fractional or masthead which is best?

[philip van praag]

i have posted this question in regard to one of the polls but have had little responce. What are the pros and cons of each type of rig fractional or masthead what would you recomend and why.
could be the choice between broadblue 385 or privilege 37??

[delmarrey]

It all comes down to your intended use.

For racing and performace boats a fractional will get you where your going.

But for serious off-shore you'll want a mast head rig IMHO................._/)

[philip van praag]

Originally Posted by delmarrey

It all comes down to your intended use.

For racing and performace boats a fractional will get you where your going.

But for serious off-shore you'll want a mast head rig IMHO................._/)

ok but why whats the prows and cons. on the money no object poll people are chosing boats with fractional rigs as the top dream boats and as they are mostly global cruisers it seems to contradict what you are saying!!

[philip van praag]

just had a look at the thread asking for characteristics for circumnavigating and nobody seems interested in the sail plan. dont understand the lack of comment in this aspect as its the main sorce of drive for 30,000 miles it must have some bearing in the type of boat you choose as it also has a big affect on the layout inside.

[delmarrey]

Here is a couple articals that our friend Jeff H posted on the web a while back. He is the owner of a fractional rig and knows them well.

Date: Oct. 05 2001 7:31 AM
Author: Jeff_H
Fractional vs. Masthead rigs These terms both derive from the point at which the forestay hits the mast. On a masthead rig the forestay hits the mast at the masthead (top of the mast). Masthead rigs are far and away the more common of the two rigs. Until the 1950's Masthead rigs were virtually unheard of. But with the advent of low stretch sail cloth and better winches, as well as, changes in the racing rules Masthead Rigs became the norm. This change came about as a rule beating method for racing sailboats. Under the CCA and IOR racing rating rules, jib size was under penalized. This promoted small mainsails and big jibs. On a fractional rig, the forestay hits the mast somewhere below the masthead (or a fraction of the overall height of the mast. It is not unusual to see fractional rigs referred to as a 2/3 (Folkboats), 3/4 (J-24) or 7/8th's (Triton) rig. Each rig has its own advantages and disadvantages. There are some big advantages to a fractional rig for cruising and racing. For cruising, you are dealing with smaller and easier to handle headsails. Not only are the headsails smaller because of the shorter headsails but, because the headsails represent a smaller percentage of the overall sail area, you don't need to have overlapping jibs. The sail area missing from the foresails is made up in a bigger mainsail. This makes sense since, using modern hardware and sail design, mainsails are easier to tack, depower and reef efficiently. Fractional rigs often have purposely designed flexible masts and, when combined with a backstay adjuster permits quick, on the fly, simultaneous depowering of both jib and sails. Mainsails are easier to reef in a manner that results in an efficiently shaped sail for heavier conditions. Smaller jib area means that you don't have to take on the expense, complication, maintenance and performance hit of a mainsail furler. Controlling mast bend you can often avoid reefing as the winds build. Roller furling genoas have notoriously poor shape when partially furled. The smaller jibs of a fractional rig rarely need reefing and when they do the fact that they are non-overlapping results in a better partially furled shape. Masthead rigs have larger running sails and so can typically point closer to dead down wind. They are a little more forgiving. Because Fractional rigs permit such a large range of easy adjustment, they can be trimmed through a range of adjustments that results in a bigger range of speed both slower or faster than a masthead rig of similar sail area. The limited adjustment of a masthead rig means that you more or less live with what you have. Therefore a masthead rig has less of the opportunity for makind fine tuning adjustments that mean going really faster and with less heel, or going much slower either. My biggest problem with Masthead rigs is that you really need to carry more headsails and make more headsail changes. This is partially a function of the responsibility of the jib for drive. If you take a Fractional Rig 100% jib on a 28-footer it might be 150 s.f. and its 150% Genoa would be 225 square feet. But on a masthead rig 28 footer the 100% jib might be as much as 225 to 250 square feet and its 150% Genoa would be 337 S.F. to 375 s.f. That is a really big sail to manhandle and the when you increase a sail by 125 S.F. vs. only 75 s.f. there is a much smaller wind range that the bigger sail can be carried in so you might end up also carrying a number 2 Genoa as well as a working jib and a 150% #1 Genoa. With roller furling you end up sailing more frequently with (much less efficient) partially rolled up sails. I strongly favor Fractional rigs for coastal sailing because the are so much easier to tack and jibe, you are not carrying around the big winches and as many large sails, and subjecting the boat to the much higher loads of a masthead rig. Jeff

Jeff H. 3/13/04

I apologize that this was written for another venue but it might still prove useful. Of the two rigs, masthead rigs are far and away the more common of the two rigs. It came about as a rule beating method for racing sailboats. Under the CCA and IOR racing rating rules, jib size was under penalized. This promoted small mainsails and big jibs.

On a fractional rig, the forestay hits the mast somewhere below the masthead (or a fraction of the overall height of the mast. It is not unusual to see fractional rigs referred to as a 2/3 (Folkboats), 3/4 (J-24) or 7/8th’s (Triton) rig.

