Simulations for the Boskalis Aasta Hansteen float-over operation


Last December Boskalis successfully completed an impressive dual vessel float-over of the Aasta Hansteen topside, following extensive training at MARIN’s simulator facilities in Wageningen.

Built in Korea, the topside was transported to Norway on the heavy lift vessel White Marlin and transferred to two semi-submersible, S-Class vessels at the Westcon Yards, creating a sort of catamaran. The catamaran was then towed by four tugs towards the spar, which was already anchored in the Stord fjord. The catamaran was kept in position for 24 hours using the four tugs, while the spar was deballasted until the topside was lifted from the S-Class vessels by the spar.

Large parts of the operation were simulated beforehand during several training weeks at MARIN. These simulations included:
• Arrival of the S-Class vessels and White Marlin with the topside at Westcon Yards
• Tow out of the White Marlin (starting between the two S-Class vessels with the topside)
• Towing the catamaran with the four tugs from the yard to the spar
• Approach towards the spar and positioning of the catamaran (with topside) above the spar using the tugs
• S-Class vessels leaving the site

Four tug masters, the tow masters, superintendents, winch operators and local Norwegian pilots all attended the training simulations. To facilitate the exercise four tug master bridges, the bridge of the White Marlin and a room representing the control room (container on the deck of one of the
S-Class vessels) replicating the work position of the tow master and superintendent, worked together in one simulation.

This project highlights how training simulations can assist to ensure the success of highly complex operations. For more information contact Ron Schoon.














September 21, 2018
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