42DS reversing performance

[Rob_Webb]

Thanks guys. In the first instance I’m less interested in bow-thruster options (nice but more expensive solution) and what I’m really looking for is anyone who has improved stopping / reversing / prop walk performance of a shaft drive 42ft modern boat like the DS by changing from one prop to another. It sounds like Gori, Brunton and Maxprop do well and maybe better than current Volvo prop?

 

[Bobc]

Brunton and Featherstream both seem to reduce walk a lot (from what people who have switched to them have told me).

 

[Malo37]

I don't think your wish list is possible. Replacing a fixed blade with any kind of folding prop is likely to negatively impact stopping and astern performance. I replaced a large fixed 3 blade with a Flexofold 3 blade on my 40ft 11 tonne boat. With the fixed prop, prop walk was significant but could be useful at times. The boat stopped almost like a car and with a blip astern the bow would dip as she stopped in less than a boat length.
With the Flexofold I got an extra 1 knot at the same revolutions, prop walk was almost eliminated but stopping distance increased by a factor of 2 or 3 times.

 

[rotrax]

Brunton and Featherstream both seem to reduce walk a lot (from what people who have switched to them have told me).

A Kiwi Prop worked well on our previous boat, an Island Packet 350, and is by far the cheapest feathering/variable pitch option.

Far from the most sophisticated, but a new blade can be easily fitted by the owner at a cost of around £50,00.

It reduced prop walk and gave better control in astern. Biggest shortcoming is that the pitch in astern is too coarse, so preventing the engine reaching full RPM. Stopping in astern was markedly improved, and she weighed in at over 12 tons with full tanks and all the cruising gear on board. Perhaps a second or two wait while the blades flipped, then it was like putting the brakes on.

Otherwise, a good product at the right price.

 

[Tranona]

Thanks guys. In the first instance I’m less interested in bow-thruster options (nice but more expensive solution) and what I’m really looking for is anyone who has improved stopping / reversing / prop walk performance of a shaft drive 42ft modern boat like the DS by changing from one prop to another. It sounds like Gori, Brunton and Maxprop do well and maybe better than current Volvo prop?

The Volvo folder has a variable reputation. However, surprised it lacks thrust at high RPM - maybe it is underpropped. As you can see from others' comments, prop walk is variable and not necessarily predictable from one prop to another. Changing props is an expensive business - not quite as expensive as fitting a bow thruster though.

Whether the reversing difficulties you experienced are a deal breaker only you can judge. There are ways of living with it and indeed using it to your advantage. Not sure that the Jeanneau is any different from other shaft drive boats of its type in this respect. Usually the main difficulty is dealing with the top hamper with bows being blown off thus making reversing in a straight line or changing direction in a cross wind difficult. This is where a bow thruster helps as it gives you more control over both ends of the boat. Whether it is worth fitting one again depends on the specifics of how you use the boat.

 

[fearmhuir]

A bow thruster can get you out of a sticky situation in a tight marina.

+1

A bow thruster is a get out of jail free card!

 

[LadyInBed]

When the wind is blowing me onto the river bank on my fore and aft river mooring a bow thruster would be a real asset. As it is, I have to deploy a kedge across the river to pull myself away from the bank.

 

[wully1]

+1

A bow thruster is a get out of jail free card!

Not quite true. It is a 'get out of jail for several thousand pounds' card

 

[Tranona]

Not quite true. It is a 'get out of jail for several thousand pounds' card

For those who choose to have one the cost is only relevant to the benefit enjoyed.

However that sentence is only a "turn of phrase" and not intended to be taken literally. In the situation envisaged its use is actually free.

 

[RupertW]

What an absolute load of tosh.

I remember the warping posts in Ramsgate Harbour when I was a kid-5 or 6-and sailing vessels using the dinghy and warps to pull the boat, usually a barge, into the harbour.

What you say rolls of the tongue easily. With todays pressure on time and the need to earn ones crust, waiting for a favorable wind and tide is not always possible for a leisure sailor.

I would love to see you trying to sail into Portsmouth Harbour entrance in anything but perfect wind conditions against a spring ebb.

With a 38HP yanmar on full rattle I have been down to under I knot!

If you offered Columbus or Drake an engine, do you really think they would have turned it down?

Are you a Luddite, by any chance?

Warping posts long gone, so how does an engineless sail boat manage now when the pro's struggled?

WHoooooosh!

 

[dunedin]

Before leaping to any conclusions after an end of season sea trail, perhaps putting a camera down or lift might be worthwhile to check the prop is clean and not covered in barnacles or similar. For the first time our prop was covered in barnacles this year, which reduced effectiveness substantially.

