Mahe 36: Rig and Sails

[Jef & Marin, Netherlands]

Hi all,
Previously we have used the standard mainsail.
The last two weeks we have sailed with our new mainsail. This was a great experience.
The new mainsail is a special version:
- It has a square top.
- It has been made of Hydranet. This is a material of Dacron and Dyneema woven together.
- It has a triradial cut
- It has 3 reefs.
I understood from Incidences it is the 2nd Hydranet sail they delivered for a Mahe.

Our boat has become notably faster in lighter winds.
With the old mainsail, we normally reached speeds of about 55% of the true windspeed. With the new sail this is about 60-65 % of the windspeed. This is 10-15% faster.
See the pictures of the mainsail and of the instruments (where you can see the boat's performance).
We now reef earlier than with the standard sail, especially close-hauled. With one reef in the mainsail, we reached the same speed as with the original mainsail without reef. This was at winds of around 16-18 knots.

The sail just fits (very tightly) in the lazy bag, so you have to take care to really fold it well to fit. Also it is heavier.... I have to eat more spinach to hoist the sail!

Of course there is a cost penalty, but for me it is absolutely worth it. Miss Poes became faster; and I hope that the Hydranet and the triradial cut will let the sail keep shape longer. And you need your engine less often.
And I hope not to need the 3rd reef.... But expect we will. Anyhow, our insurance requires a 3rd reef if we go cross-ocean anyhow.
Jef

[Ascension]

Jeff, thanks for the info and the photos. Will definitely be considering both hydranet and square top for our next main.

Just one question, have you had to adjust the shroud tensions / set up?
I've found that when beating to windward in 15/18 knots the leeward shroud is noticeably slack. I haven't been able to find any guides on rig set-up / tensions for the Mahe.

Any advice welcome!

[Jef & Marin, Netherlands]

John,
I notice the same thing, in about 18 knots the tension of the leeward side stay is zero.
With the square top sail I reef at 15-16 knots when sailing close hauled. The square top sail reaches the same boat speed with one reef as unreefed with the standard sail, and I want to let the sail last a long time. Remember that at 16 knots of wind, when close-hauled the apparent wind is above 20 knots.
It is possible that due to setting of the hulls, the tension has become less.
There is a standard guideline for tensioning the stays, which is based on the assumption that a stay with a certain diameter has a certain safe working load, and should be tensioned to a certain percentage of that working load. That is equivalent to tensioning the stay so, that it reaches a certain percentage of stretch.
This is described on page 29 of "Hints and advice" from Seldenmast.com. This book is a free download.

Another method, which I will follow, is:
- Sail the Mahe close hauled at 18 knots of wind.
- Tension the side stays manually to take out the slack
- Check once in the harbour whether you can still open the doors in the hulls (-;

I do not know what Fountaine Pajot's preferred solution is. I do know that opening of the doors really depends on stay tension.
Jef

[Ascension]

Jef
Thanks for the reply, it's good to know you've encountered the same issue.

I would certainly expect a reduction in tension of the leeward shroud when beating in fresh conditions, but at the moment its completely slack and this has got to introduce unnecessary dynamic loads and associated fatigue.

The Selden guide is very useful, I still have a copy which I downloaded for a previous boat which had a Selden rig. Though I think the static rig tensions suggested (15-20%) are probably on the high side for a Mahe.

It would certainly be nice to have some advice from FP/Z-Spars.

In the mean time, I'll continue using your second method and slowly increase the shroud tensions when sailing, as yet the cabin doors still open!

[eyschulman]

The slack lee stays are not so important - the bend of the mast and its position and any motion are what counts- adjustments under sail should be made on the lee side while rig is slack then tack over and evaluate the change.

[jean1146]

May be some of you can help me with this question. I am at the point to order a spinaker for our mahe,assymetric it is. I am trying to get by without installing a new winch,I am thinking about using one of the existing one for the starboard side which is going to be no problem,but what about the port side? I was thinking about running the sheet trough several blocks right along the traveller all the way to the starboard side and also use the same winch....what do you think? is the pressure going to be to much to go all the way around? I hope that you can see what I am trying to explain.
Thanks for any comments.
JC. Mahe#25.

