Cranes are intended to be set-up on firm, level ground. The rules change when cranes are placed on a ship or barge. Cranes mounted on unstabilized, non-jacked ships can create a major problem.
As a barge mounted crane lifts a load, the barge will push down into the water creating list or trim, causing the crane to become unlevel. Special load charts are available that compensate for up to 5°. Additional ballasts or counterweight are required to level the barge so as not to exceed the 5° allowance.
While the heavy lift vessel, BBC Coral, was commissioning her cranes, something went wrong. The two cranes mounted on the deck were being load tested by lifting a ballast pontoon. The pontoon dropped, half on the deck and half on the dock, ripping one crane from its pedestal.
Learn more about the importance of proper load testing procedures in our Mobile Crane Inspector program.