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Post by mikebz on Aug 25, 2014 20:15:47 GMT
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Post by Don Reaves on Aug 25, 2014 22:54:25 GMT
This is quite similar to what Jeanneau is putting on the new boats, including the 349. I'm glad to hear it helps.
Don
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Post by sailbleu on Aug 27, 2014 7:35:04 GMT
Do you have any pics on how it was before the improvement Mike ? For those among us who are not familiar with this (previous) setup.
Regards
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Post by mikebz on Aug 27, 2014 12:44:04 GMT
I didn't take any pics beforehand, but the difference is that the 2 blocks at the top of the strop are instead attached to the coachroof one either side, where the strop now attaches. Aha - found a pic on yachtsnet.co.uk: With the standard arrangement sideways load on the boom causes the aft most block on the boom to roll along the mainsheet allowing the boom to fall off substantially to leeward. Extra sheet tension doesn't help much other than adding leech tension.
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Post by tedp on Aug 27, 2014 20:53:41 GMT
That's an interesting idea, Mike. You'd certainly get rid of that sag of the boom to lee. Since I am one who did the traveller modification, I wonder how yours has affected performance of your boat, for instance: - Do you sail closer to the wind than before?
- What is the effect on sail shape (flattening and twist) - my idea is you may get more twist with the attachment of the sheet high up like that, which may help you sail more upright. I do the same by hauling the traveller to luff.
- How is the boat on the rudder - do you still experience round-ups in gusts?
- Have you sailed her reefed down in heavy conditions with that rig, and how does she handle?
Finally, I would recommend using ball bearing blocks for the mainsheet, as you propose. I replaced them recently and it is far better. The originals are far too stiff for easy sail trimming.
PS one change I would make is spreading the load of the sheet over the three attachment points as before. You may put too big a load on the boom if you use only two.
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Post by mikebz on Aug 28, 2014 7:02:10 GMT
We can definitely sail closer to the wind before - can now sheet the jib in properly without half of the main backwinding. With the standard system there was no option to have twist, increasing leech tension was unavoidable when trying to get the boom anywhere near the centreline. If the strop is long enough then it effectively decouples the boom angle from the leech tension, it's a matter of fine-tuning the strop length to get a good all-round combination. In my pics the main is stowed and the boom is pulled up a couple of inches on the topping lift, so the strop does look a bit too long like that. The strop could be made adjustable from clutches on the coachroof which would allow leech tension/boom angle to be fine-tuned in real time but I don't need this for cruising. The one thing it can't do which your traveller can is allow you to easily ease the boom out but maintain the same leech tension (playing the traveller rather than the sheet). I don't find the main needs a great deal of leech tension upwind - I'm used to dinghies with fat head mainsails which do need a lot of kicker to make the leech stand up. I haven't noticed any change in round-up behaviour. Ours is a lift keel which is quite tender and quite prone to rounding up especially on a fetch or close reach if you get a big lifting gust - you can avoid it by playing the sheets or just watching for the gusts coming and rounding up into them a bit. I guess on yours you can dump the traveller in the gusts. I haven't sailed reefed down in heavy conditions with the strop yet, but I can't see that it will be any different. I have thought about using all 3 take-off points on the boom - the problem with that is that when the boom gets near the centre the mechanical advantage from the blocks diminishes because the rope angles get a bit silly. As the boom nears the centreline you would be putting more effort into trying to pull the takeoff points along the boom together than trying to pull the boom athwartships - hard to explain in words. The boom is pretty chunky and the main isn't that big - I guess I'll take my chances and try to avoid crash gybing. A better solution would be to move the take-off points a bit closer together and use all 3 - they are rivetted into the boom so not a 2 minute job but not that hard. If I were racing it would be a different matter - but then I'd have a gorilla to wind the winch for me so I wouldn't care how much grunt it takes
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Post by electricmonk on Aug 28, 2014 8:07:35 GMT
I agree with Tedp, don't move the tangs on the boom spread the load, its quite easy to bend the boom as it is and I've seen a couple that have pulled out of the goose neck with a gorilla on the winch!
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Post by mikebz on Aug 28, 2014 9:55:17 GMT
I don't doubt that this is sound advice. However...
If the strop length is just right then it doesn't take a great deal of effort to get the main block to block - after that the gorilla isn't achieving anything other than trying to break the rope, rip the winch off the deck, or rip the forward turning block off the deck, and isn't actually putting any more load on the boom. With the standard system you need the gorilla and hence put a huge amount more bending load into the boom. I think the reason for the 3 spread out tangs is because you (can) put so much downward force onto the boom with the standard system, with the strop this isn't possible.
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Post by tedp on Aug 28, 2014 14:49:08 GMT
If you make the strops adjustable you'd have more trimming options. But on a cruising boat probably a good trade-off that is sufficient for most conditions will work well enough.
