Hybrid promises high speed with low power

A design combining a catamaran with a surface effect ship is creating interest in the fast ferry industry.

A patented concept of a cross between a catamaran and a surface effect ship (SES) is currently being evaluated in a test vessel and if successful will lead on to larger fast ferries and other high speed vessels. The attractions are claimed to be high speeds on low powers through the low resistance hullform, a pleasant ride free from the “cobblestone effect” usually associated with SES, good seakeeping and low wash. These results would be achieved without using flexible seals to define the air cushion.

Behind these claims lie several years of study and experiment, both at model scale and full size, by Howard Harley in Florida, USA. This led in 1996 to the granting of a US patent, and from that to a 17m (55ft) test boat which is now undergoing extensive sea trials.

A Norwegian company, SES Europe AS, of Sandefjord, has taken up the rights for Europe, Asia and Australia and is to have a 23m fast ferry built as the first commercial example, subject to the trials results coming up to expectations, with delivery scheduled for late 1999. The intention is to use this 99-passenger vessel partly as a demonstrator and partly on a fast ferry route in Europe.