Rocks & mirror
Encyclopedia of Marine and Energy Technology



DOCKWISE VANGUARD is a semi-submersible vessel for heavy transport and offshore dry-docking built by Hyundai Heavy Industries in Ulsan for the Dutch shipping company Dockwise. The vessel features a bow-less design developed by Dockwise and Deltamarine. It is provided with a free deck space of 275 x 70m, which extends the entire length of the vessel. The design allows the flow of water along the entire deck, but prevents the entry of water into the enclosures of the vessel. A bulwark is also incorporated into the design to ensure the safety of the crew.

The crew accommodation, including the lifeboats section, is on the starboard side of the vessel. The ship is equipped with buoyancy casings which can be moved to various positions to accommodate different kinds of cargo. Machinery exhausts are located in the accommodation deckhouse.

The ship was classified with a heavy lift vessel notation and categorised as a ‘Type 0’ vessel. The semi-submersible heavy lift ship (see photo above) can be ballasted down to allow the cargo to be floated aboard. The ballast tanks are then de-ballasted to raise the deck over the water surface for lifting its cargo. DOCKWISE VANGUARD can transport large FPSOs, SEMIs, SPARs and TLPs weighing up to 110,000t. The vessel is provided with OCTOPUS-Onboard for the purpose of motion monitoring, response prediction and heavy-weather decision support during heavy cargo transportations.

The DOCKWISE VANGUARD’s technical innovation surfaces a completely new offshore service:

Offshore Dry-docking. With the significant presence of FPSOs in remote areas often lacking support infrastructure, Offshore Dry-docking service becomes increasingly interesting. The Dockwise Vanguard’s FPSO dry-docking service offers inspection, maintenance and repair opportunities (amongst others) at different conditional modes. While dry-docked onboard the vessel’s deck, the FPSO remains connected to its mooring and turret system while keeping the riser systems intact and with the possibility of continuing limited production. Furthermore, the FPSO will still be capable to freely weathervane around the turret mooring.

Wärtsilä’s delivered equipment comprises two 6-cylinder in-line Wärtsilä 38 generating sets (4350kW output), two 12-cylinder Wärtsilä 38 engines in V-configuration (8700kW output) and one 6-cylinder in-line Wärtsilä 20 auxiliary engine (1200kW output). In addition to the engines Wärtsilä supplied the reduction gear system, two controllable-pitch propellers, two retractable thrusters and a bow thruster.

The propulsion system provides a maximum speed of 14 knots. When the vessel is sailing at full speed or in survival mode, all the available power is used. When the vessel is being operated at low speeds, only the smaller engines are needed and the large main gensets can be switched off, reducing the amount of fuel consumed.

Length, oa: 275.0m, Length, bp: 270.0m, Beam, mld: 70.0m, Depth, mld to the main deck: 15.50m, Max Draught: 10.99m, Submerged draught: 31.5m, Water-depth above main deck:16.00m, Deadweight: 117,000dwt, Output: 26,100kW, Speed max/service: 14/12 knots.