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Fractional Rig Strength

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Created by Zzzzzz > 9 months ago, 6 Sep 2018
Zzzzzz
513 posts
6 Sep 2018 12:28PM
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Looking at my fractional rig I can't help but wonder is it that much weaker than a masthead rig.
Is there much that can be done that will make it more bullet proof without losing the advantages of fractional rig.??

Yara
NSW, 1314 posts
6 Sep 2018 9:05PM
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A properly designed fractional rig will have mast bracing to suit such as diamond jumper stays. Hence it will be just as strong as masthead, all other things being equal. However, some fractional rigs are intended to create mast bend, and the mast might be more flexible (read weaker) by design.

Zzzzzz
513 posts
6 Sep 2018 7:20PM
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Yep that's mine mast bend fantastic but am worried by that weaker bit

shaggybaxter
QLD, 2662 posts
7 Sep 2018 5:31AM
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Hi Browny,
Horses for courses isn't it? If you have a design with a thin whippy mast with lots of bend, it will have a different max loading to a solid inflexible mast section. So, maybe less of an argument about fractional v masthead vs mast structure?
I run a cf fractional rig without runners or backstays, and we've had full sails up in 40+ knots (not by choice). We'll run kites in 30 kn, again no problem.
Look at a Mumm 36 rig. Perfectly fine until you forget the runners in a decent wind, then patooey! (is that a nautical term?)



Zzzzzz
513 posts
7 Sep 2018 3:35AM
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Hi Shaggy sounds nautical to me mate

rumblefish
TAS, 824 posts
7 Sep 2018 9:20PM
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Bendy masts with inline spreaders are a thing of the past and racing only like Mumm's .
I'd always prefer 7/8th rig with swept spreaders for cruising as the stay tension induces mast bend and stops inverting.
At 7/8th you don't need massive spreader angle to keep forestay tension as backstay will still help that.
I'd also have double spreader with inner forestay with staysail and runners at the top spreader.
Although I don't really like the mass produced mast and components, modern Hanse's have a really nice cruising rig plan

Chris 249
NSW, 3531 posts
8 Sep 2018 7:37PM
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Select to expand quote
Yara said..
A properly designed fractional rig will have mast bracing to suit such as diamond jumper stays. Hence it will be just as strong as masthead, all other things being equal. However, some fractional rigs are intended to create mast bend, and the mast might be more flexible (read weaker) by design.


I don't know if more flex means it's weaker. Some devices as critical as airliner wings are designed to flex. It's a good way of spreading loads at times.

I can recall the legendary Lou Abrahams telling me that the Sydney 38 fractional rig was the most comfortable he had sailed with in his 50 years or so of ocean racing, partly because it flexed nicely in a seaway. I'm biased though, I wouldn't really have any other rig.

Zzzzzz
513 posts
8 Sep 2018 5:54PM
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I agree Chris, after using all the adjustments I can do with the fractional rig and seeing the results i dont know how i sailed with a masthead rig



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"Fractional Rig Strength" started by Zzzzzz