two cannon balls united by a shot sequence, formerly used in naval warfare because of their particular destructive impact on a ship's rigging.
Two balls or halves of a ball connected by a chain, mainly utilized in old naval ordnance to cut-down the masts or spars of vessels or even to destroy the shrouds and rigging. It is really not used in combination with contemporary ordnance. In heraldry it really is represented in several great methods. Also known as chain-ball.