The Volvo Penta IPS system is a fully-integrated engine, drive, and control package that was designed from the ground up to replace traditional inboard straight-shaft drive systems. Some of the most important advantages of powering a boat with IPS include:
- Top speeds up to 20 percent higher
- Efficiency improvements of up to 30 percent
- Better maneuverability
- More efficient use of space (allowing for smaller engine rooms and larger cabin interiors)
- Lower emissions entering the boat
- Lower sound and vibration levels
What is Volvo Penta IPS?
The most unusual part of the IPS system is its pod drives. Rather than having a shaft running through the hull, IPS utilizes a forward-facing, twin contra-rotating propeller pod drive that’s mounted in the hull bottom. While it certainly looks unusual to have the propellers forward of the lower drive unit, this allows the propeller blades to operate without the usual hydrodynamic interruptions that can cause cavitation. It also places the propellers on a parallel plane with the hull, eliminating shaft angle and the usual loss of efficiency that accompanies it. Exhaust is expelled out of the back of the pod, so it’s carried well behind the boat in the propwash. That eliminates the “station-wagon effect” many inboard boats suffer from, and greatly reduces the smell of diesel exhaust while running.
Another very unusual feature of these drives is that as opposed to shaft drives that are fixed, the pods can rotate 180 degrees. That means they can be turned to walk a boat sideways in either direction. Better yet, they articulate independently, allowing for complete and accurate joystick control whether you want to spin the boat, move it sideways, move it forward or aft, or do a little of each at the same time. It also makes virtual anchoring possible at the press of a button (Volvo Penta calls their version DPS, or Dynamic Positioning System), since the system is integrated with GPS.
The IPS pods are designed to be powered specifically by Volvo Penta inboard diesel engines. These range from 550 hp at the low end, to 1,000 hp at the high end. It’s important to note that the engine series numbers don’t necessarily match up with their horsepower ratings. The IPS1050, for example, produces 800 hp at the propeller, not 1,050 horsepower. These model numbers instead correspond to Volvo Penta’s estimate of the corresponding traditional shaft horsepower installation. In other words, that IPS1050 should provide a vessel with the same performance as 1,050 hp diesels coupled to shaft drives.
As mentioned earlier, the integrated yet flexible nature of the IPS system allows for joystick operation. However, IPS controls go well beyond allowing you to choose between the joystick and steering wheel. IPS digital engine monitoring displays include the expected data such as engine rpm, temperature, hours, oil and turbo pressure, and warning alarms, but can also display data such as speed, tankage levels, rudder position, and more. More commonly with IPS systems, however, is integrating the engine monitors into a full-blown glass cockpit system. Developed in cooperation between Garmin and Volvo Penta, touch-screen MFDs from seven to 24-inches provide fully customizable screen arrangements, display all pertinent IPS and engine system data, and have all the same navigational functions and expandability as other networkable NMEA 2000-compatible MFDs. These units also feature low-profile flush-mounting that gives the helm of a boat a smooth, modern look.
Another component of the IPS control system is Volvo Penta’s EVC, or Electronic Vessel Controls. These are digital shift and throttle binnacle-mounted controls, which can be installed in up to six stations on any one boat or yacht. Along with the shifters and throttles they have a push-button keypad, for activating additional features like single throttle control of multiple engine systems, low speed modes, cruise control, and other functions.
IPS and Interior Boat Design
When IPS was first introduced the public’s immediate response was surprise, thanks to the unusual-looking pods with their forward-facing propellers. However, despite having to re-engineer their boats for pod drives, boat and yacht builders very rapidly adopted them. One of the biggest reasons why they liked incorporating pods was that it allowed them to shift the powerplants aft (since there’s no need for long shafts) and lay claim to segments of the craft’s interior that had always been lost to space for the engine-room. Mid cabins could be enlarged and extended, stowage areas or laundry rooms could be added, and in some cases another stateroom could be designed into the boat.
At the same time, IPS pod drives also eliminate the need for rudders. Thus, not only is useable space increased forward of the powerplants, it’s also increased aft of them. This can allow for additional stowage compartments, below-deck fishboxes, or even adding a tender garage or crew’s quarters. Or, on the other hand, a builder can utilize that space for machinery and free up more of the forward area for cabin volume.
While it’s true that pod drives in general do tend to cost a bit more than straight-shaft inboards (usually to the tune of around 10- to 15-percent), and they can be slightly more expensive to maintain, the test of time has proven that they’re quite reliable. And their advantages are not only significant, but also quite wide-ranging. As a result, it only makes sense for anyone who’s thinking about buying a new boat or yacht consider the IPS option.
For more information on Volvo Penta IPS, visit Volvo Penta.
View yachts with IPS systems.