Single line mainsail reefing on IP35

Mike:

I have been looking at the idea of removing the shuttle blocks in the boom and simply running single line reefs. The goal is to eliminate the boom shuttle so that the reefing lines run easier and free. This idea can be accomplished with out adding anything and by just using existing gear. To improved on the idea, blocks could be added at the sail friction points, but may not be needed. These lines would need to be monitored for chafe but then again, it would be very easy to simply cut off the end and tie the bowline at a new point.

My idea rigs like this: Start at the cockpit, run to the mast using existing reef gear, turn at the base of the mast go up to the reef point in the sail, turn back down run into the boom at the gooseneck. Run out the boom end and up to the sail reef point, turn and come back down to the boom where you tie a bowline around the boom.

This is illustrated here.



I have not yet installed this, but now with my boom and mast off, this may be the time to try it out.

What do you think?

It seems to me that this would work well, and there really is not much force when reefing if you drop the halyard and keep the tension off that. Then once it is in, you can load it up with the halyard again.

Hayden

Mike:
I thought I had the dimensions on a drawing but I can not find it. I actually measure my sail reef points for this exact idea. I ordered the reef lines and I have them on the boat. I will not get to the stored line for a few weeks so I do not have the measurements. I can measure this again about the 3rd week of Nov. As for line, I bought the same size as the IP factory reef lines were original.

Hayden

We have a PROBLEM.....my above sketch will not work with the factory original Isomat Auto Reffing system due to the fact that then boom sheaves drop into the boom ends from the top. So, in my sketch, you will see that the reef line forces will pull the boom end sheaves UP and out of the boom. The Isomat design pulls DOWN on the boom end sheaves and they stay in place.

So, it looks like the solution would be to drill a through bolt in the boom caps making the sheaves ride on a fixed shaft that can not lift out of the boom.

Since I do nto want to do this, I will be rebuilding my boom with factory original Isomat setup. Not sure this is the best solution, but that is what I am looking at now.

Here is the Factory Isomat Orig: Notice the direction of loads....down



www.rigrite.com/Spars/Isomat_Spars/Isoma...Isomat_AutoReef.html

Michael:
I will be rebuilding the exact same system as factory installed at this point. I will be replacing the sheaves and, like you, I plan to take apart the boom cap and make sure all is running fair. Thanks for the reminder.
Hayden

Mission completed. We now have installed our single line reefing as outlined above. The changes that needed to be made were in the gooseneck boom end cap where the sheaves needed to be thru bolted so that the reefing line pull can be up rather than down. With the bolt inplace, now we could run the standard single line reefing system and we removed the shuttle cars inside the boom. So far on our second sailing test this as worked well. It is still a lot of line to pull back up and out of the boom when you are going from a double reef to a full main sail, but putting int he reef was a breeze and worked very well. I may need to work out the leads to be a bit more fair but over all, it all worked out. Here is a link to the photo essay:

Photos here:
www.ipyoa.com/photos?view=album&aid=2404

Here is one picture:


Hayden

Don:
I could have done that, outside the boom, but the blocks are there inside the boom ends already, so I wanted to use them. It seems to work well.
Hayden

Michael:
Yes, I will add a block to the sail if I see this 1/2" line chafing or having any issues. I have never had a reef line chafe front or back over all these years and we usually sail with a reef in all the time in the ocean. I have never had a block on the back of the sail or the front.

As for pulling this all down together, front and back, it worked far better than my original factory setup. I simply lowered the main halyard with one hand on one winch and then by hand pulled in the reef lines on the other winch. I have my halyards marked so I know exactly how far to drop to the reef point. Then I can simply pull the reef lines tight and add a few winch turns to tighten them. Then it is back up a foot with the halyard and it is set.
Hayden

I have to report into this thread of my single line standard "dinghy" style single line reef. We set this up last year before we headed 1,000nm down the thorny path, Flordia to Turks to DR, to PR to USVI to BVIS. Then we sailed it all spring last year March April May in the Virgin Islands. Now this year, we sailed this from Florida to Cape Look out 525 nm offshore in 15-20. on this leg we reefed and unreefed 4 times.

Bottom line. THIS WORKS GREAT. It is so simple and it has zero friction, and here is how easily it works.

To reef, I simply slowly lower the main halyard with my right hand as I pull in BY HAND the reef line with my left hand. I have marks on my lines so I know when the halyard is down to the right place. I lower this a bit lower and then move to the reef and winch in the last 3 feet or so making it bar tight.
Now I return to the halyard and tension it up to the mark. DONE.
So, putting in a reef is crazy easy.

To take out the reef...
It works so well we can take out the reef still while sailing on a broad reach. WOW
To take out the reef we simply toss off the break on the reef line, make sure it is running free.
Then we simply winch up the mainsail to the top. It is out as simple as that.

We did add a Strong track, the plastic track in the mast and the metal sail lugs. This makes the mainsail slide easiler.

Bottom line. I struggled for 17 years with these silly shuttle cars inside the boom. They would NEVER run free and taking out a reef was a nightmare. Now, it is so simple and so easy. I wish I had done this back in 2001.

If you are thinking about rebuilding your boom shuttle cars, I say, remove them. Go with this well proven (now nearly 2,000nm) single line reef on the mainsail. It works great.

Hayden