Putting a circuit breaker in a downwind sail

[DoubleEnder]

I’m not sure if this is the correct forum, but here’s the question.

Imagine a single handed, fractional rig smallish wooden yacht say 22 feet. The wooden rig is 3/4 maybe 11/16, with a standing backstay and runners. I’m thinking about a masthead cruising chute for light conditions. So a pretty lightweight sail, no pole, lovely.

But what happens if the wind suddenly freshens and I can’t get to the mast to drop it quickly? Are there any cunning tricks to make sure the halyard breaks, before the mast breaks? A sort of fuse or circuit breaker.
I guess a careful measurement, and a length of light line in the halyard, with the appropriate breaking strength, down at the cleat? But would the strain be fully transmitted over the sheave and down to deck level? Would it be better to have the breakable section of line attached to the head of the sail?

Maybe if I’m doing this then what I really need is to lead the halyard aft to the cockpit, but I’m interested to hear any other thoughts

 

[B27]

I think relying on the halyard running out smoothly without tangling and jamming when a gust hits might be a mistake.
You could put the weak link at the head of the sail, but then, should it break, you need to drop the mast or get up there to re-reeve it.
Your runners will give no sidewise support to the masthead, unlike say, a jumper struts and diamond stays.
A decent asy will tend to put a fair side load on the mast even in quite light airs, because it brings the apparent wind forwards a lot.

OTOH, the mast takes a fair amount of pull from the backstay?
There are self-releasing clamcleats, I've used them for dinghy rudder downhauls but they are crude and not very adjustable.

I do like the idea of a big masthead asy as a 'ghosting sail' but I'd want to understand how strong the mast was...

 

[Puffin10032]

If the halyard breaks (either accidentally or by your design) the bulk of the spinnaker will fall into the water and you'll probably sail over it.

 

[r_h]

I think relying on the halyard running out smoothly without tangling and jamming when a gust hits might be a mistake.

That's what we do as standard practice when racing solo or double handed. In preparation to drop the sail we trail the halyard in the water behind the boat - that way you can be sure it won't get tangled or snagged as the sail comes down, though it does need a halyard led back to the cockpit.
As soon as the spinnaker is up and set the halyard is flaked out with the tail ready to go over the side, in case a quick drop is needed.

I really don't like the idea of a weak link in the set up - as mentioned that's a recipe for sailing over the kite and a mammoth mess to sort out.
There's also no need to worry about the backstay not being strong enough - if it's a well found boat that's well set up something else will fail, or you'll broach, a long time before the backstay gives way.

 

[Gurrig]

I’m not sure if this is the correct forum, but here’s the question.

Imagine a single handed, fractional rig smallish wooden yacht say 22 feet. The wooden rig is 3/4 maybe 11/16, with a standing backstay and runners. I’m thinking about a masthead cruising chute for light conditions. So a pretty lightweight sail, no pole, lovely.

But what happens if the wind suddenly freshens and I can’t get to the mast to drop it quickly? Are there any cunning tricks to make sure the halyard breaks, before the mast breaks? A sort of fuse or circuit breaker.
I guess a careful measurement, and a length of light line in the halyard, with the appropriate breaking strength, down at the cleat? But would the strain be fully transmitted over the sheave and down to deck level? Would it be better to have the breakable section of line attached to the head of the sail?

Maybe if I’m doing this then what I really need is to lead the halyard aft to the cockpit, but I’m interested to hear any other thoughts

Verey Pistol?

 

[PeterV]

Can you not ease the sheet in a gust like you would for any other sail?

 

[jlavery]

As others have said, a fuse is almost definitely a bad idea.

There's a seamanship/planning aspect to this problem.

If you're flying an asymmetric or conventional spinnaker short handed, then it's vital to make sure you have sea room to bear off and drop it if the wind freshens. Bearing off to collapse it behind the main is vital. That would be my plan for dropping - others may have different approaches. If it's a well found boat the rig should survive a flogging spinnaker. If there's a possibility of a rig-threatening gust, you shouldn't be flying the sail.

