How important is a bar-taut forestay?

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JimC

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A previous owner fitted my boat with twin forestays to enable a hanked-on storm jib to be used independently of the furler. Their top ends go to a small triangular plate which pivots at the mast so the tension is equal on both stays. My problem is that, with this arrangement only giving half the normal tension in each stay, I can't get a straight luff on the roller-genoa when hard on the wind - and I feel the boat's pointing ability is suffering as a result. Any suggestions? Also, am I correct in thinking a bar-taut jib luff is essential for close-windedness?
 
I had the same arrangement on a Victory 40. I also had rather heavily sagging forestay. I changed to a single forestay, and then to a roller foresaty. Yes thare was less sag. Did she go better to windward - probably - but she was not close winded anyway, and we often motor sailed to windward, especially when are destination was dead to windward.

I regreted the loss of being able to put sails up for the right conditions - the bag in the roller had a far more detrimental effect than the sagging forestay!

BUT - for cruising around locally, the roller jib was a great shortcut to getting the sales out.

I think you should draw up a little decision chart with the pros and cons. You will probably end up with a roller jib, and a detachable inner forestay for the storm jib for the convenience.

Chris
 
My problem is that if I tension the forestay (Furlex) roller system too much, it causes high forestay roller bearing forces which make furling the head sail very much harder.
My boat is cutter rigged and I have a Furlex stay sail also, experiencing a similar problem also if this is tightened too far.
 
Twin forestays, athwartships, are one of those things that look good on paper, but just don't work.

You can't get them to work together, the one with the sail sags and its brother stays tightish. Tack and the stays cross over, hanks get caught up and there is a fair amount of bad language as it all gets snarled up.

twin forestays set up fore 'n' aft can work if they're not too close together.
 
I think you have the answer there Chris. Years ago I had an old 46ft wooden boat with a "normal" forestay and a removable inner forestay. It also had a bowsprit with....but never matter! The point is that with a roller on the forestay it needed to be tight all the time and was. If and when I wanted to hank on a smaller jib (which I did sometimes as heavily reefed rollers are like a sack of spuds) it was a piece of cake to clip on the inner stay and tension it. A good rig if its just for a storm sail is a stay that can live normally clipped on to the inner forestay (assuming you have one) which is no longer than that, but can easily have a 4-1 block & tackle attached to clip on and tension quickly. The sail has to be hanked on above the B&T of course but with a stormsail its fine.
 
without going down too technical a route....

In an ideal world, your headsail should have been cut to suit a certain sag in the forestay i.e when it has it's nominal design tension. If you tension the forestay beyond it's nominal, the sail will flatten, loose power but as you say - have a tighter luff entry therefore perhaps enabling better VMG wind. The problem is that if you maintain this tension, you will be limiting the sails power when off the wind or in light airs as the tightness is not allowing the sail to develop its true designed shape.....

If you leave it too loose then it won't point up so well but will be great in light airs when your fellows around may have just given up and started to motor home!

Ideally it needs to be adjustable to suit the different sailing circumstances.

We have a mast head rig and have left our forestay at pretty much the least tension possible. When we want more tension for less power or better pointing, we consider the pressure on the main and kicker (both pulling the mast back and therefore increasing forestay tension) and if nesc, wind up the backstay to increase tension some more. This action also flattens the main too which is suitable for the exact reasons you're doing this in the first place.

Re furling systems:

The forestay tension should not be transmitted through any furling system. Almost all have the forestay running through the middle of the drum and it is therefore not part of the system. I believe the poster having drum problems may have suffered from excessive halyard tensions (which do go through the drum bearings), not forestay tensions although of course he knows his boat far better than I do!! Halyard tension and power/pointing ability is another issue....

We have a lovely tri-radial rolling head sail made by Kemp. Cut ever so slightly flatter, with padded luff and no UV stip (this builds up the diameter of the rolled up sail in all the wrong places, the padded luff pads it out in all the right places!), the sail is almost as good anywhere from 60% to full size. It's the best i've ever seen. Still can't beat individual sails though I guess.

