Possible causes of genoa jamming?

[neil_s]

I suspect your furling line feeder arm is bent so that it feeds the line into one edge of the drum instead of the middle. When you try and pull out the genny, the furling line all gets fed into one side of the drum and quickly jams it. Had this problem just after re-launch a few days ago. I guess I accidentally stood on the feeder arm while re-stepping the mast.

 

[steve yates]

When was the drum washed with fresh water?

Never, well probably when boat was jetwashed, last may, but not deliberately.
How often should it be? Its a plastic drum.

 

[steve yates]

I suspect your furling line feeder arm is bent so that it feeds the line into one edge of the drum instead of the middle. When you try and pull out the genny, the furling line all gets fed into one side of the drum and quickly jams it. Had this problem just after re-launch a few days ago. I guess I accidentally stood on the feeder arm while re-stepping the mast.

I’ll check that out tomorrow neil.

 

[steve yates]

Do not get new rigging. Stick some packing under the mast foot. That is what I did on my deck stepped 12.5 m long mast. I just put a filler under the shaped mast pad & put the bolts back through that as well as the original mast foot.

I’ve done a lot to the boat, its one of the last areas to upgrade, It uses to get used a bit heavily and prob will again if I have longer periods to play, so it would be reassuring to know that was sound. No immediate rush but definitely on the list.

 

[steve yates]

Which boat is this? If it is the Bradwell then shortening the shrouds by using lashings rather than the chain plates or screws , or even (as a very temporary proof of concept) by tensioning the shrouds together with a Spanish windlass or similar should give enough rig tension to see if that is the issue.
Not so easy on a big boat though.

It is indeed the bradwell. The fittings are swaged tho, and also, the furling has worked fine for the last year, I cant see them being this particular problem?

 

[Porthandbuoy]

Do you have a spinnaker halyard made off at the pulpit? It can get got up at any stage of the wrap and cause a jam.

Check your sheeting angles. Sheet too far aft and the foot of the sail will furl tight while the top will be slack. It’s the opposite if the sheet is too far forward. Either can result in a partial wrap before it snarls up.

Does your furling line have a fair lead onto the centre of the drum? Too high or too low and the furling line will fill up the top, or bottom, of the drum and jam with the sail partially furled.

 

[roaringgirl]

Mine did. Twice. Both sets each changed at 10 years. This last set just fitted has been cut 25mm shorter than the set just removed on uppers, mids, lowers . Original fixed length forestay has been sustituted with an adjustable one, so not sure if that has been affected

Are you sure? More likely that the hull flexed.

Stainless steel wire's elastic limit is around 60% of the breaking strain. Selden recommends you tension your rigging to around 15% of the breaking strain of the wire so you should never be anywhere near stretching it.

 

[Daydream believer]

Are you sure? More likely that the hull flexed.

Stainless steel wire's elastic limit is around 60% of the breaking strain. Selden recommends you tension your rigging to around 15% of the breaking strain of the wire so you should never be anywhere near stretching it.

I set mine at 22% on the uppers, mids & lowers are less which is where I get max performance up wind. That gives me 50-60mm pre bend & 150mm bend when backstay is on. I have seen notes where North also suggest that. 15% would give me slack rigging to leaward when hard on the wind in 18-20kts with no reef.
I always have to re tension after a few weeks when I have new rigging. Each season I usually have to take a turn on the turnbuckles.

 

[roaringgirl]

I set mine at 22% on the uppers, mids & lowers are less which is where I get max performance up wind. That gives me 50-60mm pre bend & 150mm bend when backstay is on. I have seen notes where North also suggest that. 15% would give me slack rigging to leaward when hard on the wind in 18-20kts with no reef.
I always have to re tension after a few weeks when I have new rigging. Each season I usually have to take a turn on the turnbuckles.

To be fair, I was quoting for a single-spreader rig. Off the top of my head, I don't know what multi-spreader rigs are set to. For reference, here's the Selden guide to rig setup: https://support.seldenmast.com/files/1605537330/595-540-E.pdf

I'll put a lot of money on none of them being anywhere near 60%

You're having to re-tighten as the hull moves, not as the wires stretch. I can't remember for sure, but I think this might also be covered in Selden's guide.

 

[Daydream believer]

To be fair, I was quoting for a single-spreader rig. Off the top of my head, I don't know what multi-spreader rigs are set to. For reference, here's the Selden guide to rig setup: https://support.seldenmast.com/files/1605537330/595-540-E.pdf

I'll put a lot of money on none of them being anywhere near 60%

You're having to re-tighten as the hull moves, not as the wires stretch. I can't remember for sure, but I think this might also be covered in Selden's guide.

I doubt if the hull moves up 25mm as this would be in the width , not the length & it would be at a strong point of the boat moving upwards against a keel stepped mast. Only 1.5 metres apart on plan

I built an extension on a church where the architect wanted 8mm steel wires across the bottom of the trusses to avoid heavy timbers spoiling the view up into the roof. These were to stop the trusses spreading outwards. There was a lot of discussion about how much tension I should apply. I forget the exact details, ( it was 30 years ago - I won an award for the job!!) but it certainly stretched them to the full length of a bottlescrew at one end of the wire leaving the other one to be further tightened at the 6 month maintenance period. I was not present when that was done so I do not know how much further it stretched. But it did stretch again. It certainly would not have pulled the walls, or several tons of roof, in.

