Thread: Paradox Micro Cruisers and "Bilge Runners"

Mark,

I don't wish to be a perpetual knocker of things I haven't tried, heaven knows I do that enough with things I have!

I like lots about Matt's stuff, but the bilge runners aren't one of them. WARNING: the following is just made up nonesense, the sort of thing I am often critical of others for writing:

It seems to me that when heeled the runner would present a concave face to arrest leeway, working a bit like a scoop if you like. This is both slow and inefficient. Much as I hate 'em, I think you'd do better with a long foil shaped keel as featured on so many cruising multis. Of course there goes your beachability, unless you do two of them.

I know, I know... Matt has had plenty of "racing" success, but I wonder at the quality of the opposition. I'd back myself in an identical boat with a proper foil shaped dagger board anyday!

I can't see a time when I'd have a sailing boat with a flat leeboard either mind you. I once had a Careel 18 trailer sailer, with a flat 1/2" steel swing keel. The final model of the Careel came with a foil shaped board and rudder, and despite being a huge percentage heavier than the older boat, the new model was untouchable in any conditions.... if the difference was that great in a heavy little tub like the Careel, it's hard to imagine the difference in something a bit more slippery!

Cheers,

P

Thanks BM,
Well, looking at the profile of the Paradox and the Jesse, they, like most sharpies have quite a long flat section from about 1/3 back to 2/3 back, which is where Matt has his bilge runners and I would also position the bilge runners on the Jesse there-so they would have quite a flat profile. As the side of the sharpie curves out along the line of of the chine also, that, I would imagine would also counteract the scoop effect.
I think I shall make up a rough and ready model.
I had thought of putting a long shallow keel on but I do really like the ability of the yacht to take the ground as they say-very useful for quick repairs and also the big sand flats are such interesting environments.
The race Matt Leydon won in his Paradox is quite a famous race about 350 miles long and open to all classes as long as they can be launched off the beach.
I do believe that the Paradox is quite a fast yacht for its' size and type.(although I would like to verify that), as well Matt is supposed to be a very good sailor. Apparently he also sailed somewhat offshore and used the ability to stay out overnight, whereas the other yachts and kayaks etc had to go in to camp for their rest periods.
The 'Dugong' has assymetrical foiled leeboards, however they can be difficult to adjust when under pressure and in a narrow channel.
I think I would just like the simplicity of not having to fool around with them.
Thanks again for that reply and look forward to that cup of tea sometime soon.
Mark

Howdy, was the racing success in the Everglades challenge? If so it is a rowing and sailing race over about three days. I think Matt was one of the progenitors of the event.

His division is row/sail - you can do either (or both) any time you like.

Basically it is heading down part of the intracoastal waterway, up and down a couple of rivers as well as scooting over the shallows of the Florida Keys.

In other words one of those events where rat cunning rather than outright speed can get you a big advantage. If so, It is not an open water (though part of it is) upwind downwind race by any stretch of the imagination.

I rather like his boats and have his page in amongst my bookmarks. It is a fresh and novel approach. Though having a closer look at some of the photos of boats built to his plans I worry about some of the fittings that the builders have chosen and the method of fixing.

Without further information I probably wouldn't be laying bets on the upwind performance of the boats one way or another - after all I only ever bet when it is a sure thing - and I don't know enough to say they go OK or not.

In general depth is the most important factor to get performance and the chine runners don't have that.

The second most important area is area and they don't have that either.

I did just find an article which is a bit self contradictory saying both that the small boats sailed just as well without a centreboard as without as well as saying that a sharpie with the runners "sails sluggishly" with the centreboard raised and only using the runners.

Here's the link
http://www.culturechange.org/cms/ind...d=67&Itemid=33

MIK

Well even though I'm not a betting man, I'll take you on!

I like to use the "if it's any good" they'd be doing it rule, then run off to see the 18 footers or the moths or even the America's cuppers to see if they've got them.

Nup.

No leeboards, no bilge runners. No multihulls!

Hmmmmm....

