Check out these images from Mister X /Spartan:
Mister X /Spartan is featured at Serious Male Bondage, where these images are from. The top scenario pictured above is from TIGHT SQUEEZE MISTER X.
Mister X /Spartan also has fiction in the Metalbond Prison Library.
He’s also got other writings over at Eckie’s site.
When I first visited Paris, around the year 2000, I visited the Pompidou museum and one of the exhibits had a “human transport device”. It was somehow similar to the box in this article, and it was fascinating. I have tried to find pictures of it, but I wasn’t able to.