Pod performance without the pod
Posted on 08 January 2009
Written by Chris Landry
ZF Marine system bringing joystick agility to traditional hulls earns high marks at Lauderdale show
Propulsion innovation proved to be a driving force at the Fort Lauderdale International Boat Show, with ZF Marine introducing a system that controls low-speed steering and power via a helm joystick, bringing pod-like maneuverability to conventional shaft-driven inboard boats.
“Boatbuilders are really excited, because they don’t have to re-engineer the entire hull to accommodate a pod system,” says ZF marketing manager Martin Meissner. “They can keep building traditional hulls but now can offer the maneuverability available with pods.”
The technology, called the Joystick Maneuvering System, was expected to be available by the end of the year.
“Maneuvers such as sideways docking, 360-degree spot rotation, and other complicated moves — usually difficult with standard control levers — become easy operations with the JMS system, since it also controls engine speed and transmission shifting,” says Meissner.
Trying it out
Soundings and Trade Only editor-in-chief Bill Sisson and I took advantage of an opportunity at the show to operate the system, which was installed on a Bertram 630. Both of us have driven vessels equipped with Volvo Penta’s IPS (Inboard Performance System) and CMD’s Zeus, as well as the MerCruiser Axius for sterndrives.
“I was impressed,” says Sisson. “The close-quarters maneuverability was quite similar to the pod-powered boats I’ve driven.”
JMS works with two other ZF components: the SmartCommand control system and transmissions equipped with trolling valves. The system allows movement of a traditional shaftline vessel in any direction. The joystick uses the SmartCommand system to communicate with the two main engines and the bow thruster. The bow thruster kicks in primarily during side-to-side movement. Bow thruster size is determined by the vessel’s weight, waterline length, horsepower and distance between the props.
When the joystick system is engaged, the rudders remain centered, allowing the propellers and bow thruster to do all the work. JMS is used only for low-speed maneuvering and cannot accelerate beyond a preset throttle percentage. The system transitions to conventional throttle and steering controls at higher speeds. To make that transition, the operator must press a button on the SmartCommand pad. In the future, the skipper will be able to simply engage the throttles to exit JMS.
A number of boatbuilders tested the system aboard the Bertram 630 and are interested in the technology, says Meissner. The Italian boatbuilding conglomerate Ferretti Group has the system installed in one of its yachts, which it displayed at the Genoa Boat Show in October, according to ZF executive vice president and general manager Vittorio Rasera.
Aboard the Bertram, independent captain H.A. Turner demonstrated several functions executed via the SmartCommand control pad, including “hold heading,” which uses an electric compass to keep a vessel on a specific course. ZF also plans to integrate GPS into the system, which will allow the hold heading function to adjust to tide, wind and current conditions. The “station keeping” function will keep a vessel in an exact position and orientation with the press of a button.
JMS will get even better, says Meissner. Another ZF technology called SteerCommand will be integrated, allowing the rudders to move independently at all speeds. (The pod drives in both CMD’s Zeus and Volvo Penta’s IPS can move independently of one another.) ZF officials could not say when SteerCommand will be integrated with JMS.
Even without SteerCommand, the group of editors and boat dealers aboard the Bertram liked what they saw.
Robert Hazard is vice president of sales and marketing for E.H. Yachts in Egg Harbor City, N.J. His company is installing the system on a 52-foot Buddy Davis. “I’m very impressed … very impressed,” he said after the demonstration.
A potential customer was also on board. Sam Wilson, who lives in the San Francisco area, owns a 94-foot aluminum Inace, which he converted from a commercial workboat to a motoryacht. Wilson, who plans to replace the vessel’s 550-hp Detroits with Cat C9s, is most excited about JMS’s station-keeping capability.
“It’ll be a tremendous help while waiting for bridge openings,” he says. “The fact that they have joystick control with a conventional inboard setup is amazing.”
Pricing for JMS was unavailable at press time.
This story originally appeared in the January 2009 issue.