Balance Crane—A New Type of STS Crane in Development

Liftech conceived a new crane concept, the Balance Crane (BC), for unloading containers from large vessels and developed the design in collaboration with crane manufacturer ZPMC, Shanghai, China. The BC has reduced wheel loads and tie-down loads compared to a standard ship-to-shore (STS) container crane but functions similarly. The boom is continuous from the landside legs to the boom tip. The landside girder is connected to the boom with a parallel linkage. To clear the vessel bridge, the boom and upper works rotate as a unit about waterside. The machinery house and shortened trolley girder landside of the landside leg remain horizontal while translating in a downward arc. The end results are a stowed crane with a lower center of gravity and reduced overturning moment due to stowed wind loads. In the operating position, there will be reduced trolley rail hinge maintenance due to fewer trolley cycles crossing the hinge relocated to the landside. The paper discusses selected BC design features and presents analyses and study results.