NOV TDS-11SH top drive

The TDS-11SH is a 500-ton top drive in the same portable family as the TDS-11SA, with more continuous torque. NOV publishes 54,600 ft-lb. That extra torque is what you are buying. The hoisting rating does not go up.

It fits the same class of land derrick as a TDS-11SA, with a bit more weight and height: about 28,000 pounds and 19 feet of working height. Drill pipe range is 3½ to 6⅝ inches, through a PH-75 pipe handler. If the mast and the links were sized for 500 tons, the SH does not require a bigger mast. It does require the electrical system to feed the motors that are actually on it.

Against an SA, the SH is the higher-torque 500-ton drive: 54,600 ft-lb versus 37,100. Against an HD, it is the one with slightly less published continuous torque. The HD is rated 58,800 ft-lb from two 600 horsepower induction motors. Motor horsepower on the SH itself is inconsistent across NOV documents: the brochure says two 550 horsepower permanent-magnet motors, and the current product table says two 600 horsepower. The nameplate settles it.

Do not buy an SH from the model painted on the guard. Read the motor nameplates and ask for the torque curve that belongs to that serial number. Confirm the PH-75, the 15,000 psi IBOP, and that the rig’s VFD can run those motors.