The Power of Integration

To demonstrate the power of integration, Volvo Trucks North America leadership enlisted the help of Volvo’s marine division, Volvo Penta. Their point was to show how the vertical integration of engine, transmission and control system can work miracles – whether on land or water. And they showed the paradigm changing Inboard Propulsion System for the marine world to demonstrate the potential from integration of an innovative concept with the latest control technology .

The star of the show-and-tell was the revolutionary Volvo IPS (Inboard Propulsion System), a through-hull propulsion developed by Volvo Penta about five years ago. Unique to Penta, the drive system puts the propeller ahead of the drive unit, which is located through the hull instead of behind as in a conventional inboard engine/outdrive or using a long shaft with P-brackets and rudder.

IPS mounts propellers on horizontal shafts, parallel to the hull. IPS has a host of advantages: It puts the puller propellers – contra-rotating on Volvo Pentas – in water undisturbed by the gear casing. And because they are parallel to the hull instead of being at an angle dictated by the 10-15 degree down angle in a conventional shaft configuration, there is no tendency to lift the rear of the hull and thus force down the nose. This means less water friction, less energy wasted lifting the boat and less drag on the hull. It also allows for a little additional optimization of the hull shape reducing or eliminating the “rocker” to compensate for shaft angularity.

The result, says Clint Moore, president of Volvo Penta of the Americas, is that compared with the traditional shaft drive, the IPS integration of diesel engine, drive system and the sophisticated controls that extend from the helm to the props delivers 20 percent more performance, 30 percent to 40 percent fuel savings, 40 percent longer range and likely 50 percent fewer emissions. It also brings a set of features impossible with conventional drives.

An additional benefit is that the exhaust is directed down through the drive, exiting to the rear and into the prop-wash to emerge at the water surface far behind the boat. Conventionally, exhausts exit the transom close to the waterline. The IPS arrangement eliminates the "station-wagon" effect in which exhaust is drawn onto the boat. In fact, many would-be boaters who suffer sea-sickness are not sick from the motion of the boat, according to Volvo Penta, but from the diesel or gasoline fumes on the aft deck or in the salon.

Integrated Power

The demonstrator for the technology was the 70-foot Spencer sportfisher “PentaGone” with three IPS1200 power packs. The IPS1200 is a top-rated engine, transmission, and control system that combines the drive with a Volvo D13 diesel and a control system that manages all three. Based on the D13 truck engine, the 13-liter in-line six-cylinder has changes to pistons, camshafts and fuel mapping so the D13 marine engine punches out 900 hp where the peak North American on-highway rating is 500 hp.

In the immaculate white engine room of the 70-foot sportfisher, these three IPS1200 integrated power systems make 2,700 hp at their rated 2300 rpm. However, since the efficiency of the drive system gives the same performance as a 3 x 1,200 hp conventional shaft driven boat, the drive nomenclature reflects performance delivered rather than actual horsepower. (For a 360-degree view of the engine room go to http://vt.prestigevision.com/ma853/.)

Integration of the controls is part of the IPS package. So on the Spencer, it includes the two helm positions, one in the pilot house and another on the control station above the cockpit. According to Moore, as much as 25 percent of the boat’s bill of materials was accounted for in the Volvo power installation. Other benefits come with this. The multiplexing of these controls, for instance, means an 800-pound weight savings from eliminating so much copper wiring.

The fact that three of these power packages give identical performance in the 70-foot sportfisher as 3,600 or 4,000 hp in a conventionally powered configuration shows the gains in efficiency of not just the drive system, but the integration of all components, says Volvo Truck President Ron Huibers during a run out of Palm Beach, Fla.

The efficiency shows up in fuel economy, too, and this is where the engine/drive/control integration really shines. According to Penta’s Moore, the 3,600 hp setup will consume about 140 gallons of diesel per hour at a 30-knot cruise, the IPS system uses only 100 gallons per hour – a 40 percent improvement.

Such a game-changer is unlikely in trucking but what Volvo was seeking to illustrate is the potential when integrating the power/transmission/controls. There is, of course, a direct parallel with the Volvo diesel with a Volvo I-Shift automated transmission in an over-the-road truck with attendant gains in performance and fuel efficiency, but on a different level.

Another feature of the drive system is the steering of the boat through rotation of the drive units, controlled individually and together by the integrated electronics. The steering system reportedly make for very precise steering, and handling more car-like than is the usual boating experience. It also enables several unique maneuverability features. Moore says, because it is a proprietary system with such huge benefits, it has taken Penta from a fifth-place player behind Cummins, Caterpillar, Detroit Diesel and YanMar in the leisure and sport fishing arena to a point where Volvo now commands between 50-60 percent of the business.

