i550class.org

...I've had to rectify some construction issues on Carbon,,,down to the keelbox ,it's reinforcing panels,,and woodsealing throughout the interior,,so I lifted the cockpit floor for access,,replaced the keelbox,,,shortened cabin to just aft of the mast step,, and narrowed the cockpit sidetanks----I'm not sure if the newly renovated boat still qualifies under class.org rules,,but the cabin still has a ~1.2 meter height under the maststep
...can't figure how to download pic's ,,,but here's a link to a few on 'flikr'..
..............click on pic's to enlarge,,below for some comments
http://www.flickr.com/photos/59103003@N ... 076955693/

The pictures have to be downsized, I've been using tinypic.com to do that. The 15" seams to load just fine. Hope that helps some. Tim or Kevin can probably help you out in regards to the exact size allowed for posts.

Great shots of the mods, looks like you are getting close to finishing up. Funny looking dogs though!

jray wrote:Great shots of the mods, looks like you are getting close to finishing up. Funny looking dogs though!

...ahh,,those are vid's of my kidz!,,I help at a farm,,they're 2 weeks old,,rather hilarious!

have the floor bonded,,side panels ready to go,,'cup'holders on their way, but as yer know,,
,,there's many 'devils in the details'

by Chad » Sun Jun 17, 2012 11:51 am .......... ''there's the bit about the cockpit being restricted to 106" from the tranny. Intent was to keep the crew positioning and movement similar or "equally restricted" regardless of cabin design. As you've found, weight forward is sometimes essential, and the consensus was that the open dayboat style would be the only competitive version if it was allowed, with freedom to hike out from positions all the way forward (sim to Peter's boat, if you ever saw his pics). One earlier proposal just said "no hiking straps attached more than 106" from the transom". That, and a piece of string across from deck to deck might meet the current rule requirement for this class at anything less than a Worlds level gathering... IMO.
Curious Mix, a.k.a. hull #231, "Knot Racing"...........''

...oh,too bad,,,I guess I'll build a little cabin extension for when I go on a worldwide campaign beyond the NW.

....looking at the cover picture,,and many others it's pretty common that the bow is 2-3'' out of the water,,stern in,,
,,,I guess all boat designs have their trade-offs,,,and having someone camp-out on the little bow in lightwinds will be the solution.

....hmmm,,with a 'non-classy' boat,,,should I not be posting here now?

I've often wondered if the keel and bulb were in fact too far back in this design. Every picture I've ever seen shows a problem with weight too far back, and even the drawings seem a little off. One of the problems with buying plans drawn by an amateur boat designer using an off-the-shelf cad program. This is where Chad's weight conservation comes in handy, as it allows him the ability to place ballast forward without penalizing himself. I think an extra 100# forward might do the job, maybe someone with a completed boat might try and see!!!

slowpoke wrote:I've often wondered if the keel and bulb were in fact too far back in this design. Every picture I've ever seen shows a problem with weight too far back, and even the drawings seem a little off. One of the problems with buying plans drawn by an amateur boat designer using an off-the-shelf cad program. This is where Chad's weight conservation comes in handy, as it allows him the ability to place ballast forward without penalizing himself. I think an extra 100# forward might do the job, maybe someone with a completed boat might try and see!!!

...on the other hand,,the couple of times I've been downwind in a breeze,I've wished we could get more weight further back
...just the trade-offs for having a short wide boat

The issue with post pics is probably mostly about the size you have them. anything over 1024 pixels in width will have too large of a file size is what I've found. You are uploading that pic to the server and it's stored there when you use the image tools of the full editor. That's why we limit the file size. If they are posted elsewhere and you know how to code an image tag then you can do that as well.

Chad is correct. The proposed rules as they stand this second would not work for your boat as altered. The point of that rule is to control the butt positions to stop hiking forward for frame 110 for an "even" playing field. In the past this was a contentious issue which was silly. Our proposal to stop hiking forward of 110 was a very reasonable solution for class racing yet it was met with argument and discord. This is one of those reasons why we are where we are as a class, but I digress.

Does any of the above mean you shouldn't post here. Absolutely not.

Does it mean that you could or should take the initiative to build consensus for a modification to the proposed rules to allow you to legally sail with the class. Absolutely yes. A contrasting strip at frame 110 would be one way to show where that point is and you racing with crew hiking forward of that strip would be a ding.

