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Frégate d'18 par Sané , la Cornélie


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Oh, golly, start in with l’estain and it just don’t quit (not that I mind, it’s just too legit).

 

Ok, then, top down view: fashion frame was two pieces (in effect, a couple), the fashion frame was itself but had a forward support frame. The heel of forward fashion support frame sat on, and flowed into, the aft frame of the aftermost ‘square’ couple set (Bourdiot’s FF). The heel of the fashion frame itself might be viewed as also flowing into the line of FF, but down at the bottom, everything flowed into the deadwood (le massif).

 

post-1377-0-61332700-1460144822_thumb.jpg

 

Notably, and unlike the station sections, the body plan line of the fashion frame (l’estain) is the after edge of the timbering (the red line). The body plan lines of station sections are taken from the center seam of the corresponding couple.

 

The position of FF, in the image, is totally arbitrary. Its actual location and individual timber thicknesses will depend on design definitions of frame, room and space, and what the yard dogs had for breakfast.

 

Anyway, this is the top-down view of the diagonals, based on everything else. The lines are now reconciled orthogonal to the other views. Please forgive my earlier attempts I was trying to replicate something that just didn’t fit within this paradigm. Sorry. I’ll get this into the plan set, as well.

 

John

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Ok, so things are getting exciting. To really get a handle on the shape of the buttocks, I am going to have to do some lofting. That means defining some timbers/frames and doing some fairing. I will be using Vial du Clairbois as my basis just as Boudriot did for his 74-gun ship. I kown this is a frigate, but I think I can scale appropriately given Sane's box rules in his Devis, and Vial's very clear exposition as to shape and placement. Simple geometry and trig and logarithms, and bears, oh my. Stay tuned.

 

John

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  • 3 weeks later...

Sorry for delays. Got a nice new 3D program but it needs OpenGL 3.0 or more. My legacy system has 1.7. Looked for a nice graphics card and found my power supply wasn't up to snuff. So new computer.

 

Oh ... My ... God .. !!! Can you say Woof .. !!!

 

I'm migrating slowly since all my disc boxes have SN and Activate keys on them, but I have no clue which tag goes to which version. Fortunately I register and folks at Corel and IMSI are very gracious once you get to them after 3 or 4 trips through the phone root extraction profile (pushing the wrong button).

 

Soon, soon. Will have to make a pitcher of Uncle John's Famous Baja Margaritas and fire up Master and Commander. This is just to recover my Wa, you understand.

 

John

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I don't envy that computer swap, John.   I've been giving it some thought on mine as it's getting a bit cranky occasionally.  The local shop and I think it's the hard drive.   They'll swap out the drive with an SSD, image the old disk and put it on the new for a lot less aggrevation than a new computer.

 

I guess upgrading the power supply wouldn't have solved your problems?

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John,

 

New programs require more up to date hardware - unfortunately- for often those need more speedy CPU and/or memory, and certain new hardware needs other newer hardware. I've had that problem several times. Sometimes you're just pushed into a new computer, even if your old one still suffices for general use. It's probably the best choice you made, for you might have been swapping one component after another, which - in the end - would have cost you a lot more (e.g. time spent, travell/postage, annoyance, ...)

 

Looking forward to your next update!!

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I feel your pain, John. Bought a new comp one month ago and it took me 2 weeks to set things up...still have a lot of programs to install.

But the move was well worth it, boot up phase takes 5 seconds and Blender/Gimp run smooth like silk.

 

I´d suggest some Boccherini or Lully as background music when doing the tedious stuff. Calms me down nicely :P

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Finally got the time to do some modelling:

 

post-395-0-25747200-1462378896_thumb.jpg

 

Model is still very rough around the edges (literally), but it should give a first impression of the hull shape. Which is, needless to say, very elegant :)

 

 

John, any big chance for the plan upcoming or can I continue with the set you gave me? :)

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  • 1 month later...

Been a while, but a lot has been going on. A 3D modeler (Bava) noticed some inconsistencies in topside lines for orthogonal views. These had to be fixed. That’s one of the witches of working with the original 1810 offset tables; they are not self-consistent. Ok, what the hey, I figured I would have to do a Chapelle at certain points, but basic departures from the offsets? Woof !!!