P

Originally Posted by mark_dugong

Hi Everyone,
Out of curiosity,has anyone seen any "Paradox" micro cruisers which are micro coastal cruisers designed by a Matt Leyden. These small (14 ft) cruisers have even cruised to the Bahamas which seems remarkable to me for a 14 ft yacht.
Mark

G'day Mark
haven't seen one, but a UK bloke who has one has been contributing this week on Openboat mail list at Yahoogroups. He says it doesn't perform as well onto the wind as a modern centreboard dinghy, but better than some old timers.
Am seriously thinking of conducting *another* experiment with my Bolger Teal to see if some bilge winglets would significantly help my too-small non-standard daggerboard. Without killing the rowing, that is. Right after I build a couple of canoes & fix the leak in the shower....

Layden races his Paradox very successfully in endurance races, but as he seems to only need a couple of hours sleep per week & quite happily runs a half marathon dragging the boat following a 20 mile scull up a river, it could just be that he outlasts the competition.
cheers
AJ

Thank you all,
You just about convinced me out of it!
Then I found this letter from Matt Leydon on the Microcruising website-the rest of the letter is also on the website under Forum contents-so take this you unbelievers!


The data all seemed okay, but there were fluctuations of several percent from one run to the next on each leg, and the last 2 legs were complicated by the arrival of a short rain squall that made the wind a little uneven for about 30 minutes, so I would say that there is a margin of error of at least 1/10 knot in the results, I think doing much better would probably require a towing tank.I will include a copy of the raw data in case you are interested, but the short results, averaging the 3 runs for each leg, go like this:
Downwind leg VMG: 4.53 kt.
Starboard tack VMG: 3.63 kt.
Starboard tack angle made good to wind: 51 deg.
Starboard tack VMGW: 2.29 kt.
Port tack VMG: 3.49 kt.
Port tack angle made good to wind: 51 deg.
Port tack VMGW: 2.21 kt.
(VMG = Velocity Made Good along course; VMGW = Velocity Made Good to
Windward)
These results pretty much bear out what I have observed before, so I'm willing to believe them. There may be a slight improvement in the modifcation to the port runner (the difference if any is within the margin of error so I can't say for sure) What this mostly does is tell me in numerical terms that yes, she really does go to windward passably well without a centerboard, and no, the as-built chine runners are not dismally bad though they may be susceptible to improvement. It supports my experience that in real world conditions, the rare few times Paradox has been near other small shallow-draft cruising boats, she has usually sailed right past them, upwind or downwind. This of course isn't because Paradox is a particularly fast boat but because, by and large, other other small shoal cruisers are not particularly fast either.

I watched a youtube on the Little Cruiser paradox which does have a centreboard and she was doing 4-5 kts reefed in a estimated 15 kt wind admittedly it was downwind but they were fully loaded.

By the way Boatmik that website you referred to was fascinating-I think I better start preparing for the end of the world as we know it ,start growing some vegies and learn to fish-at least I have the right yacht.
I reckon you ought to go ahead and put those "bilge" or I stand corrected chine runners on the Teal after you've finished the shower,AJ.
Mark

Originally Posted by mark_dugong

Thank you all,
By the way Boatmik that website you referred to was fascinating-I think I better start preparing for the end of the world as we know it ,start growing some vegies and learn to fish-at least I have the right yacht.
I reckon you ought to go ahead and put those "bilge" or I stand corrected chine runners on the Teal after you've finished the shower,AJ.
Mark

Not an unbeliever at all. Intrigued enough to be willing to experiment.
Got just a few things on the 'to do' list ahead of it.
By which time it may have fallen off the bottom of the list.
Or not.... ;-)
cheers
AJ

Originally Posted by b.o.a.t.

Not an unbeliever at all. Intrigued enough to be willing to experiment.
Got just a few things on the 'to do' list ahead of it.
By which time it may have fallen off the bottom of the list.
Or not.... ;-)
cheers
AJ

Howdy AJ,

It would be interesting to see how it went on the Teal!!

