The
all bronze 3 blade feathering propellor by Maxprop is our fix for
Marelle's poor stopping power, and we are hoping it will also help
with reversing and prop walk as well. The blades
rotate, so that the leading edge faces the direction of travel, and
when sailing they feather to reduce drag.
Here is the
previous propellor alongside the new one.
With
advice from Chris at Darglow http://www.darglow.co.uk/
we have chosen a slightly bigger propellor size, as well as of course
3 blades rather than 2.
Darglow
carefully machined the propellor to fit the tapered shaft so we
didn't have to cut the end off, as we wanted to keep the original
propellor as a spare. We came to fit the new propellor, but the new
nut would not fit on the thread, and Martin did not want to force it.
Chris from Darglow saved the day, making a special trip
over from Wareham to fit it for us in time for Marelle's launch.
Here are some pictures of the fitting:
Great to see how much hard work and loving care you dedicate to your yacht. I have a McGruer 8 Metre CR with the same propellor set up and it is rather challenging in marinas as you mentioned. It would nice to know if the new propellor improved the situation.
ReplyDeleteHi Pasi,
DeleteIt did improve the situation, however Marelle is still a handful. The main reasons we fitted the max prop was that I needed the additional thrust provided by a 3 blade for 3 reasons:-
1 we had an occasion when motoring into the Solent chop when Marelle stopped in the water due to the wave and wind resistance. As you will know, I am sure, with the prop behind the rudder that leaves us with no steering at all. With the new prop we will not have that issue!
2 To accelerate better from stationary, particularly out of marina moorings, if you have missed a mooring buoy or after picking up the anchor.
3 Better stopping power when mooring up, and the resulting speed you can carry when heading into the mooring.
Once we decided to have a 3 blade prop we wished to avoid the additional drag that would result.
One of the interesting thoughts was that the max prop sits further back i.e. further from the keel, and we decided to have a slightly larger diameter with the 17 inch max prop vs. the original 16 inch of the original. I believe we could have gone further as the extra 1 inch is actually 1/2 inch more from the prop shaft center and the blades are still further from the hull.
I hope the extra clearance may help the massive prop walk, but so far I have not noticed too much improvement in the prop walk.
The principle benefit is that with the extra stopping power I have more confidence in manoeuvring and that has improved crew morale with the reduced stress levels as we head towards the marina moorings!
We still request assistance from marinas when we moor up short handed.
In short I am pleased with the new prop, and would say again, pleased with the service from Darglow who worked with us to make the move over, including the up sizing decision.
Martin
Hi Martin,
ReplyDeleteThanks for your comments. Fitting a Maxprop to Nan of Clynder is something I will need to consider seriously. It is great to hear your experiences as these yachts can be very challenging to handles in marinas. Your third point would make a huge difference in heading into the mooring. I don't have much of an issue at her home port as the slip access is very good but the limited maneuverability adds excitement in tight marinas especially when it is windy !
I have attached two links if you want to see Nan of Clynder in action.
http://www.youtube.com/watch?v=yeU9x3ZtYlo
http://www.youtube.com/watch?v=v6Ny2uFvQsU
Pasi