Emergency Forestay & Storm Jib

[jimi]

Eventually I'm getting an emergency forestay fitted to my Beneteau 331. However it would appear that I've got 2 choices as to where I can fit the deck attachment
1) Immediately behind the current bowfitting
2) Bit further back behind the anchor windlass

What do you reckon?

a) where will it best be fitted so that the boat would be best balanced under storm canvas.. ie trysail and storm jib?
b) is there any benefit in having it further back so that when conditions start to look dodgy it can be put in place with the storm jib hanked on ready for launching but still allowing scope to tack with the partially furled genoa passing between the emergency forestay and main forestay?

In addition what do I do with the stom jib sheets? Presumably the normal car is too far back,and will give too wide an angle on the storm jib if working to windward particularly if the emergency forestay is further aft.

Any thought on this would be greatly appreciated, thanks.

Jim

 

[ccscott49]

I'd have it fitted behind the anchor windlass, for the reasons you give, you can have the storm jib hanked on, but still in it's bag and sail the boat normally. A couple of snatch blocks, with quick release shackles on the toe rail, would suffice for the sheets. Thats if the Ben has a perforated toe rail and it's strong enough, I would expect it to be. The added benefit of an inner stay, is you could hoist a staysail, as as cutter.

 

[MADFISH]

Here Here. it will make for a better balanced boat as well.

 

[jamesa]

Not sure using the toerail is a good idea - the loadings are going to be very high (can't remember the exact formula, but a 100% foresail @30knts generates a load around double that of 150% sail @20knts). Last thing you want in storm jib conditions is a lump of toerail and/or snatch block flying about!

 

[ccscott49]

Sorry, but a 100% storm jib? or even a 100% staysail? I'm missing something, the pull on the sheets of a storm jib will not be ridiculously high, at the point of lead, may well be high at the winch.

 

[jamesa]

Not saying the storm jib is 100% - my example was for a number 3 genoa vs number 1 ('cos those are the figures that I could remember), but the idea is the same as you move to a storm jib. Point is that the sheet loadings increase exponentially with increase in wind speeds, so loadings for a storm jib will be very high (higher than your full genoa in a moderate breeze) despite the fact that its a small sail.

 

[charles_reed]

I know the conventional wisdom is to use a temporary/babystay for your storm jib, but my experience (thank God limited) is the usual storm jib is far too large under real storm conditions (I'm talking here of 52 knots mean). This conviction is borne out by the repeated comments in the reports in the Sydney/Hobart reports.

Certainly on boats the size of yours and mine the conventional wisdom probably needs reviewing and modifying.

If you are going to affix a babystay it needs to be well inboard and in a specially strengthened area of foredeck - the forces onvolved are enormous - not so much from the wind but from the sheer weight of water filling the sail. It also needs to be led into the mast at the correct position, on a fractional rig like yours it will need to be under the current forestay - I'd suggest talking to the mast manufacturer in detail on that one because they probably have a standard fitting.

Your sheet tracks need to be well inboard and forward of your current tracks, mine are mounted on the forepart of the raised coachroof on a specially strengthened mounting, and are used for the solent and working jib as well as storm.

In fact I use my working yankee, on the roller foil, 3 turns takes that down from 128ft2 to 48ft2, which is about 80% of the storm jib size and about right for work in F8.
The yankee is on a 600mm strop, and as it rolls up it delicately withdraws its toes from the water.
I've also got a 4th reef in the main rather than the complication of trysails, alternative tracks, boom-stowage points - that's also great for reaching on the autopilot in F7, so I suspect that I won't be trying to go to windward on it and the rolled jib, but rather use the main alone for heavy weather windward work.
Certainly beating up to Lagos in 35-40 knots it worked very effectively with the motor on at a fast tickover and the jib totally furled.

If you need a 60ft2, unused storm jib, you're most welcome to it - it's actually got a 5mm luff for a foil-fixing.

 

[Roberto]

You should also consider how the boat is built.

A removable forestay attached at the stem is usually much easier to fit, basically unscrew a couple of bolts from the fixed forestay chainplate, attach a ring chainplate with all the removable stay paraphernalia and there you go.

To place the removable forestay aft you must provide a secure way to spread the *big* load to the hull structure: you may have a bulkhead, but often it must be reinforced, all perimetral glassing to the hull plus the bulkhead itself; if you do not have a bulkhead then you must glass some form of support to the hull centreline, knee, stringer, run a rod from there to the under deck backing plate of the external chainplate. Sometimes for this setup you must modify forecabin joinery - structure, etc.

then.. why not both setups?

 

[bedouin]

No - it's certainly not exponential. I think it is just the square of the wind speed.

The whole point of changing sails is to keep the forces on the boat and gear reasonable so the forces on the sheet with the storm jib up will not be significantly greater than when flying the No1 Genoa at the upper limit of its wind range

 

[iangrant]

Jim
When we get to meet take a look at Sunbeats' inner forestay, running backstays and jib sheet arrangement.

Ian

 

[AndrewB]

Interesting ideas, thanks.

I would agree with you about having the sail inboard, on a cruising boat anyway. The major consideration is access: getting it up and managing it in difficult conditions. It will also work better there for heaving-to under stormsail alone. Right at the front may cause too much turning moment without a balancing main or trisail.

