Wishbone booms

[Hirilonde]

Reefing sequence is

1 Release halyard the right amount (I've marked it at the right length).

2 Pull down tight on the luff downhaul/reefing line that is clipped with an S hook to the reef point.

3 Pull on leech reefing line on the boom and cleat.

4 Tie the lines around the sail bundle to tidy up.

A topping lift is also good to stop the boom crashing onto the deck, and easing the snotter before reefing and retightening after seems to make it easier.

That is exactly how I reef my main on my Renegade, cept I have a conventional boom.   The only thing I would add is a step between 4 and 5 where you tighten up the luff on the now reefed sail with the halyard.  Or is your halyard marking line so accurate that you can tension the luff with the new tack reefing line?

[tom151]

At the luff end I simply added another downhaul that goes to the reefing cringle and led it back to the cockpit (so you don't have to get onto the foredeck to shift the downhaul).

Reefing sequence is

1 Release halyard the right amount (I've marked it at the right length).

2 Pull down tight on the luff downhaul/reefing line that is clipped with an S hook to the reef point.

3 Pull on leech reefing line on the boom and cleat.

4 Tie the lines around the sail bundle to tidy up.

 

This has worked very well so far.

A topping lift is also good to stop the boom crashing onto the deck, and easing the snotter before reefing and retightening after seems to make it easier.

I have snap hooks to attach reefing lines and topping lift so it's very quick to rig.

 

Cheers

Peter HK

Peter,

Thanks for the video and the details above.

I don't have a similar rig but hope to, so this is of real interest.

Seeing the pic of the way you have the boom rigged to tension the clew at the reef cringle made me curious about the procedure.

I'd appreciate your thoughts on the "what if" that went thru my mind...

What if, you release the main sheet, before releasing the halyard, then pull the leech reefing line to pull the boom up to the reef cringle. Then lower the halyard. The reasoning biung that that sequence might replace the need to rig or fiddle with a topping lift altogether.

Like I said, I son't have a sprit boom rig to experiment with (yet) so maybe your experience, in real life with all the lines and rigging, you might see the error of that thinking.

Any thoughts you care to share would be appreciated,

TomH

[Peter HK]

That is exactly how I reef my main on my Renegade, cept I have a conventional boom. The only thing I would add is a step between 4 and 5 where you tighten up the luff on the now reefed sail with the halyard. Or is your halyard marking line so accurate that you can tension the luff with the new tack reefing line?

The halyard is spectra so has little stretch. I've marked it's position at the cleat so there is at most a centimetre or 2 of variation in sail position depending how carefully I cleat it. I use the tack reefing line to tension the luff. 

Cheers

Peter HK

[Peter HK]

I'd appreciate your thoughts on the "what if" that went thru my mind...

What if, you release the main sheet, before releasing the halyard, then pull the leech reefing line to pull the boom up to the reef cringle. Then lower the halyard. The reasoning biung that that sequence might replace the need to rig or fiddle with a topping lift altogether.

Like I said, I son't have a sprit boom rig to experiment with (yet) so maybe your experience, in real life with all the lines and rigging, you might see the error of that thinking.

 

Hi TomH

 

What you suggest can work with a standard boom (if you ease the vang) but not a sprit boom. A sprit boom is self vanging...the foot tension holding down the end of the boom. This is what makes the sheet tensions so low as there is no need to pull the boom down as well as in. This also controls twist when eased. What it also means is the end of the boom won't move up. In your scenario you can't pull the boom up to the reef cringle. You have to let the sail down first.

You don't have to have a topping lift but if not you might scratch the boat or have the boom caught under the coaming and inadvertently fill the main if the mizzen doesn't hold you exactly head to wind.

It takes me 10 seconds to attach the topping lift.

Cheers

Peter HK

[Joe Anderson]

Peter

 

Is your topping lift rigged when you first set up the boat and fly the entire time you are sailing?

 

My wooden sprits( the main is almost 14 feet long) are intended to take only compression loads. I am not always very quick at seeing unintended consequences.

 

On your aluminum sprits I would not think you would have to be concerned about levering on the sprit to pull down the clew, but I wonder if I do.

