Chine runners...what to expect.

[john welsford]

Re: Chine runners...what to expect.

A couple of years ago I read a report on a talk Matt Layden gave on chime runners, I believe it was at one of the Sail Oklahoma events. I would be worth digging it up.

Jim

I was there at that one, had a short talk to Matt, would love to meet up with him without 100 odd people around all wanting to talk to either or both of us. Good guy, has some interesting ideas.
In fact, Grahame Byrnes, Jim Michalac, Matt Leyden and I were looking for a chance to spend some time swapping ideas but it didnt happen.

John Welsford

[skaraborgcraft]

Re: Chine runners...what to expect.

In fact, Grahame Byrnes, Jim Michalac, Matt Leyden and I were looking for a chance to spend some time swapping ideas but it didnt happen.

John Welsford

Not that i have ever used it, but is that not a perfect reason to use the technology of something like a skype conference call ? It would be an interesting collaboration, given a set of design parameters to deal with.

[Small boats rock]

Re: Chine runners...what to expect.

I have been sailing my paradox over a pretty big chunk of the west coast of oz in a good range of conditions. The paradox goes to windward very nicely in smooth water, but does a less impressive job in rough conditions. At about 20knots wind she is reduced to around 50% sail area and no longer makes effective windward progress. I think the main issue is lack of leading edge on her lug sail, although the waves tend to knock her about too, so windward progress is not helped. On the other hand, in extreme conditions surfing downwind she never feels in any danger of broaching. There are no underwater projections for her to trip over except for the big rudder which is right aft helping her to hold her course. My boat has repeatedly reached 8 knots and sustained that until the wave passes... pretty fast for a slightly less than 14' boat. The paradox is certainly not optimised for windward performance, but she does well enough that she's carried me about a thousand miles of coastline to windward, often for many days at a time.

[amish rob]

Re: Chine runners...what to expect.

I was there at that one, had a short talk to Matt, would love to meet up with him without 100 odd people around all wanting to talk to either or both of us. Good guy, has some interesting ideas.
In fact, Grahame Byrnes, Jim Michalac, Matt Leyden and I were looking for a chance to spend some time swapping ideas but it didnt happen.

John Welsford

Yeah. I want the boat you guys design.

Peace,
Robert

[john welsford]

Re: Chine runners...what to expect.

Not that i have ever used it, but is that not a perfect reason to use the technology of something like a skype conference call ? It would be an interesting collaboration, given a set of design parameters to deal with.

SKYPE would work for sure, but I'm not sure what that would achieve, given that within our areas of experience we're all three of us capable of producing a boat to suit a given brief. I was thinking of a quiet hour over a coffee ( tea for me please) to swap ideas and methodology, horror stories about clients and the occasional victory.
I've collaborated on big design projects with others on occasions, and its never really easy, there is so much negotiation that it really slows the progress.

John Welsford

[Tom Lathrop]

Re: Chine runners...what to expect.

One year when Graham and I took Southern Skimmer to Cedar Key for the annual messabout, we had an eclectic bunch to confab with. Meade and Jan Gougeon, Matt Leydon as well as Sven Yrvind. Great time although I can't remember a single outstanding thing that was discussed. While I was never a fan of chine runners as a foil for resisting leeway, it was surprising to watch Paradox tacking upwind toward me in really thin water at Chokokloskee, in the Everglades Challenge. It pointed better than expected and tacked easily without stalling. The fact that Matt is able to get surprising performance and cruising from some unlikely boats (the 8' Sand Flea, for instance) probably had a lot to do with it. For the simplest boat and rig for sailing fun, Paradox and its sisters are hard to beat.

[MN Dave]

Re: Chine runners...what to expect.

I was going to suggest an off-centre, centreboard. I personally have pondered what a small runner of wood sticking out from the sides of a chine (parallel to the surface of the water) would do for a Bolger style box boat. I know with my GP they talk about her Chine digging in and her running off "on rails" and it got me thinking if you could keep the water from slipping under the boat, it might offer some lateral resistance when heeled

I had some thoughts, but after looking up Paradox, your idea has been tried, it works and I don't have anything to add. The following links are for those of us not already familiar with Paradox.

