Initial view: This is the motor that opens the 760 ton silo door. It is actually a pair of five-cylinder hydraulic motors ganged together to produce about 40 horsepower at 900 RPM. The gear box reduces this speed to produced the enormous torque required to move the door. While the motors are driven by hydraulics, the hydraulic system is pressurized by nitrogen gas. For details, see the text for level 1D.