Lazy Jacks

Ron20324 · May 10, 2009

You probably want them so they are a little forward of the aft end of your battens. My slip neighbor has your same boat, and I believe you might want to consider a three-leg lazy jack, if not 4?

sailingdog · May 10, 2009

I setup lazy jacks on my boat a while back and wrote about it here...

You can see what the setup looks like in this drawing:

hutch5151 · May 10, 2009

Harken has a PDF file on their web site for a medium size lazy jack that should give you all the required deminsions.

tsmwebb · May 10, 2009

Having the batten ends foul in the jacks when hoisting can be an issue. Some folks move the mast attachment out onto the spreader to help with this. Think a little bit about the loads if you do that (putting the blocks mid spreader w/o any support may well bring your mast down).

We use bungy cord to pull the loose jacks forward a bit and that helps but the bungy gets old and horrid pretty quickly.

If you're always under power and head to wind when you hoist your sails this will not be an issue for you... Maybe that should have been the first sentence...

Sorry if you read this far only to find it doesn't apply...

--Tom.

catsailor · May 10, 2009

I think 1/4" may be overkill, and I am not sure about Stay-set.

Bad Obsession said:
I am thinking that I will use 1/4 inch stay set for the lines and have the set of two that go the the cheek blocks on the mast have a small pulley spliced in at the end of the rope. The other end terminates on the mast near where the boom's gooseneck is.

I only need two lines with the jacks being that I have the full battened main and I have NO intentions of ever having a partially battened main on this boat.

The main question is how high for the Cheek Blocks and how far back for the eyelets on the boom to connect the other rigging?

I think 3/16" is plenty, and and I prefer line with a bit of stretch, so that they are less likely to interfere with anything else.

Also, since chafe is an issue, find the smoothest 3/16" or 1/4" nylon line that you can. Something with no texture. The jacks won't last as long... but the sail will appreciate the gesture.

This has been my expereince.

Roger Long · May 10, 2009

There is a long discussion on this back in the archives. Probably worth looking up.

I like a stowable system. No risk of fouling when raising sail, not chafe on seam threads. Most lazy jack systems are overkill with blocks where a simple spliced loop would work.

Here's what my system looks like:

Everything is 1/4" 3 strand dacron.

Eyestrap and thimbles on mast above spreaders with eyesplices. First leg runs down to spliced eyes with S.S. thimbles. I stow them so fast that nylon thimbles melt. Thimbles one size smaller than the rope work fine.

The outer legs are two eyestraps each side with eyesplices and no thimbles.

The running leg has an eyesplice with no thimble around the outer leg. It goes up into the standing leg then back down to cheek blocks and cleats on each side of the boom.

I have reefing hooks so I just pull the jacks forward after the sail is furled and tied, hook them under the gooseneck hooks, and make fast. Just before lowering sail, it only takes a moment to cast them off and tighten them up.

No fussing with the sail cover. Works great.

Ed Schenck · May 10, 2009

Mast height for lazy jack blocks.

'Dog's illustration makes the point. The higher you place the blocks on the mast the better. Check the drawing and see how the angle of the jax is better at the boom end the higher they originate. I have mine about halfway between the top and the single-spreaders. They should have been higher. The result is that the heavier part of the mainsail(the leech) does not provide all the support that one would like. Roger's illustration is too much like my boat, not far enough back and too angled to catch that heavy roach with battens.

Don12364 · May 11, 2009

My Solution

I faced this problem when designing my original sail cover.
Undoubtedly the batten ends will get caught in the cats cradle of lazy jacks when hoisting and, with me under the bimini, I am unable to see this happening.
So, already having a topping lift, I simply lead some 3/16" lines vertically down from this on either side of the sail. They are positioned along the boom so that they are well clear of the batten ends.
Now the sail goes up and down without catching and I can adjust the slack in the lazy jacks from the cockpit simply by using the topping lift.
No need to go up the mast either.
QED.

sailingdog · May 11, 2009

I didn't use blocks... I used 1" x 3/16" stainless steel rings. A lot less chafe and a lot cheaper than blocks.

On my system, the main lines (green in my drawing above) are long enough that the lazy jacks can be dropped and attached to the reefing tack hooks at the gooseneck, and effectively disappear... first time I did that I confused the hell out of my crew.. they thought I had removed them.

peterbud · May 11, 2009

Bad Obsession said:
There are tons of information out there on lazy jacks. I have decided that I want to "Build" my own set to my specs. It looks to be cheaper than buying a set from Harken, etc.

The design that I favor is two cheek blocks mounted up the mast (not sure how high I will go up with the cheek blocks). A line leads form the mast where the boom goose neck is to the cheek blocks and down. At the end of the line is a pulley. Another line runs from the boom, through the pulley, back to the boom.

My question is what percentages should I use for the height of the cheek blocks and the attachment points on the boom?

My boat is a Catalina 30 MKii Tall Rig, Bow Sprit. The rig specs are on here.

I built my own last year. I whent on to the Harken Website and pulled up theil manual for their Lazy Jacks. You have all the measurments and Specifications for what ever boat you are doing. It worked out for me.

Beija Flor · May 11, 2009

My boat came with the Harken lazy-jacks - I was not so pleased with them.

I put cheek blocks where the Harken block cables had been attached, about 3/4 up from the gooseneck to the masthead. Snap-in fairleads (they're nylon and have a hook to snap in the line) about 2/3 of the way out on the boom, where the Harken kit had strap-eyes for the middled (out-boom) line; I cut that line in half and tied bowlines to provide a loop to hook into the fairleads. I use the one cheek-block and cleat from the Harken setup on the starboard side of the boom, and duplicated it to port. I'm using 3/16-inch nylon braid lines.

I keep the lazyjacks tied off to the shrouds when I'm not dropping and flaking the sail; they're out of the way and they don't chafe my sail. When I am ready to dowse the main, I can hook them up in moments. And they aren't halyard-slapping my mast between uses, either.

sailingdog · May 11, 2009

I'd point out that on most boats, a four-leg design really will work much better than a three-leg design. Mine came with a three-leg design that basically sucked.

Clark · May 11, 2009

Hunter 280 here; fully battened 270 sq ft. main. Two-thrirds of the way up the mast and a 2-legged bridle. The system is retractible to a bungy at the gooseneck so no fouling when raising. The lines cleat off to shroud cleats on the lower diamond shrouds (long story on that). I used 3/16" LS line and it is perfect. I did use nylon rings and thimbles to avoid rubbing on the mast when stowed. No issues after 2 years.