One year when Graham and I took Southern Skimmer to Cedar Key for the annual messabout, we had an eclectic bunch to confab with. Meade and Jan Gougeon, Matt Leydon as well as Sven Yrvind. Great time although I can't remember a single outstanding thing that was discussed. While I was never a fan of chine runners as a foil for resisting leeway, it was surprising to watch Paradox tacking upwind toward me in really thin water at Chokokloskee, in the Everglades Challenge. It pointed better than expected and tacked easily without stalling. The fact that Matt is able to get surprising performance and cruising from some unlikely boats (the 8' Sand Flea, for instance) probably had a lot to do with it. For the simplest boat and rig for sailing fun, Paradox and its sisters are hard to beat.

Tom, this link about horizontal runners refers to you: http://www.piano-tuning.co.uk/microc...unner-concept/
Some of Jim Michalak's thoughts: http://www.jimsboats.com/1nov14.htm#Chine%20Runners

[Tom Lathrop]

Re: Chine runners...what to expect.

Dave,

The statement that Matt is soft spoken and not interested in self promotion is certainly correct but I think he does not give his knowledge enough credit. I think Matt is technically very competent. He as sailed to the Bahamas and back with this rig if my memory still works. I think his easily worked lug rig also makes Paradox work well enough to get the boat and pilot through some adverse conditions, if not very fast. It does not appear easy to get into trouble with this boat and rig.

Most of my small boat sailing has been done in hard chine boats and sailing along on the chine happens quite a bit in the very shallow water behind the Core Sound Banks. Carolina Sharpies and Sprits'ls have slab sides and flat rockered bottoms. I and many others have sailed along cutting a crease with the hard chine in the soft bottom a few inches below the surface. Make no mistake, its not either fast or efficient but you can usually get there.

[Art Haberland]

Re: Chine runners...what to expect.

Didn't the paradox have some unusual optional board and rudder positions? I seem to recall one that had a very small retractable board all the way up in the bow?

[Small boats rock]

Re: Chine runners...what to expect.

Didn't the paradox have some unusual optional board and rudder positions? I seem to recall one that had a very small retractable board all the way up in the bow?

I don't think that was the Paradox... but some of Matts paradox-like designs have made it as far as an initial sketch (titled 'ultimate cruiser') and at least one of those has the forward board you describe. Interesting idea though it begins to lose one of the advantages of chine runners in their extreme simplicity with no moving parts.

[gilberj]

Re: Chine runners...what to expect.

Before he designed and built 'Paradox', Matt built 'Little Cruiser'. Little Cruiser is owned by Dave and Mindy Buldoc, who have made a number of cruises to the Bahamas. Little Cruiser, a little larger than Paradox, has a small center-board forward and a large rudder aft, and a junk rig. The story is that Matt did not feel there was any clear advantage with that configuration and returned with Paradox to using the chine runners which he had tried on earlier boats.
There are a bunch of videos on YouTube of the Paradox 'Scout' by Sean Mulligan https://www.youtube.com/watch?v=LkaW-fu022w
Post 18 by 'small boats rock' describes a problem which to some extent is common to most cruising boats.....diminishing driving force because of reefing, when you actually need more driving force to keep moving in a larger sea. Most boats trying to work to windward in a large sea will have to bear off to 60 or more degrees to have enough speed to get over the sea.

[Art Haberland]

Re: Chine runners...what to expect.

I don't think that was the Paradox... but some of Matts paradox-like designs have made it as far as an initial sketch (titled 'ultimate cruiser') and at least one of those has the forward board you describe. Interesting idea though it begins to lose one of the advantages of chine runners in their extreme simplicity with no moving parts.

You are right, I went searching. It is Bolger's "Dovekie"

dovkie.gif

[wtarzia]

Re: Chine runners...what to expect.

I hear conflicting reports about chine runners -- some claims of unusual performance and some claims that they are not much worthwhile. The type of hull they go on is probably important, as someone above mentioned. For example, people say that the Duck Punts "do well" (never any real data, though, as from a GPS track with true wind direction!) to windward without boards because their heeled skinny hulls bite well enough. Then water depth -- is there a hydrodynamic effect that hulls get in skinny water that they do not get in deeper water, which affects leeway? Then, I have been told that boats like Hobie catamarans (no boards) go windward because their rudders are highly loaded (swept back rig too?) -- though a hull's speed would effect leeway resistance too, wouldn't it, as any leeway-device you have gets more highly loaded.

