Ariel MAYBE 3/4 the size of a Triton.
certainly not 1/4.
Ariel MAYBE 3/4 the size of a Triton.
certainly not 1/4.
Just to be clear, I am in no way making some sort of Jr. HS locker-room "Mine's Bigger" statement or comparison here...remember, If I hadn't HAD to get a larger boat I'd still be LIVING on a Commander.
Now, I'm making that punt based on interior hull volume and surface area...and it's a punt. There is an old rule of thumb (sort of like the general rule of thumb about 1.34 x Sq. Root WL=theoretical max. hullspeed) that with boats of similar design a 1-1/2' increase in overall length doubles the internal hull volume. The Ariel and Triton hulls are pretty similar, although the Ariel is actually much finer in the bow section and flatter along the run of the bottom. (Triton is much fuller--OK, it's FAT--forward of the beam) Since the Ariel/Commander hull is 25', 7" overall, and the Triton 28', 6"...you see where I am going based on a 2', 11" difference. Also, having worked in, on, under both I can very much buy into it!<G>
Toby and Wayne had DECISION hauled out in the same yard as our Triton, and while we did not have the boats directly alongside each other, the difference in actual size was amazing.
In terms of surface area, if we judged by bottom paint consumed I think we are actually looking at somewhere between 3-3 1/2 times below the waterline.
I originally figured on 2X in terms of time, expense, materials...and found I had vastly underestimated. Of course, once one finds that they have done so, if they are me they have just gotten so aggrevated about it all they do not bother keeping scientific track of things after making each one of those discoveries...lest they admit it to a wife once named (and fittingly so) Del Toro! (lol!)
If anyone has a gutted A/C hull, it would be fun to try and convince Tim Lackey to fill up his Triton Daysailor hull (currently dead bare and empty) with packing P-nuts, then do same to the Ariel...and compare how many x-gallon trash bags of P-nuts went in. 'Course, that's a lot of $$$ in p-nuts. Anyone run a large shipping department nearby Tim's place in Maine and/or also have access to a gutted Ariel or Commander nearby? I'm serious, here! As long as Tim didn't have to clean 'em all out and pick 'em up from all over his shop floor, he might just go for it for all I know. For that matter, mine is still empty enough that if anyone wants to come up with enough p-nuts near me, I'LL fill up MY hull, if they are willing to help get 'em all in--and more importantly--back out(!). It would really be interesting to know for sure, and might make me feel better about how long some of this is taking!
FWIW, a good friend of mine sails and lives aboard a Pearson Renegade, which is much shallower in the bilge than an Alberg boat, and much fuller in beam section above the waterline...it's large for a 27-foot boat, much larger than my friend's Albin-Vega 27, for example (and rafted next to the Vega, DECISION was pretty small). Having spent a good amount of time on the Renegade, and having rafted a Commander to it on several occasions, I'll say this: If you cut off the keels and rudders, you could actually put the Vega INSIDE the Renegade hull. If you put the Commander inside there, it would RATTLE. Jay did have his boat on the hard right next to mine...and while it is much fuller in some sectional aspects, the Renegade is notably smaller than the Triton.
At one point I really wished for a spiffy deal on a 30 foot Pearson Coaster. Boats are rare as hen's teeth. Looked pretty hard for one, and only after ending up with the Triton I met a fellow who had just gotten a fully-equipped and well-kept Coaster out of someone's back yard for less than 4 grand...and less than 100 miles away from me! That weighed on me quite a bit from time to time until the day last summer that I was taking all of the bottom paint off our boat with a 6" DA and an 8" vertical polisher...under a boat completely sealed to the ground with heavy visquene and duct tape...in a Tyvek suit...in the sun...on an 80-degree day. At that point I decided that I was very glad the boat wasn't ONE SQUARE INCH BIGGER!
Seriously, bring on those p-nuts! As soon as I get out all of the vertical bracing I had to stick in to hold shape while recoring, the remains of the interior will all go away in short order and I think it would be fun to actually do.
