What if you could have a high-speed propulsion system that offered better fuel economy, increased range, reduced noise and vibration and improved handling, especially at the dock?
Well, it looks like you can. Volvo Penta’s IPS pod system has been a big success with recreational boats and now commercial applications are starting to be developed. The Massachusetts Environmental Police in Boston are now operating a new 50' patrol boat with IPS that was delivered this summer from MetalCraft Marine in Ontario. And Gladding-Hearn just completed a 64-footer for emergency response around Charleston, N.C. The Boston boat has two IPS pods and the Charleston boat has three. For more power, up to four pods can be installed. Gladding-Hearn is also building another IPS-powered boat for Tampa Bay, Fla.
Several innovations characterize the IPS pods. First of all, the propellers are on the forward end of the pod. They’re also reversing and counter-rotating pairs. Second, each pod is independently operated by the electronic control system with a joystick that produces combinations of thrust and direction and can rotate the boat or walk it sideways, diagonally as well as forward and backward. Third, the exhaust is discharged through the pod underwater where it gets mixed with the wake, reducing both noise and odors.
As with any underwater appendages, there’s always the risk of hitting something and bent IPS propellers are probably common. In fact, during delivery, MetalCraft hit a deadhead and damaged the brand new propellers. But hitting a deadhead with a conventional shaft, propellers and rudder would also have caused damage to something.
In a way, IPS pods are something like Z-drives for planning boats. Each is independent and steerable, although the pods only rotate about 25 degrees off the centerline. But the combination of different angles and reverse/forward thrust can provide lots of maneuverability for operators.
Here’s a link to a Volvo Penta video about the IPS joystick on a recreational boat, and once at Youtube you can find several other videos about the system. Check it out. It’s fascinating.
