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Frégate d'18 par Sané , la Cornélie


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Mark
"The shipwright is slow, but the wood is patient." - me

Current Build:                                                                                             
Past Builds:
 La Belle Poule 1765 - French Frigate from ANCRE plans - ON HOLD           Triton Cross-Section   

 NRG Hallf Hull Planking Kit                                                                            HMS Sphinx 1775 - Vanguard Models - 1:64               

 

Non-Ship Model:                                                                                         On hold, maybe forever:           

CH-53 Sikorsky - 1:48 - Revell - Completed                                                   Licorne - 1755 from Hahn Plans (Scratch) Version 2.0 (Abandoned)         

         

                                                                                                                                                                                                                                                                                                

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  • 2 weeks later...

Making progress, but it’s retrograde. Trying to get efficient in lofting the stern, so added station IX, a la Boudriot. Didn’t work out and gave some really squirrely lines at the diagonals. Also pulled the breadth curves outward, somewhat for stations VII and VIII.

 

Don’t know what Boudriot used as a gauge for station IX. There is a kinda/sorta vertical frame (the very last one), behind station VIII, but it’s disposed forward of the IX line. It is a frame and half-frame that sits right at the intersection of the bottom edge of the fashion piece. In fact, the fashion piece rests on the top of the after half-frame portion of the couple, so the ‘station’ and fashion lines should intersect at around the 5th waterline and the red dashed vertical line of the profile. Obviously, they don’t. More work needed, but have a couple of methods that should get me there.

 

Ed Tosti writes in his book on Naiad, that the body and longitudinal lines need to be iteratively tweaked and adjusted in order to be self-consistent and fair. So, back to basics and do the lofting of the fashion piece and filling transoms in accord with with the rule. Then plot those lines. Then extend them to the station lines. Then take a slice and plot it as a ‘station’ as appropriate, and do horizontals through appropriate portions; all with simple explanations as to who, what, where, when, how, why, and who’s on first.

 

The image is not utile. It represents what one does by following a paradigm that one does not quite understand. One must, simply must, hew to what one started with.

 

.post-1377-0-69530100-1448385249_thumb.jpg

Edited by JohnE
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This way madness lies.... It begs the question, why make things simple if you can make them complicated? Good luck with this partial square/partial cant frame (if I'm seeing this correctly, that is),

Be sure to sign up for an epic Nelson/Trafalgar project if you would like to see it made into a TV series  http://trafalgar.tv

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Thanks Druxey. Thirst lurks in madness. Want water, go to the well. Plowed through Vial du Clairbois and followed the bloody instructions this time. Made a little graph thingy I call the Fashion Aide. Looked a little familiar and lo-and-behold ! wouldn’t you know it, Boudriot read Vial too and put a similar figure from Vial into his book on the 74.

 

It’s a great tool. You can develop waterlines in way of the transoms, buttock lines, tweak them back and forth till they look like what you want and then do the projection to get a profile of the fashion piece that will give you those lines. You can start at any of the three; FF profile, waterlines, or buttock lines. When you are finished, you can simply project in space and get the outside profiles of all the filling transoms, as well as their evolving bevels along their lengths.

 

All in one simple graphical representation. They sure weren’t stupid in 1787. Woof !!!! 

 

post-1377-0-74598600-1448550509_thumb.jpg

 

Apparently the shipwrights read Vial too. It rarely appears in French draughts, presumably because it’s something everybody “knows”, but there’s a draught of a Pallas class Sané frigate, built at Antwerp, that has an inset to the half-breadth that shows the additional set of waterlines in way of the transoms. Since the Dutch/Belgian yard-dogs grew up in a slightly different school, perhaps they needed that extra ounce of assistance. Anyway, proof positive that the method was used and it worked.

 

post-1377-0-98426400-1448550537_thumb.jpg

 

Right then, back in the boat and sailing in the right direction (hopefully). Good old CAD plots; set the scale, know and love your base coordinates, and just zoom in and read the offsets.

