A propeller is just a propeller, right? There’s not much difference from one kind to another, aside from obvious things like the material it’s made out of and the pitch to the blades, right? Not so! I’m constantly surprised at the innovations that people can come up with in such a tiny package (I guess that’s why I’m a writer, not an inventor). As such, the reverse hook cup propeller blew my mind.
Peter Dean, owner and president of Propco Propellers, came up with the idea years ago when he constantly received aggrieved phone calls from houseboat rental companies who couldn’t rent out their houseboats if the wind was greater than 10 knots, because people couldn’t control them.
He recalls, “I thought about it and was lying in bed one night, and thought, why don’t we cup it and just throw it in reverse and try that?”
Let’s back up and let Peter explain the issue. “Most of a houseboat’s exhaust comes through the propeller,” he says. “When you put the propeller in reverse, all it does is cavitate because it’s turning in the exhaust gas. When you’re going forward, the gas is left behind. So when you back up, the prop doesn’t stop the boat. For example, if you have a 20-ton houseboat, and you’re going along at 12 knots or so and you put it in reverse, with a standard propeller it’ll take 15 boat lengths to stop.”
The solution? There’s a 3/8-inch radius at the end of the cutting edge of the blade that controls the slippage in the cavitation.
“With the reverse hook cup propeller, it’ll stop in a third of that distance,” Peter says. “It’s got more power in reverse than in forward, actually. It’s amazing. It’s more than 200 percent extra power. If you’re standing beside the captain, even on something like a 20-ton houseboat, and he hits the throttles, if you’re not hanging on to something, you’ll fall on your face. That’s how quickly it stops.”
The maneuvering benefits of the reverse hook cup propeller are obvious, not only in open water, but especially at the dock.
“Most rental companies have what’s called a pilot man that goes out and brings the boat into the marina after a rental weekend,” explains Peter. “Now with the reverse hook cup propeller, customers can bring them in because if they’re doing 4 knots coming in to a marina berth, they can put it in reverse and hit the throttle and it’ll stop in 12 inches.”
One final thing that’s great about Propco’s offering is its POSSI Drive Bushing Hub that fits inside the propeller and gives the same protection as a rubber bushing but is fail safe. It protects it under impact and absorbs harmonic vibration as the old original rubber bushings did, and will carry up to 2000hp.
Peter says, “Other manufacturers are using a plastic insert which never stays tight and gives zero protection under impact and in turn these plastic inserts twist spines, bend and break shafts as well as creating more harmonic vibration when loose.”
If you’ve been wanting more control when piloting your houseboat, you owe it to yourself to check out Propco.