From this, the terms battering ram and hydraulic ram are derived. The Crow's Nest had a blacksmith's shop operated by a spring running a hydraulic ram. Earlier designs used a pulse of compressed air or a hydraulic ram. The gate is raised or lowered using a hydraulic ram. The steering linkage was driven by a hydraulic ram. An alternative to the hydraulic ram is the water-powered pump. It steers by the use of a hydraulic ram mounted on the point of articulation. Having decided on a hydraulic ram design Leader Williams appointed Edwin Clark as principal designer. They are installed with special hydraulic ram machinery and special dies. Near to the sawmill is a working Victorian hydraulic ram. A hydraulic ram is a water pump powered by hydropower. These balers are made of steel with a hydraulic ram to compress the material loaded. The lift was lowered by a hydraulic ram that was controlled from inside the vehicle. The hydraulic ram may be powered manually, pneumatically, or electrically. A hydraulic ram, or hydram, is a cyclic water pump powered by hydropower.