Dockwise Successfully Delivers Shenzi TLP Hull

At the end of year 2007 Samsung Heavy Industries delivered the Shenzi TLP hull to BHP Billiton, which will support the completed Shenzi facility in the Gulf of Mexico. The hull was transported by the heavy transport vessel Mighty Servant 1 from the building yard in Geoje (South Korea) via Cape of Good Hope (South Africa) to Kiewit Offshore Services at Ingleside, Texas (USA).

The Shenzi TLP hull has a dry transport weight of 11,200 tons, a height of 70 meters, a span of 85 meters (111 meters diagonally) and a floating draft of approximately 8 meters.

Special in the contract was that Dockwise engineers managed to find a way to load the unit through skidding and reposition the cargo onto wooden cribbing without offloading the cargo first, saving on time and handling for the unit.

Loading the hull onto the vessel was done by skidding, but for the sea passage from Korea to USA it had to sit on cribbing wood instead of skid beams. After the skidding it was therefore relocated from the skid beams onto a cribbing arrangement.

On December 14, 2007 the Mighty Servant 1 arrived in Geoje and deck preparations commenced. On December 29, 2007 the Shenzi TLP hull was skidded from Samsung's building quay onto a skidding arrangement on the aft deck of the Mighty Servant 1.

After the skidding had been finished and temporary seafastenings installed, the vessel was shifted to an anchorage outside Geoje harbor, with an average water depth of 25 meters.

On January 3, 2008 the Mighty Servant 1 submerged to a draft of approximately 21 meters forward and 23 meters aft, allowing the Shenzi TLP hull to float-on. In order to have sufficient stability with the deck submerged, the Mighty Servant 1 had to make use of the buoyancy of the Shenzi TLP hull. This is often the case, but because of the shape of the hull (large deadrise / rake), the vessel had to take on a considerable trim by the stern and some degrees heel first, which made it a rather precise operation. After the floating Shenzi TLP hull had been pulled forward and positioned over the cribbing by tugger lines, the Mighty Servant 1 emerged again, until the sailing draft of approximately 8 meter was reached and the Shenzi TLP hull was sitting on the cribbing arrangement that had been installed in front of the skidding arrangement. On January 4, after installing temporary seafastenings, the Mighty Servant 1 was shifted to the Samsung quayside, where remaining sea fastenings were installed and skidding arrangement removed. On January 6th the Mighty Servant 1 set off for the voyage to Ingleside, USA.

Sybren de Jong, Senior Project Superintendent says: "This project was sensational and we believed this saved our client time and money. Dockwise's scope of work included the tug boat arrangement during re-positioning the hull at the loading location and during the float-off for delivering the hull quayside at the discharge location."