Abstract: An apparatus for containing pressure associated with a well includes a ram fluid chamber, a ram piston, and an intensifier piston within a housing. The ram piston has ends associated with a ram and with the ram fluid chamber. The intensifier piston has ends associated with the ram fluid chamber and a fluid source. The end of the intensifier piston associated with the fluid source has a larger surface area than the end associated with the ram fluid chamber. Fluid from the fluid source applies a first pressure to the second end of the intensifier piston to move the intensifier piston. Movement of the intensifier piston applies a second pressure greater than the first pressure to fluid in the ram fluid chamber to move the ram piston and associated ram toward a closed position.