I find my mainsail (which is slightly larger than the standard issue as the leech has been built out) performs best if I manage to let the top fly a little, i.e. allow extra twist. The top tell-tale is always slow to stream so the sail doesn't twist naturally. I occasionally have some backwind in the main when sailing close to the wind, but possibly the sail is cut too full.
Sailing closer to the wind with the boom in the centreline is something I will have to try myself first. I wonder how it will work in 12-15 knots, without reefing.
Finally, the rounding-up problem. Another Dutch owner who has the lift keel version says he has very little trouble with round-ups due to the twin rudders, one of which will always be deep under water. I have the fin keel version, which was difficult to handle with the original sheeting system. Adding the traveller has resulted in improvements - as you say I can slip the traveller a few inches and the pressure goes off the rudder. This is especially handy when sailing reefed. My mainsail when reefed is very flat and it responds very well to traveller setting. So the traveller is something I use with a reefed main rather than with the full main.
A good approach to avoid round-ups is to take a few rolls in the genoa, which then becomes less powerful close to the wind. Recently I sailed single-handed in 25-30 knots of wind, with the genoa area about halved and the main double-reefed. Not a trace of round-ups although the boat was flat on her ear.
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Post by electricmonk on Aug 30, 2014 7:08:34 GMT
Mikebz, I am still grappling with how a strop reduces the load on the mainsail (boom), given the main sail is the same mainsail and the wind is - well the wind, the old way of sheeting in the jib until it stops flapping and put 2 grunts in the mainsheet is still the same, strop or no strop. or is it the case that with a strop you are unable to sheet the main properly - because the blocks bind up - but you can hold the boom central? I can see how the strop could be superior to a mainsheet with a single point of attachment mid-ships, but its a bit of stretch to suggest its better than a mainsheet traveller. I shall continue to contemplate this arrangement.
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Post by mikebz on Aug 30, 2014 23:29:17 GMT
With the standard system (see pics from yachtsnet archive) you have to use a huge amount of sheet tension to get the boom nowhere near the centreline, most of the tension is pulling the boom down towards the leeward of the 2 coachroof attachments - this loads up the boom massively in a downwards direction. With the strop all the effort is pulling the boom sideways until you are almost block-to-block. In practice I can now pull the boom most of the way in by hand without using the winch, which says plenty about how much less load is required. I haven't claimed that it is superior to a traveller, but it is as good most of the time and very nearly as good the rest of the time, and doesn't need adjusting every time you tack.
Or to put it more simply, it takes a lot less effort to move something to where you want it if you pull it directly in that direction, not at nearly 90 degrees to the desired direction of travel!
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Post by iancymru on Oct 14, 2014 17:36:01 GMT
A really interesting idea using the strops and I see this is the system now employed on the new S349 and in the brochure it even gives a diagram showing the advantage of this stop system over the standard system, but then they do not use this on the 379 , why after singing its praises on the 349 , I think its a simple great idea but the only disadvantage I can see is where the original blocks were attached to the coach roof in the original system the load is being shared on both the port and stbd blocks on the coach roof, with this system it appears the load is mainly taken by the windward deck fitting especially if you tighten up on that strop. I just wonder if the 349 has those coach roof fittings beefed up.
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Post by singoviv on Oct 15, 2014 0:20:22 GMT
I plan to make my 349 adjustable. Being able to drop the traveller in a blow or fetch is important to me just as being able to move the boom closer to the windward side and easing the sheet to open up the power in light airs. Stay tuned for the mod when she arrives in January
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Post by mikebz on Oct 15, 2014 22:02:33 GMT
, I think its a simple great idea but the only disadvantage I can see is where the original blocks were attached to the coach roof in the original system the load is being shared on both the port and stbd blocks on the coach roof, with this system it appears the load is mainly taken by the windward deck fitting especially if you tighten up on that strop. You need so much less sheet tension with the strop that there must be a lot less load on the coach roof fittings than with the standard setup. With the latter the best you can get, even using the winch, is to get the boom more or less vertically over the leeward fitting - like that the leeward fitting is doing nothing to stop the boom from falling to leeward so the windward fitting is doing all of that work plus both fittings are taking more load due to the high amount of sheet tension. With the strop I can virtually centreline the boom without the winch.
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Post by iancymru on Oct 16, 2014 0:29:14 GMT
I m, sold on the strop idea as it now standard on the 349 Im just still not convinced that the windward strop deck fitting is not taking more weight. It maybe easier on the sheet because it is just providing sideways pull due to the fixed windward strop and kicker controlling the vertical forces, and with a traveller and ordinary system the load is spread between two points, however being honest Im not sure just speculating. I am having a 33i delivered in Feb and have asked for the german sheeting system and you definitely got me thinking into asking Jenneau to see if it possible to get the german sheeting incorporated with your strop system as per the 349 as you have proved it does get the boom close to the centre line. Have you noticed any difference on the tensions of the windward and leeward strops when sailing.
