Canoe stern - why?

[Bob Perry]

Mea culpa. I am responsible for others false assumptions.

 

[Tanton Y_M]

Happy Stern. No matter what.

 

[floater]

Apparently the deckhouse was modelled on the cab of an early pickup truck

oddly enough, they call this a pilothouse pickup. my dad had one - three on the tree.

 

[12 metre]

Mea culpa. I am responsible for others false assumptions...

I apologize for my childish retort.

And for the record, Sidecar and See Level got it right.

I wasn't even looking at the spars in the photos.

It was a lame attempt at a joke based on what stood out to me in the photo - a dodger big enough to house Ghadaffi's harem and davits big enough to lift the entire US 6th Fleet.

But as I read somewhere recently - it's not a joke if you have to explain it.

 

[mckenzie.keith]

Good question, but there's this from a Transatlantic Record...

The Fastest Atlantic Crossing Ever Defends Its 30 Year Old Record

In August 1992, the Destriero monohull sailed from New York to the British Isles of Scilly in 58 hours, 34 minutes and 50 seconds. Since then, nobody has done better

www.elledecor.com

That is an impressive boat and an impressive feat. No doubt about it. But it is 67 meters LOA. I call that a ship.

 

[Bob Perry]

That Cheoy Lee Long Range motor sailer is owned by an Australian friend of mine. He keeps it on the Gold Coast in Queensland and needs the sun protection aft. I'm not sure if I'd call that a canoe stern. It's kind of a hybrid canoe/trawler stern. But this is a very good boat. It was designed around tankage requirements for long range cruising. In short I started by drawing the tanks then I wrapped the hull around the tanks. I was a guest aboard one for the St Francis YC stag cruise. We did 9.5 knots all the way to Tinsley Island. The only boat that passed us was a SC50. Also aboard for that trip were designers Frank McClear and Dave Pedrick. Both were surprised at the speed of the boat. I sent them the lines when I got home.

 

[veni vidi vici]

.

 

[floater]

But the big daddy of them all is weight aloft.

oddly enough - I've seen the exact opposite argued. as part of the "sea kindly" motion argument. more weight aloft has more inertia hence slows down the motion. and this is supposed to be more comfortable.

 

[floater]

personally though - I have my doubts.

 

[pqbon]

oddly enough - I've seen the exact opposite argued. as part of the "sea kindly" motion argument. more weight aloft has more inertia hence slows down the motion. and this is supposed to be more comfortable.

Except one that weight aloft has a big lever arm on the hull.
Easy way to demo it -- put someone up the rig in even small sea state and see how much the boat starts to roll!

 

[floater]

I agree with Go Left. This conversation doesn't work when you throw all double enders into the same category. That is ridiculous. For instance, look at Yves-Marie's 43 canoe stern boat. That is exactly the shape I avoid. Look at Garden's OCEANUS, maybe the prettiest canoe stern ever, just did not work well. Frankie's stern shape came from a Laurie Davidson AC bow. Look at the Calkins 50, now there's a sweet stern. My point is, this group of canoe stern boats are all very different. You'd be making an error to endow then all with the same characteristics.

To the question "why canoe sterns?" The answer is simple, because some people like them. That's it. That should be good enough. I happen to like the look of a canoe stern. It has zero to do with performance. It's aesthetics. Yes, some canoe stern boats are ugly with a stern shape that looks like it's hanging, painfully off the stern. I like a canoe stern that appears to be floating kind of like a perky tit. To get that shape you have to be very sensitive to shape. Note the slight hollow in the lower part of the Valiant 40 stern section.

Of course I like double enders, when they are well designed. I think I have designed more
double enders than any other living designer. If you know a designer with more please let me know. Designing double enders has afforded me a comfortable life style and a job I have looked forward to 96.00443% of the time. I live well and indulge my hobby and my dogs. Can't shit on the boats that made it all possible. Ironically I have far more transom stern designs than double enders. People forget that.

