Limited swing spreaders

[n12grad]

[Mikey C]

If you can let your shrouds off, yes they will be faster, only really noticable offwind...

Only reason they are limited is to stop the mast inverting and going over the bow offwind. I have always let them swing freely and not bothered with limiting them.

We are not adjusting them on the water in regards to sweep if this is what you are enquiring.

[n12grad]

[John Meadowcroft]

a couple of points

the vast majority (if not all of us) would release the leeward shroud entirely and thus allow the spreader to move forward when impacted by either the boom on the shroud or the camber of the sail on the spreader.  Some people do not allow their spreaders to move much at all, but the front of the fleet almost entirely have fully swinging spreaders.

in light winds (and I mean when we are not hiking upwind) we will also ease the windward shroud when we are sailing on a very broad reach or a run.  Only a little mind you though.  This is just to allow the mast to fall over the front of the boat a little bit as I find this to be fast.  But we are conscious that the windward shroud is holding the rig in place so we are very conservative in what we do.

Generally I think the principle to be followed is that swinging spreaders offer the rig less protection than fixed ones.  The benefit is that the sailor can achieve a wider range of mast rake between upwind (raked back) and downwind (raked forward).  We look to move the mast tip in excess of 18 inches just by adjusting the leeward shroud alone.

john

[Jimbo41]

[John Meadowcroft]

Jimbo - you will get more power, and it sounds like you need it.

Katy and I weigh in at well over 21 stone - which is at the heavier end of things.

We have a very full mainsail to compensate and need to depower subtantially upwind, principally by bending the mast to flatten the sail, but also by raking at times, although as soon as the boom is low we stop as getting underneath it when tacking is our most important priority.  Last year we managed to be a little lighter and found raking was more important than it had been before.  In the real windy stuff we (on a carbon mast) use loads of cunningham (we sometimes rig up a 4:1 purchase), moderate outhall (don't want to pull the sail apart) and will ease the kicker to get some twist int eh top of the sail and just drive the boat hard.  If the wind drops a little we use more kicker and point higher.

Downwind the very full mainsail helps, particularly in sub-planing conditions.  We still lose out when we are marginal planing but others are full on.  We also lose out if the reaches are too broad in these circumstances.  

We can square are boom to 90 degrees with minimal spreader impact on the sail.  We find ourselves to be competitive on a run.  At Burton Week last year we had excellent racing on the run with Rich Williams and Lindsey Iles (a touch lighter than us) and Ian & Alex Gore - a lot lighter.  All of us had fully adjustable rigs.  In a Force 4 there was little apparent speed difference - it was all about how you sailed the shifts and the waves on the run.

So, I totally advocate fully swinging spreaders.  One caveat is that the crew must have a hand on the control line in case a really big gust comes along, and secondly we have our shroud base mounted on tracks so that we have the additional benefit of being able to let the shroud base forward but keep tension on.

A POTENTIAL ACTION PLAN WOULD BE

1 - Make spreaders fully swinging.

2 - At windward mark, ease leeward shroud, pull jib halyard on to make mast more upright.  Consider adjusting the ram/deck control if this may invert your mast

3 - Ease outhall, kicker and cunningham from upwind settings

4 - raise centreboard

5 - Power up rig with lower shrouds

[Jimbo42]

[n12grad]

[Jimbo41]

n12 grad,

I understand from reading this thread that the spreader moves forward when not under tension from the shroud. Each is independent of oneanother. Releasing the leeward shroud allows the spreader to move forward, either when the shroud is fully off, or when the boom/rig/sail camber excert(s) sufficient foce on the attached shroud. The windward shroud and lowers are, inter alia, responsible for maintaining the shape of the rig, esp. by maintaining the mast straightness.
Meds. did mention releasing the windward shroud very slightly in a light breeze on a run, but only to cause the mast to bend forward slightly, apparently increasing the power. (I've seen that on video on Baithwaite's 18 ft skiff and I'd not want to see that happen to my mast!!! ). I don't think that the release of the windward shroud under these conditions would move the leeward spreader forward and if it did, you'd compromise on rig shape since you'd have to release the windward shroud too much.

Hope that helps and help me out meds. if I've made a boob of that one!!

Jim.