The Williams-designed Gulfstar 1 floating production system, which Hess will lease from Williams, is in the late stages of construction. The hull is being built at a Gulf Island Fabrication-owned yard in Aransas Pass.

The four-legged, 1500-tonne work deck built by Allison will be installed on top of the spar after upending operations, the company said. The 90-foot-by-120-foot structure includes a heliport, utility piping, electrical receptacles, lighting and a hydraulic pedestal-mounted deck crane.