Sail Switch From Marconi to Balanced Lug on 24'Catamaran

[John Balentine]

I'm currently building a Woods Eagle 24' sailing Cat, and I'm switching from a marconi and jib sail spec'd on the plans to a balanced lug and jib. I will mostly be sailing solo in remote locations, and i want a less expensive design to rig with less parts to break/replace, and a simpler more forgiving sailing set up. That is my reasons for switching, and I'm willing to accept the compromise in speed and upwind pointing. Mostly I'd like some opinions from designers/sailers about the balance of the helm on this design and if there is any obvious problems or reasons it won't work. My mast is shorter than the marconi rig of course, but uses the same stay wire arrangement as the original plan, the only difference being I'm attaching the wires to the top of the mast and the mast is capped with a bronze cap that has spreaders that move the wire attachment points away from the mast about 4 inches. This is to spread the wires a bit and give more room for the yard to swing. I have checked it in 3d cad to make sure the yard clears the forestay. Please review the attached image with dimensions. Thanks in advance for any feedback on this.

 

[Igor]

The bigger the balance lug is the harder it is to control the twist. The chinese lug with its multiple sheetlets to control the leech might be the answer but you would have to move the mast forward and dispense or the jib.

 

[Rumars]

I will mostly be sailing solo in remote locations, and i want a less expensive design to rig with less parts to break/replace, and a simpler more forgiving sailing set up.

Only you're not getting that by switching to a balanced lug. The total parts count stays the same since you didn't eliminate the stays. A lug that size will be more difficult to handle then a bermuda rig. The sail itself will be more expensive since only a handfull of sailmakers still know how to make a quality four sided sail.
Marconi rigs come in several flavors, simple is one of them. You don't need the full racing setup, so do a thick mast, no battens, no roach version.

 

[Skip Johnson]

I'd check with Woods for comments. The one thing I'd say is be sure to have the ability to really haul down on the boom, makes a big difference particularly to windward,

 

[Igor]

I'd check with Woods for comments. The one thing I'd say is be sure to have the ability to really haul down on the boom, makes a big difference particularly to windward,

Don't forget about luff tension on a balance lug, requires very stiff mast and a large purchase for a sail of that size, without it it will not set properly for windward work.

 

[seasquirt]

Hi John, if your sailing grounds suffer big chop, or many boat wakes, the yard will swing about often, losing power. More-so on a cat than on a monohull. Make it so it is easy to drop the jib, then tack, then hoist jib, so tacking is simple and un tangled. I have several posts about my Bermudan to balanced lug conversions. It's much simpler, and faster, to just use a Bermudan cat sail with no jib.

 

[gonzo]

the mast is capped with a bronze cap that has spreaders that move the wire attachment points away from the mast about 4 inches.

That will add a significant moment (torque) to the top of the mast. It may be enough to make it buckle and break.

 

[seasquirt]

I've had balanced lug booms turn through 270 degrees in a calamity, so your side stays may be tested, putting further stress on your cantilever mast cap. Maybe there's a reason nobody else does that. Free standing is best for a balanced lug. If you really want stays, a taller mast with uphaul pulley several inches below the mast top may work, but the forestay will always be an obstruction. One of the benefits of a balanced lug is that you can easily set it abeam or a bit past, when going down wind, maintaining a direction while adjusting sail to best speed.