 

[Daydream believer]

The tack line should be lead aft with plenty of length (+ lots of spare) so it easily reaches the cockpit. One then needs a reliable jammer or cleat that can be quickly released on the cabin top. There are some that flip over & the line flies out immediately. Of course this downhaul needs to be properly flaked to allow it to run. Then the sailor can grab the sheet & by carefully easing the halyard ( possibly unjamming it but leaving one slack turn on a winch drum for friction) he gathers the sail in under the boom, whilst stuffing the sail down the hatch until basic control has been maintained. All lines can then be taken back to their correct starting points for later use
.
One can make a flip over jammer for the tack line, by fixing a timber to the deck with a hinge at the front. At the back you put a plastic tube with a screw through it. On the deck you have 2 more plastic tubes placed vertically such that the horizontal one fits tight between the two. bending the two slightly together to form a dovetail to hold it & provide the correct tension. On the top of the wood goes a jam cleat. Its position along the wood also adjusts tension as does the length of the wood. So it is all trial & error to get the right "fly off" point.
You could just put a loop of string over the horizontal screw & a quick pull from the helm position will release it rather than fighting a jammed cleat.
You might find a pop type door catch to do the same job which would be better & adjust fly off load by where you position the cleat on the wood.
At least with this system you only get the tack released & can recover the sail. With a stopper in the tack you can pull it back in when the gust has passed.

 

[jlavery]

The tack line should be lead aft with plenty of length (+ lots of spare) so it easily reaches the cockpit. One then needs a reliable jammer or cleat that can be quickly released on the cabin top. There are some that flip over & the line flies out immediately. Of course this downhaul needs to be properly flaked to allow it to run. Then the sailor can grab the sheet & by carefully easing the halyard ( possibly unjamming it but leaving one slack turn on a winch drum for friction) he gathers the sail in under the boom, whilst stuffing the sail down the hatch until basic control has been maintained. All lines can then be taken back to their correct starting points for later use
.
One can make a flip over jammer for the tack line, by fixing a timber to the deck with a hinge at the front. At the back you put a plastic tube with a screw through it. On the deck you have 2 more plastic tubes placed vertically such that the horizontal one fits tight between the two. bending the two slightly together to form a dovetail to hold it & provide the correct tension. On the top of the wood goes a jam cleat. Its position along the wood also adjusts tension as does the length of the wood. So it is all trial & error to get the right "fly off" point.
You could just put a loop of string over the horizontal screw & a quick pull from the helm position will release it rather than fighting a jammed cleat.
You might find a pop type door catch to do the same job which would be better & adjust fly off load by where you position the cleat on the wood.
At least with this system you only get the tack released & can recover the sail. With a stopper in the tack you can pull it back in when the gust has passed.

Yes, being able to run or blow the tackline on an asymmetric is vital - as you say, it allows the sail to collapse and be retrieved with the sheet. Halyard control has been mentioned already.

 

[dunedin]

I’m not sure if this is the correct forum, but here’s the question.

Imagine a single handed, fractional rig smallish wooden yacht say 22 feet. The wooden rig is 3/4 maybe 11/16, with a standing backstay and runners. I’m thinking about a masthead cruising chute for light conditions. So a pretty lightweight sail, no pole, lovely.

But what happens if the wind suddenly freshens and I can’t get to the mast to drop it quickly? Are there any cunning tricks to make sure the halyard breaks, before the mast breaks? A sort of fuse or circuit breaker.
I guess a careful measurement, and a length of light line in the halyard, with the appropriate breaking strength, down at the cleat? But would the strain be fully transmitted over the sheave and down to deck level? Would it be better to have the breakable section of line attached to the head of the sail?

Maybe if I’m doing this then what I really need is to lead the halyard aft to the cockpit, but I’m interested to hear any other thoughts

Firstly, irrespective of any “fuse” arrangement you need to be very careful attaching a spinnaker or asymmetric any material distance above the hounds (where the side stays attach). The side forces from a spinnaker, particularly if anything goes wrong and broach, are massively higher than from other sails. What represents a safe distance depends on the mast, but some wooden masts are tapered above the hounds and could be as little as 6 inches above on a 22 footer.

