Derrick Cranes

The structure consists of central mast , jib and tie beams (rafters) formed by angles in a lattice structure. The top of mast consists of a vertically rotating journal and tie for connecting the rafters the bottom of mast consists of winch unit on a trolley which is fixed through a vertically rotating journal with a thrust bearing resting on central base which is anchored to the ground through a set of foundation botts. The winch unit consists of two sets of drives for lowering and moving up the jib and moving the load. The winch's load lifting and jib moving function are independent and can be operated simultaneously with electrohydraulic thrustor brakes for braking function.
The rotation is in corporated through a pinion driven by gearbox and motor and supported on bearings. The movement is achieved through a set of pulleys and a double J forged hook for load lifting.
The cranes are built of high quality steel structure to achieve good performance over a long period.