Small craft propulsion pod range is extended

Volvo Penta introduced its IPS system in 2005, bringing the podded propulsion concept to small vessels. First installations were available only in recreational craft ratings, but commercial and workboat versions soon followed. Volvo Penta claims that its IPS system is the undisputed market leader in small pod installations; in some markets the company says that the IPS, with forward-facing and efficient propellers, has largely replaced traditional shaft installations.

The first stage of the IPS system was based on Volvo Penta’s 4- and 6-litre diesel engines.In 2009, two new power classes were launched with larger drive units based on Volvo’s 11-litre engines.

For 2010, Volvo Penta is launching a third stage based on the Volvo Group’s 13-litre engines. The two new IPS drive packages generate the equivalent of 1,050 and 1,200 bhp, respectively, compared with conventional inboard installations. This means that Volvo Penta can now offer the IPS system for boats all the way up to 30m.

Volvo Penta says that with the more powerful units, it will focus aggressively on increasing the sales of IPS systems for commercial vessels. According to the company, potential fuel saving are tremendous compared to traditional shaft installations. The environmental benefits, as well as other advantages, mean that interest from shipyards and commercial customers in IPS is increasing strongly. Mats Edenbord, of Volvo Penta corporate communications, told The Motorship: "I think we have only seen the beginning of what IPS could mean for the commercial boat industry."

More powerful drive units Larger engines with higher power output and higher torque make high demands on the drive units. With this in mind, Volvo Penta has developed a larger and more powerful IPS drive unit as well as a completely new series of propellers for the IPS1050 and IPS1200.

This larger drive unit retains the features of the original IPS system. The underwater body and propellers have been developed with the help of advanced computerised models together with extensive cavitation tunnel tests and on-water tests. The result, says the company, is a highly efficient integrated propulsion system.

Cleaner and quieter

Their higher efficiency gives the IPS1050 and IPS1200 a claimed better performance combined with lower fuel consumption and lower total emissions. In addition, comfort in IPS boats, compared with boats fitted with a straight shaft, is said to be substantially higher as a result of lower sound and vibrations.

Volvo Penta says that the IPS1050 and IPS1200 cover a boat speed range from about 28 knots to about 40 knots, with seven propeller packages available as standard products. The engine for the new units is Volvo Penta’s D13 engine, with dual-stage turbo technology, initially available in 800 bhp and 900 bhp ratings. The first turbocharging stage is a twin-entry turbocharger that enables pulse charging – the power in each exhaust pulse is used to provide pulse pressure – which results in a high torque from low rpm. At higher rpm, a second turbocharger kicks in to maintain power levels at higher speed. A new engine control system, developed by Volvo Penta, regulates fuel injection 100 times per second. The system controls the unit injectors, one per cylinder, which operate at pressures up to 2000 bar and atomise the fuel for optimum combustion.

Total emissions satisfy the EU RCD and US EPA Tier 2 regulations and are also in line with the more stringent EPA Tier 3 regulations due to come into force in 2012.

The IPS system is offered as a double, triple or quad engine installation. This means that the IPS system covers boats from 10m up to more than 30m. The control system handles acceleration and gear shifting with twin single lever controls, regardless of whether the boat is powered by two, three or four IPS units.

The IPS units themselves are compact, offering bold design possibilities, with space and installation time reduced by 50% or more. The new IPS1050 and IPS1200 will be available on the market from autumn 2010.