Prototype jet boat restored

Press, 9 October 1987, Page 40

Prototype jet boat restored

More than 30 years ago an out-of-work engineer, George Davison, approached C. W. F. Hamilton's for a job and was sent to Irishman Creek station in the Mackenzie Country to help Bill Hamilton (later Sir William) design a jet unit for small boats. Today Mr Davison is a jet propulsion systems specialist with C. W. F. Hamiltons and he is restoring one of the first boats to be fitted with his jet unit design. About two years ago, a boyfriend of Mr Davison’s daughter mentioned that he had seen an old jet boat in a wrecker’s yard south of Oamaru. When Mr Davison saw the boat he recognised it and bought it He has spent the last two years restoring it. The only thing not

original about the boat is an electric bilge pump which has replaced an old hand pump. Mr Davison has spent about double (in today’s money) the £5OO ($1000) it cost to build the boat The hull was first built by a New Brighton boat builder, and was made out of Oregon plywood with hardwood planking. It cost £lOO ($200). A later owner added a fibreglass skin and a metal keel to the hull. A 1957 Ford Prefect 1200 cu cm engine with a supercharger was fitted to the hull providing about 35 to 40 h.p. It cost about £lOO ($200) for the engine. When Mr Davison was sent to Irishman Creek to work with Sir William, the two started designing a jet unit more efficient than a

centrifugal-type unit already designed. Mr Davison toyed with several ideas and came up with a more efficient and simple axial flow unit The unit was mounted on Sir William’s boat, powered by a 1938 Vauxhall 10 engine, for a season before several others were made and the unit transferred from Sir William’s boat into Mr Davison’s. > It is the earliest surviving prototype of the “Chinook” jet units that established the Hamilton jet in the late 19505. It was the first wholly successful jet unit in the world, and was built from scraps, the intake casting from the foundry, a piece of steam pipe used as the impeller housing, and the blades hand-made, with

the nozzle and sliding gate reverse made from small scraps. ’.a-,'--': When fully assembled and installed, the 1958 jet unit looks similar to some of today’s high performance units, and in essence the design has not changed in 30 years. The boat was completed in 1957, and Mr Davison began a long period of exploratory work in the boat Because of its ability to float on water only inches deep, Mr Davison’s unnamed boat was the first to negotiate many Otago and Canterbury rivers. Probably the most memorable incident was jetting down the Clutha River’s Cromwell rapids. Mr Davison’s boat, capable of reaching 50km/h, is a far cry from some of today’s 150km/h jet boats.

Mr Davison > not sure why. hes bought the boat but thinks “nostalgia” might have something to do with It Now that it Is working—the motor restarted about a week ago — Mr Davison is keen to try it on the Waimakariri River but thinks his swim* ming pool would be a better place to see if everything works. , 4 He is not sure what he wants to do with the restored jet boat but thinks he will keep it It will be displayed with many other jet boats at the King Edwards Barracks on October 17 and 18 to celebrate the twenty-fifth anniversary of the New Zealand Jet Boat Association and the beginning of the New Zealand jet boat marathon, running that week.