Thursday, August 7, 2014

Lazy Jacks

Phoenix's 9.8 ounce, 448 sq. ft mainsail is very heavy and stiff. When Bruce Bingham first visited us for our initial sail and he helped me flake the sail, he laughed when I told him that I'd eventually beat the sail into submission. He had little faith that at 5'2" I'd be able to tame our mainsail.

Flaking the mainsail had been a chore to date, and luckily the hardtop dodger and bimini that we built is strong enough that we can crawl, and even walk on top to wrestle with the mainsail. However, we're getting ready to install our solar panels on top of the bimini, which will limit our crawl space on top. It was fortuitous that our local West Marine was going out of business and all line was marked down 75%, so we decided it was time to make and install lazy jacks to make flaking the sails a much easier task.

When we made our sail covers, we didn't install slits to accommodate lazy jacks, and we knew we wanted lazy jacks that we could pull forward to the mast to get out of the way when we cover the sails. After quite a bit of online research, we decided to make a 4-legged lazy jack system similar to what John from Morgan's Cloud created, but modified slightly for Phoenix's main and mizzen sails. John does a good job of describing the measurements needed for determining the lower line termination and attachment points, and the basics of the overall system can be proportioned to any boom.

We used 1/4" double braid line for the lazy jacks, and knowing how to do your own double braid eye splices definitely came in handy for this project and helped maintain the cruising kitty, as each side of the lazy jack requires 5 eye splices (10 per mast, 20 in all since the Andromeda is a ketch rig). Local riggers charge $20 per splice, not including the price of the line, so 20 eye splices would definitely hurt the pocket book! Contrary to many lazy jack systems we've seen online, ours didn't take nearly as much line. We used 150' of line for the main's lazy jacks, and 120' of line for the mizzen.

Unlike Morgan's Cloud, we decided against using blocks in the upper sections of the lazy jacks and cheek blocks along the mast. To minimize chafe, we felt stainless O-rings would be a better choice against the sail on the upper segments. Along the boom we opted for eye straps, partly because we had them on hand, and partly because the system doesn't really have much load or friction, so we didn't think it warranted going out and buying new cheek blocks at the time.

There are basically three lengths of line on each side of the lazy jacks -- the upper/mast termination section, the middle section, and the longest length of line that attaches to the boom and serves as the 4-legs. The mast termination length has an eye splice at one end, and an eye splice with a stainless O-ring at the other end. The middle section has eye splices with O-rings on both ends. And the boom termination length has an eye splice on aft end.

To minimize noise and additional holes in the mast, we attached the upper end  to the lower shroud tangs, just  below the spreaders with a bale sling hitch.

Bill installing the upper, mast termination leg of the lazy jacks on our main mast

Bale sling hitch
The middle section was attached to the upper piece with a cow hitch through the upper's O-ring. The lower section was also attached to the aft section of the boom with a cow hitch, and the un-spliced end was lead forward -- through the aft middle O-ring, down through the eye straps, back up through the forward middle O-ring, and to the cleat on the forward section of the boom.
Close up of lower line going through the middle section's O-ring

Cow hitch on aft section of boom
Lazy jacks installed on the main

It helps to lay out the design on paper and dry fit before cutting the lines and putting in the eye splices. If you take proper measurements and think of the of the various segments as either a 90 degree triangle (upper and middle legs) or close to an equilateral triangle (lower legs), you can get fairly close to the correct line lengths needed. Essentially:
  • The upper leg length is the hypotenuse of a 90 degree triangle that terminates several feet directly over the middle of the cleat and eye strap. 
  • The measurement for the foot of the upper triangle can be measured on the boom
  • The forward leg of the triangle is total height (boom to lower tang attachment) minus 2 times the height of the lower triangle. In our case, each vertical leg height was approximately 1/3 of the boom to lower tang measurement. 
  • Calculate the middle leg as if it were a 90 degree triangle to get the approximate length of the hypotenuse. 
  • Once you've calculated all the lengths, dry fit with some cheap line. 
  • If all of your calculations are correct, the only line you may need to adjust/shorten is the back leg of the middle section. 
  • Keep in mind that if you want to collapse the lazy jacks and pull all the lines forward like we do, much more line is needed on the lower leg.

Sailing with the lazy jacks on the main
It took a little playing with the determine how tight/slack to make the lower legs so that the sail drops properly, but the system has plenty of line to allow us to experiment and pull the entire system forward when we cover the sails. If we have them deployed when raising the sail, you need to really make sure to point the boat into the wind, otherwise the battens can hang up on the lines. This is really important for a full batten sail like our mizzen, but equally important for our 3/4 batten main.

Phoenix's lazy jacks

With the lazy jacks in place, it is much easier to drop the main and mizzen without either sail flopping around the deck. Flaking both sails is much easier as well: simply pull the flakes aft to make them neater, attach the sail ties, and voila!

Our system was certainly cheaper than the commercial lazy jacks on the market, are tailored to fit our rig, and are very simple/easy to use. The more we use them we definitely agree with John from Morgan's Cloud -- there's really no reason for the lazy jacks to go up higher than the spreaders. Also, the system doesn't need to be wider than the mast width (i.e. attached out under the spreaders) in order to properly cradle the sail.

We do lead the lines forward every time we cover the sail (we're pretty particular about protecting the sail from excess UV damage). Eventually we may add slits to the sail covers so that we can keep the lazy jacks in spot all the time, but it's so easy to deploy and/or stow the lazy jacks at this point, I'm just thrilled that my wrestling days are over!

1 comment:

  1. Very impressive. Maybe you two should expand Rhumbline into the rigging business.