Optimising the Goat Island Skiff and lug rigs

**Boatmik** · 2nd July 2010, 02:54 PM

John Goodman wrote me a letter post the Texas 200 giving a rundown on the performance of the Goat.

This was a predominantly light to medium wind event with wind from all points of the compass at some time or another.

John provided a nice summary of the event and included some sailshape pics.

John's comments bold and indented
________________________________________________________________

Hi John, Thanks for the performance rundown!

I can hear how happy you are with the beast!.

On 29/06/2010 2:32 AM, John Goodman wrote:

Clint & Michael,

What a great Trip! The Texas 200 was a fantastic trip and the boat and rig performed very well. I think David and I were lucky this year because the previous years the wind was reported to be much higher.

Yes ... it averaged about 20+ knots. One of the reasons I was motherhennish about you guys going in a Goat was because of the previous year and how my RAID41 design had a very hard time of it. It was rushed to launch and then joined on the third day for its maiden sail.

I did sail that boat later when I was in Texas ... It is a lot of fun and quite sweet to handle, but really high sided making it hard to get aboard.

I received a few odd compliments from a few of the other sailors like; "This is the only Goat I have not seen the bottom of, most the time they are upside down.", "You did not fall out of this one?" (RAID41 comment) and "You were all over the place the first few days, now you embarrass us all by passing us when there is no wind."

A good sailor always has the advantage in light wind!

We traveled 197 miles per our GPS. That is 197 miles without a single boat related failure. That is a testament to a great boat design, great rig and good sails. The only problem was the traveler got in David's way, since he liked to sit on the aft deck to steer.

I think you need to blame the building. The boat doesn't fall apart because it has so few pieces and was put together very nicely. That's the secret - choice of owners and epoxy deserves some credit too!

Here are a few pictures of the rig in action, but not with much wind. Maybe 10-12knots of breeze. I am glad I read that this type of rig needs lots of down-haul tension. On the gusty days we were able to depower the rig easily. We began to lower the rig instead of reefing. We would drop the halyard so the tip of the boom was an inch above the gunnels. This lowered the sails center of effort and made it much tamer during the big puffs.

That is interesting. A good solution for cruising when you don't expect to tack or gybe much. Might be a bit dodgy if there is some uncertainty about needing to tack or gybe.

One thing I would consider doing is from this shot

I would suggest a loop through the clew eye and around the boom to prevent the clew moving away from the boom as the outhaul is eased. It will reduce the bending moment a little, but more importantly it will mean that the easing of the outhaul won't mean the clew moves further away from the boom. This means that your easing will be translated more directly into more depth in the mainsail without increasing the sail twist.

The yard and boom are stiff and do not flex a lot. Compared to the other lug rigs, mine was very very stiff. The mast was rock solid the whole trip. In the hard upwind, 12-15knot winds, sheeted very hard the tip of the mast would bend aft about eight inches. We very seldom used this amount of tension, but tried it for fun a few times.

Cool. Interested in feedback - maybe on the forum about settings for going upwind. Did you have some knots in the traveller to limit the boom to a 10 degree angle from the centreline?

I did that a few times and in moderate winds it gave a bit more pointing ... particularly if the mainsheet was trimmed to get the leach ribbons flowing evenly.

I guess it would be possible to run a tighter traveller and add a control line from each side with a cleat each side to limit how far the traveller block can move to the side. We used to do that in the NS14 class. A wire (now it would be spectra) bridle that was quite tight and a separate rope each side to adjust the traveller.

Might be worth trying for those interested in tweaking performance.

You could centralise the traveller in light winds to minimise the sheet tension pulling the boom down. Then drop it to the 10 degree mark for average winds or let it that extra bit out to the gunwale for stronger winds, tight reaching or choppy water upwind.

The mizzen mast was flexible and during the big puffs the tip would flex a few to 6 inches. It did not ever vibrate during the higher winds. The mizzen sail would shake the mast if not trimmed tight enough. Only once during a series of tight tacks up a busy channel did we left the mizzen flog. I just could not concentrate on the mizzen with the wind gusts, barges, ferries and other large boats crossing back and forth.

Was the shaking of the mast from mast flexibility or from fit in the partner or both?

Pics at boatmik's collections on Flickr

I see you have a halyard ... I would sneak it around to the back face of the mast if I could. even if there is a hook on the back face it can be flicked under after hoisting. Gets rid of the drag of the halyard.

There is an alternative way of lacing the sail that may allow it to be hoisted and dropped but reduce the gap between it and the mast.

