Low Verses High Aspect Ratio Main Sail

Dont know the make of boat or traveller. Many manufactures of main sheet handling systems.

Check the Lewmar or Harken Catalouge, they have a mainsheet selection chart for various systems. Its the track ,bridge, setup that is expensive.

With a boom vang to develope leach tension , a simple sailing boat doesnt need a traveller.

http://www.harken.com/charts/travelerusechart.php


And yes indeed Bill...the gaff rig is effective at raising sail away from the sea surface friction wind into the clean wind aloft with a shortest mast. A 'Block Head "mainsail on a normal rig is a simple way to do it .

 

I was waiting to hear about Junk rigs?

 

Reefing is really easy and only SAIL AREA will make a fine ghoster.

So if you are "overpowered" its a no brainer to reef at 12k , and again at 18K.

The slow boats brag of "Whole Sail even in a Full Gale' but their the 55miles a day cruisers .

Most folks prefer 100-125 .

FF

 

CaptBill, really like the gaff rig for traditional looks but i'm planning as far away from that as it gets not because of performance but for old man ease and comforth in the form of a furling main sometime down the road. Meadwhile lazyjacks will fit the bill.Visited Savannah for a week two yrs. ago, i'm a civil war nut, had a distant cousin Albert Pike was a brig, Gen. with the Confederates. Had a great time there except meeting the street car down on the lower street with me travelling in the opposite direction in my 26ft motorhome. That was fun didn't realize not a place to take a motorhome until it was too late. The street car driver was a great guy and we had a funny and friendly conversation as we wiggled by. Tnx. Geo.

 

Michael, Harken chart exactly what i needed. I didn't realize mid boom sheeting was common enought that they would actually have it listed in their catalogue. On the mainsheet chart the same rig that handles 350sq. ft of sail with end boom sheeting can handle only 300sq.ft of sail with mid, boom sheeting thats a 16% difference. So if i use a 25% increase in size of what i normally would use for end boom sheeting to go with mid boom sheeting i'm in good shape. I have a simple system i use instead of a mainsheet traveller. On prev. builds I had two attachment points for the main sheet on my wheelhouse roof , not on center but closer to the outside corners and depending the tack i'm on determins which one i use.I hold the boom with a temp. sheet while changing, many times i don't bother to change. This will also allow me the option of install a sliding hatch at the entrance to the wheelhouse. Well that answers question #1 on mainsheet gear and boom attachment. However still open to extra info on this.
Question #3 furling, boom roller furling old style, verses behind the mast furling. I didn't include, in boom or in mast systems as they are far out of my budget range but for general info these systems are also interesting to post on. Tnx. Geo.

 

Been forty years since I used "old Style " boom furling. What I remember was that its slow to hoist and strike the main.

A big advantage of the old style boom reefer is that it keeps the deck clear of three reef luff down hauls and the boom free of three clew reef lines. If someone was giving you one ...Go for it.

If I remember correctly roller booms worked best with the old style captive reel winch mounted chest height on the mast . Easier one man hoist...you reel winch the sail off the roller and lowering the main was done by rolling the boom against a bit of friction on the reel winch clutch.

I recently saw one of those old reel winches being used as a paperweight in a rigging shop.

A boom vang wont work with the old style roller and obviously mid boom sheeting wont work.

Keep a basket of winch handle handy ...crew are always dropping them while working on the boom reef ...I guess you could buy " floating" Winch handles . Fit them out with EPIRB transmitters or radar reflectors so you can crash stop the boat , then surf back down the greybeards to fetch the floater. Or you could perhaps epoxy...this G flex stuff...a ratcheting winch handle to your crews power arm.

The Rhodes Cheoy Lee boom furlers had built in handles.....

 

IF you are looking for this old style end of boom furling gear ( as shown ), and are willing to drive to Middletown CT ,to pick it up, you can have a free setup.

The boom is about 15 ft long , but its wood , so shortening is no big deal.

After 1 May .

FF

 

Fast Fred, normally i'm also down south where you are this time of year hang out in St. Augustine, Daytona, Marathon in the keys. Stayed home for the past two winters doing some renovations on the B&B and working on my new build. Hey just might bump into you over the next year or so and take you up on that offer. This forum has been a great help in my build being more engineered in it's appraoch and as a result it will certianly maximize the performance, (As much as possible with a motorsailer.) This one i want to be say on par with a heavy cruiser. Never know i just might take her south. The other option i'm looking at is behind the mast furling, say something like a pro furl setup. I have a new pro furl to install on the fore sail but have no experience with the behind the mast setup. I know in theory this setup has some disadvantages like wind pressure distorting the luff straightness and air flow pattern behind the mast but in reality what are the actual losses. Would be great to hear from someone who has converted from the standard setup to a behind the mast system and get their input. Tnx. Geo.

