Changing Old School Sail Plan

[thomm225]

Has anyone with an old school long boom boat ever ordered a new main with a shorter foot?

As we know, many experts say to have a larger jib to offset the weather helm caused by these old long booms.

If I keep my boat, it will need new sails soon so I was just thinking.....

It appears this Contessa 26 owner has bought and installed such a sail with a shorter foot than the original

https://www.youtube.com/watch?v=K3pcXWUZ5Pk

[JPA Cate]

Tom,

The deal is that you do need lots of sail area for light air sailing. You can check how you might like it by sailing all the time one season (or possibly month, if it is varied wind strengths) with the first reef in. See if you can stand it in light air, because the virtue of big sails is really apparent (no pun intended) in light air.

You still think of yourself as a go-getter, and as such, you may prefer to be able to put more sail up. It's certainly true of me, and we only raced slow monohulls.

Besides that, the boat was designed to sail best with a particular set of sails. Second guessing that is likely to be a waste of time, although your sailmaker might do well off it.

Ann

[thomm225]

Thanks Ann but usually in light air the wind is better higher up so having lots of sail at the boom level doesn't help.

As a racer we know on light air days to sail by the top tell tales.

I'm trying to go for a more efficient sail with maybe cutting a foot off the "foot" and adding a foot to the luff.

And at the same time reducing weather helm.

[JPA Cate]

You could go for a square topped sail, too, fully battened. It would get more area up there.

If you have a pretty large choice of destinations, you could buy an asymmetrical kite, too, for the light air conditions, a little easier for a singlehander than a full shouldered kite that you have to fly with a pole.

Raising the hoist a foot isn't going to get you much gain in sail area, just a foot high triangle.

Ann

[Bill O]

Originally Posted by thomm225

Thanks Ann but usually in light air the wind is better higher up so having lots of sail at the boom level doesn't help.

As a racer we know on light air days to sail by the top tell tales.

I'm trying to go for a more efficient sail with maybe cutting a foot off the "foot" and adding a foot to the luff.

And at the same time reducing weather helm.

So are you going to change the rig also to a taller stick? If not, how are you adding 1 ft. to the luff?

I'd stick w/the longer foot for increased sail area during lighter air and reef earlier if needed to reduce WH if the wind pipes up.

[Rucksta]

Mid 80's IOR rather than old old school.
Shortened foot from 6 to 5.25 mt.
Increased roach to offset some of the loss of sail area.
Lift to drag ratio slightly improved.

Some loss in very light air.
Less loss of boat speed when pinching.
Better balance on and off the wind
Can carry full main to 15 kts without rail meat.

Original sail dimensions made sense for Kevlar or carbon construction.
To engineer the load paths in Dacron was challenging for the sail maker.
Estimation was the heavier cloth required could impact light air performance as much as the reduced sail area in a lighter cloth.

An exercise in balancing compromises.
Input from Sailmaker, rigger and Shipwright was helpful to reach a satisfactory compromise

[thomm225]

Originally Posted by Bill O

So are you going to change the rig also to a taller stick? If not, how are you adding 1 ft. to the luff?

I'd stick w/the longer foot for increased sail area during lighter air and reef earlier if needed to reduce WH if the wind pipes up.

The mainsail I have now is maybe 1.5' to 2' to short.

As I mentioned before, in light air the wind is up higher up not down low at the boom so extra sail area there doesn't help.

[thomm225]

Originally Posted by JPA Cate

You could go for a square topped sail, too, fully battened. It would get more area up there.

If you have a pretty large choice of destinations, you could buy an asymmetrical kite, too, for the light air conditions, a little easier for a singlehander than a full shouldered kite that you have to fly with a pole.

Raising the hoist a foot isn't going to get you much gain in sail area, just a foot high triangle.

Ann

Very true but I've had those on my racing boats and know it won't help all that much with this old Bristol plus I sort or want the old school look.

I don't believe folks should try to improve on how a boat was engineered but we now know those long booms of yesteryear really do add a lot of weather helm.

[thomm225]

This guy's B27 has the slightly short foot as well as compared to mine.

Same with Sean D'e's B27. He has his boom all the way down to the original stop also so he will have more sail area and his foot is still a bit shorter.

