A sensor system, including signal transmission, is to be developed in collaboration with crane operators, to make it possible to establish accurately the position of the trunnions in the jaws of the hooks, and convey this information to the driver and the crane switchgear. The safety objective is to monitor the proper execution of the hooking-on process when handling molten materials in cranes, and thus eliminate the risks arising from operator error.

This system will be substantially enhance personal safety in work with cranes and the operational safety of the crane.
Sensor systems for monitoring the proper execution of the load lifting sequence have been unknown. In co-operation with the operating authority a sensor system including signal transmission has been developed which is able to detect the position of the trunnion of the ladle bail in the ground of the crane hook opening and to indicate the correct position to the crane driver.

The main topics of this works had been the development of a physical and thermal containment of the marketable sensors at the lamella hooks and of a safe data transmission because of operating conditions which are predominant in the transport of molten materials in iron and steel works. Therefore design, laboratory and operating test for safe installation of the sensors at the lamella hooks had been necessary.

The safety objective behind this development is to monitor the proper execution of the load lifting sequence when handling ladled molten materials with cranes and thus exclude risk resulting from any incorrect operation. The system for reliable detection of load pickup will substantially improve safety for persons as well as the operational safety of the crane.
Ladled molten materials are handled by cranes mounted with crane ladle bail and lamella hooks. For load pickup, the hooks should be positioned in such a way that the trunnion of the ladle bail rest in the hook openings so that the necessary contact is established between load carrier and load for safely raising the load.

The load lifting sequence is manually controlled by the crane driver who will be assisted by ground staff if necessary. The reliability, that means the proper execution of the load lifting sequence, is depending essentially on the attention and qualification of the crane driver and on the prevailing visibility. From that point of view the operating sequence is related with a high risk (potential of danger), as for lack of attention or insufficient visibility it can not be avoided that ladles will be picked up on one side only or will be carried on tip of the crane hook which already has lead to overturns and crashes. In that case injuries to persons, extremely high damages and long term operating breaks are to be expected.