In-mast furler jammed with full main out.

[Sandy Feet]

Hi all, we had an interesting experience yesterday which I thought I’d share for the benefit of others with the same in mast furling system.
Please note this post is to share the experience and not re-open the in-mast furling vs slab reefing debate which has been done to death.
The boat is a beneteau oceanis 45 with selden in mast furling. The furler has a spiral grooved drum inside the mast which only allows one row of furling line to be spooled, a semi-circular cowling around the back of the drum prevents multiple falls from building up.
We set off to sail to Rottnest Island just off the Perth coast in around 12 knots of wind. We unfurled the main with the out haul and it came out easily but then once all the sail was out the outhaul jammed with quite a bit of slack in the foot of the sail. To get the last bit of slack out when the sail isn’t luffing requires a bit of grunt so we winched away until there was quite a bit of tension in the outhaul but it wouldn’t budge. At first I thought the car was jammed but then I looked at the furler and the answer was instantly clear. A few weeks earlier I’d fitted a strap around the mast to hold the spare halyards and rail mounted whisker pole tightly to stop them banging in the wind whilst in the marina, this time I’d forgotten to remove said strap which happened to go around the furler drum mast slot about halfway up. As the furling line was spooling onto the drum whilst the sail was going out the line had been prevented from following its natural fleet angle by the strap and now the line had managed to complete one turn back over the drum. The cowling around the back is meant to prevent that and has quite a tight tolerance but with the tension on the furling line it had managed it and was now firmly jammed.
Lesson 1. Always ensure the furling slot is clear and watch it as the sail unfurls!
At initial glance it didn’t seem so bad, out came the pliers and a screwdriver to open the gap and free the line. Had the line been jammed on one side of the cowling that may have worked but was wedged solidly on both sides and the line had crossed at almost a 45 degree angle, it was rock solid, absolutely no chance! The access into the drum is very limited and apply any force is next to impossible. So the dilemma was all of mainsail out, fully jammed and within the hour we were expecting the seabreeze which was forecast to be close to 30 knots, said seabreeze at this time of year is like a light switch, it just comes on suddenly and strong. Knowing we had limited time to figure out how to unjam the sail before the whole situation went from annoying to bad we decided the safest course of action was to douse the sail. I made a quick call to the rigger that had installed the mast and sails, he suggested to just drop the sail with the halyard using the spare halyards on either side of the boom as a kind of lazy jack to contain the sail. On looking closer we saw there was in fact still one turn of sail on the furler meaning no chance of dropping it this way. The only thing I could see to do was to roll up the sail vertically starting from the clew. We connected a spare line to the clew and cut away the outhaul. Rolling the sail from the clew worked amazingly well and within 10 seconds the whole sail was rolled up neatly against the mast. Knowing the wind would get strong later and easily undo the neat package I decided to go up the mast and tie the bundle in tightly. Unfortunately I’d taken my climbing harness off the boat the previous week, I did however have some climbing webbing slings so I made a temporary harness which quickly earnt the title of “the nutcracker”
Lesson 2: Always carry mast climbing equipment on board.
With the sail fully contained we had a cup of tea moment where we could just sit back and make some decisions. In the end we agreed to keep going to our destination as we’d only need the headsail and the main was safe, we also decided that the only way to solve the jammed drum would be to extract the whole assembly from the mast. So with a chest of tools we unbolted the assembly, the gooseneck boom pin was preventing it from coming out so that had to be backed out as well after securing the boom with additional rigging but eventually the whole lot could be lowered out with the main halyard. From there it was a simple case of unbolting the cowling from the back of the drum and freeing the jammed furling line. The cowling had actually been bent a little around the line was effectively cammed onto it so there was never any way we could’ve unjammed it. This whole process actually only took about 15 min and could’ve easily been done with the sail out. Had any of the bolts not come out though it would’ve been a different story.
Lesson 3: Preventative maintenance, if any fittings you may have to remove at sea look like they’re getting corroded or seized then remove, re-grease with the suitable compound and re-fit, at the same time you’ll know if you have the right tools for everything on board.
Once everything was back to normal (apart from a furled sail on the outside of the mast instead of inside) we continued the trip and eventually dropped the pick in the crystal clear waters of Rottnest. From here we thought it was all over and we’d just unroll the main and furl at the same time but there was one more test. We started to unroll and furl but the furling was a bit too quick and part of the folded section of main went into the mast slot. It looked like the jam was halfway up and the outhaul was pulling downwards not outwards as was required. Out came the nutcracker again. On going up I realised the whole top half of the sail was jammed so I had to go up meter by meter and heave the rolled up section back out through the slot. This was actually far harder than anything else we had to deal with, especially with the wake from big passing motorboats turning the mast into a medieval style catapult. But eventually the sail was in and all was back to normal.