I don't think your wish list is possible. Replacing a fixed blade with any kind of folding prop is likely to negatively impact stopping and astern performance. I replaced a large fixed 3 blade with a Flexofold 3 blade on my 40ft 11 tonne boat. With the fixed prop, prop walk was significant but could be useful at times. The boat stopped almost like a car and with a blip astern the bow would dip as she stopped in less than a boat length.
With the Flexofold I got an extra 1 knot at the same revolutions, prop walk was almost eliminated but stopping distance increased by a factor of 2 or 3 times.

I am surprised that you found the Flexofold inefficient in reverse. I have only ever had folding props (and would never want a fixed one), but never found any issues at all with reverse efficiency - even when it was barnacle encrusted.
Would recommend a three blade flexofold as a great prop for most boats

 

[flaming]

Thanks guys. In the first instance I’m less interested in bow-thruster options (nice but more expensive solution) and what I’m really looking for is anyone who has improved stopping / reversing / prop walk performance of a shaft drive 42ft modern boat like the DS by changing from one prop to another. It sounds like Gori, Brunton and Maxprop do well and maybe better than current Volvo prop?

Symptoms sound the same as what happened to the prop on the Elan. Basically worn gears meant it was reluctant to open in reverse, and actually wouldn’t open in astern if the boat was going forwards at more than about 1.5 knots. Meant I only ever parked backwards as I would get the boat going backwards in loads of space, safe in the knowledge that the prop was fine when forwards was engaged, so I could stop the boat!
New folding prop mid season this year, and the difference is dramatic. You now wouldn’t know it was a folder by the performance u see power.

 

[Rob_Webb]

Before leaping to any conclusions after an end of season sea trail, perhaps putting a camera down or lift might be worthwhile to check the prop is clean and not covered in barnacles or similar. For the first time our prop was covered in barnacles this year, which reduced effectiveness substantially.



I am surprised that you found the Flexofold inefficient in reverse. I have only ever had folding props (and would never want a fixed one), but never found any issues at all with reverse efficiency - even when it was barnacle encrusted.
Would recommend a three blade flexofold as a great prop for most boats

Thanks everyone. Amazing response and insights!

Couple of thoughts / updates:

1. Decided to go ahead with purchase of 42DS and sort prop afterwards - is evidently fixeable (pardon the deliberate pun)
2. I know my wish list IS possible - because my current 35ft yacht behaves this way. Has saildrive and 2-bladed folding prop and behaves impeccably. Slight propwalk and obviously less bite in astern than ahead but reverses like a car and turns as well astern as ahead. Therefore this is my benchmark and my ask of the 42DS.
3. Money not an issue so prepared to pay for best folding / feathering prop on the market - I just want to know what that is!
4. Please no more comments about bow-thrusters - I KNOW they help and I will likely get one for next season but meanwhile I want to get the fundamentals of prop performance right.
5. It's not end of season but start of season - summer is just starting here in NZ
6. Boat just lifted and anti-fouled so unlikely to be fouling issue - but I will do a quick lift & hold to check mechanics functioning ok

Finally, this is an interesting review (unfortunately doesn't cover my Volvo prop) but seems to confirm Maxprop 3 blade and Flexofold 3B as v good options:

http://www.yachtingmonthly.com/gear/folding-and-feathering-propeller-test-29807

 

[flaming]

Thanks everyone. Amazing response and insights!

Couple of thoughts / updates:

1. Decided to go ahead with purchase of 42DS and sort prop afterwards - is evidently fixeable (pardon the deliberate pun)
2. I know my wish list IS possible - because my current 35ft yacht behaves this way. Has saildrive and 2-bladed folding prop and behaves impeccably. Slight propwalk and obviously less bite in astern than ahead but reverses like a car and turns as well astern as ahead. Therefore this is my benchmark and my ask of the 42DS.
3. Money not an issue so prepared to pay for best folding / feathering prop on the market - I just want to know what that is!
4. Please no more comments about bow-thrusters - I KNOW they help and I will likely get one for next season but meanwhile I want to get the fundamentals of prop performance right.
5. It's not end of season but start of season - summer is just starting here in NZ
6. Boat just lifted and anti-fouled so unlikely to be fouling issue - but I will do a quick lift & hold to check mechanics functioning ok

Finally, this is an interesting review (unfortunately doesn't cover my Volvo prop) but seems to confirm Maxprop 3 blade and Flexofold 3B as v good options:

http://www.yachtingmonthly.com/gear/folding-and-feathering-propeller-test-29807

How old is the prop?

 

[KellysEye]

We had long keel cutaway forefoot steel ketch that had serious prop walk astern what I did is blip the throttle and with the short bursts it goes straight.