I also agree with you regarding the strengthening of the deck, but don't forget the mast. A true baby-stay really ought to have running backstays to balance it in a strong wind, as the risk of distorting or even breaking the mast is high. There is an argument for carrying the stay to just below the level of the actual forestay, even if the deck fitting is inboard. And then it can be used as a true emergency forestay as well.

I'm not so sure about size. There is an argument for two storm jibs. One that is capable of being used with a tri to keep the boat moving: in extremis to beat off a lee shore in say a F8. The other is not for sailing but holding the boat stable when hove to or running before the wind in even stronger winds. The latter should be smaller. My solution is to have a reefable storm jib.

And I don't agree with you on the position of the tracks. I've tried both in heavy weather and see no advantage in a separate, inboard sheeting position. Just use the normal tracks, and sheet wide. This will probably simplify access to the main sheet winches.

 

[dickh]

The position for the emergency stay should be no more than 12" down from the top of the mast, and the bottom going to the just behind your windlass. You can by Emerency forestay kits from sailmakers, I believe Crusader do one, with full fitting instructions and all bits & pieces. However, unless you have a bulkhead immediately under your windlass you will have to reinforce it to transfer loads to the hull. I have fitted a small wire strop with a turnbuckle leading to a "U" bolt fitting in th stem, with a stainless backing plate on the outside. Not very pretty but plenty strong enough. For the deck fitting I used a pair of deck plate, back to back, through bolted. For my stay, I already have an extra wire halliard and I use this winched tight, and the spinnaker halliard for the storm jib halliard. For the sheets, you will have to experiment for the best postion. On mine an extra block at the front of the genoa track is about right. Also I fitted the storm jib on a tack strop about 18" long to raise the foot and to see easily underneath.
Never used it in anger yet but seems to work OK when fitted in moderate conditions.

dickh
I'd rather be sailing... /forums/images/icons/smile.gif

 

[snowleopard]

re sheet leads, a recent article (PBO feb, p61) suggested that if the genoa track is too far aft you're better off using a block on a line as a barber hauler to alter the angle of the sheet rather than a potentially weaker second deck fitting. lines led from the toerail will usually give too wide a sheeting angle.

my old sailmaker told me to add a wire strop of around 1m to the tack of my storm jib so it was well clear of any green water coming across the deck. that also meant i could sheet straight to the genoa car and primary winches.

 

[charles_reed]

Yes the forestay fitting is far more critical than it at first sight appears, especially on a Beneteau where there is little in the way of over-design.
If you lead the babystay in at a spreader level and you have straight spreaders, you can probably get away without using running backstays, but with swept back spreaders, which you nearly always have on a fractional rig they are needed - hence my suggesting contacting the mast manufacturers - they'll know how much extra they've put into the calcs for cyclic shock and will probably have a standard fitting allowing you to take 2 forestays off at the forestay tang - certainly Z-Spars and Selden have them.

I have to vehemently contradict your point about sheeting tracks.

If you want to be able to use the jib to get to windward you need :
a) to reduce the slot
b) get the sheet lead far enough forward to get the right angle to keep luff and foot drawing
c) reduce the length of the sheet, between deck-block and tack

Normal genoa tracks are utterly useless on small sails - I know, I've tried.

 

[jimi]

I've actually got a masthead rig and there is an existing baby stay going to the spreaders but it really is too far back to use as a forestay and I'd also like the comfort of a 'true' emergency forestay as well! However I did think that I could perhaps barber haul from the baby stay U bolt to the storm jib sheet?

 

[ccscott49]

The only way, you will see if it works, is to rig it up temporarily and see how all the sheet runs work. You can use a halyard to simulate the inner forestay etc. Charles knows what he is talking about, obviously tried and tested, I would tend to listen.

 

[AndrewB]

\'Ping\' rather than \'twang\'.

I think you are correct that the loading per sq metre of sail is proportional to the square of wind speed when sailing with the sails stalled, i.e. running. But does the same apply in 'air-foil' mode on other points of sailing? And how do gusts affect the situation?

It certainly feels like exponential. My genoa sheets have never been as heavily loaded as the storm jib sheets on a couple of occasions (ping rather than twang), and indeed we now go up a size for the storm jib sheets.

 

[AndrewB]

KISS!

Things like a barber hauler are irrelevant to storm jib sheets, unless you sail on a lake. A close beat in an F8 plus on exposed sea is quite impractical: "full and by" is the word.

Try to keep things as simple as possible: think of rigging on a pitching foredeck, sea-sick, on a dark night, deafening noise, with a rather panicky crew trying to cope with the steering. What's more anything not simple, robust and well-tested could well get tangled and add to your problems.

 

[Strathglass]

My storm job (88 sq ft) has a 24" wire strop fitted by the sailmaker (Hood) on the tack. This lifts the sail clear of the guardrails.
The sail has been cut with a high clew which when combined with the strop enables the normal genoa track to be used. This means that the sheets are in their normal position which takes another complication away in heavy weather.

 

[webcraft]

Has anyone tried these storm jibs that snap on round a furled headsail?

<font color=blue>Nick</font color=blue>
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