In summary the experience was all about a seemingly minor oversight that lead to some much bigger problems. It has however given us a lot of confidence that if the worst should happen with the in mast furling it’s actually not that bad if you have access to the mast and the right tools to dismantle everything. Hopefully we wont have a next time (lesson learnt) but if the same happened again we wont bother trying to douse the sail, we’ll secure it, and pull the furler again as we know we could probably do it in under 10min next time. When I was doing my research on in mast furling I couldn’t find much info on what to do when it all goes wrong so hopefully this story will help somebody sometime.

[Dockhead]

Yikes! What a story! Fantastically useful; thanks for posting.

I had actually never heard about anyone getting a jam in the furling line mechanism itself -- very instructive. I also have a Selden in-mast furling system, but it sounds different to yours -- on mine, the furling line just takes a half turn around a drum which is located outside and behind the mast, with a horizontal axle. If that jams, you would just remove two screws to remove the shroud and Bob's your uncle. You can pull off the furling line altogether if you like and furl or unfurl directly with a winch handle. I wonder whether yours is a new or older system than mine?

Thread drift warning: One think I dislike about my furling system is that you really can't use it single-handed. You must keep tension on the lazy side of the furling line, in order to engage the drum. If you fail to keep tension on both sides of the furling line, the drum can get out of control, and with it, your sail, which you really, really don't want to do in tougher weather. So that does not leave a hand free to tension the outhaul, which you also must do in order for the sail to roll in smoothly. I have done it solo since I single hand sometimes, but it is a real juggling trick, and I think not very safe.

What is needed is some kind of self-tailing mechanism to keep tension on the lazy side of the furling line without having to do it manually. I wonder if anyone knows a way to do this.

[OldFrog75]

What is "’"? It keeps showing up in the OP.

[carstenb]

Originally Posted by Dockhead

Yikes! What a story! Fantastically useful; thanks for posting.

I had actually never heard about anyone getting a jam in the furling line mechanism itself -- very instructive. I also have a Selden in-mast furling system, but it sounds different to yours -- on mine, the furling line just takes a half turn around a drum which is located outside and behind the mast, with a horizontal axle. If that jams, you would just remove two screws to remove the shroud and Bob's your uncle. You can pull off the furling line altogether if you like and furl or unfurl directly with a winch handle. I wonder whether yours is a new or older system than mine?

Thread drift warning: One think I dislike about my furling system is that you really can't use it single-handed. You must keep tension on the lazy side of the furling line, in order to engage the drum. If you fail to keep tension on both sides of the furling line, the drum can get out of control, and with it, your sail, which you really, really don't want to do in tougher weather. So that does not leave a hand free to tension the outhaul, which you also must do in order for the sail to roll in smoothly. I have done it solo since I single hand sometimes, but it is a real juggling trick, and I think not very safe.

What is needed is some kind of self-tailing mechanism to keep tension on the lazy side of the furling line without having to do it manually. I wonder if anyone knows a way to do this.

Dockhead, I had the same problem when I had in-mast. I solved by lengthening the "endless" furling line enough that I could put my foot on it to keep tension. This worked well enough in calm weather, not so well when the sh*t hit the fan

[Tingum]

Well done!

[Sandy Feet]

I think ours is a new system as it's quite a new boat. Here is a pic of the jam but you can't see the cowling that trapped the furling line.

[Sandy Feet]

Where the line comes put is were the strap was so it stayed in the right position for a long time before skipping away. Btw ours is easy to furl/unfurl single handed.

[JPA Cate]

No offense intented, but there is one more lesson I take from the experience: if something starts to require more force than you expect, that is the moment to start checking everything. Our winches can really increase our problems because cranking on them ups the forces so much. So, if it wants to unroll or roll up, fine and good, but if it resists, go hunting for anomalies.

[Vasco]

Originally Posted by Ann T. Cate

No offense intented, but there is one more lesson I take from the experience: if something starts to require more force than you expect, that is the moment to start checking everything. Our winches can really increase our problems because cranking on them ups the forces so much. So, if it wants to unroll or roll up, fine and good, but if it resists, go hunting for anomalies.

Good advice. If it takes more force than usual stop and check. There's usually a reason. More force doesn't help, just breaks things. And like most I learned the hard way.

[leftbrainstuff]

Great narrative. Thanks for sharing.