Lift-off for cats

Howard Harley?s Skirtless SES patented technology has had an important breakthrough. The EFFISES (Energy Efficient SAFE Innovative Ships and Vessels) project, which was initiated last year by SES Europe of Norway and partners, has received ?2.15 million ($1.98 million) funding through the EU 5th framework R&D Growth Programme. EFFISES is based on Harley?s design. The concept of the surface effect ship, or SES, has been around for a considerable number of years. Its main problem, like the hovercraft, is the skirt. However, Harley claims his design overcomes this. It is a hybrid between a catamaran and a hovercraft. The hull combines dynamic lift with an air cushion and is claimed to generate lift corresponding to as much as 80-90% of the vessel?s full displacement. The injection of extra funds will enable the consortium to perform in-depth investigations and research to refine and adapt the technology for a wide range of fast vessel applications. SES Europe says the results from the first conceptual model tests at SSPA Sweden, were very encouraging. They demonstrated improvements in high-speed efficiency of at least 30% compared with current state-of-the-art catamarans and monohulls. It believes that a 16m prototype vessel has already proven this claim, as well as other important benefits including low wash/wake. First demonstrator The building of the first European demonstrator, a 17m long by 5.2m wide 60-knot patrol boat, started last August. SES Europe says that comparative preliminary studies between this design, which has an 18.5t operational displacement, and a similar length and displacement monohull patrol boat with a narrower beam of 4.6m, showed remarkable advantages for the new Harley ALC design. It says fuel consumption at 48 knots was reduced by almost 50%. In addition, its says the range doubled and the power required to reach 48 knots was only 55% that of the monohull. Harley points to the twin V-hull and planing surface design. He says this contributes to the dynamic lift effect and enables the hull to quickly to attain planing speed. This then allows the air cushion system to work at peak efficiency. Rigid walls around the hull contain the air and reduce the amount of leakage. This enables the hull to maintain a more efficient air cushion. However, Ulf Tudem, SES Europe?s general manger admitted at FAST 2001 held in Southampton at the beginning of September that the company had not solved all the problems with leakage. Harley says the design is not limited to small vessels – “the bigger and heavier boats are, the more suitable the design is,” he declares. The National Technical University of Athens (NTUA) will test the larger models at its ocean facilities. Further investigations cover vessel operation, accelerations and motions in a sea state, safety, air management/ventilation, environmental effects (pollution, emission and wash/wake etc) and a number of economical analyses. Fast ferry feasibility The company is looking to apply Harley ALC technology to a 40m fast passenger ferry with a service speed of 70 knots. It is also looking at a roro/ropax vessel of about 150m length with a service speed of 50 knots and a 100-plus knot military craft. SES Europe says it is currently negotiating with several European yards for car and passenger ferries in the 70-100m length range with service speeds of 60 to 70 knots. In the US, a 60-knot ferry based on the Harley ACL concept is nearing completion at Royal Crown Yachts? shipyard in Tampa Bay, Florida. Owned and operated by Bradenton-based Fast Cats Ferry Service (FCFS), the 30.7m by 8.6m, 149-passenger PurrSeaverance is being built to US Coast Guard Subchapter “T” requirements. It is powered by four Caterpillar 810kW 3412E diesels driving 2500 Pulse Systems surface-piercing drives through ZF 1:1 transmissions. It will have a draught of 0.6m at speed and a claimed service wake of less than 30cm at operating speed. Two 230kW Caterpillar 3208 lift motors maintain PurrSeaverance?s air cushion. The design features light weight all-composite construction consisting of a Kevlar hull and a carbon fibre superstructure.