ALE has successfully completed the transport, load-out and jacking-off of a liftboat, weighing 5,800t, at Eversendai Offshore’s fabrication yard in Ras Al Kheimah, UAE.
ALE used 204 axle lines of SPMTs in a configuration of 6 x 2 file 34 to perform the transportation and load-out of a liftboat. After the liftboat had been loaded-out, the liftboat’s legs were lowered onto the seabed. Then, on a falling tide, ALE simultaneously ballasted the barge, allowing the liftboat to be clear from the SPMTs and be self-supporting.
The weight and Centre of Gravity (COG) of the liftboat, combined with the capacity of the barge and the high quayside at site, severely restricted the suitable tides for the operation. The tide had to be closely monitored before ALE could perform the load-out with a -300mm difference between the predicted and actual tides. Only three days per month had a strong enough tide to allow the operation to proceed. ALE executed a night load-out on the last possible tide of the month.
The barge selected had a limited gap of just 140mm between the liftboat legs’ spudcans and the side of the barge. This meant the accuracy of trailer locations was strictly controlled, along with the removal of the barge via a winching operation being operated with extremely tight dimensional control.