Start at one end like normal. then go around the mast to the first eyelet. Instead of continuing the spiral, come back the same way you came from (ie reverse direction to keep all the rope on the front of the mast). Then go to the next hole, put it through and reverse direction again. You might be able to get it a bit tighter to close the gap between the mast and sail.

On performance compared to the Sea Pearl 21 & Core Sound 17.

On the real tight upwind work in the channels the Sea Pearl had 2 tacks compared to our 6. Once off the breeze slightly we were faster in the mid range conditions. The day we slowly pulled away from both the Core Sound and the Sea Pearl it was a tight reach upwind in 10-15knots of breeze with some frustrating lulls down in the 5 knot range. One tack for 22 miles. We were full sail as they were. And yes, my competitive sailing skills were back and I was not about to let them pass me.

Haha ... it comes out so easy doesn't it!!! Did you adjust the outhaul much ...to get 10% camber in the bottom of the sail might help pointing in medium conditions and footing upwind in choppy and strong conditions. Flatten out when overpowered. For reaching with attached flow over the sail (tufts flying) you could adjust to a 1:7 camber for lots more power.

The narrower boom angle might have reduced the number of tacks a bit. Also trim the mizzen for a little bit of weather helm. Tiller at about 3degrees to windward. Measure it so you know what it looks like.

That is all for now. It's time to finalize the next 300 miles of my trip.

Heard about the hurricane. Glad it wasn't last week!

Best wishes
Michael

**Boatmik** · 2nd July 2010, 03:03 PM

Does anyone have a bookmark for the datapage where the boom and yard bend measurements are stored. Be nice to consolidate them here.

**jmk89** · 2nd July 2010, 03:28 PM

Mik

Could you edit your post so it is a bit easier to tell your comments from John's? EG could you put yours in italics or bold or bold italics?

**Boatmik** · 2nd July 2010, 04:05 PM

Straightaway ... sorry about that.

**woodeneye** · 2nd July 2010, 08:17 PM

Here you go. Not much here yet though.

Originally Posted by woodeneye

Let me know if this works for you. Those with better skills than mine can make it look better and feel free to make changes.

Login username: GisSparData
Password: goat

Open the file on the left titled "Welcome"

Zoho Sheet - Untitled

**john goodman** · 3rd July 2010, 02:57 AM

One of my biggest problems was with the outhaul line cleat. First was finding the correct location and 2nd was getting the line to hold properly. The new Specta did not like the Ronstan cleat. The rope was not soft enough to settle into the cleat and jam. We had to purposely push the line into the cleat to get it to stay. I use the same size cleat for the mizzen halyard & sheet which use softer line and they cleat easily. I think the next larger cleat would solve this problem using the same Spectra line. Locating the cleat I am still working on. We did move it during the trip, but still do not like where it is. It needs to be over the middle seat as a starting point. Any further aft aft and you cannot reach it while sailing. If you have a crew most of the time, move it forward. We use small bungie cord loops around the boom to hold the outline tight against the boom. This keeps me from hanging myself or crew during tacks/gybes when the outhaul is loose.

(Mik) I would suggest a loop through the clew eye and around the boom to prevent the clew moving away from the boom as the outhaul is eased. It will reduce the bending moment a little, but more importantly it will mean that the easing of the outhaul won't mean the clew moves further away from the boom. This means that your easing will be translated more directly into more depth in the mainsail without increasing the sail twist.

I have a stainless steel rig on the end of the boom that the outhaul passes thru. It can slide bad or forward on the boom in reference to the reef points. It has a bad habit of sliding backwards when I loosen the outhaul. On this trip we did add a sail tie in the clew grommet to help control the lifting when we reefed. The stainless ring worked about 75% of the time just fine.

(Mik) I see you have a halyard ... I would sneak it around to the back face of the mast if I could. even if there is a hook on the back face it can be flicked under after hoisting. Gets rid of the drag of the halyard.

There is an alternative way of lacing the sail that may allow it to be hoisted and dropped but reduce the gap between it and the mast.

Start at one end like normal. then go around the mast to the first eyelet. Instead of continuing the spiral, come back the same way you came from (ie reverse direction to keep all the rope on the front of the mast). Then go to the next hole, put it through and reverse direction again. You might be able to get it a bit tighter to close the gap between the mast and sail.

I only used the halyard 1 time during the trip. It involved a downwind docking maneuver. Dropped the main sail in a small harbor and approached the dock going downwind. To decrease our downwind speed we dropped the mizzen a few meters from the dock and used the oars for steerage/stoppage. I might consider just lacing the head. We stored the sail wrapped around the mizzen mast every night. So dropping the sail with the halyard it not done much. The lacing was very loose at the beginning of the trip. They were tightened up as the event went along after I talked to other boats owners that had mizzens and learned a few more things. I had cut all my lines a little long. This lacing was fun to do and I liked the looks of it, but there were far more examples of simple lacing on other boats.