 

Back to work. John

 

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Following the rules, things are looking much better. The blue lines are the fashion profile and the profile of my bogus station IX. Station IX is only there to help adjust the waterlines where curvature gets complex. It is the last square couple in the ship. The heel of the fashion frame sits atop its after half-portion, so the lines necessarily converge. Below (abaft) the convergence is the line of the ‘massif’ (deadwood) fairing to the keel and stern post.

 

post-1377-0-75537300-1448554952_thumb.jpg

 

Station IX is not ‘official’. It is user defined. Knowing frame spacing and the location of the heel of the fashion frame on the profile plan defines a location for “Station IX” in my set of drawings. Clearly, other designs will differ, but I think it a valid positional reference for a Sané designed frégate d’18.

 

Yes, Druxey, station IX is a projection off my handy dandy Fashion Aide. I doubt I could use it for psychological projection … I’d be in a white jacket in a rubber room faster than you could say “buttock line” :dancetl6: . When I talk to my friends in France I always apologize for mon atroce français. After reading a lot of period works, my French is getting much better but it’s français ancienne, and still atroce, so my poor friends are so confused.

 

John

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Druxey, Je vous remercie infiniment. I have this suspicion that they are laughing with me instead of at me. Yes, my French is atrocious, and yes the French are a bit arrogant. They believe if one can’t speak French, one simply isn’t civilized. But they do give a lot of points for effort.

 

Ok, so body plan. I think the lines are exquisite. They fair perfectly on waterlines and diagonals. Next is the half-breadth, with the inset for the transoms. Beginning to be a very happy camper.

 

post-1377-0-86399300-1448732946_thumb.jpg

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  • 2 weeks later...

A prochain indeed, Mr Druxey. Lots of progress. Woof ! Starting to look like a French frigate !  Did the masts. Different from Boudriot's paradigm. He took the heel and went vertical. The Rochefort draught had the same heel position but raked the main and mizzen. so wtfo? Went to Villemaurin's reports on Cornélie and did a judicious tweak on his "sweet-spot" and the next-most upright rake angle. It's a bit less than what's shown in the Rochefort draught, but somewhat more than what Boudriot denotes.

 

post-1377-0-88457900-1449430128_thumb.jpg

 

The lines look good. There may be a few small tweaks here and there, but the plots are internally self consistent and follow the nominal of several period draughts from 1797 to 1809. I'm a happy camper.

 

John

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Sweet, John.   Those are some nice lines.  For some reason, even though most of my research books are for English ships, I find myself be drawn into the French side.  Which creates headaches since I neither read nor speak French.   My Admiral says I barely speak American some days.  :D  :D :D  

Mark
"The shipwright is slow, but the wood is patient." - me

Current Build:                                                                                             
Past Builds:
 La Belle Poule 1765 - French Frigate from ANCRE plans - ON HOLD           Triton Cross-Section   

 NRG Hallf Hull Planking Kit                                                                            HMS Sphinx 1775 - Vanguard Models - 1:64               

 

Non-Ship Model:                                                                                         On hold, maybe forever:           

CH-53 Sikorsky - 1:48 - Revell - Completed                                                   Licorne - 1755 from Hahn Plans (Scratch) Version 2.0 (Abandoned)         

         

                                                                                                                                                                                                                                                                                                

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Hello, Idaho. That’s basically the plan (pun, arr, arr, arr).

 

There aren’t any modeling plans for an Empire period Sané firgate, so I decided to make a set. It involved basically designing a vessel from first principles, using Sané’s notebooks and instructions, and a set of period treatises used as how-to manuals by the shipwrights.

 

The thread is about CAD being an invaluable tool for getting all the arcs, curves, angles, dimensions, and projections smooth and self-consistent in all 3 views; sufficient for a building plan of the vessel. Gotta have a good lines plan, or else nothing else will fit. CAD is also good for scaling. I draw/construct at 1” = 1’ and use French feet (pieds, pouces, lignes) as the dimensionality metric because that’s what the period documents use. Once finished, it’s simply a matter of scaling up by 1.06575 to get to English feet and then scaling down to 1 : 36 or 1 : 48 to produce a useable set of plans. Those should be ready fairly soon.

 

Once the lines plans are finished, it’s off to specifying the pieces of wood: keel/bow/stern, disposition of frame, internal hull fixtures, deck plans, cabestans, brioche ovens, wine cooler dispensers, and the like; almost everything one would need.