And if you want to keep the knuckle in, then store your motor forward of your compression post. Heck put the beer cooler up there too on light days if you have to. There are already rules about corrector weights so you can't balance the boat with those. And as you mentioned, you don't always want the weight forward so you wouldn't want to put your corrector weights in that way anyway.

Kevin.

..thanks for the information in regards to Carbon's 'classiness' issues.
...I'm not going to bother to try and lobby for a rule-change,,as I've said,it's unlikely I'll travel beyond the NW,,
,,and I can build a cabin extension or comply otherwise if I travel outside the NW,,
,,and I really prefer the weight placement this modification affords,
.....and the safety of not making kerry cling to the bow all day in light winds!

I know what you mean about not worrying about it. I'm going to put a 2 foot sugar scoop on the back of slowpoke so I can meet San Diego phrf requirements. Also, a lot of the races here have a 20 foot minimum length written into the nor's . I'll just add a " + " sign after the i550 decal. I figure it'll be a while before any other i550's are around to race against!

..hmm,,here's a good question for the measurer .....the aft edge of Carbon's cabin meets the deck at 109'',,easily adjusted to 108'',,,does this mean she can still be legal ??...or is the measurement to the aft of cabin'top'???
.... ..while at the same time,I might have an unintentional rule-beater , where the 2nd picture shows the slot I made for hiking forwards of the shrouds.
....I expect fairly light winds when someone needs to be there,,so didn't design hiking straps for the position.

EDIT,,,oops,,when in doubt,,read the instructments!!--thought it was 108'',,106'' effectively closes that 'loophole',,my bad
RULES....
2.6 Cockpit may only extend 106" (2692mm) forward of the aft face of the transom.
2.7 Cockpit and interior layouts are optional

Remembering the intent of this rule as it was written, the goal is to keep the feet of the inward-facing hiking crew aft of 106" from the transom. As mentioned elsewhere, one method originally discussed was to limit hiking strap attachment to this distance. This background, together with the definition of cockpit:

cockpit: "a sunken, open area, generally in the after part of a small vessel, as a yacht, providing space for the pilot, part or all of the crew, or guests."

...would seem to make the geometry of the cabin top unrelated to the cockpit rule. As I read it, the "sunken, open area" or cockpit floor needs to stop at 106" from the transom. I suspect a class measurer would accept a number of ways to meet the intent of the rule, if the geometry of the actual boat did not...

Chad wrote:Remembering the intent of this rule as it was written, the goal is to keep the feet of the inward-facing hiking crew aft of 106" from the transom. As mentioned elsewhere, one method originally discussed was to limit hiking strap attachment to this distance. This background, together with the definition of cockpit:

cockpit: "a sunken, open area, generally in the after part of a small vessel, as a yacht, providing space for the pilot, part or all of the crew, or guests."

...would seem to make the geometry of the cabin top unrelated to the cockpit rule. As I read it, the "sunken, open area" or cockpit floor needs to stop at 106" from the transom. I suspect a class measurer would accept a number of ways to meet the intent of the rule, if the geometry of the actual boat did not...

...okay,,with the requirement of a certain cabin height,,and length of cockpit the rule seems almost** effective at preventing a sailor from sitting forward of the shrouds**,,,,,,what does this accomplish since it's -very- clear the boat -needs- weight forward in many conditions??......now ,in light winds,one crew -must- camp on the bow---all designs and rules have a trade-off,,,this is definitely not the safest or most comfortable option,,,and for what purpose??

**though the rules don't seem to prevent the cabin from being quite narrow above gunnel-height,,which would allow a person to 'sit' forward of 106''(similar to the pdx design),no?

...I'll have to check,but I'm also wondering if my keel is forward of the 106'' mark?... is it placed correctly?...if so,,how can I have a short-cabin design that -legally- puts the keel outside the cabin??

Crew can still hike legs-out anywhere they want:


The cockpit rule is really only aimed at legs-in hiking. The premise is that having crew forward and legs-in hiking gives a boat a trim "advantage" as well as a maneuverability "advantage" (since the crew could just cross straight through, without clambering over the cabin or behind somebody else). Tacking Josh's boat in the pic above takes many more seconds per tack than if the two forward folks were legs in, for instance.

