Thread: Slack Forestay
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K. Smith
 
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wrote:
I have been experiencing a problem when beating in moderate+ winds. My
foresail is a masthead rig(?)a large genoa & really 'bangs' when
sailing close to the wind, this in turn is transmitted down the mast. I
know that the rigging is probably on the slack side, particularily the
forestay (its at the end of its adjustment at the bottlescrew), would
this be the likely cause or should I be looking elsewhere?



You don't emntion the backstay(s), assuming it has plenty of travel
left in the turnbuckle you han tighten the forestay with that, indeed
that's how most forestay tension is controlled.

You use the forestay to position the masthead, a small movement forward
or aft can change the handling (influencing falling off or rounding up
when close hauled, cruising boats can be also self steering into the
trade winds once the masthead position is tuned), then usually once
that's sorted you use the backstay (adjustment) to control forestay tension.

This has two benefits, the forestay need only be really right on the
wind & if the forward lowers are adjusted right, as you tighten the
backstay even with a masthead rig, you'll put a little aft bend into the
mast which has the effect of flattening the main, so it also performs
better to windward.

On modern glass production boats you will only get so much outright
"tension" (the hull has some movement) but it's still plenty for good on
the wind performance.

If your backstay is "adjustable" say hydraulic or a wheeled
turnbuckle??, get into the habit of letting a bit of tension off when
leaving the boat.

No matter how you try you'll not stop some forestay movement on
windward beats in open water, there's lots of forces going on. Don't
over tighten the rig.

Seems I recall a certain Ozzy america's cup boat that broke in two &
went down in less than a minute, by a combination of over zealous crew
pumping the backstay, rough water & a hull design way too light for the
job; oops:-)

K