 

John

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Whoah, Idaho Crackers. Is that anything like Montana Chips? You seem to be right down the road from my favorite ski place in the US in Ketchum. It's probably good to be you, at least in ski season.

 

Not a genius, just an anal retentive plodder. Lots of other modelers do much the same for their favorites.

 

As for the lines plans, the idea is to talk with a few people and use their input to get them into shape for publication and then give them to NRG to do with as they wish. I can hope for NRG making the files available, perhaps free to members, perhaps charging a nominal fee to others, whatever, but just getting the design plans out there is my fondest wish.

 

John

Edited by JohnE
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I wish to thank everyone for the 'likes' and comments.

 

More progress. Mr handy-dandy Fashion Aide has been doing a wonderful job.  Added 5 additional closely spaced (1 pied intervals) waterlines, in way of the transoms, to the half-breadth as an inset. Did several sanity checks on the results, and they pass muster (don't drool, eat flies, or howl at the moon). This should help lofting the stern. Everything is in place for a set of buttock lines, and the good old Mk-1 eyeball doesn't see any obvious glitches.

post-1377-0-22058100-1449764700_thumb.jpg

So buttock lines on the profile plan; lines of decks on the half-breadth plan; and detail finish work on the profile view; chains, bitts/bollards, head, etc. and maybe I can put the basic lines plan into the can. Lots of labeling and scaling to do, but that's fun fiddly bits. Can't wait to get there.

 

John

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Ok, buttock bow lines. Sweet. They begin and terminate at the intersection point with the first (top) waterline in the body plan. Buttock lines in way of the transoms will be on an inset that goes from the lisse d'hourdy (wing transom), through the filling transoms and extending to Station VII aft (like in the waterline inset).

post-1377-0-73265500-1450116611_thumb.jpg

I take back everything I said about the French being more concerned about the "perfect solid" bow and dismissing the stern. I was wrong. Mea culpa, mea culpa, mea maxima culpa. If you read Howard Chapelle carefully, he makes note of the "straightness" of the mid-line buttock as it crosses the waterline, as an indication of "potential" speed. I note that Sane's buttock lines are quite relaxed (a very good thing) and the mid-line is pretty straight as it crosses the design LWL (a very, very good thing). Looking at these with a jaundiced racing sailboat designer's eye, I am pretty impressed.

 

When you take the run of the lines back through the transoms, it's pretty clear that there's some high velocity curvature going on above the waterline mark. If you think Chapelle, it makes a lot of sense that French ships were very sweet and quick, when loaded to the design LWL. It also makes a lot of sense why they were 'dogs' when over-loaded to typical RN standards.

 

Boy, oh boy, this is so much fun!

 

John

 

 

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Oh, Lord. Thought I was a happy camper, but found some nastiness in the CAD program paradigm. Seems that rotation does not apply to a uniform "square" object space, but rather some rectilinear space that morphs/modifies in both x and y when rotation is performed. I have built a 'y' model of a series of 'waterlines' and then rotated it through 20 degrees. The length of the line connecting the dots, when upright, is 7.00 inches. When rotated through 20 degrees, the same line is 7.97 inches. The damn program doesn't even follow the sine rule.

 

Gonna pull down the inset waterlines and calculate them again with Corel. Sometimes you gotta love CAD programs, sometimes you gotta hate them. Thing is, they never tell you what they are doing internally. You just have to try, and cut, and fit, and find out it's all blithering nonsense. Woof !! Ok, off to 1:1 printing and a pair of Staedtler dividers.

 

John

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Well, every blivet is a learning experience. I'm sure Mark would agree with me on that one. I'm thankful I'm only trashing electrons and not wood; that would be a real bummer.

 

Found out what I did; actually didn't do.  Some things are easy in Corel, but counter intuitive in TC. Likewise, there's things you can do in TC that you can't do in Corel (at least not very well). Only real solution is to do some things in one, and some things in the other.

 

Live and learn. Always measure twice before you tweak, and then measure again to make sure you tweaked it right.

