Three shipunloaders, transported on behalf of Swiss client Rio Tinto Alesa, required very close coordination between our Operations, Engineering and CAD departments. The unloaders had to be moved from Jebel Ali, U.A.E., to Al Taweelah, U.A.E., Ras Al Khair, Saudi Arabia and Richards Bay, South Africa.
Measuring 54 x 27 x 33 metres and weighing 593 mton, the largest of the three ship unloaders, was modelled by the BigLift CAD specialists using the 3D Eagle design system. This made it possible to simulate the lifting operation in great detail and thoroughly check every step of the process. In this way, it was possible to fine-tune the operation before the actual execution.
In order to lift giant ship unloaders like these, BigLift uses specially designed 24 metre long lifting beams which are placed underneath the unloaders. By the way, the whole rigging to be able to lift the unloader, weighs 93 mton alone!
Since the unloader was too wide to be placed the Happy Rover’s weather deck straight away, a steel structure was designed for this transport to support the unloader during the voyage. With this structure in place on the weather deck, it was even more important to check lifting heights extra carefully for the moment when the ship unloader would move over this structure. This resulted in a clearance of 20 cm. The 3D modelling proved its worth once more in providing a very meticulous, detailed, realistic and therefore very valuable simulation.
After a smooth berthing and clearing of the vessel, the real challenge started. For the installation of a support structure for the cargo, the fly jib of crane 2 had to be rigged up. In the meantime, two 600 mton beams where waiting for us at the quayside and these also needed time to be rigged up with the so called “spacer beam”. While the crew of Happy Rover was busy preparing the vessel, employers of Rio Tinto Alesa worked at getting the cargo in reach of the ship’s cranes using SPMTs.
After a day and a half of preparations, we started lifting on Friday morning. The actual lift only took three hours, thanks to the careful preparations. Then, the crew was busy for two days to lash the cargo to the ship’s deck and assist Rio Tinto Alesa with rigging the boom support as well as loading some more generals. Five days after we moored, we let go of our lines again and started our voyage to Richards Bay where we had to discharge the shipunloader.