New inventions usually start with someone asking, “Is there a better way?” That’s the question our engineering team asked in the mid-1990s as we looked for opportunities to expand our portfolio outside of traditional inboards, based on an emerging customer demand.
Consumers wanted bigger, faster boats. But that would mean more powerful diesel engines that naturally were heavier, thus counteracting the additional power being created — known as the downward design spiral. Our challenge became how could we meet these expectations without the design compromises that came along with them?
We had made incremental improvements in the efficiency of our diesel engines in the 1990s, but they would not be enough. What was needed was something radical, similar to the invention of the Aquamatic sterndrive in 1959 and the DuoProp drive in 1983.
One idea was to develop larger stern drives to accommodate the bigger boats. We built and tested a prototype heavy-duty sterndrive, but it quickly became apparent that the oversized drives would meet too much market resistance. So we looked for other possibilities that would leverage the benefits of our DuoProp technology. We even played around with a sterndrive with forward-facing DuoProps — a concept that would reappear more than a dozen years later with the Volvo Penta Forward Drive.
The concept and design of a rudder-less, direct-drive system with individually steerable forward-facing dual counter-rotating props was a group effort. In the early phase of development, the project was referred to internally as THD, for Through-Hull Drive, but it eventually became known as the Inboard Performance System or IPS.
IPS and joysticks proved to be a big hit as boatbuilders developed new models in twin, triple and quad systems. Within four years, more than 10,000 IPS systems had been delivered.
The first prototype of what would become the IPS was designed, built and tested in 1997. The direct-drive units were built with integrated rudders located on the trailing edge of the drive unit. But this solution provided poor steering response. The next step was a hydraulically steered system, which was an improvement, yet still not good enough. When a hydraulic component failed during a test, the team decided to swap it out and replace it with an electrically steered unit. The rest is history.big breakthrough came in 2003 with the development and introduction of Electronic Vessel Control (EVC), a comprehensive integrated electronic platform that enabled the engine, controls and instruments to communicate and exchange data. This was an important behind-the-scenes enabling technology for IPS and joystick controls. EVC let us create a fully integrated helm-to-prop solution and replace traditional mechanical hydraulic steering systems with individually steerable electric motors.
The initial prototype was installed in a Carver Trojan 400 at the Volvo Penta Test Center in Suffolk, Virginia. The year was 1999. Beginning in mid-2000, testing continued at our home base in Gothenburg, Sweden.
In one of our early tests with the Trojan, our engineers were perplexed by the poor top-speed results achieved with the IPS boat, when compared to a similar shaft-driven boat. Finally, someone pointed out that the two tests had used different units of measure — one in knots and the other in miles-per-hour. How embarrassing. Once this was discovered, the difference in performance was obvious. IPS had a higher top speed, was more fuel efficient and had faster acceleration. The tighter turning characteristic associated with IPS today came later.
Back at our R&D center in Gothenburg, testing continued. For comparison purposes, we bought a pair of identical Cranchi yachts. We replaced the builder-installed diesel and shaft system with an IPS in one of them, then initiated a series of side-by-side tests under all possible conditions of sea, swell, temperatures and other variables.
The results were 40 percent longer cruising range, 20 percent higher top speed and 30 percent better fuel efficiency than a conventional inboard. There were also important side benefits. We measured a 30 percent reduction in CO2 emissions and 50 percent lower perceived noise levels. All of these were made possible through the introduction of forward-facing propellers. In addition, since the props were operating in undisturbed water, cavitation was virtually eliminated. One additional benefit, particularly to the designers, was the reduction in required engine space — due in part to the integrated exhaust.
Finally, in 2005, after nearly 10 years of development, IPS made its US public debut at the Miami boat show on boats from Tiara, Cruisers, Four Winns and others.
The first year of the product launch did not include the joystick that we speak so much of today. That addition came a year later and significantly improved the operational experience.
IPS and joysticks proved to be a big hit as boatbuilders began developing new models specifically for IPS in twin, triple and quad systems. Within four years more than 10,000 IPS systems had been delivered. Now we’re up to more than 24,000 units with 540 builders worldwide.
We continued to upgrade the IPS over the next few years, adding new models across the full product range of power. Also part of the advancement was joystick steering as well a docking mode, followed by dynamic positioning under GPS control, sportfishing mode and clear-wake mode in the late 2000s, followed by Glass Cockpit and other enhancements, all built around the EVC CAN-bus architecture. They were all part of our “Easy Boating” vision to make boating more fun and less difficult.
Someone recently said, “If IPS and joysticks are so easy a child could drive a boat, prove it.” So that’s what we did. We got together with Boating magazine and staged the publication’s Joystick Challenge, pitting one of its writers against his 13-year-old daughter driving and docking a 44-foot IPS-powered yacht. Guess who won.
This article originally appeared in the May 2019 issue.