A yacht is not determined by the vessel but by the care and love of her owner.

 

"The other option i'm looking at is behind the mast furling."

This is easy to use but lousy from an airodynamic point of view.

The gap between the mast and sail hurts windward work, perhaps less important in a MS , but "much ungood" on a cruising boat.

IF you could have a 40 ft long heavy brush section that could slide in the old sail track created , it might help.

The roller furling boom is currently located in Ortona FL.

FF

 

Well other than installing some sort of foil wings to fill in that space, which i know is done on some mast extrusions it's just another loss which i can't afford either way. The build is progressing, started a thread under Boatbuilding of the work. I realize it's a conversion and some in the field frown upon it but in reality it's not the fools errand that many profess it to be if built proper. This hull has nice lines and should be good under sail. I have hired a designer to give me the computerized hull lines and specs. In conjunction working with world class forum input, I am making informed decisions on some of the systems so it should be well engineered, The pressure will be on my accumulated years of experience to do the same with the construction. Fred just tracked down where you are located in Florida, You certainly would see alot of Canuk plates there. It's one of the Nova Scotia hot spots. A whole group from right here in Bayside have winter abodes in that area. Did a bit of sailing out of St. Petes a few years ago which is the Newfoundlander's hangout in Florida.I grew up on a USAF air base on the South west coast of NFLD. Earnest Harmon AFB, commonly known as Harmon Field and 3 of 4 of my sisters married US servicemen so as a result i have alot of recent relatives south of the border (US border that is) not that spot on I 95. I say recent as I also have relatives from the early early times 16 and 1700 's and of course in the early 1900's nick named (Fish) working steel in New York City. Small world, historically NFLD is often refered to as the mother country on this side of the pond and considered by many as the first New England Colony. As a "Sea" people we certainly don't like to be too far from water and likewise if you ever sail this way a private dock and mooring always available. Thanks Geo.

 

HAHA!

Motor home in Savannah. Bet that would have been fun to watch! Hard enough in a car. All the old trees make it pretty tricky.

 

I haven't read every post, but in scanning this thread I haven't seen any mention of righting moment. This should really be your starting place. If you have an existing boat in the water, the best way to determine righting moment is with an inclining experiment. If not, the primary determinants are vertical center of gravity and waterline beam. If you can determine VCG and know your waterline beam you can make a pretty good guestimate. Better still if you know your boat's displacement and vertical center of bouyancy -- but the really important factors are vertical center of gravity and waterline beam.

Now here's the rule of thumb I use: assume you will reef down when sail pressure exceeds 1 lb/ft^2, and that you want this to coincide with the boat's heel angle exceeding 30 degrees. That means you want 1.0*Sail Area*heeling arm to equal RM(30) [your boat's righting moment at 30 degrees heel, in foot-pounds]. Discuss with your sailmaker whether 1.0 lbs/ft^2 at 30 deg heel is the right value to use, but in my experience the value should be close to that.

There are other ways to approach this of course, such as Dellenbaugh Angle. Note that the heeling arm will be different for the taller, higher aspect ratio rig, so the right amount of sail area will be less for the taller rig.

 

Thanks Stephen, being a builder more than a designer this is the first time i have seen this info. Often wondered how to tie the two together i.e. the general rule of thumb. I am seeking the sail info for a surfboat to motorsailer conversion i am working on. About 6 months. ago i purchased a damaged 34ft wooden motorsailer for salvage and in addition to about $25000 in gear and fittings i salvaged a new set of sails. It's wooden mast was the same height as my planned alum. mast 32ft. but i am working with a smaller hull and am concerned about it's main sail 28ft. luff on a 17ft boom overburdening my hull so plan on talking with the sailmaker on reducing the foot length to fit a 12 or 14 foot boom. This is where your info will definately come in handy. My hull lines have been taken off and given to a designer to process in his computer program from which i will get the numbers to pass on to the sailmaker also. I am posting the actual build under "Boatbuilding" (The Nancy G"---) thread. and would really appreciate any input you might have as the build proceedes. Thank you Geo.