A Swiss partner, specializing in customized metal constructions, engineered a complex crane set-up for a railway maintenance centre. The workplace will be used to maintain locomotives and other rolling stock. It comprises three overhead cranes on three different parallel tracks, and two gantry cranes on a single track perpendicular to the overhead cranes – a set-up that requires intelligent anti-collision protection combining absolute safety with maximum room for manoeuvre.
In close collaboration with the client, a zoning plan was designed that takes all potential dangers into account without restricting more than is necessary. At the heart of the plan are three cross zones which are shared by overhead cranes and gantry cranes. If a cross zone is occupied, another crane approaching it will come to a forced stop. There is also a transitional zone before the cross zone where the overhead cranes have to slow down. The gantry cranes have a similar transitional zone but are forced to slow down only under the condition the cross zone ahead is occupied.
The cranes are all equipped with multi-level limit switches to monitor their position. Each overhead crane has one i-C4C control unit, while each gantry crane has two i-C4Cs, connected to each other through CAN bus. Each crane’s control unit communicates to a central stationary i-C4C control unit. This master unit aggregates the position data from all cranes and sends back zone clearances or restrictions to the individual crane controls. A one-to-many Bluetooth communication system assures the connection between the central unit and the various crane control units.