Thread: Goat Island Skiff in Berlin, downwind-rigging

Hi Fabian, nice to think of the Goat sailing "over" the Berlin Wall!

Looking at your thumbnail, the downhaul appears close to the front of the boom. MIK usually advises, as I do, placing the downhaul a little further back along the boom. This helps not only with downhaul but with stopping the boom lifting as well.

Because I hate to capsize the way you describe, I always use a kicker as well. Not normally used with the lug rig, but it completely prevents the problem you are having running downwind.

Here you can see it in between the mid boom mainsheet tke off and the mast on sail number 249.



Brian

Brian I think you missed something. Fabian, I think you have inadvertently turned your balance lug into a standing lug. The sail should project forward of the mast by 12" or maybe less. (Somewhere we have a diagram with the amount).

http://www.storerboatplans.com/GIS/GISRigging.html

The above is you guide. Looking at the picture, it appear that the forward end of the boom is attached right at the mast which would peak up the yard by a lot and cause the boom to lift a ton more. The beauty of the balance lug is that the boom doesn't fly as much as in a standing lug. Downwind, never let the yard get in front of the mast while running. That gets really, really interesting, I'll tell ya!

I think the answer to your problem is to set up the sail correctly. Someone may know the amount the sail should stick forward of mast. I'll look for that.

Clint

Fabian,

Both Clint and Brian are spot on: the downhaul needs to be moved further back the boom to allow for 40 cm of sail in front of the mast. If you do it this way, the boom cannot turn upwards.

More information on how to rig the GIS can be found here:

http://www.storerboatplans.com/GIS/GISRigging.html

The diagram that Clint is referring to is included here. Hope this helps.

Best regards,

Joost

Joost, Do you recal seeing a diagram that I think MIK put up with a little measurement of the stick out of the sail?

Here is from the link
"The sail needs to be set in the right position relative to the mast. Peter's boat has the front corner of the sail where it attaches to the boom around 400mm (16") in front of the mast. For boats of other design looks closely at the designer's sailplan for the boat and duplicate the position and angle of the boom in the drawings for the boat."

I have a scale drawing....will measure it up.

Clint

Is there any reason why the downhaul should not be split to spread the forces and improve the kicker effect and help keep the boom in the same position relative to the mast?

Like this:

At first glance I don't see why Bruce's rig wouldn't help a little but. First, we need to get Fabian's sail rigged like a balance lug and not a standing lug. First thing first.

Clint

Originally Posted by woodeneye

Is there any reason why the downhaul should not be split to spread the forces and improve the kicker effect and help keep the boom in the same position relative to the mast?

Like this:

Your single line system would induce far too much leach tension. It did this when I used a double strop, about 6" apart, to attach my downhaul. Boat was hopelessly slow in light winds with a completely closed leach.

Using two separate control lines is how I have my current lug set up. By splitting it two ways I can absolutely control leach tension. I fitted leach tell-tales and found they fly much better, especially in lighter winds, when using this two part system.

It is more complicated, but is much better for me when racing.

As you say also, I can freely adjust and control the boom position depending on which control is pulled on first.

Brian

Originally Posted by Compass Project

Joost, Do you recal seeing a diagram that I think MIK put up with a little measurement of the stick out of the sail?

Here is from the link
"The sail needs to be set in the right position relative to the mast. Peter's boat has the front corner of the sail where it attaches to the boom around 400mm (16") in front of the mast. For boats of other design looks closely at the designer's sailplan for the boat and duplicate the position and angle of the boom in the drawings for the boat."

I have a scale drawing....will measure it up.

Clint

Clint,

If you follow the link in my post (and your post) above and scroll down the rigging guide, you will see the drawing included which has the 40 cm's measurement. I have it like this and it works a treat.

Brian,

The balanced lug rig on the GIS has a lot more boom and sail in front of the mast than your Lymington River Scow. Somehow when seeing your rig on the scow, I do feel it looks a lot like a standing lug, and hence you would appreciate the addition of the kicker more than on a GIS.

But I have not tried this (yet) on my boat, so maybe I would like your set-up as well.

Best regards,

Joost

Originally Posted by keyhavenpotter

Your single line system would induce far too much leach tension. It did this when I used a double strop, about 6" apart, to attach my downhaul. Boat was hopelessly slow in light winds with a completely closed leach.

Using two separate control lines is how I have my current lug set up. By splitting it two ways I can absolutely control leach tension. I fitted leach tell-tales and found they fly much better, especially in lighter winds, when using this two part system.