The reason for the rule is to protect the existing fleet, such as it is. If an open boat can break an original-rules boat's cover by just throwing in two tacks that can't be matched, then that is an advantage that can only be cured by hull surgery (such as you've done to CO). One of the premises of this rule set was that any hull, carefully built to the original plans, shouldn't be disadvantaged by allowable hull mods that reduce the usefulness or value or identity of the boat. We can generally buy most of the other components of these boats, but the hulls are handmade by the builders, and nobody (in this class!) wants to see their handmade creation cut up to stay competitive with rules that don't protect the results of their labor.

The max hull length it 216", most keels are a skosh aft of station 110, which should also then be behind the 106" distance from the transom.

..thanks for the thoughtful answer and -great- picture!
....I guess that's where the -great divide- exists,,how important is it to have a larger cabin,versus sailing qualities.

...I hadn't thought you'd still be needing weightforward in the breeze level in your picture

...is there a measurement for minimum width on the cabin?

Josh has a long cabin boat, so his cockpit is mebbe 90" long- in the pic I think only one person is forward of the shrouds- I think that's what Donna is holding with her aft hand.

I'd say the "great divide" has more to do with allowing hull shape mods than this cockpit business- a pdx boat meets the cockpit rule for instance, and a pdx hull also meets the more stringent "from the plans" clauses of this Class. But they've chosen to open both parameters to development, opening the door to obsolescence of their existing fleet. If they're on the right track and they can get folks to get so engaged in that level of i550 racing that folks are willing to rebuild their handmade hulls to keep up to date, then that would be awesome, amazing, and unlikely!

No min width for the cabin in the current rule. The cabin rule (and the shortened P) was aimed at making the vangs all equally inefficient. But with boats going to gnav's, I think the point is moot and these rules act as an arbitrary class divider. (Disclosure: my boat breaks both rules, which were "passed" after the respective components were built.)

..hmm,,a fair bit to 'digest' there,,,
,,I guess I'm of the opinion that there's little to be gained from hull-shape variations so long as length,beam,and flat bottom are fairly fixed aspects....methinks that even though there's little to restrict the rocker 'measurement',,and -much- to create variation amongst builds(until a solid jig is used),,,it's probably the greatest potential variable in hull speed potential,,,,yet not controllable anymore anyways from the look/sound of things,,,and probably not an overwhelming potential advantage anyways,,except possibly if someone at some point were to hone a shape specifically for all drifters,,or all planing

...it's an interesting project to have picked up a boat,and joined the I550 scene in the way I have...interesting indeed!
...no regrets,,,looking forward to taking things to the water.
......since Carbon's builder was of pretty similar skillset and building experience as many others,and was conscientious to folow build methods for the i550,I'd think it good to do an article sometime about some ''do's and dont's'' of building a wood/epoxy boat

Yeah, this class has a pretty generous rocker allowance- I think it was discussed a bit in the rocker thread you started a while ago. Basically adding the tolerances created by a reasonable interpretation of "hull panels cut to the plans" and "meeting at the chine" gives something like an inch of allowable variability.

I don't know, but I suspect that rocker will be less important than section shape and beam or RM. This Class does a much better job of controlling those parameters.

I think the story of the Fireball is well known, where an allowable deviation of 9mm is used to create "wide bow" boats which dominate the original design boats. I think that will be the case eventually in this class too, but limiting the tolerances as best we can will reduce the delta between the optimized and the original shapes. An original Fireball can still play at the club level since the shape variation is small enough that it takes well matched, high level sailors to show the inherent speed difference.

Get the mods done and go sailing. I believe it will be years before some of this can be proven and addressed. Great points and discussion though. If you find your way down to the Flathead guaranteed we will have some fun racing. If I get to nervous about giving up the cockpit area I will have to invoke a local rule and have you haul the cooler lashed somewhere aft of 168. Of course any beer consumed would lessen the weight penalty but may cause another. As chad stated earlier I'm more concerned with hull manipulations and sail area differences then your cabin mod, even if it dose not fit the rules right now. You could insure no one sits forward of 110 and in my view nothing has really changed. Looking forward to meeting up some day.

.Chad,,..with the Rocker,,,I'm pretty sure that there'd be an inch of variability between 2 boats built on a -full- jig,
,,,but with boats built upright on the floor,,,there's lots of settling-forces,,,and panel distortion going on--try 5-6'',
I promise!!

