operation rules of wire rope grabs

Wire rope grab operation:
the grab is controlled by wire rope without the engine driven. The opening and closing are finished by pulleys driving down beam.
There are pulleys in the up and down beam. The closing wire ropes round. Closed rope and wire rope connected to a crane, hoist with the lifting of the rope, led by through girder, the grab completion of closure and open.

Notes
1)  In order to avoid damage to the grab, grab does not allow high-speed impact collisions or material lifting equipment, walls, floors, car and other objects.
2) In order to achieve the greatest amount of crawling, should grab the level of operatin location.