 

[Tranona]

Thanks everyone. Amazing response and insights!


Finally, this is an interesting review (unfortunately doesn't cover my Volvo prop) but seems to confirm Maxprop 3 blade and Flexofold 3B as v good options:

http://www.yachtingmonthly.com/gear/folding-and-feathering-propeller-test-29807

Things have moved on a bit since that article, although the main thrust (?) remains correct. Volvo props are less popular, perhaps because in the early days they had serious quality problems with rapid corrosion. Mostly cured now since relatively large anodes were added. However these wear rapidly and are expensive to replace. The observation earlier that the poor thrust in reverse may be due to wear/erosion of the gear teeth is worth investigating.

You may already know that Jeanneau now fit the 3 blade FlexoFold as a factory fit option, so you may get some owner feedback from the Jeanneau owners forum.

You might also consider the Featherstream which is made by Darglow Engineering who among other things were the Maxprop and FlexoFold agents in UK for many years. This has many advantages over the Maxprop (and other feathering props) in that the blades are stainless steel and have shape (others are flat) and pitch can be adjusted individually forward and reverse. It is also significantly cheaper than other feathering props and comparable with folders.

I have an interest in that I have known the company for 40 years or more and have both an early version of the Featherstream and a Flexofold (on 2 different boats!). They are very knowledgeable on props and you will find unconnected customers are usually very complimentary about their products and service.

 

[Tranona]

We had long keel cutaway forefoot steel ketch that had serious prop walk astern what I did is blip the throttle and with the short bursts it goes straight.

What help is that to the OP who is buying a fin keel Jeanneau?

 

[dunedin]

Thanks everyone. Amazing response and insights!

Couple of thoughts / updates:

1. Decided to go ahead with purchase of 42DS and sort prop afterwards - is evidently fixeable (pardon the deliberate pun)
2. I know my wish list IS possible - because my current 35ft yacht behaves this way. Has saildrive and 2-bladed folding prop and behaves impeccably. Slight propwalk and obviously less bite in astern than ahead but reverses like a car and turns as well astern as ahead. Therefore this is my benchmark and my ask of the 42DS.
3. Money not an issue so prepared to pay for best folding / feathering prop on the market - I just want to know what that is!
4. Please no more comments about bow-thrusters - I KNOW they help and I will likely get one for next season but meanwhile I want to get the fundamentals of prop performance right.
5. It's not end of season but start of season - summer is just starting here in NZ
6. Boat just lifted and anti-fouled so unlikely to be fouling issue - but I will do a quick lift & hold to check mechanics functioning ok

Finally, this is an interesting review (unfortunately doesn't cover my Volvo prop) but seems to confirm Maxprop 3 blade and Flexofold 3B as v good options:

http://www.yachtingmonthly.com/gear/folding-and-feathering-propeller-test-29807

Sounds like a good plan. And enjoy your new boat.

One final thought - I bought a cheap (under £20) waterproof endoscope camera, attached to a pole on the end of the boat hook and showing on laptop computer screen. This allowed us to safely watch the folding prop actually in operation, which was quite illuminating. This would allow you to check opening properly.
As others have stated, Jeanneau seem to factory fit Flexofold as do X-Yachts and others, so might be a good safe option

 

[Kurrawong_Kid]

Brunton and Featherstream both seem to reduce walk a lot (from what people who have switched to them have told me).

I get a huge amount of propwalk astern with a Brunton. In any wind across the boat from starboard when going astern and she just pirouettes as the propwalk is to starboard in reverse and the bow blows off. I’m considering adding an outboard to make her twin screwed to try and make some chance of steering in reverse, rather than installing bow thrusters.

 

[NormanB]

What an absolute load of tosh.

I remember the warping posts in Ramsgate Harbour when I was a kid-5 or 6-and sailing vessels using the dinghy and warps to pull the boat, usually a barge, into the harbour.

What you say rolls of the tongue easily. With todays pressure on time and the need to earn ones crust, waiting for a favorable wind and tide is not always possible for a leisure sailor.

I would love to see you trying to sail into Portsmouth Harbour entrance in anything but perfect wind conditions against a spring ebb.

With a 38HP yanmar on full rattle I have been down to under I knot!

If you offered Columbus or Drake an engine, do you really think they would have turned it down?

Are you a Luddite, by any chance?

Warping posts long gone, so how does an engineless sail boat manage now when the pro's struggled?

Sorry I missed your rather erudite response.
You clearly do not do irony.
I was responding,ironically, to all that jumped on the bandwagon of ‘bowthrusters are for losers’ or words to that effect.