Mast head vs. fractional rig

[CWSmith]

I'm trying to wrap my head around a seemingly simple problem. I regret it has nothing to do with WOODEN boats, exclusively, but I hope you find it interesting.

Consider a boat like the J-29 (fiberglass, sorry). It has been built in both fractional and mast head rigs and I have read that the mast head rig is faster. If you look at racing fleet pictures, the mast head rigs outnumber fractional rigs 10:1.

Coming from dingy racing, the fractional rig is a very big deal and allows you to tune the sail shape. Obviously, boats too big to bend the mast make this less useful, but a 29 footer is still small enough to bend the mast when the wnid calls for it and sail the boat like a dingy.

I suppose the mast head rig has a bigger genoa and spinnaker, but sail shape is critical to speed and pointing ability.

So, why do mast head rigs appear to be faster?

[John B]

I suppose the mast head rig has a bigger genoa and spinnaker

That'd be it right there I would think.
A long time ago I came to the conclusion that 'the best' bermudan rig would be a 3/4 or 7/8 th because the geometry is most stable. Have a look at commonsense of yacht design ... there's a nice sketch by LFH of the s bend( fore and aft) that a masthead forestay imposes on a mast. Its why there there tended to not be wooden masthead rigs, they were usually 3/4 or so and had jumper struts etc to prevent bend back.LOL.

Incidentally, this boat ( I was sailing on it on the weekend) is 39 ft, has a really quite large fractional rig as you see and sails like a dinghy. Tons of backstay on, cunningham and outhaul makes that main nice and flat and blades off nicely in 20 plus.


Brilliant to sail. Wooden too , a hollowed out kauri log. perfectly capable of 20 knots in the right conditions.

[TerryLL]

More leading edge higher up would be my guess, plus additional slot effect at the head of the main.

[James McMullen]

Extra sail area is extra sail area. But in development racing classes where total sail area is strictly controlled, fractional rigs or even jibless single sail rigs are what shakes out. Look at The C-class Cats for illustration.

[gilberj]

I think the fractional rig will normally perform better in moderate to strong winds. The mast head rig will have a little advantage in light to moderate winds. I remember watching some boats in the Southern Straits race some years back in strong winds. 1 boat shortened sail to a 7/8 blade and took off leaving the boats carrying mast head genoa's wondering what happened.

[Ian McColgin]

Somewhere I read a remark by Bob Perry, designer of so many double headsail cruising boats, that his own perfect rig would not be a so close to amidships mast and two headsails, but rather the mast a bit more forward, the biggest main he could imagine, and a 3/4 or maybe 7/8 foretriangle with a smallish jib. For all that people grump about mast turbulence and all that, it's really hard to beat the driving power in all directions of a sail that's got a spar on the leading edge.

Rating rules and fashion favor bigger jibs. Pity there's even such a thing as "free" sail area in the overlap past J and the high roach of some abaft the mast sails with huge full battens. While the fractional rig with small jib is probably the most efficient way to carve up some fixed pile of canvass, not to mention the fun of bending the mast to shape the sail a bit, there is much to be said for keeping a dead straight column and the structural simplicity of a masthead rig.

Like everything else in boats, the answer starts with, "It depends . . . " and ends in compromise.

[John Bell]

One reason for a lot of masthead rigs was due to handicapping rules that penalized large mains and didn't penalize large genoas.


The J/29 is an interesting case. Even though the mast is 4 feet shorter on the MH J/29 than on the fractional, the I-dimension on the rig is 5 feet longer. This allows the MH boats to carry a much larger genoa upwind than the frac boats. Even though their 100% sail areas are nearly identical, the MH boat gets the benefit of extra sail area when flying a 150% genoa compared to the fractional's 150. More sail area equals more horsepower and gets you to the windward mark first. Also, the spinnaker is much larger on the MH boats as well because it's flown from the mast head instead of the hounds. the additional 5' of spinnaker up high gives the MH boats a lot more horsepower downwind, getting them to the leward mark first. The reason the masthead J/29s are faster is simply the fact they carry more sail area than the fractionals on the same hull.

As an aside, I think the fractional J/29 is one terrific looking sailboat.

[bamamick]

The best rig for my money is a fractional rig with a masthead spinnaker. Down here in the light air of summer fractional rigs get killed off the wind in the big boat races. I always thought that a 7/8 rig with a masthead 'chute would be the ticket for sailing on the northern Gulf Coast.