MIK

Originally Posted by mark_dugong;533227
[FONT=Arial

By the way Boatmik that website you referred to was fascinating-I think I better start preparing for the end of the world as we know it ,start growing some vegies and learn to fish-at least I have the right yacht.[/FONT]
Mark

A boat with a vegetable garden - OK midge - where are those links of yours!!!!

MIK

"A boat with a vegetable garden - OK midge - where are those links of yours!!!!"

Vegetable gardens ?? On the "Dugong" !!!
Come on Mik, whaddya reckon about the Paradox sailing data. Any ideas?
Cheers
Mark i'm getting sick of this guy.

Howdy - if you want some comments .. here they are.

GPS readings are next to useless. What was the current at the time? That's what you need to know. And we don't know the windpeed or the water conditions.

2.2 as VMG upwind is OK for such a little boat, but I don't think I've sailed anywhere but at Goolwa where there is current of less than half a knot. Its almost too small to perceive if you aren't reaching or running using a transit. On my former racing grounds on Sydney Harbour a couple of knots was more common.

But bye and bye - like Peter - there doesn't seem much evidence of a performance breakthrough. I'd sure like to know how Matt's boats go with the chiny things planed off.

Part of it too might be that the microcruisers are being asked to carry a considerable displacement in a narrow and short hull making it quite deep enough to develop a good degree of lateral force itself. I wouldn't be guaranteeing that a shallower boat would show the same pointing angles.

Woudl be nice if the experiment can be done on the windsprint! Rough water will be where the performance will drop off - as it does with any boat with limited lateral plane.

But just to be clear - I REALLY LIKE MATT'S BOATS - AND I KNOW MIDGE IS A FAN TOO.

MIK

Originally Posted by bitingmidge

I like lots about Matt's stuff, but the bilge runners aren't one of them.

Originally Posted by Boatmik

But just to be clear - I REALLY LIKE MATT'S BOATS - AND I KNOW MIDGE IS A FAN TOO.

Just to be doubly clear!

I'd hate to see a theoretical discussion turn into a bagging of something that we haven't tested!

Cheers,

P

Originally Posted by Boatmik

Part of it too might be that the microcruisers are being asked to carry a considerable displacement in a narrow and short hull making it quite deep enough to develop a good degree of lateral force itself. I wouldn't be guaranteeing that a shallower boat would show the same pointing angles.

Woudl be nice if the experiment can be done on the windsprint! Rough water will be where the performance will drop off - as it does with any boat with limited lateral plane.

But just to be clear - I REALLY LIKE MATT'S BOATS - AND I KNOW MIDGE IS A FAN TOO.
MIK

I wonder just how much parallel there is between bilge runners & Bolger's rudder plates, where he is (supposedly) getting 'bite' far out of proportion to very small rudders. I had a very small 'temporary' rudder for several years on Teal, & most of the time it was .... adequate. However, in rough water "performance dropped off" indeed !!

In the shallower boat, wider winglets might be a better bet, extending perhaps 4 or 5 inches outwards & 18 - 24 inches long. I don't know the maths at all but it seems to me that these would greatly reduce the tendency of the light-displacement sharpie to skate sideways. Especially when lightly loaded. Would also reduce the tendency to skid in sharp turns under oar when playing 'tag' with the kids in their canoes.
cheers
AJ

Howdy,

Yep bilge runners and Bolger's rudders are close relatives.

As are bulb keels.

Wing keels too - but you can't design effective ones without considerable computational power - otherwise they are just a high tech looking cartoon - rather than working as per the advertising. )

All of this is quite well known in design circles. Bolger in his books also mentions that the external chine logs of his sharpies "MAY" (his word) reduce crossflow at the chine.

The rudders do work. But the horizontal fin is large compared to the size of the rudder.

You've got to love the way Bolger is always so careful with facts. That's one of the great things for careful readers of his books - you can see what he actually thinks because of his careful use of language.

I really reckon that the hi tech yachting world owes him a debt - he was playing with canard steering yachts and publishing his thinking in one of his books not long before they tried them in 12 metres in the '80s.

The modern bunch of canting keelers might not be around if it wasn't for the 12 metre.

Interesting!

MIK