Rig and Foil Optimization at Modest Cost.

More Details, Launching and First Racing

The Orange Boat Part 2
More on sailing the Orange boat including early racing
Another Storer keel design - "The Fallen Keel"


Appearance:

Initially the “orange boat” was a bit of a joke amongst the Duck Flat Staff as it gradually was hacked to pieces - but as it started to come together the questions changed from comments about “generating firewood” to “just how fast do you think it will be?”.  Ted was going to paint it orange again, but as the boat started looking more and more striking, he decided to go with a white hull and deck with light grey non-skid paint. 



By this time it was attracting the interest of almost everyone who entered the factory.  A new set of kevlar/carbon sails arrived, put together by the excellent (and very helpful) Brett Averay at Binks Sailmakers in the city (Adelaide!).

Nervousness:
As the designer I was nervous about a number of things.

A good example was the question from the Duck Flat workers as the boat started to take shape - "How fast will it be?".  The only answer I felt really comfortable with was "I don't know, but it will be a lot faster than it was". 

After all we had reduced the displacement by over 25%,  increased the stability, added more sail area, made the boat much stronger and stiffer.  All of it looks good on paper.   But where paper falls down is that it never counts on the interactions between all the different factors.

So on launching day my concerns were

1/ Would it float in trim?  Not too bow down or (worse) stern down.  The calculations showed that the weights were all a little further aft than ideal.  It would have been possible to do a full computer model of the boat, but there was no-one to pay for the time involved.  If we had been able to do a computer model concerns 1 & 2 would have been completely resolved and #3 would have been mostly resolved.

2/ Would if float high enough for the transom to be out of the water?

3/ Would there be enough stability to carry the larger sail area?

4/ Would that fancy keel section work effectively to stop all that sail area from sliding the boat to leeward?  The conventional thinking is to get good upwind performance, just add draft and put the lead on a bulb.  Because the boat was being sailed at Goolwa at the bottom end of the Murray River, the draft had to be limited to 3ft (900mm) because of the shallow water.  Would the newfangled Eppler section work at such a short span?

5/ How would the boat balance?  Would it have weather or lee helm - would the rig be able to be moved enough to make sure it did balance nicely?

Launch Day:
After Ted and I loaded the boat onto the road trailer and chucked everything we could think of (including the kitchen sink) into the car we started on the hour drive down to Goolwa.  We stopped along the way at the local weighbridge to find that we had removed 320 kg (plus or minus 10kg) from the original 1000kg boat - in line with our target.

The first moment of truth was as the boat floated free of its cradle . . .  (pic left)

As you can see, both bow and stern are free of the water and (Hooray!), she is sitting very nicely on her lines.  The top of the antifoul is now about 65mm above the water at the bow and 50mm above the water at the stern.  Formerly the top of the anifoul was 25mm under the water.  I could cross #1 and #2 concerns off my list.

With Ted and I aboard we could now move about the boat with impunity - with both of us on one side the heel was about 10 degrees . . . Very Acceptable - but the sail area still looked large in relation to the draft of the keel.

Sailing - First Sail:
As you can see from the above pic, wind was very light 5 to 7 knots with occasional gusts - so it wasn't going to be a test of straightline speed.    However upwind, my guess was we were doing about 4 knots in 8 knots of wind -  quickly overtaking a Farr 750 that was sailing back from Clayton.  Considering that 4 knots was the MAXIMUM upwind speed before the mods, to be hitting it in 8 knots of breeze was highly reassuring.

Maneuverability was excellent, the boat able to spin around in its own length - feeling much more like a racing dinghy than a yacht - the result of a good rudder section and minimising the gap between the rudder and the hull.

Downwind with the jib extended on the whisker pole the boat felt quite slippery, accelerating in even the smallest gusts.  Tacking angle was pretty close to 90 degrees - not too bad for the light wind.

I went on a quick solo sail while Ted snapped some pics.  By that time there was hardly enough wind to fill the sails, but as I came into the dock it was clear that the boat had a great deal of speed (pics left and below)

Ted and I walked away from the first sail pretty happy with ourselves.


Sailing - the first race:
Two days later we were down at Goolwa again - rigging for the race while fending questions about about the "New", "Cool" boat.  "er, actually it's the old boat"
A nice little breeze - 10 to 14 knots - so a perfect test of the basic concept.  Our 22 competitors are mostly hot trailer sailers - Rosses, Elliots, a Blazer, a couple of Magnums, a Spider, the Soling, a Diamond (YW Keelboat), some Restricted 21s with their clouds of sail - all quick classy company.

We are a bit disorganised so we decide to sit just below the start line, and sheet in as the fleet comes up to us immediately before the start.  Really rotten tactics, but it is easy to organise!!!

Fleet is coming up fast, gun goes, we have no speed and Ted is tending to pinch a bit, so I get him to sail a bit full and let the boat accelerate - the boat about 4 metres to leeward gets a bit miffed as we drop down on him.

After 30 seconds of settling down we are starting to match their speed, then a bit more, until it is clear that despite having the smallest mast in the fleet we are going to be 5th to the top mark.

Reaching and running, there is no need for excuses as we easily hold our place.  We reach the bottom mark at the front of the second bunch (still 5th), but the first 4 boats had a slightly stronger wind so have pulled away from the rest of us.

Upwind again and we finally get completely clear air - quickly pulling away from the surrounding boats and making up almost all the distance to the first bunch - really fast.  Ted was finding it hard not to smile!  I was somewhat on the cheery side myself.

Since then we have raced the boat six times.  It usually finishes within the top 5, occasionally dropping down to 8th if we have a bad race.

It still has the smallest mast in the fleet and is tremendous fun to sail for two or three, quick to rig and derig, and it looks very nice indeed!

Upshots:
One of the reasons the project was successful was the excellent speed potential of the hull - we just had to get the “wings” (rig, keel and rudder) right as well as getting a great deal of weight out of the boat.



Until this project it was fairly rare for Duck Flat to have much to do with racing yachts, but a great deal has been learned from this project.  The hi-tech is almost all in the design approach - the materials are just common ply and epoxy and fibreglass, the methods are no different from those seen elsewhere in these pages (Fig right shows another optimisation project - also with a shallow draft criterion - we provide the foil shapes printed full size and can provide laser cut aluminium templates).

We are now starting to think about the next sailing optimisation project - the restoration of the gorgeous "5.5 Meter" yacht "Kirribilli" which was built for the 1956 or 1960 Olympics, but was eliminated in the trials.  Looking at her keel I think there are a couple of reasons that may explain why.


Another Storer Keel - The Fallen Keel


Now Duck Flat and I can offer:
1/ Keel and Rudder optimisation without expensive materials using simple methods - requiring simple skills.
2/ Lightweight alloy masts up to trailer sailer size at a fraction of the cost of similar mast - “do it yourself” kits are available.
3/ A range  of weight reducing strategies for many older wooden boats that also make the hull stiffer and stronger.

Enquiries about masts and rigging
Duck Flat Wooden Boats
email



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