Mickey Lake

[Ted Hoppe]

It really matters where you sail. I find here in San Francisco a fractional rig works quite well and is quite balanced where the often afternoons can have 20 to 25 kts sustained winds and a 3 kt tide. Here boats more often seem to uncomfortably broach or have sever weather helm with masthead rigging (which can catch you off guard or ill prepared) - both I do not want that when sailing the Slot in summer.

If it happened with my wife aboard, I would posting to the motorcycle forums only.

[John B]

Although I agree with Ted in general terms , that its easier to depower a fractional main and easier to reef a main than change a headsail, furlers have come a long way .Its pretty easy to go down the gears via that path now with good mechanisms and modern stable sailcloth with a wide range.
Hell, I have both on my boat. Masthead main with a gorilla of a jib ,and fractional mizzen.

[John Bell]

The best rig for my money is a fractional rig with a masthead spinnaker. Down here in the light air of summer fractional rigs get killed off the wind in the big boat races. I always thought that a 7/8 rig with a masthead 'chute would be the ticket for sailing on the northern Gulf Coast.

Mickey Lake

Agree totally, that is if I was racing. For just knocking around or cruising, I've gotten really fond of the cat ketch rig.

[johnw]

It seems like usually, the fractional rig is better to windward, but the masthead rig gives you a bigger chute.

[Gerarddm]

Well, the fractional rig is more aesthetic, yes?

[ramillett]

Fractional rigs let the crew have something to do

[Michael D. Storey]

That'd be it right there I would think.
A long time ago I came to the conclusion that 'the best' bermudan rig would be a 3/4 or 7/8 th because the geometry is most stable. Have a look at commonsense of yacht design ... there's a nice sketch by LFH of the s bend( fore and aft) that a masthead forestay imposes on a mast. Its why there there tended to not be wooden masthead rigs, they were usually 3/4 or so and had jumper struts etc to prevent bend back.LOL.

Incidentally, this boat ( I was sailing on it on the weekend) is 39 ft, has a really quite large fractional rig as you see and sails like a dinghy. Tons of backstay on, cunningham and outhaul makes that main nice and flat and blades off nicely in 20 plus.


Brilliant to sail. Wooden too , a hollowed out kauri log. perfectly capable of 20 knots in the right conditions.

I have had a tendency to check the bilge pump before I put tons o', backstay on a wooden boat

[John B]

I might have exaggerated when I said it was a hollowed out log. It is hollow though.

[Andrew Craig-Bennett]

IF you don't mind the extra workload imposed by the genny, the masthead sloop is, in sizes around 30ft, the most bullet proof you can get. However it does nothing for sail shape and as John has said the mast needs to be a stiff section.

For ease of handling I will always go with a cutter or cutter headed yawl

[John B]

I certainly seem to use the ketch reef a lot these days. Maybe its just our season, It seems to have been 5 knots or 25 knots with little in between.

I'm racing on a quintessential kiwi masthead rig boat tomorrow, a Townson 34. Des Townsons early boats , dinghy classes and early keelers were fractional and really , knowing his style, I wondered why his later and more established keelers were all masthead. So I asked him one day and the answer was that it was a combination of factors but largely because the period , his heyday, was all the one tonner rage and that was the fashion.

[CWSmith]

The J/29 is an interesting case. Even though the mast is 4 feet shorter on the MH J/29 than on the fractional, the I-dimension on the rig is 5 feet longer. This allows the MH boats to carry a much larger genoa upwind than the frac boats. Even though their 100% sail areas are nearly identical, the MH boat gets the benefit of extra sail area when flying a 150% genoa compared to the fractional's 150. More sail area equals more horsepower and gets you to the windward mark first. Also, the spinnaker is much larger on the MH boats as well because it's flown from the mast head instead of the hounds. the additional 5' of spinnaker up high gives the MH boats a lot more horsepower downwind, getting them to the leward mark first. The reason the masthead J/29s are faster is simply the fact they carry more sail area than the fractionals on the same hull.

As an aside, I think the fractional J/29 is one terrific looking sailboat.

I did not know this about the J/29. I had assumed the mast was the same height. Very interesting. Thank you.

