Category: Cranes: Seismic Issues

Published in Port Technology International, Fifty Seventh Edition, March 2013
This article presents several seismic retrofit options for existing quay cranes.

This article focuses on seismic design considerations for new cranes.

Container cranes have evolved to serve ever increasing ship sizes. Today’s typical container cranes are about triple the size of the first cranes, much heavier, and more vulnerable to damage from seismic events.

Today’s typical container cranes are about triple the size of the first cranes, much heavier, and more vulnerable to damage from seismic events.

Our studies indicate that many jumbo cranes will be extensively damaged in moderate earthquakes, and many jumbo cranes will be severely damaged, or collapse, in the contingency level design earthquake.

Video of linear elastic response of cement unloader on typical West Coast wharf subjected to ground motions transverse to wharf from Port of Los Angeles design earthquake with 475 year mean return interval. Analysis based on no damage to unloader structure.

The vulnerability of jumbo cranes to serious seismic damage is much greater than that of smaller cranes. This report presents the issues surrounding current design criteria and Liftech’s suggested criteria.

Container cranes have evolved to serve ever increasing ship sizes. Today’s typical container cranes are about triple the size of the first cranes, much heavier, and more vulnerable to damage from seismic events. The seismic vulnerability of these large cranes was only recently recognized as a result of detailed time history analysis.