It is more complicated, but is much better for me when racing.

As you say also, I can freely adjust and control the boom position depending on which control is pulled on first.

Brian

Brian, you make perfect sense. Michael has set up the Goat very simply to keep costs down and it does a great job for most people's usage of the boat. The standard setup is a very good compromise. I fully appreciate your need to have separate controls for both leach and luff for racing.

Originally Posted by Compass Project

Brian I think you missed something. Fabian, I think you have inadvertently turned your balance lug into a standing lug. The sail should project forward of the mast by 12" or maybe less. (Somewhere we have a diagram with the amount).

http://www.storerboatplans.com/GIS/GISRigging.html

The above is you guide. Looking at the picture, it appear that the forward end of the boom is attached right at the mast which would peak up the yard by a lot and cause the boom to lift a ton more. The beauty of the balance lug is that the boom doesn't fly as much as in a standing lug. Downwind, never let the yard get in front of the mast while running. That gets really, really interesting, I'll tell ya!

I think the answer to your problem is to set up the sail correctly. Someone may know the amount the sail should stick forward of mast. I'll look for that.

Clint

Fibian,

To add on this;

I did a lot of Finn sailing and always used a stopper-knot at the end of my mainsheet. That prevents the boom to go too much to the front of the mast, even if you loose grip on your mainsheet ( in case of gybing or any other messy situation with lots of wind on your back ).
When you rig your Goat, push the boom out to a 70 degr angle ( approx ) and put a knot in your mainsheet just after the foot-block. You can adjust this knot a little while sailing and you get a feeling how far the boom could go out without getting uncomfortable.
If I raced my Finn and I needed to turn around a can into a running course, I could just lest my mainsheet slip. The knot stopped the boom in the right position and I could concentrate on steering and other boats around me.
I am shure this works well on any boat with unstayed mast and prevents lots of stress and occasional swimming on a running course.

Regards
Ralph

Ditto what has been said regarding the need to set the boom with about 40cm in front of the mast.

But what the OP has described sounds like what I call a death roll. It happens when the top of the sail gets out in front of the mast forming an airfoil that pulls the top of the mast over to windward. You're flying downwind and maybe you let a little mainsheet out to depower. Say you're hiking out on the port side to hold her down, the boom is way out to starboard, then all of a sudden the boat capsizes the "wrong" way, to port. That's a death roll. The twisting of the boom is not the cause; easing out too far on the mainsheet is.

Geez you guys are good!

I am camping beside Timothy Lake in the Oregon Mountains - went sailing in David Graybeal's Goat yesterday, had a nice little frolic with a Core Sound 20. One up in the light stuff was matching OK, even a little faster, but a bit more wind and the goat was powered up and the bigger boat started pulling away.

All the advice is good above - thanks guys.

Get the basic system working then, if there is a need, look at variations.

Also don't underestimate Ralph's point about the mainsheet. Ease it out too far and the forces will suddenly reverse. Quite familiar to Finn and Laser sailors, but can be a surprise to those who have sailed boats with stays.

The only thing I would add is that the downhaul tension is a lot more than you thing.

In very light wind when it is hard to get the boat moving do it reasonably tight, but you should still be able to see the sail twist a little. Maybe up to 3 or 4 knots of breeze.

Once the boat is moving reliably it needs to be very tight. Maybe up to 10 knots of breeze

When you start having to ease the sheet a lot - be absolutely brutal with it.

This is all with the standard trucker's hitch setup on the rigging page. If you used a ball bearing block system above 3:1 on as shown you might have to be a bit more careful to not break the boom.

But with the truckers hitch or 3:1 blocks it is pretty unlikely.

Pretty special to get a Goat in Berlin! Well done.

Best wishes
MIK

Oh .. I think ... not sure ... that in 7 or so knots I was faster downwind than the Core. I will examine the question today!

MIK

Hello,


thank you for the good advise! When I posted the picture of my Goat, I should have added a comment. It shows the very maiden voyage and in the excitement around it, I got the rigging partly wrong. I changed this the next time I went out.
When the capsize happened, the sail was very much rigged the way Michael describes it on his homepage. But I did have an angle of 90 degrees boom to mast. In lighter winds this is very efficient. But strong winds make you feel like riding a rodeo.
Will restrict the angle and try an additional downhaul. Thanks again for your help and commitment to the issue!

Fabian