Patent ID: 7766577

Claim:
A method for operating a ship lifting mechanism having a platform including a plurality of main transverse beams (“MTBs”), each MTB supported by at least one hoist, comprising: reading a load on each MTB; determining whether the load on any MTB is different from the load on any other MTB by more than a predetermined amount; selecting at least one MTB which has a load different from the load on any other MTB by more than a predetermined amount; determining at least one safety limit by which the selected MTB can be vertically moved with respect to adjacent MTBs; vertically moving the selected MTB with respect to the other MTBs within the safety limit to transfer load between the selected MTB and the other MTBs; monitoring the loads on each MTB and the position of the selected MTB as vertical movement of the selected MTB proceeds; comparing the monitored loads and position with the safety limit; and stopping the movement of the selected MTB when either the desired load transfer is completed or the safety limit has been met.