A halyard fuse at the top might save the rig - but cause bigger problems when boat stops dead with full mainsail, as sail falls under the hull.Yes race boats may talk about “blowing” the halyard, but they have crew waiting to pull in the sail, and often another person on mast who can slow the drop if risks dropping into the water.

So a spinnaker at hounds level, and not above, plus a tack line release - or better furler system - might be best.

 

[jlavery]

As others have said, a fuse is almost definitely a bad idea.

There's a seamanship/planning aspect to this problem.

If you're flying an asymmetric or conventional spinnaker short handed, then it's vital to make sure you have sea room to bear off and drop it if the wind freshens. Bearing off to collapse it behind the main is vital. That would be my plan for dropping - others may have different approaches. If it's a well found boat the rig should survive a flogging spinnaker. If there's a possibility of a rig-threatening gust, you shouldn't be flying the sail.

Summary "seamanship/airmanship is the art of using judgement to avoid the need for skill".

 

[oldbloke]

The important thing when "blowing" the halyard is to ensure the sheet is , and remains, pulled in hard. Then the kite will flow out to leeward and remain out off the water.
Letting go of any one of the corners will work, but don't let two go.
Paradoxically, oversheeting also works and is often used by fast boats , skiffs, cats etc as it is more controllable and avoids flogging and shaking b7t probably not useful to the poster's situation.

 

[Chiara’s slave]

Getting rid of the thing is not much of an issue, surely. We are asymmetric powered, when sailing as deep as we can. Blowing the tack line while bearing off collapses the sail in the lee of the main. That is the reason that our handbook has ‘DO NOT USE THE SPINNAKER WITHOUT THE MAINSAIL’ in bold capitals. We use a snuffer even so. Some love them, some hate them, ours is just a lot of material to deal with for one person.
We’d never oversheet to deal with too much power, it would have to be a bear away, and PDQ too. Easing the sheet works too, just not as easy as bearing away. Personally I wouldn’t consider a ‘circuit breaker’. Just be on top of your game when flying spinnakers.

 

[B27]

Some asy dinghies, the main leach tension helps stop the kite pulling the masthead forwards, so the main must not only be hoisted, if it's windy it needs shhet and some kicker.

I think there are quite a few boats around with fractional rigs which would take a masthead kite in light airs, it's not useful to generalise too much.

 

[Chiara’s slave]

Some asy dinghies, the main leach tension helps stop the kite pulling the masthead forwards, so the main must not only be hoisted, if it's windy it needs shhet and some kicker.

I think there are quite a few boats around with fractional rigs which would take a masthead kite in light airs, it's not useful to generalise too much.

I daresay ours needs mainsheet tension, but that’s not really an issue, it’s always got that. The kite halyard is well above the hounds.

 

[dunedin]

I daresay ours needs mainsheet tension, but that’s not really an issue, it’s always got that. The kite halyard is well above the hounds.

…… but on a rig professionally designed and built to have a masthead spinnaker.
It is the addition to a rig not designed for it that is the issue

 

[Chiara’s slave]

…… but on a rig professionally designed and built to have a masthead spinnaker.
It is the addition to a rig not designed for it that is the issue

Of course. Ours has the factory rig, it’s very simple, just a 13.6 m carbon round 8’’ tube with diamond stays. They take the pressure from the main leech. The kite puts no more pressure on than the diamonds probably. The OP should certainly bear in mind the strain on his rig. His way around that seems to be the idea of an automatic release. I don’t see that working.

 

[DoubleEnder]

Thanks everyone. It’s hypothetical and I’m grateful for the input. The rig in question is made of spruce, is quite slender above the hounds, and is supported by diamonds and a jumper stay. I think you guys are tight & realistically that the masthead kite idea is unwise, and even more so as I’d be single or shorthanded. It’s not a big boat, and has a very small foretriangle. A chute set from the hounds would of course be better than nothing but I was trying to think of a way of juicing things up a bit. I am now persuaded this is a bad idea!