Why fractional rigs?

1) A lot of this has been driven by ratings for racing over the years, a huge overlapping genoa being advantageous in the sixties but punished now.
2) a fractional rig has more easily handled genoas, and often a taller mast,so its 'a bigger main' rather than a shorter jib
3) The fractional mast bends, giving control over main fullness.
4) the higher aspect fractional rig, with less headsail overlap will point higher.
5) Masthead rig looks old fashioned now.
 
It allows a more adjustable setup, as mast bend is controllable by backstay tension, hence good for racers. The degree of bend can be a useful factor in getting good mainsail shape to suit the wind strength.
Masthead rig is less adjustable, but is a good choice for strength in a cruising yacht.
 
Due to the unsupported upper mast some fractional rigged yachts also need runners to give added support to the mast and rig, n addition to the backstay, so not a simplified rig either.


ianat182
 
2) a fractional rig has more easily handled genoas, and often a taller mast,so its 'a bigger main' rather than a shorter jib

I had a masthead and now I have a 9/10 fractional. I did not think there was a difference in handling the genoa. Although now I find it more difficult (with the fractional rig), but I thought it because the boat is bigger the genoa has a much heavier cruising cloth and it is a No1 instead of No2.
 
Due to the unsupported upper mast some fractional rigged yachts also need runners to give added support to the mast and rig, n addition to the backstay, so not a simplified rig either.


ianat182

That is usually when an inner forestay is used or to provide extra support for the mast when going to wind in heavy weather. On most crusing fractional rigs that part of the mast is supported by swept back spreaders - although that can limit downwind sailing.
 
So if it is good for racing I can understand that but you see it on so many boats that are generally cruising and never designed for racing.
 
Think you just hit the nail on the head there “good for racing” bit like flappy paddle gearboxes in cars, from all accounts great on a race track but not a lot of use when trying to park in the local high street.
 
So if it is good for racing I can understand that but you see it on so many boats that are generally cruising and never designed for racing.
Not so sure that just because something originated in racing - although in this case it actually did not - many older designs were fractional for reasons other than adjustability, does not mean it cannot be adapted to cruising applications. "Conservative" cruising fractional rigs are not the same as full blown racing rigs with complex staying and runners etc necessary to keep them in one piece.

There are advantages for cruising. Sail areas are better balanced, loads are more easily transmitted to the hull, self tacking headsails easier to arrange and spinnakers are smaller and more manageable. Downside is swept back spreaders which limit how far the main can go out and cause more chafe; arguably there is less redundancy in the rig should there be a a failure.
 
The changes have generally been driven by a cruising yachtsman's needs which have themselves been compromised by the technology available at any one time. Back in the '70s we all carried about 4 foresails of different sizes until furling genoas became available, which made the masthead rig manageable up to quite large sizes with a small or weak crew. At the time, stowing a large mainsail was difficult, but lazyjacks, StakPacks and fully-battened sails, as well as furling mains, have meant that there is almost no limit to the size of sail we can cope with.

Even cruisers value performance and I suspect that much of my boat's advantage over the previous generation's is due to the better rig, which happens to be 19/20ths with straight spreaders.
 
The changes have generally been driven by a cruising yachtsman's needs which have themselves been compromised by the technology available at any one time. Back in the '70s we all carried about 4 foresails of different sizes until furling genoas became available, which made the masthead rig manageable up to quite large sizes with a small or weak crew. At the time, stowing a large mainsail was difficult, but lazyjacks, StakPacks and fully-battened sails, as well as furling mains, have meant that there is almost no limit to the size of sail we can cope with.

But is there really a direct correlation between having a masthead rig and a big genoa? While small mains and big genoas were in favour masthead rigs were, too, I suspect. What's to stop a masthead rig having more of an emphasis to the main (i.e. a shorter/steeper forestay and longer/shallower backstay)?
 
So if it is good for racing I can understand that but you see it on so many boats that are generally cruising and never designed for racing.

I'd say it was the other way around. IOR encouraged racers with masthead rigs with large overlapping genoas and that spread to the cruisers of the time.

Look at something older like a Folkboat with its fractional rig as a comparison.

I have to admit I far prefer fractional rigs. I find masthead rigs frustrating at times because there is so little you can do to adjust the sailshape.
 
But is there really a direct correlation between having a masthead rig and a big genoa? While small mains and big genoas were in favour masthead rigs were, too, I suspect. What's to stop a masthead rig having more of an emphasis to the main (i.e. a shorter/steeper forestay and longer/shallower backstay)?

They did vary somewhat. From what I remember, Rivals tended to have their mast further forward than many others, though they weren't exactly known for having a sparkling perfomance.
 
I have a 33 footer with 7/8 fractional rig, keelstepped, no runners. I find it an adequately powered, well balanced sailplan and easy to handle due to the smaller headsail which with some practice can be tacked singlehanded with minimal winching from light airs up to about F4-5 windspeeds. In my opinion the fractional rig is a more interesting setup than masthead if you enjoy tweaking the rig - even if you dont race the boat.
 
But is there really a direct correlation between having a masthead rig and a big genoa? While small mains and big genoas were in favour masthead rigs were, too, I suspect. What's to stop a masthead rig having more of an emphasis to the main (i.e. a shorter/steeper forestay and longer/shallower backstay)?

Big foresails ruled in IOR because the overlap was not rated sail area - so small maimsail large genoa rigs were popular, not necessarily becuase they were better, but because they got a lower penalty.
 
Due to the unsupported upper mast some fractional rigged yachts also need runners to give added support to the mast and rig, n addition to the backstay, so not a simplified rig either.


ianat182

There are some masthead boats that also need runners to keep the stick up. Depends upon the section of the mast and angle of the spreaders.
 
In my particular circumstance I've found masthead much easier to sail as downwind the main can go out much further. When you have a long narrow body of water that makes a difference. "Tacking" downwind with a fractional rig is a pain.

Windermere Class Boats are, I suppose, technically fractional, but have straight spreaders so can sail directly downwind.

7Augustsail4.jpg
 
F-rigged boats often have more complicated masthead rigging arrangements. Triatic stays come to mind. Why bother with the complications, to say nothing about swept back spreaders, useless for almost everything.

That said, those who have them may have learned to deal with them and may actually like them (unless they have to sail dead downwind a lot, as we do).

Be interesting and welcome to hear their thoughts.
 
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