The best rig for my money is a fractional rig with a masthead spinnaker. Down here in the light air of summer fractional rigs get killed off the wind in the big boat races. I always thought that a 7/8 rig with a masthead 'chute would be the ticket for sailing on the northern Gulf Coast.

Mickey Lake

Which raises an interesting question. With backstays you would think that a fractional rig could carry a mast head spinnaker, but you don't see them very often. You could throw some bad curve into the mast, but the adjustable back stay should counter the forces. You don't see them very often.

Although I agree with Ted in general terms , that its easier to depower a fractional main and easier to reef a main than change a headsail, furlers have come a long way .Its pretty easy to go down the gears via that path now with good mechanisms and modern stable sailcloth with a wide range.
Hell, I have both on my boat. Masthead main with a gorilla of a jib ,and fractional mizzen.

I was thinking about this. In a dingy, you can't change head sails, so you absolutely need the adjustment the bendable bast gives you. In a 30 footer, you carry 3 or more headsails and you adjust accordingly. I suppose that accomplishes some of what mast bend can do, although you can't change a main very easily in a race around the marks.

Thanks, everyone. This helps my thinking considerably.

BTW- thanks for the photo in #14 - EXCELLENT!

[John B]

Most modern fractionals have a masthead option and come to think of it , a lot of the older fractionals.... 70's /80's have been retrofitted with masthead spin halyards.
That boat in my photo has both and its an oldie,1985 thereabouts. Probably why it has the little spreader/jumpers at the forestay come to think about it. Its a matter of selecting the right kite for the wind strength.

[johnw]

I did not know this about the J/29. I had assumed the mast was the same height. Very interesting. Thank you.



Which raises an interesting question. With backstays you would think that a fractional rig could carry a mast head spinnaker, but you don't see them very often. You could throw some bad curve into the mast, but the adjustable back stay should counter the forces. You don't see them very often.



I was thinking about this. In a dingy, you can't change head sails, so you absolutely need the adjustment the bendable bast gives you. In a 30 footer, you carry 3 or more headsails and you adjust accordingly. I suppose that accomplishes some of what mast bend can do, although you can't change a main very easily in a race around the marks.

Thanks, everyone. This helps my thinking considerably.

BTW- thanks for the photo in #14 - EXCELLENT!

As for a masthead spinnaker with a fractional rig, the Thunderbird class is working with this, and I expect you'll see more classes adopt this.

[John B]

It seems you can take a masthead rig boat , add a few feet on the top of the main via fractional mast and do very little else. Balance is compensated for by a flatter main or more main shape control, and light wind performance is improved via more main area. I can think of a couple of local types let alone numerous one offs which have followed that route.
One of the aspects I like about Relentless is the way the rig, which is a bit of a noodle, is stayed. Its kind of a compromise in that it isn't truly noodle like with in line spreaders but isn't like a full swept spreader rig either... somewhere in between. The runners( which are only needed for kite or security blanket/drama days) have their own second pair of chainplates a couple of feet behind the aft lowers and they live there tensioned up on block and tackle most of the time and adding something to rig integrity . Just like the extra swifters on a gaff rig, So they're no issue at all short handed.

[John Bell]

Which raises an interesting question. With backstays you would think that a fractional rig could carry a mast head spinnaker, but you don't see them very often. You could throw some bad curve into the mast, but the adjustable back stay should counter the forces. You don't see them very often.

There are a few fractional J/29s that have added MH kites. They are apparently quite a bit better off the wind, maybe even better than the MH boats.

I think the big issue for converting existing frac boats to MH kites is whether or not the mast section is up to the task. That and whether or not the rating authorities would unfairly penalize you for making the change.

[CWSmith]

Let me see if I can get some advice in going the next step, since the boat in #14 is either not available or certainly out of my price range:

J-27 or Olson 30. The latter is mast head rigged, 200 lbs lighter with 270 lbs more weight in the keel, almost the same draft, 1 foot more beam, and 16 sq ft more sail area (not including chute).

It seems like the J-27 is the go-to boat but the Olson sells for less.

I want a fast, responsive boat for day sailing and maybe racing, but not cruising to speak of. A small cabin to store sails is good. I feel like I'm missing something because on paper the Olson looks faster and more responsive, but it's the J that attracts all the attention.

