Ash can

Ash can: A US Navy term for a Depth Charge, used for attacking enemy submarines. Suggested by its shape. A Depth Charge was a steel cylinder, filled with high explosive and fitted with a simple firing appliance, set off by the pressure of the water and adjustable to explode at any desired depth. Every anti-submarine vessel, destroyers etc., carried a number of depth-charges, dropped over the side at the place where the submarine was believed to be.