British company BCB invented The Wall Breaker, a non-explosive, compressed air cannon which fires standard plastic water cooler drums to breach walls, gates and doors for rapid quick entry. It can be fired every 10 to 15 seconds. The water jugs can be filled with water, sand, or other materials.
The firm have already sold the system to security forces and the military in a number of countries including the USA and Thailand. The company says: "Security teams and counter-terrorism officers often use explosives but if you're trying to rescue a hostage, that's pretty dangerous."