I have my boom tied off a bit higher due to my dodger.

Sean's Mainsail looks like an old Catalina 270 sail maybe recut?. I don't know if that is the sail he crossed a few oceans with or not

[Don C L]

As you probably know already, the placement of the mast was done with the center of effort in mind, which the big old school main helps determine.
In my own boat, reefing the main first helps offset the weather helm that may develop and she still sails very well. Maybe go with the same old main design and a more shallow first reef?

[thomm225]

Originally Posted by Don C L

As you probably know already, the placement of the mast was done with the center of effort in mind, which the big old school main helps determine.
In my own boat, reefing the main first helps offset the weather helm that may develop and she still sails very well. Maybe go with the same old main design and a more shallow first reef?

Sounds like a good idea. I thought I'd just get some opinions to consider.

The boom on my last beach cat would fit in my jeep cherokee whereas a Hobie 16's boom was way too long for that.

It was just the old way. Low aspect sails and sail plan.

My last two boats (Nacras) had high aspect everything. Main sail, daggerboards, rudders, etc

Funny thing is all including the Hobie 16 topped out at about 26 mph max speed.

[Don C L]

Originally Posted by thomm225

Sounds like a good idea. I thought I'd just get some opinions to consider.

The boom on my last beach cat would fit in my jeep cherokee whereas a Hobie 16's boom was way too long for that.

It was just the old way. Low aspect sails and sail plan.

My last two boats (Nacras) had high aspect everything. Main sail, daggerboards, rudders, etc

Funny thing is all including the Hobie 16 topped out at about 26 mph max speed.

Sure but those are really fast boats that can take advantage of the high aspect design.

[Pauls]

Don't know where you got the idea that "long old school booms make weatherhelm" but that just isn't true. Your boat has weather helm because the actual center of pressure of your sail plan is aft of the actual center of effort of your underbody.

Old, stretched out sails that have become cupped can move the center of pressure aft significantly. If you haven't, it would be worth checking with other owners to verify if they all have this problem, in an attempt to ascertain whether it's a design problem or just shot sails.

If you conclude it's a design problem I'd suggest you consider adding a bowsprit. You will move the center of pressure forward and add sail area at the same time. More sail area beats the hell out of less.

[psk125]

It sounds like the plan is to reduce weather helm by reducing sail area. We had friends with a Bristol 27. They were always the last boat to arrive on any cruise because it was so slow. Is there so much wind on the Chesapeake that you can afford to reduce sail area and not have the boat be even slower than it already is? To actually spend money to make this change to new short-footed sails before exploring other options is absolutely baffling. As others have pointed out, weather helm can be caused by blown-out sails - which your comments make it sound like you have. Rake adjustments can also fix weather helm problems. Shortening the foot of the sail in this situation is like cutting off the bottom of the centerboard when you hit an oyster bed instead of raising the board with the pennant.

[thomm225]

Originally Posted by Pauls

Don't know where you got the idea that "long old school booms make weatherhelm" but that just isn't true. Your boat has weather helm because the actual center of pressure of your sail plan is aft of the actual center of effort of your underbody.

Old, stretched out sails that have become cupped can move the center of pressure aft significantly. If you haven't, it would be worth checking with other owners to verify if they all have this problem, in an attempt to ascertain whether it's a design problem or just shot sails.

If you conclude it's a design problem I'd suggest you consider adding a bowsprit. You will move the center of pressure forward and add sail area at the same time. More sail area beats the hell out of less.

I guess I got that idea by knowing the main sail is used to bring the boat to weather when say you are using the sails to steer the boat for example at the starting line for a race when you are holding the boat still the last minute or so.

The Bristol 27 review in from Practical Sailor even mentioned the weather helm caused by the large mainsail

"Gusts caused the boat to dig in a bit further and to round up slightly on its own; the stronger the wind, the higher it pointed. Except for a hint of weather helm caused by the relatively large main and small foretriangle-no problem for an afternoon sail but potentially tiring on a longer passage-the boat handled easily on all points of sail. The sensation of excessive helm is easily solved by a reef in the main or the use of a larger jib; with a 150-percent genoa, the owner of our test boat said the Bristol 27 balances perfectly."