I think the plusses and minuses of canoe stern boats has been well covered here. Most seem to understand that subject. Others don't have a clue. Can't help that. The appreciation of canoe sterns is a subjective thing. George Day, publisher of BLUE WATER SAILING, upon finishing his circumnavigation wrote, "There are more Tayana 37's cruising the world than any other design." That makes me feel really good. I am constantly getting posts on my FB fan club page from TY 37 owners from all over the world. They built 600 Tayana 37's. I was 26 when I drew those lines. Of course I feel good about that boat. I like all my children. View attachment 578944 View attachment 578945 View attachment 578946 View attachment 578948

so I did a Bing search on "seakindly", and this is what I got:

 

[12 metre]

oddly enough - I've seen the exact opposite argued. as part of the "sea kindly" motion argument. more weight aloft has more inertia hence slows down the motion. and this is supposed to be more comfortable.

Agree, but I was referring to pitching moment and more from a performance perspective.

Similar notion applies to low and high VCG. A higher VCG isn't usually considered beneficial from a performance perspective, but it tends to extend the roll period - making for a more comfortable ride. I've heard lots of stories about boats that have been dismasted and the crew describing how awful the motion is.

I have no evidence to support this - but from a comfort perspective, I suspect the period of oscillation is more important than the amplitude. Provided you aren't dealing with crazy large amplitude.

 

[floater]

I've heard lots of stories about boats that have been dismasted and the crew describing how awful the motion is.

that's a nice way to think about it - imagine your boat with no mast at all. otoh, the sailboat also has sails, and wind on the sails. so, reality is more complex than just the mast weight I suppose.

what's the average airspeed velocity of a laden mast?

 

[sledracr]

oddly enough - I've seen the exact opposite argued. as part of the "sea kindly" motion argument. more weight aloft has more inertia hence slows down the motion. and this is supposed to be more comfortable.

again, both... sort of.

There's no question that the mass of the rig acts as a weight on a pendulum. It has inertia. Once it starts moving (eg, when the boat pitches) it's going to want to continue moving until opposite forces neuter it. The more mass, the more inertia, the more force (and time) involved in countering it.

But it's also true that the motion changes dramatically when that mass is absent. If you've ever been on a dismasted sailboat in a messy sea, the motion is downright violent, VERY different than the motion before the rig came down. My guess is that the mass of the rig "dampens" the motion a bit.

If I were to take a stab at generalizing the phenomenon, I'd say the rig adds to the amplitude of the motion, but damps the frequency.

 

[floater]

the rig adds to the amplitude of the motion, but damps the frequency.

makes sense. as frequency and wavelength are inversely proportional. and that is helpful, as I have been consistently flummoxed by statements such as weight aloft is not always such a bad thing.

*and no. I have zero experience aboard a dismasted vessel. not even rounded down - nor ever even lost a boom. perhaps a couple of mainsheet tackles busted though.

 

[knh555]

makes sense. as frequency and wavelength are inversely proportional. and that is helpful, as I have been consistently flummoxed by statements such as weight aloft is not always such a bad thing.

*and no. I have zero experience aboard a dismasted vessel. not even rounded down - nor ever even lost a boom. perhaps a couple of mainsheet tackles busted though.

An imperfect comparison would be a sailboat without sails up vs. a powerboat recognizing that the powerboat does have a purposefully and differently designed hull and weight distribution.

 

[Go Left]

A sailboat without a mast & sails is an ugly experience. Been through it 3 times. Not hoping for a 4th.

Not only is there no weight/dampening aloft, there is nothing to counteract the mass of the keel slewing around in the wave action.

 

[floater]

three. damn. what do you win?

 

[sledracr]

A sailboat without a mast & sails is an ugly experience. Been through it 3 times. Not hoping for a 4th.

Not only is there no weight/dampening aloft, there is nothing to counteract the mass of the keel slewing around in the wave action.

2-1/2 for me

(the half was the rig of an Andrews-70 in a Big Boat Series.... mast broke at the upper spreader, but we managed to keep the rest of it from coming down. Did *not* envy the guy who had to *climb* from the topping-lift exit up to that point in order to cut the luff-rope on the main so we could get it down....)

 

[Bull City]

Another reason why: