WALLINGFORD, UK – HR Wallingford has assisted Shell with the recent tow of the 488-m (1,601-ft) long PreludeFLNG vessel from South Korea to its final destination, 475 km (295 mi) offshore Western Australia in the East Browse basin.
The contractor, using its Australia Ship Simulation Centre in Fremantle, created what it claims was an accurate and detailed navigation simulation of the vessel to prepare the towing crews of the tugs for likely maneuvers at sea.
HR Wallingford’s involvement extended to real-time navigation simulation for the facility’sdeparture from the Geoje shipyard along the Busan Channel; positioning and mooring Prelude once on site; and conducting berthing and departure simulations of the LNG, LPG and condensate offtake tankers that will moor alongside the FLNG.
It also created for Shell Australia a web-based, decision support tool to assist with operations planning.
Dr. Mark McBride, HR Wallingford’s Ships Group Manager, said: “There was a need to assess many aspects of this unique offshore floating facility, which included the maneuvering issues associated with the arrival and departure of the offtake LNG carriers.
“For this we used real-time navigation simulation, so that we could identify the limiting conditions for safe manoeuvring, as well as the tug requirements, and for developing appropriate manoeuvring strategies.”
Up to six integrated simulators at the Australia Ship Simulation Centre were applied to simulate the FLNG vessel and the tugs for the shipyard departure operation, and for the positioning during connection of thePrelude’s mooring lines at the installation site.
The program included recording and modeling of actual wind, wave and tidal conditions were recorded to allow the crews to accurately test the capability and power of the tugs in advance.
The simulated positioning operation helped prepare for the real-life operation in which the tugs were attached to the FLNG facility by 700-m (2,296-ft) long wires, weighing around 30 metric tons (33 tons) each.