NOV 610-E drawworks

The drawworks is the hoist. It reels drill line to raise and lower the traveling block, which is how the rig trips pipe and holds weight on the bit. The 610-E is the smallest machine in NOV’s conventional chain-drive table, rated 750 horsepower. The E means an electric drawworks with band brakes.

This is a hoist for a smaller land rig, not a 1,500 or 2,000 horsepower drilling package. With 8 lines, in low clutch and low transmission, the catalog hook load is 167.5 tons. The same 8-line string in high gear is 42.5 tons. The mast, the drill line, and the traveling equipment have to be rated for whatever load you intend to pull. The drawworks figure is not a mast rating.

An 80-UE is the next step up, at 1,000 horsepower, and it is a unitized package that still uses band brakes. A 110-UDBE is 1,500 horsepower and uses disc brakes. If a listing says only “National drawworks,” the brake type and the horsepower are the two things that change the price and the parts.

Confirm the motors are on the skid and that the band brakes have linings left. Ask about the auxiliary brake, usually a separate eddy-current unit, because it is not part of the E name. Count the lines the rig is reeved for before you quote the 167.5-ton figure as the capacity.