Incredible - 6 out of 18 K-Class submarines lost through 'accidents'.
The K Class submarines earned the unfortunate nickname “Kalamity-class” within the Royal Navy during the first world war. This was largely because, of the 18 built, none were lost in action but six were sunk in accidents.
These were steam-powered submarines with a huge boiler-room which made them almost unbearably hot. Because of the complicated system of ballasts and chambers needed for diving and surfacing, they often failed on their own – without any help from the enemy.
Because of their extreme length , and the large area of the fordeck they were apt when diving to go out of control.
Quite a few times was the spectacle of a K boat stern poking skywards, with the bows stuck in the mud.
The supposed quip was, " I say No 1, my ends diving ,what's your end doing"