[DtM]

Hi JC,

Back in April 2008 you said you were going to retro fit a bowsprit. Did you do that? you will obviously need something to project this sail well forward at the tack. you will need to be able to downhaul the tack as well.

We had a bowsprit from the factory and they also installed a winch all the way aft on the port side for the screecher sheet. We use this for both sheets running the starboard sheet across the cockpit in line with the traveller (as you describe). The turning blocks are all the way aft under the stanchions.

I am not sure that using the winch in front of the helm will be very easy but I guess that you will only use this sail on long legs. No doubt you have checked the angles. I don't think there will be any pressure issue. Maybe a friction issue but again I assume it will be long legs in set and forget mode.

d

[Jef & Marin, Netherlands]

Hi Jean,
We got the spifurl and bowsprit from FP.
This comes with a winch on the port side (Harken 32 ST2). The starboard sheet can either be put on the startboard (mainsail) winch, or on the port spinnaker winch.
We have sailed with this configuration for two years, and were unhappy with it for the following reasons:
1. When under spinnaker. especially when sailing over starboard, you need to walk forward a lot to watch for ships and buoys under the spinnaker. The spinnaker sheet running right of the helm is then a PITA.
2. It becomes hard to adjust you mainsail when the winch is in use ...
3. When you use the port winch for both sheets: It is nicer to have two winches when gybing the spi, especially when there is wind.
4. This has to do with the shape of the jib, and the position of the jib sheet blocks on the roof: The jib is only set nicely when close-hauled. When the wind is beam, the jib loses a lot of power due to being too loose at the top. We then use a 3rd sheet on the jib, with a block tied to the midship mooring clamp. This sheet goes to the spinnaker winch. But there was no spi winch on starboard...
With a beam wind, the force is distributed about evenly over the two sheets. In aft winds, almost all force goes to the outer sheet.
Especially when running with the wind, sails in butterfly configuration, the jib is much more stable when you use the block attached to the middle mooring clamp

Seeing all the above, this winter I mounted a Harken 40ST2 on starboard. I am very happy with this. Except that he Harken 40ST2 is too big, a 32ST2 would have been sufficient. This would have saved money and weight.

I would advise you to mount stainless steel plate under winches. And mount stainless steel plates where you attach the spi sheet blocks, above and under deck. Otherwise you get gelcoat cracks. See picture. Position of spi sheet blocks could be better: a little bit more to the outside.

[jean1146]

Well you know I am not planning on having a bow sprit,instead I probably will use an ATN tacker,I understand they work very well,you can check it on the internet,and tell me what you think of it. Another solution would be to have the tack point on each bows,anyway I will only use the spinaker on long haul. I have not decided anything yet on another winch and its location.
JC.

[DtM]

Agree with Jef in relation to barber hauling the jib sheet once off the wind.

On the Mahe we use a snatch block on the shroud forward of the turning block.

On the Orana we use a snatch block led down to the midships padeye (as Jef does).

This can be a very powerful sial combination.

d

[Jef & Marin, Netherlands]

Jean,
I would worry about a few things with an ATN tacker:
-The force on the aluminium profile within the jib, in stronger winds. The tacker will go a strong force which is quite localized.
- Wear on the UV shielding part of the jib, e.g. when gybing the spi. We gybe the spi quite a lot, becuase we do downwind tacking. When the wind is e.g. at 1650-160 degrees, we butterfly part of the trip, and the other part sail at 120-140 degrees.
- Less effect of the spi since it is less forward than on a bowsprit.

Maybe I worry too much, on the other hand Murphy is especially valid for yachts.

