How does it work? Leech reefing line passage in the boom.

[szymk]

Ahoy!

The respectable users of this forum already helped me to explain several mysteries of my second-hand Irwin 41 that I'm getting to know. The puzzle for today is: how is this supposed to work? I'm talking about the reef line system that you can see in the photos attached to the post. Namely, there is a pulley for each line that runs from the cringe on the leech of the mainsail inside of the boom and then there is... right, what is this thing? :neutral: It's a solid metal ring with knurled surface mounted on an excentric axis. In the little schema I show how I use it today: I thought it might be just a simple cam cleat. But then, the pulley doesn't make that much sense... And the knurled surface makes pulling the rope through it that much harder...

I bet many of you have seen this solution already or even have it on your boat. So, what's the secret?? How am I supposed to use it?

Greetings to you all!

Szymon

 

[Gunni]

It looks like a version of a single-line reefing system. Google that up and see how the line routes.

What I think you will find is that the reefing line ties off at the boom end, up to the aft reef point, down to a boom-end sheave (white like the one you picture), and forward to the gooseneck where it wraps the white sheave, heads up to the forward reef point and then back down to that black eccentric sheave which looks very much like a reef line cleat. Report out.

 

[Apex]

Re: How does it work? Leech reefing line passage in the boom

the offset cam: think mini-blinds: It is for holding power.

 

[Ron20324]

Re: How does it work? Leech reefing line passage in the boom

I assume your reef lines do not run back to the cockpit, looking at how they hang loose. This would indicate you have to be at the front of the boom to reef, then operated that "cam" cleat to secure the reef. I'd say the white sheaves are there to lift the line off the cams somewhat, but not completely. The cams should drop away from the cleated postion normally, but maybe they are rusted shut, making your lines harder to pull?

 

[szymk]

It looks like a version of a single-line reefing system. Google that up and see how the line routes.

What I think you will find is that the reefing line ties off at the boom end, up to the aft reef point, down to a boom-end sheave (white like the one you picture), and forward to the gooseneck where it wraps the white sheave, heads up to the forward reef point and then back down to that black eccentric sheave which looks very much like a reef line cleat. Report out.

That must be it! I don't think the original owner finished the implementation but that's something I can actually try! So, the eccentric rings are just jammers, but they are probably made for a rope which comes from above, not from the end of the boom.

Ron: they actually work pretty well, but they make tightening the rope more difficult.

Thanks, guys! Another question (probably) solved by the vigilant sailboatowners community

Best regards,

Szymon

 

[Joe]

Re: How does it work? Leech reefing line passage in the boom

What happens if you reave the lines UNDER the white sheaves, then over the black cam. Could that provide the leverage/contact needed to activate the cam action?

Quite frankly, I would simplify the system rather than spend too much time on one that obviously has issues.... redirect the control line back to a cleat near your cabin top winch and you have a much more reliable set up. There are many yachts that have the reef lines led internally through the boom to a set of blocks at the end, up to the reef cringle then tied round the boom in the appropriate location. The idea is to get a backward pull on the reef cringle to remove any camber from the lower section of the sail. The end boom design also facilitates the control lines being easily lead aft for crew convenience

My experience on my friends Island Packet, which is set up like this, is that the first reef has somewhate adequate tension on the clew, but second and third reefs do not, because the reef clew is so far from the end of the boom, there's just not enough downward tension with that angle. You have to manually tension the line that's stretches between reef clew and the boom end to get it snug.... then lash the reef clew to the boom with a separate piece of short stuff.