Patent ID: 7083004

Claim:
A drilling rig capable of being used offshore comprising: a. a cantilever, which is mounted for offshore use so as to be moveable in a first direction and a second direction with the cantilever projecting outside the drilling rig; b. a multi purpose tower is fixedly attached to the cantilever, wherein the multi purpose tower comprises a mast disposed on a top side of the multi purpose tower provided with cable blocks fixedly connected to the mast and a gripper provided on a bottom side of the multi purpose tower, a trolley movably fixed on the mast, a hoist, a hoisting cable attached to the hoist and a winch, the hoisting cable being guided over the cable blocks, and wherein the trolley is moveable relative to the mast with the aid of the hoist; and c. at least two friction reducing devices attached to a supporting cart, which are slidable with the supporting cart relative to the drilling rig and relative to the cantilever.