Did you know a World War II German submarine was sunk by a toilet?

We’re fond of remembering men who died and vessel that were sunk in heroic action against the enemy. Protecting vital convoys, desperately attacking a superior ship, or just carrying on with the mission in the face of overwhelming firepower: such losses, while tragic, feel justified.

There are also run-of-the-mill losses in war, just being in the wrong spot at the wrong moment.
 
And then there are stupid losses. One such loss was that of the German U-boat U-1206, which was sunk by a toilet malfunction. Last week’s “Did you know?” article was about how a toilet (or rather, a toilet break) saved someone’s life (LBJ’s Toilet Break); this article is about how another one caused an entire boat to get “flushed.” 
 
On April 6, 1945, a mere month before the German surrender, U-boat U-1206 left Norway on her first-ever combat patrol, under the command of rookie Lieutenant Commander Karl-Adolf Schlitt. She was a Type VIIC, the workhorse of the U-boat force. The boat carried a new, special piece of technology: a high-pressure toilet.

Toilet systems were different on Allied and German subs. Allied toilets emptied into internal septic tanks, while German designs saved on space and mass by flushing toilets directly into the sea. The latter method, however, had a significant drawback: it didn’t work underwater, since the increased external water pressure would “push back” and flood the toilet. During extended periods of submersion, the crew had to use buckets, which could only be emptied once the boat surfaced.
 
Eventually, German engineers came up with a special high-pressure flush system that emptied the toilet’s contents into a small airlock that ejected it into the sea with a burst of compressed air, much like a torpedo. The downside of this system was complexity: a number of valves had to be opened and closed in an exact sequence to prevent seawater from rushing back in. So complicated was the system that each crew had to have a few “flushing specialists.”

On April 14, off the coast of Scotland, someone mishandled the flushing valves on U-1206, causing sewage and seawater to flood out of the toilet. Some sources suggest it might have been Captain Schlitt himself; others that it was an engineer trying to fix the captain’s incorrect flushing attempt. Regardless of the perpetrator’s identity, the inrush of water flowed down into the compartment directly below the toilet – which happened to contain the massive batteries powering the electric engines when submerged. The chemical reaction between seawater and battery acid started creating deadly chlorine gas.
 
The ship surfaced to vent the gas out, and, since they were within sight of the coast of Scotland, was soon spotted and attacked by British airplanes. Unable to dive due to damage from the air attack, Captain Schliff evacuated his 50-man crew into lifeboats, then scuttled the ship. 4 crewmembers died during the accident: one in the attack and three drowned in the attempt to make it to shore. All others were either picked up by rescue ships or captured after making it to land.