 

If the sequence attach topping lift, lower halyard, tension luff, tighten reefing line at clew is followed are there no significant bending loads on the sprit? Perhaps ease snotter should be in there somewhere.

 

When I followed the reefing discussion in the earlier thread there was a heavy fog, but it is beginning to lift. Thanks!

[tom151]

Hi TomH

What you suggest can work with a standard boom (if you ease the vang) but not a sprit boom. A sprit boom is self vanging...the foot tension holding down the end of the boom. This is what makes the sheet tensions so low as there is no need to pull the boom down as well as in. This also controls twist when eased. What it also means is the end of the boom won't move up. In your scenario you can't pull the boom up to the reef cringle. You have to let the sail down first.

Peter HK

Peter

I can see your point on the geometry of the foot of the sail vanging the boom, thanks for for further explaining.

[Peter HK]

Is your topping lift rigged when you first set up the boat and fly the entire time you are sailing?

 

My wooden sprits( the main is almost 14 feet long) are intended to take only compression loads. I am not always very quick at seeing unintended consequences.

 

On your aluminum sprits I would not think you would have to be concerned about levering on the sprit to pull down the clew, but I wonder if I do.

 

If the sequence attach topping lift, lower halyard, tension luff, tighten reefing line at clew is followed are there no significant bending loads on the sprit? Perhaps ease snotter should be in there somewhere.

I attach the topping lift when rigging and it stays there while sailing...there is an adjustment on the boom for length.

The only lever could be if you reef without easing the snotter- then the reefed clew can be forward of the end of the boom resulting in the pull of the mainsheet  being some distance from the clew. This could result in breakage. The solution is easing the snotter so the boom can move forward, the loop of the reefing line around the boom slides aft and the reefed clew is pulled to near the end of the boom, eliminating the lever arm.

Re-tension the snotter after it's all done

 

Cheers

Peter HK

[Joe Anderson]

Holy Cow I had not thought about that at all.  I had thought that one of the advantages of this type of reefing as opposed to resetting the sprit tip in the reefing clew was that you would not end up with half of the sprit sticking out forward of the mast.

 

OK We do not want the reefing clew too far from the sheet.

 

That is worth a cheer.

 

Joe

[tom151]

OK We do not want the reefing clew too far from the sheet.

 

That is worth a cheer.

 

Joe

Joe, I was imagining that (with PeterHK's system) the forward end of the sprit would end up at very nearly the same distance from the mast as when not reefed. And not thinking that would be a problem because of the very light sheet loads these rigs have.

So, is that your concern (sheet loads bending the sprit)- or is it something I'm not getting?

Any thoughts PeterHK?

Thx,

[Joe Anderson]

The only lever could be if you reef without easing the snotter- then the reefed clew can be forward of the end of the boom resulting in the pull of the mainsheet  being some distance from the clew. This could result in breakage.

 

If you double reef without moving the sprit boom forward the clew could end up attached to the sprit boom a couple of feet forward of the sheet attachment.(Just guessing) Now add 25 knots of wind and an accidental jibe and I think you could snap the sprit.

 

You are right the sprit boom has lower sheet loads than a traditional boom, but I think that has to do with the sprit boom holding the clew down so the sheet only pulls the sail in and out. I would presume the same effect could be had by adjusting the boom vang on a traditionally rigged boat. The sail is only attached to the sprit at the clew so all forces generated by the sail are concentrated there. There must be a reason I have 4:1 blocks on my mainsheet.

 

Jibes with sprit booms are remarkably tame I think in part because of the light weight of the sprit boom, but in a good wind you can generate quite a pop.

 

I did not consider any of this until Peter mentioned it.

[Peter HK]

I suppose the important thing about a lever is that it amplifies the force put in depending on how long the lever arm is.

Here are some photos showing how the clewline is rigged and also how far forward the clew can end up if you don't let the boom move forward by easing the snotter. 2 of these photos were taken when I was first fitting the system during the build and testing the 2nd reef. The boom isn't designed for this so I think it is good practice to not to stress it, remembering when you reef is usually in heavier conditions when the forces are likely to be higher and sheet tensions significant.

Peter HK