 

John

Edited by JohnE
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I've heard that one, but there's no one to blame but myself for this one, druxey. Ok, so do it right.

 

Transom buttocks finished. Every point sits in the assigned spot in 3-space. All 3 orthogonal axes are satisfied. Buttocks are smooth, fair, and well rounded, just like ... um ... er ... you know. Shape and form is the elegant everything. Cannot imagine the French doing things in any other way.

 

post-1377-0-85617600-1450549839_thumb.jpg

 

Ok, so the lines are a wrap. Now off to do pretty fiddly bits on the profile plan and make her look like the proud frigate that she was.

 

More to come. John

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Thank you very much, druxey, but the thumbnail doesn't really do it justice. I did some cleanup and polishing with my old trusty Eppler Keel Analysis program and got things a teensy bit tighter (and prettier). This sub-forum is about using CAD, after all. Made a nicer capture that avoids the reduction blivets. Hope you like.

 

post-1377-0-88219100-1450635838_thumb.jpg

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Thank you very much, druxey. Your appreciation warms the cockles of my heart. Again, thank you.

 

So, off to prettiness. Here's a work in progress Profile Plan.

 

post-1377-0-83334300-1450814782_thumb.jpg

 

Lots to do, still, Have to do projections of frames up to top-timbers on the forecastle for bollards and the actual placement of the sabords dans les galliards. And then there's midship rails, and such, Mostly later model additions, so will be in dotted-lines. Yep, rudder will be included along with fixturing.

 

Anybody else out there that wants to see something? I been mostly talking with the Pros-From-Dover, but welcome and encourage input from anyone.. 

 

John

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Sweet...  John.

Mark
"The shipwright is slow, but the wood is patient." - me

Current Build:                                                                                             
Past Builds:
 La Belle Poule 1765 - French Frigate from ANCRE plans - ON HOLD           Triton Cross-Section   

 NRG Hallf Hull Planking Kit                                                                            HMS Sphinx 1775 - Vanguard Models - 1:64               

 

Non-Ship Model:                                                                                         On hold, maybe forever:           

CH-53 Sikorsky - 1:48 - Revell - Completed                                                   Licorne - 1755 from Hahn Plans (Scratch) Version 2.0 (Abandoned)         

         

                                                                                                                                                                                                                                                                                                

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Good catch, Druxey... that made my day.  :D

Mark
"The shipwright is slow, but the wood is patient." - me

Current Build:                                                                                             
Past Builds:
 La Belle Poule 1765 - French Frigate from ANCRE plans - ON HOLD           Triton Cross-Section   

 NRG Hallf Hull Planking Kit                                                                            HMS Sphinx 1775 - Vanguard Models - 1:64               

 

Non-Ship Model:                                                                                         On hold, maybe forever:           

CH-53 Sikorsky - 1:48 - Revell - Completed                                                   Licorne - 1755 from Hahn Plans (Scratch) Version 2.0 (Abandoned)         

         

                                                                                                                                                                                                                                                                                                

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Ah, yes, the famous flottant sabord.. Guaranteed to twist your kilt. Have a little problem, though.

 

In early days, armament was different from later days, on the identically same ships. Just before the Revolution, a frigate would nominally have 28 x 18pdrs on the main deck and 8 - 10 x 8pdrs on the gaillards. French didn't rate ships on number of guns, but rather caliber of the main battery. That's why you see French frigates rated as 36s or 38s or 40s or 44s, all on identical hulls..

 

The 1793 devis of the original Cornélie lists her with 28 x 18pdrs on main deck, 10 x 8pdrs on gaillards, and 4 x 36pdr "caronades", specifically "sur le gaillard d'arriere". Life goes on and in 1807 there was a 'Reglement' that set an 8x 8pdr and 8x x 36pdr standard. Who did what to whom and when is entirely unknown, but the regulation is out there. Period records talk about ships having a pair of 8prds, flanked by "caronades" on the forecastle. Ok, so that's 2 x 8pdrs and 4 x 36pdrs on the bow and 6 x 8 pdrs and 4 x 36 pdrs on the quarterdeck.

 

So what do I choose? I have my predelictions, but would rather rather have input from 'higher'. Ya'll got any?

 

John

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