 

The underwater lines conform nicely all the way from Boudriot’s 1782 Venus to the 1821 Armide, with appropriate adjustment to the principal dimensions according to the “reglement”. It’s topsides that are biting the big one.

 

Reconciling curves don’t really reconcile; perhaps they do for a couple of stations, but then they depart.  This period was one of transition, and it’s very hard to a good grip on this for a ship of “general” configuration. The whole tumble home thing was undergoing the same examination as for the British, but not quite to the same extent. Cornelie’s topside lines are way outside the Venus, and way inside the Armide.

 

They are close (but no cigar) to the Rochefort Justice, the Chaumont Sane, and the Sane Erigon. Mathematics is indicated. AAaarrrggh !!

 

Can do this. Ciao. John

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John, any big chance for the plan upcoming or can I continue with the set you gave me? :)

Soon, my friend, soon. You have tweaked me right where the sharpie should go. I'll get you something a bit more righteous.

 

Ciao. John

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That is a rather nice phrase, isn’t it? I have learned so much from Howard Chapelle’s and Merritt Edson’s  notes and journals about the techniques of ‘reconstruction’. To name the process for Chapelle seemed the fair thing to do (pun intended).

 

Better lines plans coming very soon. They will be accompanied by some Excel files that have the table of offsets, separately, for the underwater waterlines and the additional topsides horizontals. Excel data points are in ‘decimal’ French pieds with a next column in metric. It’s ‘decimal’ pieds because TCAD works in decimal and it’s not all that hard to go between ‘decimal’ pieds and pieds/pouces/lignes. I used some of Chapelle’s  technique suggestions and math and I will be dipped if the topsides didn’t simply drop into the Chaumont Draught paradigm.

 

Not too many changes, but I’m afraid Mademoiselle  l’estain got tweaked (I have as much trouble with that as you, Bava, but I think I have her worried).

 

Ciao John

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Have a sneak peak of the carvings. The only known reference to the carvings of the “real” Cornélie is a few sentences in dockyard records. Not much to go on, but her figurehead was described as Cornélie, “hair bound in roman fashion and holding a vessel of the sacred flame”.

 

Cornelia Scipionis Africana, mother of the Gracchi, was the touchstone of motherhood virtue (home and hearth) in Rome; the only woman who ever got a statue in the forum. She refused the marriage proposal of Ptolemy Physcon, who offered the crown and treasures of Egypt, by bringing out her sons and saying “These are my treasures.” Who would not love a ship named for such an incredible woman.

 

The Roman goddess of motherhood (and virtue, and other stuff) was Vesta (the Greek Hestia) who was keeper of the sacred flame of home and hearth and virtue. Her statues and images show her holding a ‘vessel’ of the sacred flame. Some of these are brass cups having the flame, but most are of the ice cream-cone shaped bundle of rods with la flamme sacrée issuing from the top.

 

post-1377-0-81478600-1466524423.jpg

 

Since I can’t draw, one of our members and contributors offered to come and play. He did the perfect figurehead. Can’t begin to say how well this works.

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And then, following the paradigm of reconstruction, the artist did a cove carving that was too perfect for words.

 

The ‘original’ Cornélie had a note of a busy cove carving that may not have been done in actual practice, but looked good in dockyard records. Since this ship is not of the ‘original’ Cornélie , it seemed good and right to let the artist have the freedom to play.

 

This was the result: Cornelia and Vesta offering, together, to la flamme sacrée. It is  right in line with the figurehead. Oh, gosh, an artist that “knows” ships as well as “knows” his Greek and Roman. Life doesn’t get any better.

 

post-1377-0-95857300-1466526751.jpg

 

Ciao John

 

 

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Well then, druxey noticed some inconsistencies in the transoms, Bava noticed some inconsistencies in the topsides, and I found a couple others. So I did a Chapelle. By that, I mean proving the lines in all views so as to have them 'fair' and let the offsets fall where they may.

