Who's right Who's wrong? Is A Canoe Stern Better Performing Than A Double Ender?

[kudu]

I've been scanning this site trying to to get a firm answer to my question...IS A CANOE STERN A BETTER PERFORMING STERN THAN A DOUBLE ENDER???? It seems that there are many theories floating around, who's right...who's wrong???

[Willallison]

Originally Posted by kudu

It seems that there are many theories floating around, who's right...who's wrong???

Depends who you ask!

[LP]

Forgive my ignorance, but what is the difference?

[FAST FRED]

define better "Performing"

FAST FRED

[SailDesign]

Originally Posted by kudu

IS A CANOE STERN A BETTER PERFORMING STERN THAN A DOUBLE ENDER????

Neither, because a canoe-sterned boat IS a double-ender.
If you mena is a canoe stern better than a CRUISER stern, then we might have an argument to get stuck into. The canoe stern, generally, has "tumblehome" while the cruiser stern doesn't. VERY generally....
And the question has to be asked, as FastFred did, what do you mean by "performance" in this question?
Steve

[Bergalia]

As my colleagues point out, Kudu, a canoe stern IS a double-ender.
And it's a valid question - what do you mean by performance. In a 'racing' hull there's no doubt that a 'fantail' creates less tumbleholme.
But in heavy following seas a double-ender gives a greater sense of security(or in my case it did). Which begs the question - where do you intend to sail her. Inshore sheltered waters - or blue ocean.
For an idea of a double-ender capabilities you might like to browse:
www.mavc2002.com/caledoniayawl/aegre
It is an account of a 20 foot Shetland foureen taking a 12,000 mile voyage acroos the Atlantic - well illustrated.

[dougfrolich]

A heavy slower boat will benefit more from a double ended design intended for bluewater, than a lighter faster boat, The transom of a TP52 for instance has Lots of volume, much more than a double ended design of the same length, for that reason as a following sea approaches (usually you would be over taking waves though) the transome rises with the wave, even with an open transom green water does not rush into the cockpit- even backing down in 25kts. to free debris from the underbody. The configuration may not make "feel" secure though.
A heavier slower boat that finds itself being overtaken by waves and white water probably benefits from the back looking like the front for that reason- Strapped into a deep cockpit surrounded by high bulkworks adds to a "feeling" of security, But I think a modern cruiser will fall someware inbetween the two extreems.

[JonathanCole]

How about for a catamaran for protected and inland waterways. Are there advantages to the double ended "canoe" type design. It seems to be that there would be less turbulence at the stern with a double ended design.

[yipster]

that again depends on performance like forexample speed

[Skippy]

A double-ender will have more turbulence above hull speed, which is typical of light catamarans, than will a squared-off transom. Water separates cleanly from the square stern, leaving only air and a smooth water surface behind it. Whereas the canoe stern pulls the water in toward the centerline, forcing it to turn again quickly once the water flows on the two sides of the hull crash into each other. Ultimately, the square transom will start to plane if it reaches a high enough speed.

[safewalrus]

Double ended catamaran? is that not a proa? two 'sharp ends' and you 'tack' the rig not the boat. Apparantly goes like smoke!

[Bergalia]

Originally Posted by Bergalia

For an idea of a double-ender capabilities you might like to browse:
www.mavc2002.com/caledoniayawl/aegre
It is an account of a 20 foot Shetland foureen taking a 12,000 mile voyage across the Atlantic - well illustrated.

I love quoting myself...I'm that kind of chap...But as friend Skippy points out...I quoted wrong....


The correct thread for the 'Aegres' Saga is: http://www.mavc2002.com/caledoniayawl/aegresum.htm
Still worthwhile all that keying in...
And thanks Skippy. You're a good man to have on the bridge

[Skippy]

Aw, shucks. *blush*

sw, a proa ama is usually narrower and at least slightly shorter than the main hull. On a Pacific proa, where the ama is on the weather side (lee side = Atlantic), the ama is much shorter and smaller than the hull. The hull is symmetric between the two ends, but can and ideally should be asymmetric between the windward and leeward sides. Whereas a canoe hull is symmetric along the centerline, and somewhat but often not quite symmetric fore-n-aft.

The rig has to pass through a plane perpendicular to the hull and ama rather than parallel. Proa rigs also tend to do things that are not necessarily tacking. The tack of a traditional oceanic lateen is moved from one end of the boat to the other, and the Gibbons rig swaps head and foot interchangeably. You need two rudders, one on each end, and usually two centerboards to control the helm balance.

Pacific proas reach fantastically because they're light and it's easy to fly the ama (hence the name "flying proa"). But I've been wondering recently whether they would point better than a cat, since the cat's big windward hull would provide more righting moment as long as you can fly it.

[kudu]

I'm feeling quite foolish...I was under the impression that a double ended sailboat has a hull similar to the Colin Archer "Redningskoite" type boat or an Ingrid, and that a canoe type hull resembled the much broader transom shape of the Aage Walstead.

[kudu]

Originally Posted by Skippy

A double-ender will have more turbulence above hull speed, which is typical of light catamarans, than will a squared-off transom. Water separates cleanly from the square stern, leaving only air and a smooth water surface behind it. Whereas the canoe stern pulls the water in toward the centerline, forcing it to turn again quickly once the water flows on the two sides of the hull crash into each other. Ultimately, the square transom will start to plane if it reaches a high enough speed.

This comment puzzles me...Does it really matter that the water from both sides of the hull crashes into each other? It seems, at that point of interference the transom would be one step ahead of it, no?