Articulated Balance Crane Design

Liftech conceptualized and designed the Articulated Balance Crane (ABC) concept, a design that reduces the weight and wheel loads of ship-to-shore (STS) cranes.

Operationally, the ABC functions similar to a conventional STS crane. For stowage, the elongated boom and apex rotate as a unit about hinges near the top of the waterside legs, providing vessel clearance, while the machinery house and shortened trolley girder lower while remaining horizontal. Compared to conventional STS cranes, the stowed ABC has a lower center of gravity and reduced overturning moment due to wind loads. The boom is supported by closely spaced bridge strands, instead of traditional forestay linkages, resulting in less boom weight. Locating the girder-to-boom hinge near the landside leg reduces the trolley cycles over the hinge and reduces rail maintenance.

The ABC concept design is for a rope-towed trolley and is based on analyses of the primary structure, including a second order analysis of the behavior of the stays with the boom in the raised position for storm wind. The ABC analysis methodology and design criteria are similar to those Liftech has used for hundreds of STS cranes operating worldwide.