Tuesday, October 18, 2011

Powerboat Circumnavigation Challenge


Fiat Engine, Castoldi Waterjet for Powerboat Circumnavigation Challenge

By George Backwell at October 15, 2011 08:19
Filed Under: General
The goal of veteran adventurer Alan Priddy as he sets out in his 90 ft (27.4 m) wave-piercing powerboat Good Heart later this year is to try one more time to better the 61-day record for a world circumnavigation set almost a decade ago by the trimaran Earthrace. The record-breaking attempt, comprising five separate legs, will start and finish in Gibraltar, and in accordance with rules set by the Union Internationale Motonautique both the Suez and Panama canals are to be transited en route. How is the boat being constructed and with what propulsion for this epic 24,000 mile race against time?

Construction
Not a traditional boat builder, but  metal-working fabricators, Micklewright Structures, situated at Dudley in the U.K. were chosen to build the uniquely designed powerboat and fashion the aluminium plates of its futuristically shaped hull on to steel structural members: "I particularly wanted their engineering skills and welding capability" explains Priddy.

The ‘dreadnought-style’ bow form is designed to pierce through waves at high speed rather than ride them, so too is the aerodynamically shaped narrow hull form (beware water on deck) where the proportion of Good Heart’s 16 ft (4.9 m) maximum breadth to its 90 ft (27.4 m) length overall speaks for itself; a unique design that Priddy (on his 'Global Circumnavigation Challenge' website) attributes to knowldge gained through his own extensive ocean racing experience.

The Fiat main engines are as fuel-efficient as any, yet fuel tanks for a 5,800 nm maximum range are of necessity huge, with a 30,000 ltr (7925 US gallon) capacity, and there will also be a walk-in engine compartment; accordingly, crew accommodation will be basic.

Good HeartImage credit – Alan Priddy/Global Circumnavigation Challenge
Propulsion

The propulsion setup on which the success of the venture largely depends will consist of a pair of well-proven Fiat PowerTrain type C13 500  6-cylinder in-line marine diesel engines  rated at 500 hp (368 kW) each at 2000 rpm driving twin Castoldi waterjet pumps. These CastoldiJet type 490 HC units have an integrated gear box that allows the centre of thrust to be kept low in the water (helps prevent unwetting in rough weather, improves manoeuvrability) and also saves space in the machinery space. Maximum light displacement speed is expected to be 47.5 kts, while a 27.5 kt average speed is targeted for the record attempt.

Castoldi Type 490 HC Waterjet: Image courtesy of CastoldiJet

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