The battering ram was a close-range siege weapon designed to knock down obstacles. They were usually made out of ash, fir or oak. Variations of battering rams were thought of to be used by the Chinese, the Romans, and the Greek. The size of each battering ram depended on the material at hand and the target needed to be destroyed and ranged from 20 to 120 ft. The Bore was a variation of the battering ram. The metal head of the ram was designed like a drill and could be used in more limited space. The metal head 'bored' at the wall until it crumbled, allowing men to enter. Another variation of the battering ram was the Penthouse. A timber roof/shed was built around the battering ram to protect the soldiers from arrows. It is derived from the French word 'pente' which means 'slope'. The battering ram or Bore was suspended from the penthouse roof with chains or rope, which allowed the battering ram to swing and hit its target with greater force.