This article was originally published with the title “ New Improvement on the Hydraulic Ram ” in Scientific American Magazine Vol. 8 No. 18 (January 1853), p. 139 doi:10.1038 ...

Patented by Richard Dudgeon in 1851, hydraulic jacks consist of six main components; ... a main cylinder and a ram piston. They are widely employed in the automotive, trucking, oilfield, ...

In this diagram of a blowout preventer, the hydraulic rams are the horizontal, piston-like protrusions. The rams are designed to cut and seal the pipe in an emergency, shutting off the flow of oil.