 

So I did that and 'lo' I can drop this girl into a Boudriot book and have her go unnoticed. I fought with the topside lines (made some specific horizontals) and then plotted the results as 'special' waterlines (a la Boudriot) and worked things iteratively till ... it necessitated a bit of tweaking for certain stations at the top waterline, but hey, what's CAD for anyway.

 

The topsides are smooth and fair; no bumps or hollows. And the lines connect up with the gallery top view, within a half pouce. Pretty good. I ran everything through my NACA Matlab program and the results are striking. I don't want to use a modern curve-fit program, for obvious reasons, but it's nice to know that a yard dog's batten was sweet.

 

So, final, final, on the body plan and the half breadth. So final that I made a table of offsets. Talk about commitment, Woof. Offsets are in French pieds, expressed in decimal. Next column is the same measurement in decimeters. It's in 4 sig-figs, so going to millimeters is brainless. Plans are drawn in 1:12.

 

Oh yeah, S is the line of the sheer rail; M is the line of the main rail (hemi, demi, semi, equivalent to the English top-timber line).

 

post-1377-0-91921800-1466962041.jpg

post-1377-0-27833400-1466962109.jpg

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Thank you all. Appreciate it a lot.

 

I’ve generated offset tables for the horizontals; waterlines, topsides, deck lines, and lines of the sheer and main rails based on the reconstructions of the body plan curves.  I use a particular definition of the placement of the line of the fashion frame (lisse d’estain), and thought it appropriate to include an explanation with the offset tables. But also thought it nice to include it here, such as it is.

 

The basic French station line bisects the corresponding couple. L’estain is also a ‘couple’. The aft fashion has an aft edge, the forward fashion has a forward edge and there is a centerline where the two frames join. Different designers used different lines; some using the aft edge, some using the centerline. I chose to use the aft edge and had to make sure the body and water lines conform to the choice.

 

Here is a very simplified frame drawing showing position of the lines in profile. The red dashed line is really just a projection down. The physical aft fashion stops where the heel rests on the deadwood of the massif. The massif also has some surface contour and defines/continues the lower portion of the fashion frame’s body line.

 

There is nothing much behind l’estain to define measurement locations in profile. The filling transoms live in the space behind the lazy s. Behind l’estain’s upright top timber edge are filling timbers that go back to the side counter timber, leaving room for the door to the head. So, l’estain is truly the aftermost “line of reference” of the profile that defines lines in the other orthogonal views (the stern rabbet notwithstanding since it simply defines termination points for lower waterlines).

post-1377-0-70015800-1467554672.jpg

 

John

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Plotted deck lines on the half breadth plan and they are looking shiny. Right off the off-set tables. Either I'm living right or I have a bit too much El Jimador in my margarita and am fooling myself that I'm seeing clearly.

 

Bava might appreciate the conjugation, since deck lines were a problem when he put the old files into blender. Gosh, I love the people here. They push and poke and prod and make one do it right. Anyway ...

 

post-1377-0-54214100-1467821324.jpg

 

John

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Well then, druxey noticed some inconsistencies in the transoms, Bava noticed some inconsistencies in the topsides, and I found a couple others. So I did a Chapelle. By that, I mean proving the lines in all views so as to have them 'fair' and let the offsets fall where they may.

 

So I did that and 'lo' I can drop this girl into a Boudriot book and have her go unnoticed. I fought with the topside lines (made some specific horizontals) and then plotted the results as 'special' waterlines (a la Boudriot) and worked things iteratively till ... it necessitated a bit of tweaking for certain stations at the top waterline, but hey, what's CAD for anyway.

 

The topsides are smooth and fair; no bumps or hollows. And the lines connect up with the gallery top view, within a half pouce. Pretty good. I ran everything through my NACA Matlab program and the results are striking. I don't want to use a modern curve-fit program, for obvious reasons, but it's nice to know that a yard dog's batten was sweet.

 

So, final, final, on the body plan and the half breadth. So final that I made a table of offsets. Talk about commitment, Woof. Offsets are in French pieds, expressed in decimal. Next column is the same measurement in decimeters. It's in 4 sig-figs, so going to millimeters is brainless. Plans are drawn in 1:12.

 

Oh yeah, S is the line of the sheer rail; M is the line of the main rail (hemi, demi, semi, equivalent to the English top-timber line).

