Bristol Harbor Marine Design (BHMD) introduced their newest design, the Liberty 129TM fast ferry, at the International Workboat Show held in New Orleans in December. From the keel up, Liberty 129TM is an all-American design. It is 129-ft. (39.3-m) in length, has a 36-ft. (11.0-m) beam and includes interior seating for 321 passengers. The catamaran hull can be
powered by either twin or quad diesel powered water jets. It is designed for high-speed commuter ferry runs.
BHMD has wrapped up all but a few minor details for this new design. It is ready for licensing and production. Model tests conducted in October
at the Marine Hydrodynamics Laboratory
at the University of Michigan
(U of M) confirmed vessel design speed in excess of 32 knots. 3-D solid
modeling has optimized the final designs for ease of production. A Tonnage Review was completed by an independent consultant too assure
conformance with the United States Coast Guard
(USCG) Sub-Chapter K 100 Gross Registered Ton (GRT) requirement. The USCG Marine Safety Center
Washington DC, examined the General Arrangements, Fire Boundary, and Safety Evacuation drawings and found them satisfactory, with a few minor
comments, that were incorporated into final designs. The Hull and Deck House structural drawings are being prepared for submittal to the
American Bureau of Shipping
for review and approval of conformance to the structural Rules for Building and Classing High-Speed Craft. Recent
design changes include addition of spray rails and bow loading capability.
The U of M tests were conducted on a 1/16-scale fiberglass model
of the catamaran hull. It was 7.75 ft. in length and 2.25ft in beam. The model
was constructed by Janicki Industries of Sedro-Woolley Washington. The U of M model basin is 360-ft long, 22-ft. wide, and 10 ft. deep. Effective
Horsepower tests were run at four displacements and various trims to determine the greatest hull efficiency. Data were extrapolated using
Froude s Method. Ship wake measurements were also taken to assure minimal environmental impact from wave generation in confined waterways.