Dave
IF the Ariel was 1/4 the size of the Triton , it would displace 1732lbs , not 5120.
The Ariel is more like 3/4 the size of the Triton or 73% to be exact.
Oh No!
This box packed by weight, not by volume. Some settling of the contents may occur!
Last edited by marymandara; 12-20-2003 at 11:18 AM.
Captains.
BACK OFF! Looking at the lines of a boat (take my favorite page in the Manual, pg 144) there is enough information there of the shape and the volume of the A/C. to start a website. NO? There's no formula for that?
You mean in this computer age there is no program that will instantly give the volume with all that information? Sure there is! Who's got it? For actual estimated volume you subtract the hull thickness, an estimate of the volume of plywood, cockpit, and the ballast. BAM! Triton vs A/C No arguement. Just beer, no peanuts.
Displacement is a problem here, Suppose I add a 1000 lbs of lead under the cabin sole - which isn't going to take up that much volume. You might end up with almost the same three dimensional space inside but the displacement would be 6200 lbs, whatever. Right? Talking about party room, not how low in the water the vessel is.
Happy New Year!
Last edited by ebb; 12-23-2003 at 06:47 PM.
But Ebbbbb.....
I wanna fill up my Triton hull with p-nuts. Then your Ariel! More fun that way!
Dave
I think I got lost in the shuffle. Is the question at hand the volume of the boat below the waterline, or the volume of the boat upto the top of the cabin top?
the former is pretty easy (64lbs h2o/cuft.)
so ~6000/64 = 93.75 cuft. below the waterline. and i think this is somewhere on the lines drawing.
-km
aka, "sell out"
S/V Beyond the Sea
C&C 35 mkIII
Internal volume of the hull up to the deck clamp, was where I was going with it...but then that also leaves the question of whether the old rule of thumb in question is including the entire belowdecks volume in "...the internal volume of the hull is doubled..."
Dave
If you can find accurate information regarding the prismatic coefficient of either--or both--designs, you can easily figure the relative volume to an extent that will quelch this pointless debate.
However, I've not seen this figure for these boats, so have no idea. FWIW, interior volume is typically affected more by increases in beam than length. With only a 3" difference in beam between the A/C and Triton, we're not looking at an exponential difference in volume.
The pointlessness of this thread generates pointless remarks.:
An attempt to find the prismatic coefficient for the A/C
Cp = displacement / 64 / midship area X LWL
5280 / 64 / 7 X 18.5
82.5 / 129.5 = .637
I read that the ideal should be around .56
What they're doing is dividing the real volume of the hull under water by the volume of the prism that is rectangular at the waterline and pointy at the lowest point in the water. A box sitting in the water rates the number 1. The smaller the number the faster the boat, .48 to .65 (D. Dix) So what this boy came up with seems too stodgy for a hull that sometimes exceeds other formulas designating hull speed.
7 square feet I came up with for the midship section below the waterline.
by guesstimating off the lines from the Manual. It is a T shaped area that looks vaguely like a wine glass where the stem joins the bowl, with thw bowl cut off and no foot. 'Prismatic' refers to the vaguely inverted trianglar shape of this section.
[ If you seriously wanted the area of this piece for the formula above, you'ld blow up the lines to scale, inch per foot is easiest, then you'ld cut the section out, cut it into pieces and assemble it onto one inch squares. This would be square foot area in scale. I didn't go this far. That would be pointless.]
For example, if I measure across the section at the waterline, I get approx 6 7/8s inches. or 6' 10 1/2". When I measure up to the waterline from the bottom of the keel, I get 3 3/4s of an inch or 3' 9". Give or take the thickness of a line, and the distortion from the copying process.
Cp does not produce any numbers related to real volume, it suggests relationship between displacement, waterline beam, and how pointy the ends of the boat are. Cp is a number used to compare boat shapes. The high number is rather disappointing and my name isn't Carl.
Last edited by ebb; 12-27-2003 at 09:10 AM.
the marymandara anomaly
and methods to solve the volume question.
