Offshore staff
LUXEMBOURG – Jan De Nul Group has installed the four medium-voltage export cables and upgraded the onshore substation for Taiwan Power Co.’s Changhua Phase 1 offshore wind farm project.
The company’s cable-laying vessel Willem de Vlamingh installed the four subsea export cables from the wind farm site, 10 km (6.2 mi) off the coast, to the shore where they were connected at the landfall area near Fangyuan.
For the beach pull-in operations including passing over a shallow water sandbank, the company teamed up with its Taiwanese partner Hung Hua Construction who provided essential marine equipment, including a jackup barge.
Due to the presence of a nearshore oyster farm and an important shipping lane for fishermen on the subsea export cables route, the cables had to be pulled through 1-km (0.6-mi) long underground ducts, which had previously been installed by horizontal directional drilling (HDD) up to 21 m (69 ft) below the seabed.
Jan Kop, Project Director at Jan De Nul Group, said: “Originally, the HDD’s were stipulated in the contract to be 300 m [984 ft] long, but Jan De Nul decided to extend them in order to prevent any damage to the sensitive coastal zone and fish farms.”
After the cable installation, trenching works started. For the nearshore trenching works, the company’s Starfish excavators used an in-house developed plough-skid and jet-skid. For the offshore trenching operations, the Willem de Vlamingh also acted as a trenching support vessel.
Together with its Taiwanese subcontractor Chung-Hsien Chen, the company completed the installation and commissioning of new electrical equipment, including high voltage transformers, high-voltage and medium-voltage switchgear, a new SCADA control room and emergency power supply, inside the onshore substation in Da Cheng. This custom designed upgrade was essential for the substation to be able to receive power generated by the new offshore wind farm, the company said.
After passing a 24-hour energization test, the upgraded substation was successfully connected to the national grid for the first time in this new configuration.
In addition, the offshore foundation installation of 84 pin piles and 21 jackets is making steady progress and the company’s consortium partner Hitachi Ltd. continues preparing the wind turbines in the Taichung marshalling port. The turbine installation campaign, due to start in August, will feature Jan De Nul’s jackup installation vessel Taillevent.
08/03/2020
