Jim Christley spent a fair part of his submarine career on Guppy boats. I used to love to talk with him at SubCommittee Regattas, as you pick up little pieces of wisdom when speaking with him. Like wear old jeans when doing battery well inspections (spilled sulfuric acid eats holes in them) and don't wear jeans that have metal studs. You are climbing among DC busbars which don't mix well with metal studs. Also, how they would run submerged on diesel with the snorkle, and when the snorkle was dunked in rough sea states, the diesels would suck air out of the submarine compartments. This caused suddenly decreased pressure with eardrums and sinuses becoming painful. Then when the snorkle cleared the waves, the pressure would shoot back to normal. Rinse, repeat for hours on end. Sleeping became impossible. This was a particular problem on Guppys, as the US diesels were 2 cycle vs. the German Type XXI 4 cycle engines. The 2 cycles had blowers and needed a lot more air; hence larger diameter snorkels and when dunked, a more rapid decrease in air pressure due to the 2 cycle diesel air demand. I don't think those guys who served in that early Cold War period have ever received the recognition they deserved.
Let me know which Christley articles you have. I have all of his SubCommittee articles on Guppy sub & happy to send you some PDFs..
Jim had a web site but alas, much of it is gone.
More sources are:
https://quietwarriors.wordpress.com/smoke-boats/guppys-and-fleet-boats/http://rnsubs.co.uk/articles/development/guppy.htmlStill some final work to do on these models (like add the screws, decals, and mount them on a finished board)