RTGs and top pick container handlers safely rolled onto the barge

Project Summary

In June 2005, two ZPMC 40 LT rubber tire gantry (RTG) cranes and two Kalmar top pick container handlers were transported by the cargo barge EM 1105 from Long Beach, CA, to Tacoma, WA. For the relocation of this container terminal equipment, Argonautics Marine Engineering was hired to provide the full naval architectural scope, including the structural analysis of the cargo. Because of the very short lead time, the project was fast tracked and the seafastening arrangement design was based on readily available materials. The shop drawings and supporting engineering documents were delivered on schedule and within budget.

Mid June, the units were safely rolled onto the small cargo barge at high water. After installation of the seafastenings, the barge was towed to Tacoma and the RTGs and top pick container handlers were successfully delivered to their new terminal.     

Scope of Work

The project scope included:

• Verify suitability selected cargo barge;

• Model barge and calculate initial and large angle stability;

• Determine design environmental criteria for the tow;

• Calculate resulting barge motions and cargo accelerations;

• Design seafastening arrangements for the RTGs and forklifts;

• Provide shop drawings for the pre-fabrication of the seabracings;

• Structural analysis RTGs subject to the design accelerations, using FE;

• Loading and offloading calculations.

Acknowledgement

Photograph courtesy of Rigging International.