Everglades Challenge 2013

[Doug Cameron]

As we move into day 2, Alan and Paul Stewart's CS 20 and Phil Garland's beautifully built and high-tech CS 17 (carbon fiber masts, wishbone booms, square-topped high roach sails) are battling for first. The many multi-hulls took off in the building norfherlies at a pace that even planing mono hulls cannot match. Now, after 26 hours, two Core Sounds are battling for first. Not since Graham raced the Norseboat have monohulls been in the lead! Check it out at watertribe.com and hit the mapper link.

[Designer]

It is certainly an exciting race with about 100 boats on the starting line; but there is a long way to go yet. I know from experience, fortunes change, sometimes quickly and unexpectedly.  Again, Randy Smythe in his fast, but fragile, scissoring trimaran has capsized after building up a huge lead.  It was reported that he was heading for Ft. Meyers, after sustaining some damage in the capsize.  We are all glad that Randy, himself, is okay.  There was another catamaran rescued by the Coast Guard yesterday.  Additionally there is the usual run of broken rudders etc...

 

It is also an interesting tactical race.  For those who have not followed this race before, there are checkpoints, but how you get from one to another is not mandated...there are "inside" and "outside" options. It has been reported that there was good size swell at the beginning of the race, and many boats opted to take the inside passage. Both of the Core Sounds elected to stay outside, which is the faster course.  The two boats were very close together at that point.  Phil elected go inside at Venice and lost some ground to Alan and Paul.  After check point one, Paul & Alan elected to go inside through Pine Island Sound, while Phil went outside and not only picked up what he had lost, but also gained about 7 miles. 

 

Currently Paul and Alan have opted to take the short cut through Caxumbus pass, while Phil has taken the outside route, around Cape Romano.  There are also a couple of cats not too far behind, so it is still anyone's race as they head into the shallow twists and turns with strong currents and other hazards of the Everglades as they head into checkpoint 2 at Chokoloskee.

 

Doug is right that since the big cats came into the race a few years ago, they have dominated the overall lead, however I did win the overall race twice since the race he was speaking of (with the Norseboat) which was our first year in the race. 

 

To follow this race, go to www.watertribe.com. and go to the tracking map for the 2013 Everglades Challenge.

[ecgossett]

Those wishbone masts are made by Chinook Sailing Products in Cascade Locks, Oregon.  http://www.chinooksailing.com/products/product_info.php?cPath=1_82&products_id=267

 

I got this info from Phil a while ago. If you want to purchase them at a decent price, talk to Paul, he orders mass quantities of those supplies.

[tom151]

Those wishbone masts are made by Chinook Sailing Products in Cascade Locks, Oregon.  [/size]http://www.chinooksailing.com/products/product_info.php?cPath=1_82&products_id=267

 

I got this info from Paul a while ago. If you want to purchase them at a decent price, talk to Paul, he orders mass quantities of those supplies.

If you don't mind... after seeing his CS17 with the wishbooms I am interested in those too.

So, Paul who?

Thanks a lot

[ecgossett]

Philip Garland

 

[brigait1]

I decided to build laminated wooden wishbones for GoodFoot. It wasn't very difficult, and I'm very happy with the sail shape they give. They are a bit heavy tough. I will probably take a stab at making some out of carbon fiber at some point, but these are great for now. One thing I did was use sewn nylon loops and shackles to attach the snotter and sheet blocks. This way there is no hardward bolted or screwed into the spars themselves. You can kinda see what I'm talking about in this pic. This is the snotter attchment loop for the main.

 

[Doug Cameron]

Alan and Paul finished in just a few minutes over two days - a new monohull record. Phil was running on fumes and got a few hours of sleep in Flamingo so he could cross Florida Bay in daylight. He was only 20 minutes behind Alan and Paul, and Alan said it was only because oars are faster than yulohs. Congratulations to Alan and Paul for a fantastic run!

[Howard]

Congratulations to Alan and Paul and to also Phil. Normally, we only concern ourselves with winners but considering what was accomplished, that is a remarkable feat by both boats.

 

Since the race is over, and since this thread had already swerved to the topic of wishbones, I had a question or two about the wishbones in Pete's photograph. As I understand it, curved sprits of the type he shows have a few problems. Ostensibly, the intent of the curved sprit is to assume the shape of the sail and thus not distort the sail shape, but that comes at a price. The problem with curved sprits is they have very little strength in compression. The normal gust response to sails with a straight sprit is to remain straight and in compression, instead, the tip of the unstayed mast bends, flattening and thus de-powering the sail. Exactly the type of response you want to happen. With curved sprits, such as Pete's, since each side is already curved, it has little resistance to additional compression, so one potential response to a gust is for the sprits to curve even further, allowing the clew to move forward and instead of the sail flattening, it actually becomes fuller and powering up in the process. The exact opposite of what you want to happen. In short, the shock absorber in the system needs to be at the masthead and along the leech, not at the clew and along the foot.

