High Quality Content by WIKIPEDIA articles! High explosive squash head (HESH) is a type of explosive ammunition that is effective against buildings and is also used against tank armour. It was fielded chiefly by the British Army as the main explosive round of its main battle tanks during the Cold War. It was also used by other military forces, particularly those that acquired the early post-World War 2 British 105 mm Centurion tank, including Sweden, India, and Israel. In the United States, it is known as HEP, for "High Explosive, Plastic".