleet Surface auxiliary Cruiser, operating at Fleet speeds on the surface.
How was this wonderous performance to be achieved? STEAM.
Yes, Ripley’s “Believe It Or Not” couldn’t have done it better: a Steam powered submarine.
Further technical details on the monstrosities once I dis-inter them.
Enough for now to say they had an interesting service life to say the least, and that none survived into the Second World War, for which RN personel can to this day give thanks. (Relevant quote, First Lieutenant, in stern motor-room of K boat, to Captain, in control room, via intercom:“I say, Sir, My end is diving – what’s your end doing?” This, as several tons of water attempt to add themselves to the vessel by way of the funnel covers.)
They did have offspring though, three of which did survive into the very earliest days of WW2.
These were : X1, M1, Surcouf (essentially, French copy of M1).
Further offshoots include the IJN I1400 class, which was considerably more successful and considerably more refined.
Feel free to contribute, I’d be interested to see more information, especially on the K boats, but any of the near relatives is welcome in this thread also.
Regards, Uyraell.