[Capt Zatarra]

I used to race on an Olsen 30, we routinely smoked the J27's like a cheap cigar. In my opinion it was not the boat nearly as much as the skipper, this guy would whisper to the boat and stroke the tiller and I swear you could feel the boat shimmy with delight and give him another half knot. Knowing your boat and it's idiosyncrasies will but you miles in front of a "faster boat" with a mediocre skipper. The Olsen 30 is fast, responsive, and fun, personally I think that Js are good boats but with hyped up cult like following, it also seems to me that the extra beam and the better weight distribution of the Olsen gives it the edge over the J. But that is just me, what do I know, I gave it all up to go cruising. Capt. Z.

[bamamick]

The Olson will be easier to sail fast than the J/27, and it is simplicity itself.

Every now and then when the goofy big-boat bug bites me I think about picking up an Olson 30. Thankfully I think I got that all out of my system awhile ago, but of course, I sail the Dragon against Olson 25's and J/24's and 22's all the time, and I will do the same with the 210 once it's home.

Mickey Lake

[Garret]

Let me see if I can get some advice in going the next step, since the boat in #14 is either not available or certainly out of my price range:

J-27 or Olson 30. The latter is mast head rigged, 200 lbs lighter with 270 lbs more weight in the keel, almost the same draft, 1 foot more beam, and 16 sq ft more sail area (not including chute).

It seems like the J-27 is the go-to boat but the Olson sells for less.

I want a fast, responsive boat for day sailing and maybe racing, but not cruising to speak of. A small cabin to store sails is good. I feel like I'm missing something because on paper the Olson looks faster and more responsive, but it's the J that attracts all the attention.

Don't forget that the larger # of J boats makes it more appealing for some - especially racers.

[bamamick]

If you REALLY wanted a very fine sailing J-boat you might want to look into a J/80, but you would be hard pressed to find one cheaper than the numerous Olson 30's out there in the market.

Not that this has anything to do with anything, but I actually had a J/24 for awhile and raced it here locally. I found that boat to be the least balanced boat I have ever owned, and though they sail alright if you pay constant attention to them, it amazes me that they took off the way they did. Of course, a guy at my club owned one of the first of them, and it came essentially as a kit boat and was less than $10K US new. I have sailed on J/22's, J/30's and J/35's, and liked all of them pretty well. J/30's are still a very popular class around here (in New Orleans).

Mickey Lake

[John Bell]

From what I can tell J/27s are highly sought after, if you can find a dry one. Their reputation is as a sweet sailing boat and very competitive in handicap racing.

[johnw]

If you REALLY wanted a very fine sailing J-boat you might want to look into a J/80, but you would be hard pressed to find one cheaper than the numerous Olson 30's out there in the market.

Not that this has anything to do with anything, but I actually had a J/24 for awhile and raced it here locally. I found that boat to be the least balanced boat I have ever owned, and though they sail alright if you pay constant attention to them, it amazes me that they took off the way they did. Of course, a guy at my club owned one of the first of them, and it came essentially as a kit boat and was less than $10K US new. I have sailed on J/22's, J/30's and J/35's, and liked all of them pretty well. J/30's are still a very popular class around here (in New Orleans).

Mickey Lake

A friend who made his name in 6 meters refers to J-24s as "horrid little boats," an opinion that he has never expressed, for example, about the Thunderbird. J-24s have a pretty active class organization, which helps.

[bamamick]

From what I can tell J/27s are highly sought after, if you can find a dry one. Their reputation is as a sweet sailing boat and very competitive in handicap racing.

I have a good friend with a J/27 and he does pretty well around here with it, but from what he tells me it is very crew-dependent.

Mickey Lake

[bamamick]

www.sailingtexas.com has an Olson 30 with trailer for about $9K US. It's in Florida, and looks pretty good. If you are interested in that kind of boat give it a look.

Mickey Lake

[CWSmith]

I have, Mickey, which is why I started the other thread on balsa cores. That hull seems to have pinpoint punctures all over it and the text says the moisture readings are high below them. You can see the discoloration in the photo. I'm nervous and before I move on it I want to know if this is dying boat. I do like the price.