If you don't want a bowsprit, maybe you could use 2 lower lines on the spi, one going to the lower end of the jib, the other one going to a bow. And then tune the lengths of the two lines depending on wind angle.
I can't do this since we have a furling spi, but if you use a spi sock I guess it is not difficult.
For gybing the spi 3 lines would maybe be easier.
Good luck, Jef

[jean1146]

Jef.
I think you are right about the ATN tacker. I will use the bows and a bridle to adjust the height like some one suggested earlier in the thread,very simple.
Thanks .
JC.

[Jef & Marin, Netherlands]

We probably all know what happens to the port jib sheet sometimes. For instance when reefing the jib, or when tacking:
The port jib sheet disappears from your reach at the helm station, and you have to walk around to retrieve it.
Finally, after sailing over 10000 nm with Miss Poes, I found a good rope guide. See the pictures.
This guide has a stainless steel core. This is most probably necessary, a simple plastic one would wear out. Also I think the construction is strong enough to withstand the force on the sheet from a flapping jib.
Additional benefit is it keeps the sheet off the roof, maybe reducing wear from the anti-slip on the sheet.

A small improvement.....

[MKB53]

Hi All

I currently have the gennaker that I got as a standard option. This works well in the right conditions (as high as 50deg apparent) but when sailing deep it is not much good unless goosewinged.

I am thinking of getting an assymetric spinnaker and would appreciate any feedback on
a: Offwind performance improvements
b: What size? What is the standard Spi size and would you go bigger?
c: Does it work off the prodder when sailing deep? I am thinking of taking the tack lines to the bows for real downwind conditions.
d: Is it worth putting this on the furler or sticking with a sock. I am thinking of the sock.
e: I have the old drum furler on the gennaker but am planning to replace this with a continuous line furler as the drum is not good with a flying sail. Any comments on using a continuous line furler would be appreciated.

Jeff - I fitted a jib sheet pad eye similar to yours - it makes all the difference!

Cheers
Martin

[Jef & Marin, Netherlands]

Matin, others,
i have the spifurl as supplied by FP. I don't know the size. It has a Facnor FX2500 continuous furler. Answers to your question:
a. Performance:
TWA - True wind angle, TWS - True wind speed.
Optimum at 120 TWA. We reach speeds of max. 70-75 % of TWS, even 80 % below 6 knots TWS in flat water. With the square top sail. e.g. 4 knots of boat speed in 5 knots TWS.
Can be used until 100-110 TWA with flat water. At 100 TWA hardly better than the jib, because it is too round.
Good at 140-120 TWA. Useful at 150 TWA, but large coverage by the mainsail. Useless at 160-170 degree TWA due to coverage. OK at 180 in goosewing of course.

b. Size - don't know. But bigger is not useful I think. Only by attaching a spu higher up the mast, but maybe that is not allowed due to forces on the mast.

c. Taking the spi to the bow for deep wind angles would really be useful, but it has the following problem:
It is i.m.o necessary to be able to remove the spi in the windshadow of the mainsail, for safety in increasing wind. As a consequence you have to be able to move the spi from upwind to centre position when deployed. I would not know how to solve this safely with the continuous furler and double lines at the bottom of the spi. Any suggestions?
There are (at least) 3 option for mounting the spi off-centre:
1. Using double lines at the bottom, one to the bowsprit and the other to the luff hull.
2. Using a track for the spi, like on the Gemini 105; very attractive but needs to b engineered well;
3. Just flying the spi off the luff bow. I think Lori has told us on the forum that she did this once, using a spi from her previous Gemini.

d. Furler or sock: Furler is nice, works well. Can be done shorthanded, deployment can be done single-handed, for furling it is nice but not necessary to have someone who lets go the sheet while the other furls.
And sometimes we set the spi with the jib still on; don't know if this works with a sock.
But sock is simpler and cheaper.

e. Continuous furler:
Risk with a continuous furler is unwanted unfurling, so I tend to always remove the furled spi when switching to jib, except in light winds when I expect to need the spi again.
And a single-line furler would need a lot of line for a spi which rolls around the forestay, especially if the spi is furled from the centre like with the spifurl.

I hope this helps.
Jef