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Post by mikebz on Oct 19, 2014 20:58:30 GMT
As soon as you ease the sheet the leeward strop goes slack. That doesn't mean the windward one is taking more load though. There is so much less tension in the sheet when close-hauled that there has to be less load on the windward deck fitting than you have with the standard system and big tension winched onto the sheet - the sheet tension is transmitted directly into the deck fittings. With the standard system the leeward fitting is only contributing to holding the boom 'in' if the boom is substantially to leeward of the fitting. If the boom is directly above it then all the pull on it is vertical, thus the windward fitting is doing all the work of holding the boom in. If the boom is to windward of the leeward fitting then that part of the sheet is pulling the boom to leeward thus increasing the load on the windward fitting.
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Post by iancymru on Oct 19, 2014 23:29:36 GMT
It definitely sounds like its working well on your boat and have seen the bavaria 37 uses a two separate mainsheet system, one coming from each of the block position either side of the coach roof so you can pull up on the windward one to get the boom up into the wind so perhaps the weight is not that much of an issue. The disadvantage of that system is I suppose if you may not be able to spill the wind if the leeward one still on the clutch (just leave it off). Very interesting though definitely got me thinking.
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Post by mikebz on Oct 20, 2014 6:56:00 GMT
I should have added that the one time there will be more load on the windward fitting with the strop is when the boom is well eased - the standard setup loads both fittings quite evenly in that scenario. However when the boom is well eased the sheet loads are very low compared to when close-hauled.
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Post by iancymru on Oct 20, 2014 10:07:47 GMT
I did have a chat with the dealer about seeing if I could have a strop arrangement fitted on the 33i like the 349 (same as yours) and intimated that they were not happy doing doing it as it not a standard fit which Im not surprised at really and I think Jeanneau are monitoring how things pan out with the strop arrangement on the 349. Like you say once the boom is close to the centre line and as long as strops short enough the strop system will be sharing the load as the boom vertically above it, it would be interesting to hear from 349 owners to see how they are fairing as it seems a good solution for those with coach roof main sheets dreaming of a traveller.
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Post by kenlewis40 on Oct 20, 2014 14:09:39 GMT
I converted my SO 32 to the strop system a few months ago as suggested by Mikebz. While the new pulley arrangement works well in all sailing situations beating reaching etc, I am still worried about beating in heavy weather.
I was sailing this weekend, reefed in 26kt winds and all the strain was definitely on the windward strop and the one U bolt. Not a problem, if I you are sure of the fastening to the roof. The only way is to remove the headliners and have a look and possible strengthen the area and spread the load, which may not be an easy task. The U fixing is on raised platform on the deck therefore the nuts are probably in a recess under the deck.
Has anyone removed the headliner and had a look at the fixing and thickness of the deck?
Meanwhile, I will probably revert to the original sheet/pulley arrangement for the time being. Fortunately, it is only a fifteen-minute job to convert.
Ken Lewis
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Post by iancymru on Oct 20, 2014 14:47:09 GMT
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Post by kenlewis40 on Oct 20, 2014 18:23:22 GMT
Interesting comment from the above forum from "maby"
Quote from an engineer "He did recommend making up some reinforcing plates to put on the underside of the coach roof where the pillars supporting the track are bolted through - he was not confident that there was enough strength in the GRP to take the load in the event of a heavy gybe."
That's what worries me. Ken Lewis
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Post by iancymru on Oct 21, 2014 11:10:40 GMT
A slight distraction away from the original post but thought it of interest wrt strengthening have a look at page 28 on this forum and the article titled 'fitting a rooftop traveller to an SO32' Very interesting but very expensive too. Enjoy
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Post by ankl on Aug 7, 2018 12:06:44 GMT
I should have added that the one time there will be more load on the windward fitting with the strop is when the boom is well eased - the standard setup loads both fittings quite evenly in that scenario. However when the boom is well eased the sheet loads are very low compared to when close-hauled. Hi, mikebz I read your message about improved mainsheet system dated 2014. I am planning to do something similar for my SO32. Are you still using that system? Any positive/negative feedback? Any problems with load on attachment points?
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Post by mikebz on Aug 7, 2018 13:16:39 GMT
Yes still using it, still the original bit of rope from the bag of random bits of rope. No problems, works perfectly. It puts much less load on the that attachment points than the standard system because you don't have to grind on huge amounts of tension with the winch just to get the boom vertically above the leeward attachment. A lot of the time you don't need the winch at all, just pull it in by hand.
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