Jumbo widens deck of heavy lift vessel to transport two cranes
Jumbo has transported two Ship-to-Shore container cranes, a cargo in excess of 1500 tonnes, from Taicang, China, to the Port of Immingham on the UK’s east coast. To ship two cranes this size in one go, the Fairpartner’s deck had to be widened by 6.1 metres. The transport also had to pass locks with just 60 centimetres to spare.
It is the first time that two cranes of this size have been transported together on a single heavy lift vessel. The client for this contract was Chinese crane manufacturer Nanhua International. The cranes were delivered to the Associated British Ports-operated Port of Immingham. Jumbo used one of its J-class heavy lift vessels, the Fairpartner, to perform the transport. The two cranes weighed 788 and 810 tonnes apiece, both with heights just under 75 metres above deck.
Deck widened using tweendecks
The footprint of the cranes called for some intuitive engineering skills, as is shown by the loading process. ‘We used the vessel’s own deck-mounted cranes to lift the first container crane onto temporary rails placed in the middle of the deck,’ explains Jumbo’s Senior Project Engineer Otto Savenije. ‘We then moved the container crane forward to its stowage position behind the ship’s accommodation.’
To make this possible, however, Jumbo had to widen the portside of the deck by using the vessel’s own tweendecks as deck extensions. ‘This created the additional 6.1 metres necessary to hold the rails. However, to offset that extra weight on the portside, we had to position a 100-tonne counterweight on the starboard side during lifting operations.’
Compared to this complex process of loading the first container crane, loading the second container crane to its mid-ship stowage position was a comparatively straightforward process.
The Fairpartner made the voyage from China to Immingham in 36 days, staying below air draught restrictions under the Mubarak Peace Bridge on the Suez Canal by lowering the jibs of the container cranes.
Tight fit through Immingham locks
The most technical part of the transport came on arrival at the Port of Immingham. Access to Immingham is gained via a lock that accepts a maximum vessel beam of 26.8 metres. With a more standard cargo, this would be no problem for the Fairpartner. However, the overhanging deck extensions as well as the protruding jibs of the container cranes meant that this would not be a run-of-the-mill lock passage.
Jumbo’s solution was to raise the jibs of the container cranes and to pass the locks at high tide. ‘After changing our ballast configuration to stabilise the effect of raising the jibs, this meant that we could pass the locks safely, without risking collision with things like buildings, bollards or lampposts on the quayside,’ says Otto Savenije. This meant the Fairpartner passed the locks with just 60 centimetres horizontal clearance to the lock wall and 3 metres vertical clearance from the deck extensions to the quayside.
The passage of Jumbo’s Fairpartner through Immingham locks is perhaps best seen in this video: