proper shroud tension

Status
Not open for further replies.
H

Harry Dask

I just bought a 1976 Oday 25. I measured the tension of the outer shrouds at 25, of the inner shrouds at 45, and of the backstay at 35. Are these numbers reasonable? I am especially worried about the outer shrouds. They seem to me too loose and I am afraid of being dismasted in a fresh breeze. I would appreciate any information you might have on proper shroud tension for this boat. Thanks a lot in advance Harry Dask
 
R

Russ Marcks

Rig Tension

I don't know what your numbers mean. If they are percent of breaking strength, you're 3 to 4 times to high and will end up pulling the deck off the hull. Rig tension is one of those items of minor controversy where everyone thinks a bit different. Tension should be about 8 to 15% of your breaking strength. I tend to like the lower numbers. If Don [Evans] responds....[HI Don! :) ], he seems to like the higher numbers. In either case, do not tighten to much or you'll induce undo compression forces on the mast, the mast step and on the rig. Just make sure your mast track is straight when you eye the mast, then play with your backstay/forestay tension and mast rake for best performance. The leeward shrouds will be loose will sailing. Whatever you do, DO NOT TIGHTEN THEM WHILE UNDER SAIL. You will damage something. As long as they are not flopping in the breeze, this is not a concern. They do need to be tight enough to keep the mast from imposing a shock load on the rig should the wind [or you ;) ] suddenly shift. Russ
 
D

dave

what did you use to measure the tension???

Your "upper shrouds" should be tighter than your lower shrouds. If these numbers are from a loos tension gauge then check the instructions that came with it. They give proper rig tension as a guide based on wire size. This puts you in the "ballpark" and you can make minor adjustments from there. If you lost the paper perhaps someone can copy it and post it on the website as a scanned photo, be careful of copyright violations however dave
 
J

Justin - O'day Owners' Web

Rig tension

Harry - I like to err to the high side of reasonable, but definitely don't tighten too much or your can wreck the mast step or the chainplates. A local O'day 25 owner says that he rigs his uppers to deflect about and inch with a twenty pound push at head level, and the lowers not quite that much. Fore and back stays are tensioned so that the jib luff is straight and rig is raked and bent appropriately. This ought to mean that both are slightly more tensioned than the uppers. Justin - O'day Owner's Web
 
Status
Not open for further replies.