Crane Systems | by STAHL CraneSystems | Nov 10, 2015
Mechanical engineering company Kurtz Ersa required a new crane to lift larger and heavier components into a new milling machine. It needed to lift 16 tons and travel on the existing crane runway. The lifting height and restricted clearance above the crane bridge also played a part. Stahl- und Kranbau Oeder, one of STAHL CraneSystems’ partners, developed a customized low-headroom crane with a unique design.
At the beginning of August 2015, Kurtz Ersa commissioned a new traveling column milling machine that operates from 0.017 mm accuracy to 10 m with which larger and heavier components can be processed. However, neither the existing crane nor the crane runway were designed for the required lifting capacity of 16 tons.
Limited clearance between crane runway and ceiling was a consideration, and simultaneously the lower edge of the load hook could not collide with the milling machine’s spindle motor. A specialist for customized cranes, Stahl- und Kranbau Oeder found the optimal solution. “The crucial requirement of the system was the restricted installation situation and the existing crane runway that we could not reinforce,” said Rudolf Lang, an engineer from Stahl- und Kranbau Oeder. Oeder supplied a customized crane with a 943 mm headroom from the upper edge of the wire rope hoist to the lower edge of the hook, that utilizes the lifting height and still operates with the restricted space above the crane runway.
The starting point was a standard crane kit from STAHL CraneSystems with two 8-ton wire rope hoists from the SH series. The solution is based on a number of non-standard crane designs. “We had to devise a special construction for the crane bridge,” Rudolf Lang explained. “On this crane, two SH wire rope hoists with modified trolleys travel on rails mounted inside the bridge girders. Only this feature together with a change in distance between the bogie end carriages made it possible to build such a compact crane.”
The load is distributed onto coupled crane endcarriages with a total of eight wheels so that the maximum load capacity of the crane runway is not exceeded. The weight suspended from the hooks appears on the display of a radio remote control. The crane is also equipped with the safety features necessary for tandem operation. This can be activated via the remote control and enables lifting heavy and long workpieces safely.
Restricted conditions: The existing crane runway and the low ceiling left Stahl- und Kranbau Oeder very little space for the new crane.