As for boat bending. I do know that the designer of a 3/4 tonner (Dingo) stretched a line from bow to stern through the boat & then tensioned the rig & measured something line 1.5 inches of bend on the boat. They measured from the keel to the line as the boat bent. That was something that pleased him as he thought that amount of bend was quite small.
So boats do bend quite a bit & a masthead rig with tight backstay & forestay could bend a boat. However, I do not have a mast head rig.

 

[Refueler]

I was replying to you not Steve

Then make it clear that the quote used is such. Because it is understood that a quote is the intended recipient.

 

[Refueler]

Mine did. Twice. Both sets each changed at 10 years. This last set just fitted has been cut 25mm shorter than the set just removed on uppers, mids, lowers . Original fixed length forestay has been sustituted with an adjustable one, so not sure if that has been affected

Usual .... all ropes / wires when a laid construction will slightly extend over their life. It is usually only a few mm ... but its there.

 

[Sandy]

Never, well probably when boat was jetwashed, last may, but not deliberately.
How often should it be? Its a plastic drum.

I wash the drum with fresh water at every opportunity as it stops the build up of 'salt crystals', personally I consider it to be the build up of crap from the air - but I have overwintered the boat beside the M5 (you should have seen the amount of crap I removed from the decks) and sail in areas where the big ships spew out exhaust gasses from the engines. If you have not washed down the drum then it might be worth doing and applying some grease if they are greasing points. If you are enthusiastic and have the instructions stripping it down and giving it a full service just like your winches would be in order.

 

[Refueler]

I wash the drum with fresh water at every opportunity as it stops the build up of 'salt crystals', personally I consider it to be the build up of crap from the air - but I have overwintered the boat beside the M5 (you should have seen the amount of crap I removed from the decks) and sail in areas where the big ships spew out exhaust gasses from the engines. If you have not washed down the drum then it might be worth doing and applying some grease if they are greasing points. If you are enthusiastic and have the instructions stripping it down and giving it a full service just like your winches would be in order.

If Plastimo ... not generally advised to grease ... just wash out the crap and that's it.

I've seen people use / suggest hot water .... some even boiling ... personally IMHO - no. Warm OK - to help dissolve salts etc. - but not hot. Its plastic !!

 

[bignick]

Check the top of your foil as you unfurl your genoa. If the top swivel isn’t turning freely then the halyard can wrap around the top of the foil as you unfurl it, which causes exactly the symptoms you describe. This normally happens if you’ve either got lots of halyard tension on or if you haven’t got a halyard deflector fitted below the sheave.

 

[roaringgirl]

I doubt if the hull moves up 25mm as this would be in the width , not the length & it would be at a strong point of the boat moving upwards against a keel stepped mast. Only 1.5 metres apart on plan

I built an extension on a church where the architect wanted 8mm steel wires across the bottom of the trusses to avoid heavy timbers spoiling the view up into the roof. These were to stop the trusses spreading outwards. There was a lot of discussion about how much tension I should apply. I forget the exact details, ( it was 30 years ago - I won an award for the job!!) but it certainly stretched them to the full length of a bottlescrew at one end of the wire leaving the other one to be further tightened at the 6 month maintenance period. I was not present when that was done so I do not know how much further it stretched. But it did stretch again. It certainly would not have pulled the walls, or several tons of roof, in.

As for boat bending. I do know that the designer of a 3/4 tonner (Dingo) stretched a line from bow to stern through the boat & then tensioned the rig & measured something line 1.5 inches of bend on the boat. They measured from the keel to the line as the boat bent. That was something that pleased him as he thought that amount of bend was quite small.
So boats do bend quite a bit & a masthead rig with tight backstay & forestay could bend a boat. However, I do not have a mast head rig.

You are clearly more experienced than me at working with rigging. I am keen to learn. What part of the stress/strain graph have I not understood?

 

[oldbloke]

It is indeed the bradwell. The fittings are swaged tho, and also, the furling has worked fine for the last year, I cant see them being this particular problem?

I was addressing your ,reasonable, concern that a lack of rig tension was causing the issue and that your current setup meant you couldn't increase your rig tension .
Another even easier way to increase forestay tension on a small boat is just to heave the mainsheet in as hard as you can.

 

[Refueler]

Check the top of your foil as you unfurl your genoa. If the top swivel isn’t turning freely then the halyard can wrap around the top of the foil as you unfurl it, which causes exactly the symptoms you describe. This normally happens if you’ve either got lots of halyard tension on or if you haven’t got a halyard deflector fitted below the sheave.

Add to the causes : Slack forestay ....

 

[Sandy]

If Plastimo ... not generally advised to grease ... just wash out the crap and that's it.

I've seen people use / suggest hot water .... some even boiling ... personally IMHO - no. Warm OK - to help dissolve salts etc. - but not hot. Its plastic !!

My late mother returned to nursing after I was born some 61 years ago, family legend goes, Sister shrieked at Doctor as he put plastic instruments in an autoclave. Materials had moved on since she left on maternity leave, but yes if there is a manual refer to it about the maximum temperature to wash you drum - I wonder if it goes as far as recommending soap or detergent

I carefully said if they are greasing points and am quite sure that @steve yates understood what I meant.

 

[KAM]

What type of furling gear is it. I had a quick look at posts but couldn't see any mention.