In the lists of formulas and lessons "in artistry & proportion" to be learnt at a yacht design school, there is a lesson on "Use of Space" but nothing on the actual volune of a craft. If there is a method of predicting where the waterline will be in a design using weight of ballast and materials, then there must be a simular equation for just how much force it would take to immerse the vessel up to it's sheer, and for that matter over it's coach roof.
MuNaughton has an interesting lesson in "Interesting the Visual Portion of Brain with Proper Use of Strengthening and Loosening Curves" which sounds like a literal can of worms - both subjectively and pychologically.
Perhaps there could be a lesson in comparative volumes and their comfort ratios in offshore cruising, or day racing.
But I woke up this morning thinking about Capt Dave's packing peanuts method of volume determination. Ping pong balls would be more accurate because you could come up with a number for the spaces between closely packed spheres. Some may think that comparing the volumes of an Ariel and a Triton to be apples and oranges - one could tailor the method to where you are in the States.
In Maine you might use potatoes or sardines.
On the West Coast, cell phones or grapes.
In the Mid West you'ld use beer cans.
By far the simplest method is to sink the boats and measure how long it would take for them to drain in gallons per minute out a thruhull of known circumference. No brainer.
"Needs TLC"
You guys are great!! Snowing hard here, and not much else to do. I was thinking of horse turds here on the farm for measuring volume. I'm still back figuring out how weight relates to displacement.
Happy Holidays!
wet willieave maria
- but certainly the weight of a boat is its displacement. Boat displaces a volume of water whose weight is the same as the boat's.
Well, I did as I suggested because I knew none of you really cared what the Cp is. You rotters. Me neither, but I again woke in the middle of the night and had to do something about it. I traced the underwater athwartship portion, cut it up, pasted it onto 1" squares, came up with 8.25 square feet.
5280 (displacement) divided by 64 = 82.5 cu ft (volume of displacement)
8.25 (area of displacement in maximum cross section) times the waterline = a 'prismatic' shaped volume
which is divided into the actual volume of displacement.
The answer is .54
You will visualize the prismatic displacement if you take the maximum beam mid section at the waterline and place it at both ends of the waterline, at the bow and under the stern. It's a rectangular shape that has the same three-dimensional shape of the midsection from bow to stern. It is a volume that is only real to create the Cp. number.
Imagine a large pingpong ball. When put in the water it sinks in 1 foot and has an 18.5 foot waterline. Float another sphere of different material, it sinks in 2 feet and has an 18.5 foot waterline. Now float a third sphere that has a different diameter and floats at 3.5 feet with an 18.5 foot waterline. The prismatical shape of the spheres would all be squares (on the water surface with a U-shaped quanset hut roof like volume going from one end of the waterline to the other. Each sphere has a different displacement and a different prismatic volume. Guess which sphere will push thru the water easiest. Corse I could have toll you without all this rigamarol, It's the first and biggest sphere. It would have the smallest Cp value. [What would be the athwartsphere area at the WL of the third and smallest sphere - how like or unlike the Ariel? shape doesn't matter!]
But there is something strange here. I got more square area the second time (8.25 vs 7) and I guarantee it's pretty accurate, why did the larger area generate a smaller Cp? Supposedly, the further away from 1 the faster the boat. ???
I've had some dealings with a N.A. recently. Maybe I'll ask him. This is it for me on this eye glazer. .54 Cp sounds pretty good to me for a sailboat that has half of it's weight in lead! And any of this high-fallutin math have a form ula for the ingredible sexy underwater shape of these boats? Whatever.
As the prince said to Cinderella, "Hope the shoe fits!"
Last edited by ebb; 12-29-2003 at 01:36 PM.
Hey Ebb, just fyi, got a new shoe coming from a guy that had an ad in 'good old boat', parting out a Vanguard. The shoe looks identical, although it's in much better condition! And the vanguard wasn't designed by Carl. Must have just been a Pearson thing?
Anyway, thank's for offering yours, this should work great.
wet willie
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