weight limit on a trapeze wire!!!

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roger
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Re: weight limit on a trapeze wire!!!

Post by roger » Thu Jul 14, 2011 5:56 pm

I seem to remember a 5o5 mast that was seriously bent by James and Toby but I think it was more to do with bouncing it along the bottom of the solent with a boat attached to the other end.
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JimC
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Re: weight limit on a trapeze wire!!!

Post by JimC » Thu Jul 14, 2011 8:13 pm

I used to dangle 14 stone from the Cherub wire with wire rope .5mm thinner than standard 'cos I reckoned it was overspecced.

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Ed
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Re: weight limit on a trapeze wire!!!

Post by Ed » Thu Jul 14, 2011 8:37 pm

But I guess it all depends on whether we are talking about a 'new' boat or a 'classic' one.

I am sure that any new boat should be built strong enough for anybody fit enough to get out there....but with a classic boat it is a bit different.....I would of thought?

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Re: weight limit on a trapeze wire!!!

Post by JimC » Thu Jul 14, 2011 11:07 pm

Ed wrote:...but with a classic boat it is a bit different
Ah right, you mean the boat surviving rather than the wire...
Some loads are actually reduced, others increase. a crew dangling on a wire is putting much less torsional load on the structure than one hanging on toestraps for instance. The vertical load down the mast increases of course.
Keeping the mast straight can be a challenge. This isn't going to be too big a deal for 60s boats with treetrunk spars, but late 60s early 70s very flexible masts gets more interesting... By that era masts relied on the spreaders to keep them straight. All fine, but if you have most of the weight dangling off the mast then the spreaders are going to be doing very little unless you have loads of rig tension - 150-200 lbs or more. I can remeber seeing the windward shroud actually go slack when there was too little rig tension to keep the shroud loaded when I was on the wire. I used to run 600lbs on my foam/epoxy Cherub... But if you run that sort of rig tension on an old wood or polyester/csm boat then, like hundreds of old 470s, its just going to bend up, and you may lauch with 200lbs tension, but only have 75lbs when you finish the race... On the other hand if you don't have that sort of tension then every time you get on the wire the mast bends double, all the power goes and you have to get off again. Running diamonds rather than spreaders works a treat, but is pretty unoriginal on most boats. Running check stays from the shroud points to the base of the spreaders also helps, but is even less original. Play it by ear I guess, and maybe have the small wife/girlfriend on the wire and big hefty helmsman actually *sitting out hard*...

FDGorilla
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Re: weight limit on a trapeze wire!!!

Post by FDGorilla » Fri Jul 15, 2011 1:02 pm

roger wrote:I seem to remember a 5o5 mast that was seriously bent by James and Toby but I think it was more to do with bouncing it along the bottom of the solent with a boat attached to the other end.
Oi!!! I'm not that fat! The mast had a major interface with the real estate in big waves/breeze. All very ugly.

At my heaviest in the FD I was 18.5 stone for about half a season as I was training for a big boat programme. Never had a wire snap on me but did check the terminals every time we could and scrapped them if there were any broken strands. We also used rope trap 'wires' during the last few years and never had a problem. The early breeds of rope felt a little springy bouncing the rig off a start line but generally weren't a problem at all - they would occasionally coil up around the spinny pole but that was a different story!

Adhere to the basic maintenance rules and you'll be fine!
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ianmgds
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Re: weight limit on a trapeze wire!!!

Post by ianmgds » Fri Jul 15, 2011 6:36 pm

Glad I asked, got my answer and quite a few giggles along the way. Hope nobody from weight watchers comes on here, could make a fortune!!

regards

Ian

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