DEME gives go-ahead for installation vessel with 4000-tonne crane

Together with its Taiwanese partner CSBC, Belgian offshore contractor DEME has decided to build another installation vessel with a huge crane and dynamic positioning (DP). The Green Jade is being built by CSBC in Kaohsiung and should be ready in two years time.

The ship will be over 200 metres long and will have a crane with a lifting capacity of 4000 tonnes. It is the first floating DP3 heavy lift and installation vessel to be built in Taiwan. According to the Belgian contractor, the Green Jade offers an ‘an exceptional combination of high transport and load capacity, impressive lifting heights and green technology.’

Such characteristics are also attributed to the comparable Orion, also from DEME, which suffered an accident during the ultimate load test in Rostock, Germany, a few months ago. The crane hook broke at a load of several thousand tonnes, causing the crane to collapse. It is still unclear how long it will take to repair the tens of millions of major damage.

Dynamic positioning instead of jack-up

The similarity between the two ships is that they both work with DP and are not jacked up, as is usual when installing wind turbines at sea. The difference is that the Green Jade is designed to install foundations for wind turbines and that the Orion also has to install the hundreds of tonnes of heavy generator houses (nacelles) from water level at altitudes far above one hundred meters.

DEME is the only one so far to have opted for the floating installation concept, in which the ship is held in place by an advanced DP system. Because even a small movement of the ship can lead to a considerable sway of the enormous crane arm, extreme demands are placed on the accuracy and reliability of this DP system.

The Belgian company set up the CDWE joint venture with the CSBC shipbuilding group in Taiwan two years ago. It now acts as the client for the project and has won two contracts for installation work at the Hai Long Offshore Wind Project and at Zhong Neng for Zhong Neng Wind Power Corporation Preparatory Office.

With the Green Jade, the joint venture seeks to meet ‘the trend towards larger capacity turbines and bigger wind farm projects, which deliver energy at lower costs,’ says Robert Tseng, CDWE Chairman. ‘Green Jade will be capable of installing mega monopiles and jacket structures at greater water depths. With DP3 technology, this special offshore installation vessel can continue operations under the most challenging conditions.’

Author: Mariska Buitendijk

Mariska Buitendijk is one of SWZ|Maritime's journalists as well as the magazine's copy editor.