Reefing line position

[Stemar]

The single line reefing on Jissel (24ft, so loads aren't enormous) are tied off at an eyelet on one side of the boom, go up through the leach cringle and down to a fixed block on the other side and forward. On my old sail, both were a bit aft of the cringle when it's pulled down.

My new main has a longer foot and more roach than the old one, so I need to move the blocks and eyelets aft, giving me an opportunity to rethink how they work. Most professional systems seem to have the line tied off round the boom more or less in line with the cringle and a block in the end of the boom. Is this just because it's easier to put all the blocks at the end of the boom, or is there an advantage to having one side vertical(ish) and the other pulling aft, compared with having both pulling at the same angle when the reef's pulled down?

If having both sides at the same angle is better, what's the optimum?

 

[vyv_cox]

I think that if both the fixed end and the turning block were at the end of the boom the mainsheet loading would cause very high loadings along the axis of the boom. There is a strong likelihood that the cringles would pull out, especially on second/third reefs. The method in which the end of the pennant is tied off around the boom offers the greatest vertical strength and the aft-led line to the turning block tightens the foot of the sail.

 

[john_morris_uk]

Bearing in mind that many boats are rigged with reefing pennants that tie round the boom at the fixed end and are free to slide, I am not sure that you need to panic too much. If you are going to have a fixed end to some sort of eyelet then it must certainly be just aft of the reefing point of the sail. The reef must be pulled down and aft to be effective.

 

[Poignard]

Bearing in mind that many boats are rigged with reefing pennants that tie round the boom at the fixed end and are free to slide, I am not sure that you need to panic too much. If you are going to have a fixed end to some sort of eyelet then it must certainly be just aft of the reefing point of the sail. The reef must be pulled down and aft to be effective.

That's exactly right.

On my boat the ends of the reefing pennants are attached to eyelets below the boom. These are positioned 3 to 4" aft of the reef cringles. Each pennant leads up from the eyelet, through the reef cringle, then around a sheave at the end of the boom and along the boom (internally) to the gooseneck where there is a rope clutch for each pennant.

As the pennant is tightened it pulls the reef cringle down and aft.

Once the reef is pulled down, I pass a lashing around the boom and through the reef cringle - just in case the reefing pennant breaks or comes free (it never has yet )

 

[charles_reed]

The single line reefing on Jissel (24ft, so loads aren't enormous) are tied off at an eyelet on one side of the boom, go up through the leach cringle and down to a fixed block on the other side and forward. On my old sail, both were a bit aft of the cringle when it's pulled down.

My new main has a longer foot and more roach than the old one, so I need to move the blocks and eyelets aft, giving me an opportunity to rethink how they work. Most professional systems seem to have the line tied off round the boom more or less in line with the cringle and a block in the end of the boom. Is this just because it's easier to put all the blocks at the end of the boom, or is there an advantage to having one side vertical(ish) and the other pulling aft, compared with having both pulling at the same angle when the reef's pulled down?

If having both sides at the same angle is better, what's the optimum?

Of my two single-line reefs, the 1st, on which both bitter end and block are angled, always pulls in better than the 2nd, which follows standard practice of the bitter end around the boom, below the reef cringle, and the pulley to the aft end of the boom. Whilst at first sight that might be contrary to Vyv's theory, it might also be down to the fact that all the pulleys are ultra-low friction Harken Aerolite (now CarboAir) on the 1st reef but have two plain bearing blocks in the second.
I can confirm that the loads are considerable - just inside the SWL for the then-largest, 60mm block they produced. All the negotiations were with Harken US, who were very helpful (UK were slightly out of their depth).
I'd opt for having both ends at the end of the boom - but my mainsheet is in the centre of a 110mm deep boom for a mainsail of only about 32m2. With and end-of-boom mainsheet fixing the boom loads would be far better distributed.

 

[Stemar]

Thanks, everybody.

I found that the load needed to pull down the leach was excessive when the line just went through the luff cringle and down the other side, but got a lot better when I put blocks at the luff cringles.

Tying the bitter end round the boom is a non-starter for me as I have a homemade stackpack with boltrope in the boom slot. Ideally, I'd have a few feet of track that would allow me to experiment, but I'm far too tight for that, so when I fix things, I have to get it right first time! I should be able to do something temporary with some string to experiment, though. I'll have a play this weekend.

 

[Daydream believer]

If at any time you decide to place slots in the boom cover i would suggest not fixing the dead end of the reef line to an eye but to take it under the boom & fix it to the block. This will give a down ward pull on the block to counter the upward pull of the reef line on the block. This supports the fixing & one only has to worry about the high horizontal load as the reef line goes forward to the gooseneck

 

[john_morris_uk]

Thanks, everybody.

I found that the load needed to pull down the leach was excessive when the line just went through the luff cringle and down the other side, but got a lot better when I put blocks at the luff cringles.

Tying the bitter end round the boom is a non-starter for me as I have a homemade stackpack with boltrope in the boom slot. Ideally, I'd have a few feet of track that would allow me to experiment, but I'm far too tight for that, so when I fix things, I have to get it right first time! I should be able to do something temporary with some string to experiment, though. I'll have a play this weekend.

We have a stack pack with rope in the boom slot. The stack pack has zips in it that allow the reefing pennants to pass through and round the bottom of the boom. Three two way zips on either side so you can adjust the gap so its 'just right'. Sometimes sailmakers know what they are doing?

 

[John the kiwi]

I had to set mine up from scratch.
I needed to use a fixed point on the boom as a starting point as the sail foot is in a track. I figured that the resultant or net direction of force from the reef line on the leach cringle is found by bisecting the angle that the reefing line makes on each side of sail.

I wanted a lot of outhaul effect as well as pulling the sail down as i have older dacron sails so i set the fixed point in the boom a little aft of the position of the cringle. The rope then goes almost horizontal to the outboard end of the boom, round a sheave and internally to the goose neck.
(After all, no point in reefing if the resultant smaller sail is so baggy that it catches more wind than the full sail did. This was actually the reason i had to change systems.)

Maybe i fluked it but i achieved the effect i wanted: firmly down and firmly back using just the reefing line.
I know that some people just use the reef lines to pull the sail down and reattach the out haul to pull the sail back.
Trying to reconnect the out haul on the end of a boom that is shaking around in the conditions that caused you to reef in the first place held no appeal for me.

Good luck