What the - a loo in the gallery

When the first submarines were commissioned, they were fitted with the same type of plumbing accessories used on land. World War One saw a large numbers of submarines in action. However, anti-submarine weapons were fairly limited in their range and effectiveness, so it was rare to be subjected to an intense depth-charge attack.

However, during the Second World War, as underwater detection devices became more refined, attacks on submarines became more accurate. In the Royal Navy it was found that the porcelain fittings in submarines would often shatter under depth charging, leaving the crew with no loos or basins, assuming they survived, and a pile of broken porcelain rattling around on the deck. Whilst the former is a serious inconvenience, the latter was potentially disastrous as underwater detection equipment could easily pick up the sounds. Thus, stainless steel fittings were installed in new submarines.

When the Oberon Class submarines were built, they were fitted with equipment such as the artefact on display here. However, history has gone full circle because underwater sound detection equipment has been refined to the point that the sound of a stainless-steel loo being flushed can be heard from a surface ship! So, modern submarines are fitted with porcelain fittings because they absorb any sound. Also, nowadays, anti-submarine weapons are self-guided homing torpedoes and missiles so, you don’t need to worry about broken porcelain because your chance of survival is pretty much nil.

Diagram of Oberon class submarine toilets. From C.F. 'O' Class Submarines - Miscellaneous Systems and Equipment.
Credit: San Francisco Maritime National Park Association