The cylindrically-shaped platform, to be stationed in 250 m (820 ft) of water, will employ a semi-taut leg mooring system. This will consist of 14 polyester lines in three clusters of four, four, and six lines.
Two clusters will have longer lines, which should provide the lateral restoring force needed to keep the platform on station.
The Gama 98 polyester rope tethers are made from parallel laid sub-rope cores within an outer braided jacket. During manufacture, Lankhorst stressed, all sub-ropes are monitored to ensure equal tension and length, leading to a completely torque-free rope.
Western Isles takes in the Harris and Barra oil fields, 12 km (7.4 mi) west of the TAQA-operated Tern field center. The FPSO will be linked to five production and four water injection wells, with oil offloaded to shuttle tankers.