 

I think if you go back and look at the wishbone sprits Phil used on his boat, the sprits themselves are more or less straight and the relief gained in the middle to avoid the distorted sail shape comes from a wide head board on the forward end. While the difference may seem subtle, it is significant.

 

If you wanted to build them out of wood, you could lighten them up by using smaller sized straight sprits, or build them out of hollow birdsmouth or even as a hollow square box.

[tom151]

Congratulations to Alan and Paul and to also Phil. Normally, we only concern ourselves with winners but considering what was accomplished, that is a remarkable feat by both boats.

 

Since the race is over, and since this thread had already swerved to the topic of wishbones, I had a question or two about the wishbones in Pete's photograph. As I understand it, curved sprits of the type he shows have a few problems. Ostensibly, the intent of the curved sprit is to assume the shape of the sail and thus not distort the sail shape, but that comes at a price. The problem with curved sprits is they have very little strength in compression. The normal gust response to sails with a straight sprit is to remain straight and in compression, instead, the tip of the unstayed mast bends, flattening and thus de-powering the sail. Exactly the type of response you want to happen. With curved sprits, such as Pete's, since each side is already curved, it has little resistance to additional compression, so one potential response to a gust is for the sprits to curve even further, allowing the clew to move forward and instead of the sail flattening, it actually becomes fuller and powering up in the process. The exact opposite of what you want to happen. In short, the shock absorber in the system needs to be at the masthead and along the leech, not at the clew and along the foot.

 

I think if you go back and look at the wishbone sprits Phil used on his boat, the sprits themselves are more or less straight and the relief gained in the middle to avoid the distorted sail shape comes from a wide head board on the forward end. While the difference may seem subtle, it is significant.

 

If you wanted to build them out of wood, you could lighten them up by using smaller sized straight sprits, or build them out of hollow birdsmouth or even as a hollow square box.

 

Thanks for that thoughtful and complete treatment of the sprit/wishbone issue - it should be the basis of it's own thread so that future users/visitors can find it easily and gain the benefits of it.

 

It will be most interesting to get Phil's assessment (and that of his crew - the sailmaker for the rig) of how well the production made wishbones worked in terms of their stiffness and ability to maintain their effective length (as you described).

 

One of the issues (difficulties) with building wooden parts for such things is that even with precise dimensions, the properties of the wood used in the parts can vary significantly and so the overall propertirs (bending resistance) are not as expected.

 

One benefit of the 'production' pieces is that they are likely to have reproducable properties (the price seemed quite reasonable all things considered).

 

For a given sailplan - the loads the the sprits or wishbooms are subjected to are the same - the shape (geometry) of them effects where the most bending takes place - therefore where the most strength is needed

 

You observation of the wide head board on Phil's wishbones might be a lesson for design of wooden alternatives as the forward corners might be 'relatively' easy to reinforce with carbon tape to get the required bending stiffness.

 

If anyone out there has used CF to stiffen wooden wishbones - their experience (and layup) surely would be a great addition to the thread.

 

PS -- That record-breaking finish was indeed amazing - and within two minutes of breaking the "Two Day" barrier - truly amazing.

[Howard]

BTW, why were Alan and Paul on a CS 20 and not Dawn Patrol?

 

[Steve W]

I thought Dawn Patrol was a CS20 with a cabin added.

[brigait1]

Howard, Dawn Patrol IS a Core Sound 20, but with a cabin added. Your point on curved sprits is well taken, but in my experience it has not been a problem. One thing to consider is how light and easily driven Core Sound hulls are. The forces necessary to bend the sprits to any significant degree seem to be well beyond those that would either accelerate the boat off the wind, or heel it significantly when going to weather. Either way, on my boat something other than the sprits is going to be an issue well before they are. Now perhaps that means they are more heavily built than is warranted. When I build the next set, i will try to go much lighter and with the straight sections as you describe to achieve the same stiffness with a lighter build.

[Howard]

Ooops............my mistake.  I guess the cabin tricked me into thinking Dawn Patrol was an EC22.

 

Pete:

 

Hopefully my concerns were unfounded.......sounds like that is the case. You may have built yours strong enough that the point that bends first is still the mast.......and, BTW, lovely to boot!