Each rig has it advantages and disadvantages. There are some big advantages to a fractional rig for cruising and racing. For cruising you are dealing with smaller and easier to handle headsails Not only are the headsails smaller because of the shorter headsails but, because the headsails represent a smaller percentage of the overall sail area, you don’t need to have overlapping jibs. The sail area is made up in the mainsail.

The best fractional rigs often have purposely designed flexible masts and, when combined with a backstay adjuster permits quick, on the fly, depowering of both sails. Mainsails are easier than jibs to reef in a manner that results in an efficiently shaped sail for heavier conditions. It means that you don’t have to take the expense, complication, maintenance and performance hit of a mainsail furler. Controlling mast bend you can often avoid reefing as the winds build. Roller furling genoas have notoriously poor shape when partially furled. The smaller jibs of a fractional rig rarely need reefing and when they do the fact that they are often smaller or eveb non-overlapping results in a better partially furled shape.

Masthead rigs have larger running sails and so can typically point closer to dead down wind. They are a little more forgiving for a new sailor. Because Fractional rigs permit such a large range of easy adjustment they can be trimmed through a range of adjustments that results in a bigger range of speed both slower or faster than a masthead rig of similar sail area. The limited adjustment of a masthead rig means that you more or less live with what you have. Therefore a masthead rig neither has the opportunity for going really faster and with less heel, or going much slower either.

My biggest problem with Masthead rigs is that you really need to carry more headsails and make more headsail changes. This is partially a function of the responsibility of the jib for drive. If you take a Fractional Rig 100% jib on a 28-footer it might be 150 s.f. and its 150% Genoa would be 225 square feet. But on a masthead rig 28 footer the 100% jib might be as much as 225 to 250 square feet and its 150% Genoa would be 337 S.F. to 375 s.f. That is a really big sail to manhandle and when you increase the size of a sail by 125 S.F. vs. only 75 s.f. there is a much smaller wind range that the bigger sail can be carried in so you might end up also carrying a number 2 Genoa as well as a working jib and a 150% #1 Genoa. With roller furling you end up sailing more frequently with (much less efficient) partially rolled up sails.

I strongly favor Fractional rigs for coastal sailing because the are so much easier to tack and jibe, you are not carrying around the big winches and as many large sails, and subjecting the boat to the much higher loads of a masthead rig. The lower rig loads can also mean a longer standing rigging lifespan and lower stresses on the boat. Fractional rigs generally lack the redundancy of masthead rigs in that a properly designed fractional rig only has a single set of lower shrouds.

Jeff

[senormechanico]

I've had both. Imho, a fractional rig is more weatherly, whereas a masthead rig is better for off the wind.

Steve B.

[44'cruisingcat]

The vast majority of cats have what look like fractional rigs. But they are a bit different to a fractional rig on a mono. The main difference being, the cat does not have backstays. On a mono, the shrouds and backstays go to the top of the mast, and (on a fractional rig) the forestay goes some fraction of the way (ie 4/5, 7/8 etc). Often running backstays are needed to counter the bending force applied to the mast by the forestay being lower than the backstay(s). This can complicate tacking, and may require additional crew.
On a typical modern cat rig, the shrouds and forestay meet at the same height, but not at the masthead. The top metre or so of mast is either unsupported, or supported by a jumper. So there is no bending force applied to the mast, and no need for running backstays.
One way to look at the "fractional rigs" on cats is, basically like a masthead rig, but with a bit of extra mast added on top.

[philip van praag]

this still does not help in chosing between the two but thanks for the post

[schoonerdog]

having had both, I must admit that the fractional rig seems far easier to sail through a tack than my mast head design and sails significantly better to weather. My mast head was almost impossible to tack with less than 15 knots of wind while keeping any speed. My fractional rig seems to do it with ease. All of which would make sense from the larger roach main. The principal advantage of a mast head was that the design in my mind was a more redundant in terms of supporting stays (two forward, two side and two aft to the transom), but with sufficiently overbuilt stays for a fractional rig that really wouldn't be a problem. The older mast head design also had stays coming aft to the transom which tended to be a bit more "in the way" (causing chafe on the arch, water ingress into the aft water tight compartments as they were through bolted plates for connection on the transom were partially submerged).

[Pura Vida]

There are other design considerations when choosing a mast head or fractional rig. The sail plan is designed into the location of the mast, the hull shape and other features and they will vary from boat to boat. My recomendation is to use the rig that the designer planned for the boat.

[philip van praag]

i was not suggesting a change to a boat design but which would you chose for cruising and why,
so affecting the boats you would consider
(im new to the forum perhaps someone could tell me how to put this up as a poll or feel free to go ahead.)

[44'cruisingcat]

Originally Posted by philip van praag

this still does not help in chosing between the two but thanks for the post

It should have helped. Basically, on a cat a fractional rig is pretty much the same as a masthead rig with a little more mainsail area available.

Better upwind performance, easier tacking, yet similar downwind.

[philip van praag]

Originally Posted by 44'cruisingcat

It should have helped. Basically, on a cat a fractional rig is pretty much the same as a masthead rig with a little more mainsail area available.

Better upwind performance, easier tacking, yet similar downwind.

and what is your prefferance and why?

[philip van praag]

so why would anyone want a broadblue yet still seems a popular boat

[44'cruisingcat]

I guess because they are buying a boat, not a rig.