Yeah, those things have nearly as many unpleasant failure modes as a Saniflo...
I spotted the talk of submarine toilets on this thread last week but was away from home and couldn’t face trying to write my contribution on the phone. So here it is now a week overdue.
For many decades now RN submarines have had two methods of emptying their waste tanks, pumping or blowing. Pumping is much preferred as blowing can be problematic in the following way:
Just over ten years ago while at sea on an unspecified (but now decommissioned) submarine we were having to regularly blow our waste tanks on account of a defective sewage pump.
So just as we had done for several nights before we lined up to ‘blow doms’. This involved shutting off every valve connecting a waste pipe to the domestic tanks before pressurising the tanks above sea pressure and opening the sewage hull valve.
On is occasion things didn’t go as planned. As the sewage tank came up to pressure an isolating valve connected to the heads (navy speak for toilets) on 1 deck just off the Control Room failed. The result was a spectacular shit fountain as the sewage tank emptied itself through the head.
Very quickly the Control Room filled up with sewage, I was sat at a fire control desk with a torpedo tube bow cap open, I couldn’t stand down from this position until the bow cap was shut. All I could do was lift my legs as the jobbies floated past.
As the sewage started flowing into the Wardroom the XO (second in command) came in and ordered a bow up (angle of the boat), this sent the sewage into the CO’s Cabin so he countered be ordering a bow down. All of this continued until the Chief Stoker appeared, launched himself into the fountain and isolated the head.
Anyway by this time the stuff had gotten everywhere, down the periscope mast wells, down pipe conduits, into the galley and messes below on 2 deck. Needless to say we went alongside for a good clean up.