Hope some of that may help!

Cheers, Rob
 
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Twin forestays, athwartships, are one of those things that look good on paper, but just don't work.

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I wouldn't say that. The tension is not good, to the extent of the stays crossing as you've said but I've never had the hanks snag. All I can do is wind up the halyard as hard as possible. If you use wire luffed sails and wire halyards with a rope tail this will improve. I'm also told that getting a sail maker to cut the foresails to take account of the sag will help.
Personally I value the convenience when reefing above other factors, I much prefer rope luffs for ease of handling and put up with only tacking through 100 degrees.
 
[ QUOTE ]
My problem is that if I tension the forestay (Furlex) roller system too much, it causes high forestay roller bearing forces which make furling the head sail very much harder.
My boat is cutter rigged and I have a Furlex stay sail also, experiencing a similar problem also if this is tightened too far.

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I'm pretty sure from what I remember of my Furlex that what you describe should not happen because the extrusion is simply rotating round the forestay independant of the load on it.. Indeed, the greater the tension on the rig, the easier should be the furling since you are not trying to furl an extrusion which has a curve in it.

If your memory is correct (ie you are not mixing up the tension on the rig and that on the haliard) then check your rig because it suggests that some load is being transferred from forestay to extrusion and the extrusion is contributing to holding the mast up.

Better still, talk to Selden in case I'm talking rubbish.
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[ QUOTE ]
[ QUOTE ]
My problem is that if I tension the forestay (Furlex) roller system too much, it causes high forestay roller bearing forces which make furling the head sail very much harder.
My boat is cutter rigged and I have a Furlex stay sail also, experiencing a similar problem also if this is tightened too far.

[/ QUOTE ]

I'm pretty sure from what I remember of my Furlex that what you describe should not happen because the extrusion is simply rotating round the forestay independant of the load on it.. Indeed, the greater the tension on the rig, the easier should be the furling since you are not trying to furl an extrusion which has a curve in it.

If your memory is correct (ie you are not mixing up the tension on the rig and that on the haliard) then check your rig because it suggests that some load is being transferred from forestay to extrusion and the extrusion is contributing to holding the mast up.

Better still, talk to Selden in case I'm talking rubbish.
/forums/images/graemlins/ooo.gif

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I have Furlex gear, what you say makes sense, I wonder too, is the lead from the halyard to top swivel at the right angle to give the swivel a chance i.e. min 5-10deg., makes a huge difference.
 
Yes certainly get rid of the redundant forestay. If you need another forestay for storm jib this should be inboard (behind) the main forestay and removable at deck level.

Yes the forestay will always sag and the jib hopefully has some concave cut in the luff to suit. (but this is probably cut on the assumption of tight forestay) You should have an adjustable backstay so more trension can be put on the forestay when beating in strong winds to make the jib as flat as possible. Less backstay in light winds. good luck olewill
 
As previous posters have said the current system will not work and always produces the problems you discribe. There is however a third option between a single roller furler and a removable inner forstay called the 'slutter rig'. This has a second fixed stay for either hanked or roller headsails mounted to fill about 90% of the fore tryangle ie 10% from the masthead and 10% back fron the stem. It has its own bottle screw so each stay is tensioned independently and this get around the problem with the setup you have where whichever stay the sail is set on sags because of the sail load. The down side is that it creates significantly higher mast compression and rig loads as you still have 2 loaded forestays and the load has to go somewhere. Clearly if you want to do this you need to consult a rigger or the boat designer to check that she will stand the extra load.

The other issue is that if you get too much sag in roller gear it can cause chafe between the foil and the stay. This can cause the roller gear to stiffen (that might be you problem) but more importantly can damage the forestay and cause the rig to fail. I think you are right to be concerned as if the forestay fails the mast is apt to land in the cockpit rather than overboard!!
 
Thanks everyone for your advice. I shall now dispense with the second forestay and fit a demountable inner stay for the storm jib when needed.
 
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