Stromag Series 51 Limit Switches for Drilling Platform Pedestal Cranes
A leading global crane OEM needed high quality limit switches for use on its line of heavy lift offshore cranes with lifting capacities up to 2000 tons. The specialized cranes are mounted on a kingpost that supports the crane’s rotating upper structure. The kingpost is mounted to a fixed pedestal substructure for additional stability and support. Each crane features a primary (main) hoist and auxiliary hoists with lower lifting capacities than the main hoist.
Limit switches are installed on each of the crane’s hoists as safety devices that set the precise travel range of the hoist. The switches ensure the safe stopping of the cranes cable (rope) preventing potential load and rig damage. The upper limit of hoist travel is set using a hook-operated limit switch. A limit switch mounted to the cable drum sets the hoist’s lower limit of travel.
After considering various sources, the OEM selected Stromag Series 51 limit switches based on the unit’s high quality and competitive cost. Stromag engineers collaborated with the OEMs engineering team by visiting their facility and providing technical application support.
Series 51 geared cam limit switches are universal, mechanical switchgear that can map a wide range of shaft rotations to the angular displacements of the installed cam discs. They are often used where angles or distances cannot be limited directly by switchgear, but only indirectly on the basis of the measured angle of rotation such as limiting the hook lift of a crane hoist. Units are easy to install and adjust.