ChesapeakeGem
Senior Member
Advise on using our twin screw 36’ SeaRay aft cabin with one engine
Boat handling advise
We have Borg Warren velvet Drive transmission
Boat handling advise
We have Borg Warren velvet Drive transmission
A little more difficult to steer, you will not be able to go as fast. Otherwise, not a problem. You will not hurt anything.
Why do you want to run a twin on one engine? To save fuel? Maybe but not much. The only objective analysis of this possibility was done by Bob Lowe, a former boat yard owner and compared fuel economy with one vs two engines for two boats, a Grand Banks Alaskan 45 and an Ocean Alexander 50. The difference in fuel economy was negligible. See the attached pdf graph.
You can run on one engine without locking the prop on a Velvet Drive transmission. Bob Lowe's detailed comparison of freewheeling vs locking the prop on the dead engine didn't show any conclusive advantage to either method.
One downside is that you may be overloading the single engine. The only advantage in addition to a little fuel economy is less maintenance on one engine vs two running all of the time.
All in all, I wouldn't do it.
David
Sounds like you're planning on continuing to enjoy your boat while sorting out an issue with one of your engines. If so, I would remove the prop from the engine that's down. As far as handling, you'll be fine in open waters. The challenge is putting the boat back in the slip as most twins have small rudders. But you can practice and get a feel for it and then determine if it's doable. Hope it works out. Good luck.
We have a failed starboard engine but would still like to take the the boat out on just the port engine
Here's my recent experience. While up-locking the eight stair step locks in Ottawa the Drivesaver saver coupling on the port side fractured thus parting the shaft from the BW transmission. We had to drive 18 miles on the Rideau Canal on one engine to reach a repair marina. At 1,300 RPM we achieved slightly more than 5MPH. It seems to me that this would have consumed noticeably less fuel than running on both engines. Our boat is a Defever 44 and weighs 56,000 lbs with water and fuel tanks full which they were at the time.Why do you want to run a twin on one engine? To save fuel? Maybe but not much. The only objective analysis of this possibility Ihave seen was done by Bob Lowe, a former boat yard owner, and compared fuel economy with one vs two engines for two boats, a Grand Banks Alaskan 45 and an Ocean Alexander 50. The difference in fuel economy was negligible. See the attached pdf graph.
You can run on one engine without locking the prop on a Velvet Drive transmission. Bob Lowe's detailed comparison of freewheeling vs locking the prop on the dead engine didn't show any conclusive advantage to either method.
One downside is that you may be overloading the single engine. The only advantage in addition to a little fuel economy is less maintenance on one engine vs two running all of the time.
All in all, I wouldn't do it.
David