Semi-automatic spreaders are fixed to the hooks of gantry crane, plant crane or portal cranes. Twist lock control is carried out mechanically by means of control pulling the wire rope.
Hooking/unhooking is carried out without help of crane workers. Simplicity and convenience of spreader installation allow converting from hook crane into container crane in a short time. There is no necessity to arrange power supply for the spreader and to update the crane control circuit.