I do not consider my boom and yard flexible compared to the Lagunas we sailed with. They had very bendy booms and yards. In consideration of that idea, that might be why we would heel so quickly during a gust, because the rig would not give way. The Lagunas would heel very little but accelerate slowly. We would heel get it under control, then accelerate. By the way, my boom is not round or square, it's a rectangle with it's corners rounded.

More rain and now minor flooding here in Houston due to the remnants of hurricane Alex.

**callsign222** · 3rd July 2010, 08:55 AM

Another good conversation.

So what I get out of this:

A outhaul could go back to a ring/bock/line loop at the end of the boom, and the line could then pass forward to a cleat along the boom around amidships to help adjust outhaul tensions a la Laser.

Also, I had the same problem with my spectra line in my cleat, almost need a larger cleat even though it's rated for the size spectra I'm using.

She points is a little less than other boats, as the Sea Pearl? I had an O'Day Day Sailer outpointing me two days ago but not by much, just a few degrees. Their jib definitely helps.

**callsign222** · 3rd July 2010, 09:14 AM

Originally Posted by woodeneye

Here you go. Not much here yet though.

I just added mine.

**CCBB** · 3rd July 2010, 12:26 PM

I added my data for Gir's sticks. The yard has more taper, so the ends of the yard are closer to the original.

My bend data is 1/3rd of the sail area in weight added to the halyard attachment point.

The yard will work more in stronger winds. Looking at the photos, it looks like the end is deflecting a bit. In heavier air it will move much more. I was shooting for a stiff boom but a yard that could take a lot of downhaul tension but still bend high up when the gusts come. My 50x50mm size is in line with what Joost is doing for his new yard. It will be interesting to see his results.

The important thing to remember is that the sail shape is cut to match yard bend. This is why I really appreciate sailmakers who want the data and really seek it out. Once the sail cut matches the yard, things will work out well.

**callsign222** · 8th July 2010, 12:10 PM

Originally Posted by Compass Project

The important thing to remember is that the sail shape is cut to match yard bend. This is why I really appreciate sailmakers who want the data and really seek it out. Once the sail cut matches the yard, things will work out well.

But what do you do if you lose or break a yard?

**woodeneye** · 8th July 2010, 02:52 PM

Originally Posted by callsign222

But what do you do if you lose or break a yard?

You inch home?

**Boatmik** · 8th July 2010, 03:50 PM

haha.

The main thing is that a yard of the right type of bend will match the sail OK.

Those who want to strive to the perfect sail and spar combination can work at it.

If they find something nice they should measure the bend so if they break the can make a new one up and plane it down to match the same bend.

I do happily note that the only person who has broken a storerboats spar ... that I know of is me. Beth's mizzen mast during a high speed capsize.

MIK

**woodeneye** · 8th July 2010, 08:38 PM

Originally Posted by Boatmik

I do happily note that the only person who has broken a storerboats spar ... that I know of is me. Beth's mizzen mast during a high speed capsize.

MIK

Sorry Mick. We just can't pass up an opportunity like this, so here goes another one that slipped your memory....

[ame=http://www.youtube.com/watch?v=5PVkPHGE2c8]YouTube - Crash and Burn[/ame]

**Boatmik** · 8th July 2010, 10:13 PM

Haha ... OK ... I am the expert!

If the biting midge was around he would have to come forward and tell you that he was responsible for some 2:1 scarfs. I said we would have to redo them and he said we would reinforce them with a block on the inside.

I ran my normal line about ... if it works then it is my great design, but if it fails it is your too short scarfs.

In reality it failed for both reasons ... I just didn't allow enough for the stability of the PDR - I think the mast may have survived, but there was a real lack of power on a reach - it just bent too easily and completely overflattened the top of the sail and the sprit dropping at the outer end made the lower sail a great big bag. I think with proper scarfs and fewer knots it might have survived OK

The final 12% thicker masts included in the official plan were just scale ups of those ones and have nice consistent power on all points of sail.

So let me rephrase that ... The only spar from official plans that has been broken is me breaking BETH's mizzen in a high speed capsize.

I still had to watch the video a couple of times. I like the way the biting midge (filming) almost capsizes himself when the mast breaks!

MIK

**robhosailor** · 11th July 2010, 09:31 PM

Originally Posted by Boatmik

So let me rephrase that ... The only spar from official plans that has been broken is me breaking BETH's mizzen in a high speed capsize.

BETH's mizzen mast is really thin stick (max diameter 37 mm) and relatively long (circa 179 cm)

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