In an R&D project contracted to Shun Tak Ferries in Hong Kong, Unistel Technologies PTY Ltd of the University of Stellenbosch organised a Hysuwac foil system that was designed by FASTcc for a 45m Tricat ferry with 212t.
Built by FBM Marine Ltd, propelled by twin Taurus 60M Gas turbines driven by KaMeWa Waterjets 90S 11 (900mm internal diameter), which were allowed a maximum power output of only 3600 kW each (for extended maintenance cycles!).
Model tests in the towing tank at the University of Stellenbosch, RSA indicated that the 41 knot ferry should reach top speeds of over 50 knots due to the foil system with about 20% fuel consumption improvement.
A prototype foil system was built by Gascon Pty Ltd in Cape Town and delivered to the foil installer in Hong Kong, Wan Tak. Sea trials were run Oct/Nov. 2006 in Hong Kong.
The foil system seemed to work well and as predicted but at 46 knots the waterjets showed strong torque fluctuations which are believed to be caused by some air entrainment into the waterjets.
Further high speed tests were prohibited and the trials interrupted for further research into the causes of the aeration by detailed model tests.
The foil system was dismantled to allow the ferry to continue commercial operation. See the Tricat with Hysuwac foil system at about 42 knots for which fuel consumption was about 12% down in the attached photo.
The accompanying photo shows the forward foil system which spans 10,5m.