 

attachicon.gifCornelie Body Plan French.jpg

attachicon.gifCornelie Half Breadth Decks French.jpg

 

 

Beautiful lines John,

 

the frame body plan as I understand shows typical french lines, very elegant design...

 

Nils

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Bava might appreciate the conjugation, since deck lines were a problem when he put the old files into blender. Gosh, I love the people here. They push and poke and prod and make one do it right. Anyway ...

 

 

We´re good at nit-picking, aren´t we?

 

And thank you very much for the email!! Sent my request today, maybe there will be two versions of La Cornélie, one according to your plans and one as La Cybéle as a frégate rasée.

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Thank you Nils. French lines sure were elegant.

 

Bava, is your Cybele the Nymphe class frigate by P.A. Lamothe? I can't seem to find another Cybele in the lists anywhere. Just fyi, if she is the Lamothe frigate, Thetis was another Nymphe and much of a muchness with Cybele. The British captured Thetis in 1808 and NMM has plans of her as HMS Brune. Might be good for comparison purposes. Just sayin'.

 

Put some thoughts on the Lamothe Cybele on the research sub-forum. I think she is worth considering.

 

Ciao. John

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John,

 

I was reading the monograph for L'Hermione, and thought this interesting and maybe give you a chuckle.   There's two sets of framing diagrams included..  One is the "as designed" which is nice and neat.  The other is the same diagram but with the dimensions from the wreck for the frames and space.  The frames are so much thicker and the space much reduced on what they found from the wreck.   Makes me think the yard dogs built it the way they thought it should be.   ;)

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Mark,

 

That is really cool and doesn't surprise me. My copy is still lurking in the bowels of the Customs Service, but I'll make sure to check that out and get my chuckle when it finally arrives. I see that a lot in the wreck archaeology reports from TAMU and from the Canadians working on provincial marine wrecks. There's always a couple pages, if not a chapter, describing the differences between the wreck timbers and what's shown on plans.

 

T'is exciting stuff for a model builder or plan designer. It pretty much says that one is not straight-jacketed by strict conformance to scantling or dimensionality. It's good to do good plans and faithfully follow them, but sometimes, departures must be made. We are yard dogs in scale. Nice to know the big dogs did the same thing.

 

One day someone will do a monograph on yards and yard dogs that focuses on their knowledge, professionalism, and that je ne sais quoi that lets them get away with it. I'll be all over that one. Thanks, Mark.

 

John

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  • 2 weeks later...

Speaking of yard dogs, I've been a yard dog with the Cornelie design. I have been doing a complete reconstruction of the lines plans according to the paradigm set out by Howard Chapelle and Merritt Edson, and it has been an astonishing experience. I have found that much of the original French tablature is quite relevant and accurate (most of it, actually). But there were some significant grey areas in the regions from Station VII-a to the stern, particularly in the region of the 'malicieux et capricieux' estain. She has been an absolute witch for over a year, but I think I got her attention, now.

 

Plotting the new lines has been fun. Overlaying the old lines shows just how closely the old and new coincide in pertinent part. Those areas that differ, do so by a matter of a pouce (1:1 scale French feet). Amazing what one pouce here, one pouce there, actually does. Most of the tweaks were in terms of lignes (1/12 of a pouce), on a full scale drawing - Woof !!!

 

So have a serious set of offsets and plotted the diagonals Only minimal tweaking required to the body plan, that did not disturb waterlines. Looked really good, so decided to have some fun and plot the diagonals on the profile plan. These are the French 'lisses' which are the batten positions according to the documentation of the design "devis".

 

These look very good as well. Mr Mark-1 eyeball is pleased. Everything from VIII-a to VII-f is smooth and uniform. From VII-a, VIII-a to the fashion, things diverge, but I look at the lines between VII-a and l'estain, and I can see the curve velocity and convexity change such that I can visualize the complex curvature of the stern, just from the lines on the profile.

 

Howard Chapelle, Merritt Edson, Jr. The yard dogs vade mecum. Woof !! Woof, woof, woof !!

 

John

 

post-1377-0-01066300-1469031589_thumb.jpg

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