Volvo: 'changing boating forever'

These were the words that greeted the world's boating press at the launch of Volvo Penta's Inboard Performance System (IPS) at Mallorca in September.

The demonstration prior to the presentation showed two Cranchi 41s going head to head on acceleration. The IPS powered boat powered away.

The two boats went for a fly past to let the journos hear the boats. The conventionally powered boat rumbled past.

The IPS boat whispered past.

Sea trials emphasised the differences between the two boats. The conventional shaft driven boat dug its hole in the ocean and roared along.

The first thing that hit those on board the IPS boat was the silence. The boat simply got up and went. No fuss. No noise.

No exhaust smells whipped back into the boat.

And when the boats were thrown around, it was obvious the IPS boat was far more manoeuvrable.

All in all, the assembled journos - usually the most sceptical people on the planet - were thoroughly impressed with Volvo Penta's IPS.

So what is IPS? Simple. They took the Duoprop and turned it around so the props face forward. Each unit turns to give the instant steering response we noted. The exhaust runs down the unit and exits through the propeller boss straight into the wake, cutting noise.

VP says the efficiency of the units means the IPS 400 with 310hp at the crank corresponds to a conventional inboard output of around 400hp. The IPS 500 offers 370hp at the crank, the equivalent, says VP, of around 500hp from a conventional unit. VP says it's pitching IPS at the same price of a twin 500hp shaft drive installation.

Tests run on the two Cranchi 41s - measured by GPS - showed 31kts from the shaft version and 37kts from the IPS 500. On acceleration, the shaft boat took 15.2 second to 25kts against the IPS' 13.3 seconds.

Electronic measurement of fuel flow while cruising at 30kts showed 95 litres/hour from the IPS 500 against 135 litres/hour from the shaft driven boat.

5 years, 2 months and SEK2bn According to Lennart Arvidsson, technical project leader on IPS, it took VP five years and two months to develop the system. And the quoted cost was SEK2bn.

"Conventional inboard installations were beginning to seem like a dead-end, " said Arvidsson.

"It simply was not possible to squeeze much more out of the technology." So VP gave its designers a free rein.

"Forward-facing propellers are in fact entirely logical, " Arvidsson said. "They can function in undisturbed water and thus achieve maximum efficiency. The propeller backwash is absolutely parallel with the bottom of the boat, so that all the power developed drives the boat forward."

The same principle of pulling propellers is used for aircraft, he noted.

The IPS system is designed for twin installation. The entire system - from steering wheel to propulsion units - is electronically controlled and integrated with VP's EVC electronic platform. Each propulsion unit is linked to a steering gear powered by an electric motor.

The system actually takes into account how the water flows along the bottom of the boat at different speeds.

Lifted into place Each IPS unit is mounted in a hole in the after section of the hull and each propulsion unit is lifted into place from beneath the hull, together with two heavy-duty rubber rings for sealing and vibration damping.

The propulsion unit also functions as exhaust pipe, noise damper and cooling-water intake, so boatbuilders do not need to create any extra hull lead-throughs. This simplifies and speeds up installation and increases reliability.

The engines used in the IPS are basically the Volvo Penta D6, adapted to the requirements of the system. Both engines are turbocharged and aftercooled and the IPS 500 also has a mechanical compressor to generate maximum torque directly from low rpm.

VP says exhaust emissions are extremely low and will meet the overall emission requirements planned to be introduced in the EU and the US in 20062007, as well as enhancing onboard comfort in combination with the IPS system's efficient handling of combustion gases.

Minimise grounding damage IPS is designed to minimise the damage caused by running aground. Watching the video of VP's test is quite alarming - everyone winced as the boat came to a crunching full stop.

The propulsion unit is built to withstand low-speed groundings, but if the boat runs aground or strikes an object in the water at planing speed, the propulsion unit will break loose, minimising damage and reducing the risk of leakage.

The entire propulsion unit can then be replaced.

Each propulsion unit is tested exhaustively and test-run fully assembled. The key test data for each individual unit are stored for future use.

The first boat incorporating the IPS prototype was launched in 1998. Since then, IPS units at various stages of development have undergone many thousands of hours of testing in Europe and the US, but principally at Volvo Penta's own marine testing centre at Krossholmen near Gothenburg.

Volvo Penta has chosen to launch IPS at the Schroders London Boat Show with VP's UK marine engines sales director, Ian Benning, performing the duties. VP says at least 15 different boat models equipped with IPS will be on sale at next spring's boat shows - certainly Sealine and Fairline had IPS-equipped boats out in Mallorca, so ought to be showing them - along with Princess - at ExCeL.

Rodman and Astondoa in Spain, Cranchi, Innovazioni e Progetti and Airon Marine in Italy, Beneteau in France and Tiara in the US are just a few of the other boatbuilders which will be launching IPS boats in the new year.

"The IPS system takes up considerably less space than a conventional straight shaft installation and is simple to install, " said Volvo Penta's head of European operations, Goran Gummeson. "The boatbuilders are delighted to be able to offer their customers boats with a propulsion system that has superior characteristics in all respects."