,,as much as I disagree with you over the above,, I fully agree with you otherwise,,and jray too...
.......let's get these boats (back)to the water,,,have some fun

The original rocker thread, with some of the same points (and I'll reiterate here the 5" variance you describe is actually twice the actual rocker delta):
viewtopic.php?f=3&t=114

I'd be curious how the pdx boat with the deliberately enhanced rocker fares with the "tyvek test". I recall when testing Ben's boat, the chine very closely matched the designed hull panel curve. I recall Ben didn't use a jig at all, just the stitch er together and go for it method.

I suspect that members of this class (and even Watershed?) would prefer to keep that as an acceptable build method since it helps promote the "easy to build" aspect of the boat. Any new rocker requirement would pretty much require build cradles or jigs. I would never build without one, but it seems a little contrary to the spirit of the class to require one...

Don't know how to reconcile rocker limits and the desire for jigless construction.

Chad wrote:The original rocker thread, with some of the same points (and I'll reiterate here the 5" variance you describe is actually twice the actual rocker delta):
viewtopic.php?f=3&t=114

I'd be curious how the pdx boat with the deliberately enhanced rocker fares with the "tyvek test". I recall when testing Ben's boat, the chine very closely matched the designed hull panel curve. I recall Ben didn't use a jig at all, just the stitch er together and go for it method.

I suspect that members of this class (and even Watershed?) would prefer to keep that as an acceptable build method since it helps promote the "easy to build" aspect of the boat. Any new rocker requirement would pretty much require build cradles or jigs. I would never build without one, but it seems a little contrary to the spirit of the class to require one...

Don't know how to reconcile rocker limits and the desire for jigless construction.

I guess it's a point I'm trying to make about rockers--you either have -overly simple- or -consistent-,,,though I'll bet that once a jig is built,,there'd be a lot of -efficiencies- achieved through less 'torturing' of the plywood,,and less fairing as a result,,as well as a few other efficiencies and consistences along the way!
....from talking with eric and the pdx'ers ,my impression is that the flatness of pdx-1 was unintentional,,perhaps caused by over-use of weights during the build process,,,the panels were from a kit,no?...the group used a small floor jig to hold the bottom-panel in place after #1,,a step in the right direction....I'm looking forward to seeing the other boats,,,and the Camas one ,,methinks it was built on a full jig,,all with kits.
....overall,,I'd contend that this variable,,and the fact that it IS a variable AND not contained either by the build methods OR the rules,,,obsoletes a rules concern of most any other variation possible in an i550's build intentional or not!

...I've joked about level-class on SA,,but really that's as close as these boats will -ever- be to OD racing,,and that's fine with me,,,wether it's jibing keel,,dual rudders,,simple single short aspect rudders or tall hightech ones,,,,or ALL the other variables people bring in intentionally of otherwise,,,,let alone the variables brought in by the act of sailing them,,,let alone the variables in the wind ,,,it's all good,,,let's go sailing!!!

That guy is a bit of a slippery one. When the flat boat was built, he wrote:

...we are experimenting with hull shapes as allowed by the current rules. We have built a boat that is significantly flatter (fore to aft) than the plans, but still fits within the printed rules. We are finishing a hull that will be shaped as per the plans fore to aft, but will have significantly more rocker from side-to-side. Again, both will measure to the current rule, but will have significantly different hull shapes below the water line.

...and that's all I'll say about that!

If any of the oddball things I've done with my boat turn out to be wildly successful (I wish!), then I think it would be a fair question for the Class to ask if that/those item(s) were good for the Class- does everybody want to make X modification to their boat to make it cooler and faster, or do they want to ban it. As long as the reason is "the good of the Class", then I'll happily accept a restriction against something I've done- just about all of my tweaks can be undone in a weekend.

But you can't change the rocker or other underwater hull shape once it's built- what should the Class do about that? Clearly, it's better for the Class to have similar hulls, but is it too much of a barrier to participation to require jigs or to have builders risk missing a rocker tolerance and having a worthless hull? I'm sure this question will become more important as time goes on and more boats see each other on the water.

I'm going to go sand now.

Chad wrote:
I'm going to go sand now.

heeh,,good idea
..if I could post pictures on this site,,I'd be looking for the 'dead horse' about now,,amazing what comes up!


...time will tell

,,,all panels are bonded now,just gotta shape the inside coamings,,and the forward closure,,,then skinning,,footstops,refinishing,refitting,,the cup-holders.......

..........and a 'few' other details