Australian International Moth Association

Rigging Up

Rigging up a International Moth can be nearly as challenging as sailing one (nearly), especially when the breeze is up! This is especially critical with the pocket luff rigs.

It makes good sense to leave as much of your rigging in place at all times, even when trailing. Ideally the boom should be attached with the mainsheet, kicker and outhaul in place. Most helms also leave their cunnigham in place as well, using a quick release fitting or shackle. With all of this rigging in place an experienced Mothie should be able to rig a bolt rope sail rig in about 10-15 minutes and a pocket luff sail in around 20 minutes.

Pocket Luff sails

Pocket luff sails were reintroduced to the International Moth after a hiatus of about twenty-five years. The Lake Macquarie, NSW World Championships in 1994/95 marked the debut of this style of rig with many of the top Australian sailors unveiling the new breed of pocket luff sails. Since then many sailors throughout the world have used them. For more information on pocket luff sails, please read an article written by Mark Thorpe.

The first step is to make sure that all of you control lines are slack so that the boom can be attached once you have the rig up. Then roll out your sail, making sure the zippers are on the topside if you have such a sail. Slide the mast into the pocket, I prefer to place the mast on top of the cambers as it is then easier to snap them onto the mast. You can either snap the cambers onto the mast before or after you put the rig on the boat, depending on your preference and type of sail. Although on a windy day it is easier to deal with the cambers and apply a bit of batten tension prior to hoisting the rig aloft.

Once you have dealt with the sail and mast it is time to attach it to the boat. Make sure that the rig will be facing into the wind once it is aloft. Tip the boat onto one wing and lie the rig across the mast stump with enough slack to attach the sidestays. Then attach the forestay, tying it loosely in place. Now you are ready to put the rig up. Stand with one foot on the wing bar, check that the stays are not tangled, or can snag on anything and raise the rig in one smooth motion. Once you have the mast in position in the mast stump, grab hold of the forestay and push forward, taking up the slack. You should be now be able to let go of the rig, holding it in place with the forestay. Now undo the half hitch you tied in the forestay and pull on some tension. Now your rig should be in place and you should be able to manage this on your own on all but the windiest of days.

Once your rig is aloft, the rest is elementary, attach the cunningham to the luff of the sail and pull on a little bit of tension. Then attach the boom to the mast, followed by the outhaul. Once this is done, you should be nearly ready to go sailing. One last point, on batten tension, it is easy to use too much. Especially in light airs, be careful because you may have problems with the battens popping onto the new tack.

I find that this technique works well and minimises the risk of dropping your rig onto your foredeck or elsewhere. Other techniques such as raising the rig up, putting it in the mast stump and then attaching the stays also works but you need a friend to assist you and on windy days even with two of you, it can be a bit of a handful.

Bolt Rope Sails
Bolt rope sails have some advantages over pocket luff sails, they are simpler to maintain, rig and if set up correctly can generate more power and possibly more speed in light winds. The disadvantages are that in order to keep up with the pocket luff rigs when the breeze picks up, they generally need to be to be flattened off earlier using stiffer battens which help to keep the leech of the sail tighter and more stable/controllable.

First of all the mast track should be smooth and free from sharp edges, polishing the inside of the track can help the sail to slide up and down. The battens should be tensioned just enough to remove the vertical wrinkles in the batten pockets, any more and: You may have difficulty in flicking the battens over after a tack or gybe.

It could lead to damage as it puts excess strain on the ends of the batten pockets at the luff and leach of the sail. 
Rigging is fairly straightforward, attach the shrouds, lift the mast onto the step and tension the forestay. Attach the boom, lean the boat over on its side and feed the sail onto the mast, connect the cunningham and pull on some tension This makes it easier to attach the clew of the sail onto the boom if you leave your kicker connected up. Then tension your sail controls according to the conditions.

Other tips
The narrow International Moth designs are much easier to sail with some foam or an airbag in the outer wing pockets. There is a fine line between too much and too little. Too much will make the boat want to turn turtle immediately when you capsize. Too little will be of no benefit. Don't be concerned about the hardcore scoffing at you, all of the top sailors utilise some form of buoyancy in their wings. It makes the boats much easier to control in a breeze, especially when you are trying to keep you speed down prior to a start.

Another good idea is to have a piece of elastic on your tiller so that it is self-centering. Do not fit this too tight, just enough so that you feel a light resistance at five degrees of helm or so.

Another tip to make your capsize recovery as quick as possible is to have righting ropes under your wing bars so that you can lean back from the wing bar whilst you are standing on the centreboard to give you some extra leverage. Use a piece of ski rope with some elastic threaded through the middle, this will stay tidy and above the water when you are once again upright.