Clearly, Volvo would like to do the same in the trucking market, but it doesn't have that same paradigm-shifting fuel economy from the technology change. Nevertheless, the I-Shift transmission has increased penetration in Volvo Trucks in North America to 40 percent since its 2007 launch. That popularity is obviously from its unique set of deliverables that come from the full integration of engine and transmission.

Feature Rich

The deliverables of the IPS are amazing. For example, the fully electronic control-by-wire means the forward and reverse, and clutches that are part of the propulsion system are individually controlled to help the boat maneuver. That is most ably demonstrated by two quite remarkable benefits: full joystick control and virtual anchoring.

When maneuvering into a tight dock, joystick control can make a duffer look – and behave – like a seasoned captain. By vectoring the drives, the boat can be made to go absolutely sideways or rotate about a vertical axis with the control system positioning and choosing drive direction purely through the drives. This 70-foot Spencer has no bow thruster. There’s no need to juggle forward and reverse gearshifters. The joystick allows for fine control for slow-speed maneuvering into the tightest space, even going completely sideways. Try doing that with fixed drives and no bow thruster!

Another convincing demonstration is the virtual anchor, where GPS interfaces with the engines’ controller to keep the boat exactly in place. And that’s within 1 meter and 5 degrees headway irrespective of wind and tide. As skipper, you simply press a button to sit and wait in the channel with water flowing by waiting for a bridge to raise. When bottom fishing, the same feature allows the captain to put the boat over a hole and sit there, or when diving off the boat keep stationary for the scuba divers.

It's absolutely uncanny to sit stationary in a channel with water flowing by and have the engines engage and disengage the drives to keep the boat in stationary. Another application would be ‘parking’ the boat in the slip in moving water and sidewinding while the captain single-handedly attends to the lines.

Again, such features are game-changing, but the I-Shift truck transmission has its share of goodies too, including taking over engine control. In a Volvo truck with I-Shift, the driver commands the transmission and the transmission tells the engine what’s needed. In doing so, it makes the driver's job very easy, with the transmission selecting the right ratio for the task at hand and managing the shifting, while optimizing conditions to save as much fuel as possible.

Size Matters

Optimization in the marine package brings some other significant benefits. The package can be extremely compact – less than double the length of the engine alone. In the 70-foot Spencer, the center IPS sits back in the engine room toward the transom and low in the V of the hull. The two outboard engines are installed with jackshafts putting them farther forward in the engine room. Since they mount higher in the hull, it’s necessary to allow for sufficient clearance above for service to the overhead and still maintain the lowest possible cockpit deck at the back of the boat.

Some of the boat systems such as the chiller that’s part of the boat’s climate control, normally in the engine room are relocated and the front wall of the engine room has moved so far aft that PentaGone uses the freed-up space below for an additional en-suite stateroom. So with the IPS power, PentaGone can sleep six in splendid granite, marble and carbon-fiber luxury. And there are crew quarters for three – all in 70 feet.

The highway equivalent I-Shift integration allows no added space in-truck, but when comparing performance and economy, the optimization from the I-Shift with the D13 has some parallels to the marine power. Through its fuel efficiency, IPS power not only gets by on less fuel, the boat carries less fuel yet has the same range as the 3,600 hp installation. And those 13-liter Volvos are mapped for great torque so they literally pop the hull – lighter by thousands of pounds because of engine and fuel weight – up on to the plane in seconds. The surge as the throttles are pushed forward is remarkable, even with 14 people aboard for our sport fishing outing into the Atlantic. The I-Shift also will give a boost to performance in a truck with corresponding economy gains. A canny operation could translate this into less fuel capacity on a truck and a more productive piece of equipment.

Moore says the nearly $5 million ticket for the boat includes $0.75 million for the IPS power package. Included are all the highly complex electronics, controls and software with Volvo supplying everything from the helm to the hub cover in the middle of the propellers.

Captain Mike Meyer, who put the PentaGone through its paces, say the boat was necessary to demonstrate the features enabled by the IPS drive system in combination with Volvo Penta D13 power: "You don't sell this system out of a brochure," says Moore. "You have to let the customer experience it, see and feel what it can do, and be convinced"

And, says Volvo Trucks president Ron Huibers, it's much the same with I-Shift. Once a fleet customer has one in the fleet the word quickly goes around, and drivers, dispatchers and purchasing staff are quick to spot the benefits and demand more Volvo/I-Shift VNs in the fleet.

So Volvo makes no apology for vertical integration in its powertrains. As Volvo Trucks Ed Saxman, product manager – powertrains, says, don't think of it a something that's being forced down your throat. It’s vehicle integration and it’s vehicle optimization. It's not a penalty but an opportunity, he says.

LOA: 70’6”
Beam: 20’4”
Draft: 5’1”
Displ.: 83,000 lb.
Fuel: 1,380 gal.
Water: 220 gal.
Engines: 3 x 900-hp Volvo IPS diesels

IPS Weight: 3 x 2,300 lb.