Propellers That Pull, Not Push
The Age
Saturday April 2, 2005
Volvo Penta's believes its radical new Inboard Performance System (IPS) is a stroke of genius from an engineering department tired of trying to reinvent the wheel. But it could just as easily have been the result of an executive looking out the window of a jumbo.
So what is this IPS system? In short its an underwater drive with a propeller like any other powerboat, however, it faces forward to create pull instead of push - much like the blades of an aeroplane engine. "Forward-facing propellers are in fact entirely logical, it's just that no-one has taken this approach before in our industry," says Arvidsson. As the propellers are perfectly parallel with the boat's running surface, there is no wasted thrust. Compared with the same boat fitted with a shaft drive, which often have shaft angles up to 15 per cent, IPS generated 20 per cent greater top speed, 15 per cent better acceleration and halved noise and vibration levels, claims Volvo. Instead of using rudders, the boat alters course simply by changing the direction of the underwater drive(s) in response to the wheel. From all accounts, this takes some getting used to, but electronics manage the entire IPS system. Volvo has designed IPS so that, should you hit the bricks at a great rate of knots, the leg will supposedly break from its mounting base below the boat, leaving a watertight through-hull opening. Most of the world's major boatbuilders are now developing dedicated production boats in the 10 to 15 - metre range for Volvo Penta's new IPS 400 and IPS 500, which use the company's low-emission D6 310hp and D6 370hp diesel engines respectively. The first local boat sporting IPS will be a 46-foot Mustang Cruiser made in Queensland that's due to hit the water in the next couple of weeks. The final cost of IPS in Australia hasn't been set, but it will be priced comparatively. Graeme Avers, the CEO of Eastern Engine which distributes Volvo Pentad in Australia, says IPS is not designed to replace shaft-driven boats, but will create a niche market. Details: Eastern Engine, PO Box 78, Bulimba, and Queensland, 4171. Phone: (07) 3902 5444, www.volvopenta.com.au Contact the writer at lockwood@intercoast.com.au
© 2005 The Age
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