[bamamick]

I have a good friend who works on performance sailboats and is respected around the world for his work (which is pretty cool for a guy in a two-man shop in an old sheet-metal building in Mobile). Anyway, another friend has a J/30 that he wanted the works done to under the waterline. If I recall what was said correctly at the yacht club bar my boat-repair friend told the other (after being asked what that would cost) that he could spend as much as $25K US to strip the underbody down to bare bones and then put it all back and finish it. He might have even said $35K but I was choking on my beer at the time and didn't hear it all.

The lesson here is simple: find a boat you can live with - within reason, bring it up to your own standards of finish and expected performance - within reason, and then go sailing. There is no 30' boat made anywhere in the world that you can buy for less than $10,000 dollars that doesn't have major issues, at least potentially. I bought a 1963 model 210 for less than $3,000 and have already invested about $1500 just in 'stuff' to get her going, and I haven't even laid hands on her yet.

Mickey Lake

[CWSmith]

I hear you Mickey. My worry is that I want to go sailing, not just buy someone else's end-of-life soft hull. If I could get a solid boat for under $10k, sail it for 5 to 10 years, then give it away to some kid I would be happy. I'm wondering how many of these balsa cored boats still have 10 years of life in them, but that's the topic of the other thread. Here, I have learned that mast head rigs really can make more sense than a fractional even though it is less adaptable. I'm learning.

[John B]

Here, I have learned that mast head rigs really can make more sense than a fractional

Gee, I wouldn't agree with that because there's fractional and there's fractional just like you can get some really light noodle masthead rigs which are just as dependent on backstays and checks.
I'd be looking for the boat I wanted and or the boat that was in best condition and evaluate the rig configuration second.

balsa. what a worry... totally out of my experience but I can see your concern.

[Jay Greer]

I took on the re-design of my own boat Common Sense V aka "Red Witch" when she was dismasted many years ago. The boats were originaly 3/4 rigged with the ability to carry a masthead light air genoa and a mashead chute. I opted to change over to a mast head rig with the mast moved aft by six inches to create a larger fore triangle on the J. First of all, the boat now has a very large arsenal of head sails for a variety of wind conditions and direction of sail. The original rig was set with a large main and a self tacking working jib. with this set up she went to weather very well in fact she was more close winded than with the mast head set up. I am just about to draw up #7 of the series and will be returning to the fractional rig which, in addition to what is already mentioned, puts less strain on the hull and rig and is easier to work with. Oh did I mention that it will go to weather better with the fractional rig than she will with the mast head set up I used on #5?
Here are some shots of #1, prior to her rebuild and #5 with her mast head rig. Which one do you feel is simpler and would require less crew to race or cruise with?

[Ted Hoppe]

I took on the re-design of my own boat Common Sense V aka "Red Witch" when she was dismasted many years ago. The boats were originaly 3/4 rigged with the ability to carry a masthead light air genoa and a mashead chute. I opted to change over to a mast head rig with the mast moved aft by six inches to create a larger fore triangle on the J. First of all, the boat now has a very large arsenal of head sails for a variety of wind conditions and direction of sail. The original rig was set with a large main and a self tacking working jib. with this set up she went to weather very well in fact she was more close winded than with the mast head set up. I am just about to draw up #7 of the series and will be returning to the fractional rig which, in addition to what is already mentioned, puts less strain on the hull and rig and is easier to work with. Oh did I mention that it will go to weather better with the fractional rig than she will with the mast head set up I used on #5?
Here are some shots of #1, prior to her rebuild and #5 with her mast head rig. Which one do you feel is simpler and would require less crew to race or cruise with?

Did you change your jumpers? There is more to this Red Witch magic... I'd expect nothing less from you and always elegantly done.

[Jay Greer]

"Red Witch" has an entirely new mast and rig which is supported by running backs and standing back stay. All chain plates were moved aft along with the mast step. The new mast is an eliptical German box with 5/8" walls, 3/4" on the after track side. It is 44' feet in length, made of air craft spruce and weighs 160lbs. unrigged. In this picture the lee backstay is just being released.
Jay

[Ted Hoppe]

Jay - I would love to see what you've done. is there some pictures of your boat in a recent publication?

[Jay Greer]

Ted, the boat is in my facility in Port Townsend awaiting repairs that resulted from being run down by a power vessel while we were becalmed.
I am sorry to say that there are no current sailing photos of her. I have posted a bit of information on this site from time to time. I you would care to know more, I can give you a rundown on the history of the class.
Jay