A final factor is the human one. Matt Layden's Watertribe nickname is "Wizard" and that was given for a reason. The guy has extensive on-water experience in tiny boats. In one Everglades Challenge his time-to-finish was extraordinary for the short boat he was in (I believe it may have been his 9-foot Elusion with chine runners, but it may have been another boat). He admitted to some luck (maybe, but he is very humble) but also said something about playing the tides and currents well. If the rest of us do not have such wizardry, expect less from chine runners, perhaps, and put great though into the loaded rudder if windward work is critical?

Another final factor -- WHY can you not have both chine runners and a leeboard or (in this case) off-center daggerboard/centerboard? Can a person design for universal shallow/deep windward work? -- WT

[Canoez]

Re: Chine runners...what to expect.

SKYPE would work for sure, but I'm not sure what that would achieve, given that within our areas of experience we're all three of us capable of producing a boat to suit a given brief. I was thinking of a quiet hour over a coffee ( tea for me please) to swap ideas and methodology, horror stories about clients and the occasional victory.
I've collaborated on big design projects with others on occasions, and its never really easy, there is so much negotiation that it really slows the progress.

John Welsford

Still think that would be an interesting exercise. You could do a joint design and name it the Platypus.

(Just kidding)

It's very difficult to do collaborative design work at a very high level as the amount of give-and-take required is pretty big and folks really need to let pre-conceptions drop.

[Chris249]

Re: Chine runners...what to expect.

I hear conflicting reports about chine runners -- some claims of unusual performance and some claims that they are not much worthwhile. The type of hull they go on is probably important, as someone above mentioned. For example, people say that the Duck Punts "do well" (never any real data, though, as from a GPS track with true wind direction!) to windward without boards because their heeled skinny hulls bite well enough. Then water depth -- is there a hydrodynamic effect that hulls get in skinny water that they do not get in deeper water, which affects leeway? Then, I have been told that boats like Hobie catamarans (no boards) go windward because their rudders are highly loaded (swept back rig too?) -- though a hull's speed would effect leeway resistance too, wouldn't it, as any leeway-device you have gets more highly loaded.

A final factor is the human one. Matt Layden's Watertribe nickname is "Wizard" and that was given for a reason. The guy has extensive on-water experience in tiny boats. In one Everglades Challenge his time-to-finish was extraordinary for the short boat he was in (I believe it may have been his 9-foot Elusion with chine runners, but it may have been another boat). He admitted to some luck (maybe, but he is very humble) but also said something about playing the tides and currents well. If the rest of us do not have such wizardry, expect less from chine runners, perhaps, and put great though into the loaded rudder if windward work is critical?

Another final factor -- WHY can you not have both chine runners and a leeboard or (in this case) off-center daggerboard/centerboard? Can a person design for universal shallow/deep windward work? -- WT

Good points, and I too was wondering whether the water depth accentuated the effect of chine runners.

Your reference to Hobies got me thinking. The main problem with shallow draft hulls as leeway reducers must be the induced drag of the low-aspect foil that a hull presents. Induced drag drops by the square as hull speed increases, rather than increasing with speed as one of your sentences may perhaps imply if I'm getting it right.

The Hobie 16 gets along pretty well with low aspect "foils" partly because they load up the rudders as you note but also because it's intrinsically quite quick even when compared to contemporary similar cats - it's actually almost 17ft long and has a very big rig - it's about the same size as the 20ft Tornado's rig was. That power probably allows it to benefit a lot from the squared reduction in induced drag created by the extra speed.

A small mini cruiser will however suffer (rather than gain) from a squared increase in drag, and as you imply the loss would be disproportionately greater if the sailor was less skilled and the boat therefore moving slower still.

Theoretically, having chine runners and a board should be problematic because a low aspect foil like chine runners should work best at a different angle of attack to a high aspect foil like a centreboard. In reality, as some racing windsurfers and Hobies demonstrate, there doesn't seem to be a noticeable issue.

It would be interesting to see some more short course racing among the mini cruisers, to isolate the boat's performance from the factors you mention. I see there's some of it in San Francisco.