Thread: Lug Rig Heaven Part 2010.1

Originally Posted by nickpullen

It was blowing about 10-15km/h, thing is I found that I wasnt able to point up wind as much as I used to with the Spirit rig. My suspisions are that the down haul needed more tension? the sail seemed to be bagging very deeply...

Any ideas?

Hi Nick, your mention of the sail bagging very deeply does point to lack of downhaul by the sound of it. When anyone new to lug rigs joins us from other classes it's realising how much downhaul is needed that has to be the first lesson with lugs.

We use 6:1 and pull hard to give an idea. Every part of the rig has been strengthened through breakages as more and more downhaul has been applied through racing. The Avon Scows even use 16:1 and have specially reinforced luffs.

So, try pulling on as much as you can at the beach and perhaps more outhaul on the boom to flatten the sail.

You know it could be the case the the sprit rig just points higher anyway. The luff is fully supported by the mast, so no sagging and the sprit is used to bend the mast like a bow, so the whole sail area has good tension. Plus of course MIK's luff round in his sail design matches the mast bend perfectly. So it is a rather well developed rig! And a large one as well. Is the lug the same size, I cannot remember.

Good sailing

Brian

Thanks Brian.That was very informative.

I'm very new to this sailing business, so what do you mean by "more outhaul on the boom"?

MIK's lug does have more sail area than the Spirit, as far as I can remember...

I will pull harder next time when tightening the down haul... I may even add an extra block to get the ratio up...

Originally Posted by nickpullen

what do you mean by "more outhaul on the boom"?

Sorry my apologies, your PDR is so nice it's easy to presume years of experience!

What I mean is the clew of the sail, that's the corner which attaches to the very end of the boom at the back of the boat, can be used to adjust the draft of the sail.

Your line ties the clew to the boom through a hole drilled in the boom end. By either easing out the clew or pulling it tighter you can adjust the draft of the sail.

So, if it seems baggy, then tighten the line which fastens the clew to the boom. This will pull the clew out towrads the end of the boom and will flatten the sail. Too tight and the sail will crease and be very flat, you do want some draft / shape in the sail, but for going upwind in 15 km/hr you would want a fairly flat sail, the wind itself will create shape.

Hope that helps and is clearer. It's really difficult to put things into words.

Brian

That's great, your explanation is excellent. I will give that a try next time...

So the more the wind the tighter you want the sail, ie less wind = less depth?

Originally Posted by nickpullen

So the more the wind the tighter you want the sail, ie less wind = less depth?

Yes more wind the tighter you want the sail.

ie more wind = less depth!!!!

medium wind = medium depth

light winds = slightly flatter again to keep the air attached to the sail.

If you had an adjustable "outhaul", the clew line going through a block to a cleat forward on the boom, which meant you could adjust the sail when changing course out on the water, you would flatten the sail for upwind and then release some line to make the sail fuller when sailing on a reach and a run.

Brian

Man, I can see how you are still learning after 10 years... A well, just got to play around and experience/learn what different settings do...

Cheers.

Howdy Nick,

One thing that can resolve issues really quickly is to take a snapshot and post the pic here so we can see. We can probably diagnose really quickly if you do that.

Brian might have fixed the problem with his advice.

The other thing that can make a difference is if the sail is too far forward relative to the mast.

In light winds me in a sprit rigged boat could not keep up with Mike in a lug rigged boat. So there is some potential there.

MIK

Howdy - this is a good thread to post what I want to here ... there are a number of racing classes which sail on a run or broad reach with the forces going the opposite way to normal.

Those interested can read about it here
Downwind sailing - the 4th Dimension

You can see some boats at quite interesting angles and crew in strange places. Like this. What looks like on the wrong side of the boat.



Part of the idea is to reduce the twist in the sail without using too much vang - might be a very useful method for those wanting to get more out of their Goats.

And who have enough time to practice to reprogram their sailing brains.

MIK

Hi Michael,

Will this also work for a PDRacer with a lug rig ?

Hi David,

If you want to explore the higher levels of performance it is a good option. And it explains how the forces really work which is useful.

But most will sail in a very much more conservative way. Racing I use this a little, but like most Australian performance sailors we would regard these as very advanced techniques.

Most people sail much more conservatively than this and try to keep the wind coming at least slightly from the opposite side to one the sail is on.

This method relies on having the wind coming slightly from the side the sail is on already.

I think it is an interesting intellectual exercise - but way too advanced for most sailors.

MIK

Hi Michael,

Thanks for that explanation, I am inclined to at least try sailing that way, just to see what, if any advantages there are for getting the most out of the PDRacer, but for now I could just settle with some practise with my 34'' R/C ( racing rig ) Model Yacht ( using the sail winch and rudder, it can duplicate any manoeuvre possible for a PDRacer ), it seems the safest way to experiment with this sort of sailing technique.

Very good point. When i get out into a boat again I want to give it a good try as well. Most people avoid the situation completely, but if it increases real knowledge of the real forces on the rig (even if you have to remember to ease the sail to get more power and pull it on to get rid of power) then it is a really useful thing.

Half explanations of something are never good! (ie "avoid sailing by the lee - if you do you will capsize).

BTW it will only really work well for unstayed masts.

MIK

Hi Everyone,

Would the arrangement pictured below increase the Kicker ( vang ) effect of the Downhaul for use in sailing downwind, preferably without compromizing upwind performance, or just plain getting in the way while sailing ?.

Is there a better way, that is still fairly simple ?.

Originally Posted by dhgomm

Hi Everyone,

Would the arrangement pictured below increase the Kicker ( vang ) effect of the Downhaul for use in sailing downwind, preferably without compromizing upwind performance, or just plain getting in the way while sailing ?.

Is there a better way, that is still fairly simple ?.

In fact, from my experience it would pull too hard down the leech. Having the second boom fixing just 6" back from the first downhaul position caused me loads of issues with the leech too tight and stalling the exhausting wind. Boat went much better when I just cut it off.

"Is there a better way that's simple" Yes very much so. I need to stress that although I use a lot of downhaul, when I am talking about the kicker/vang I am not looking for any force downwards, much more a simple preventer to stop the boom lifting when running downwind. So no multiple purchases need, just a simple line used.

Using your sketch the simplest 1:1 preventer would start saddle at the base of the mast, go up to the boom about 2' back from the mast, through a small block looped to the boom, back down and through the saddle and back along the deck to a small cleat. This is an adjustable kicker that will do what you need. Remember the mainsheet pulls down plenty when going upwind, so the kicker just goes slack, it only needs to work to stop the boom lifting too much as a safety thing.

You could even have it simpler, by just looping a line around the boom so it does not slip, as per MIK's rigging guides and tying it to the saddle.

So, in summary, keep downhaul to a single fixing to boom and only a simple kicker arrangement needed.

Brian