DERRICK CRANE

This heavy duty crane facilitates the handling of marble blocks at the quarry. It’s Rational Structure i.e. Boom, Central Mast and Rafters are made out of heavy duty structural steel frame work, duly stress relieved. The base of Central Mast is fixed to the hoist unit, which in turn rotates on specially designed thrust bearing, anchored to the Central Foot by means of bolts, grouted in concrete foundation or rock. The Hoist unit comprises of special crane duty motor, connected to variable speed reducers and helical gear box, duly coupled to a grooved steel drum. Hydro-thruster brakes are used to control the smooth lifting of weight. The hoist unit rotates on specially designed thrust bearing by means of multiple step down gears, built into the Hoist Foot. The hook block is equipped with a forged steel forked revolving hook. Wire rope is of 6 x 37 construction. Electric operations are controlled with push button control unit, independent from the position of hoist unit. Limit switches for rotation, boom lowering and lifting & load lowering and lifting are provided to ensure accident free operations.

Technical Details:

  • The Jib, Column and Tie Members are made of welded M. S. Angles.
  • The Tie Members and Pulley Blocks for the Jib are connected by a special hinge arrangement made on top of the Column.
  • The Platform of the Winch rotates on Special Thrust Bearing.
  • The Winch unit consists of Electric Motors driving a Variable Speed Gearbox that in turn drives a Helical Gearbox manufactured by a reputed company.
  • There are different Motors for different movements like:
  • 1. Lifting and Lowering of the Hook.
  • 2. Lifting and Lowering of the Jib.
  • Hydraulic Thruster Brakes are provided for both the Hook and the Jib movements.
  • Rotation of Derrick Crane takes place with the help of a Reduction Gearbox and a Chain of Gears
  • The pulleys are mounted with special heavy duty Bearings.