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Does anyone know if a composite hull such as Cutty Sark would have had has ever been modeled? Plank on frame of a composite clipper would involve much more skill I would assume. Has anyone seen a source for model sized angle steel that could be used to do this? How would one go about it? Enquiring minds just want to know. Maybe once Ed finishes his Young America.....  ;)

 

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I've thought of this quite a bit as I build in brass a lot for people wanting RR models. [ www.vonstetinaartworks.com , or on U-Tube also.] The problem is with mechanicly fastening the planking to the frame, glue is not enough, although epoxy might hold up archivaly, MIGHT. [i think the US Navy model program accepts it.] Each bolt or rivet would need to be soldered, or the frame threaded with a tap so small and expensive it would blow your mind. Then they need to be covered with a plug as they don't show anyways. The angles are available in brass from Scale Shapes. You would probably be spending thousands of $ on brass. Also you could use "Z" angles rather than joint the 2 apposing angles. Or you could mill them yourself. Have at my friend, and let us all know! It would be interesting.

 

Von Stetina

 

Build log Extreme Clipper LIGHTNING 1/96

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Hello Sailor, 

 

While building a cross section of a composite at a bigger scale to demonstrate the technique would be both feasable and interesting, I believe doing a model of an entire ship in composite build largely exceeds the possibilities of an average modeller. Also, it is worth saying I would not believe such an extreme approach would actually "pay off" in modeller terms.

 

You also have to know that composite built is a bit more complex than just putting a layer of wooden strakes over a structure of iron frames. What you miss from the picture is the strong electrolytic reaction which occurs between iron and English oak in presence of salt water.

 

Therefore, I don't know exactly how was Cutty Sark made but I have found the original papers of the training ship Mircea in the Romanian Archives and I can tell you how was this ship made. The builder was Thames Iron Works at Orchard Yard, Blackwall, which is east of London on the Thames and the year was 1882. Just to make yourself an idea, they first make the frames using iron angles, then they do the inner layer of planks which are bolted with iron bolts to the frames; the bolts are driven from outside with heads placed in recesses made into the wood and the nuts are put inside.  Then they do the outer layer of planks over it which are fixed on the first layer with copper clench bolts. The inner layer of planks is teak, the outer canadian rock elm or english oak, and great care is taken that no iron piece ever touches the oak. If there is no other possibility, they put a plank of teak between them to protect the iron. All the iron work is protected with red lead and between the first and the second layer of planking they may have put a continuous layer of tarred horse hair tissue.

 

Now, do you really believe a modeller could do all this stuff to his scale model without getting crazy? :D

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This would be a very interesting project, but would presuppose a fine skill in miniature metal working, as building a metal frame at model scale would be a major undertaking - although having said that, I'm aware of a model tea clipper built at a scale of 1:48 entirely from tinplate salvaged from used food cans.

 

Most composite ships were built with a single layer of planking and, given the skills to build the metal frame, the next problem (as has already been raised) would be securely fixing the planks.  It may be possible to drive headed pins through from the inside of the hull or, failing that, then fixing the planks with epoxy and then drilling through both plank and frame to insert pins, bolts or rivets.

 

If the challenges mentioned above can be satisfactorily resolved (and I'm sure that they can, given a little thought and experiment), then the next question would be why build a composite model at all.  The amount of work involved in such a project - far more than would be required of a model such as Ed's 'Young America'- would only be really justified if a cutaway model was planned.

 

I'll be interested to hear any further thoughts that you have on such a project.

 

John

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I have absolutely no intention of ever building such a model. I agree it would only make sense if one were to display the insides of the ship. I was simply raising it as an interesting discussion point. FYI Cutty Sark's hull was built of teak. ALL teak. Her frames were iron of course but all of her single thickness of planking was teak. Her keel was American Rock Elm. (Replaced in part under the Portuguese as recent research has shown us).  I understand about galvanic action and the corrosive action of a metal ship in seawater.  I do however think the composite hull an incredibly ingenious use of the materials available to the shipbuilder of the time. A bending of the material to the builder's mind in that he thought outside the box in order to overcome a set of problems. In great engineering fashion, he came up with a solution that works.

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Working in some stuff in homeyard, I realised that during welding some simply  metal construction, it warms and because heat rises and re-raises. To weld can anyone (even me) ,  but to put right dimensions of the parts of the metal structure to  fit with heated parts - it can be done only by master. In opposite, you will probably have curves or holes instead straight lines. Now, imagine the same thing in proportion 1:100. In my opinion, impossible mission. And what will be point of this, if it will not be accurate 1.000.000 % ?

 

Maybe folks who make jewelry can be able to do that. And a half life time to do this work. Only reasonable point could be - half opened model with some lights inside ( in CS there are no gun ports  in twin deck for light entrance). I have not hear that anybody make CS on that way. To be clear what was done, I think minimum scale must be 1:50 or greater. And that will be model about 2m long, 1m tall. And if you put sails on, imagine how large must be aquarium to keep model. 

 

With my scale ( 1:96 I think) I can even now smell problems with Admiral where to keep it one day when She will be launched out od shipyard. And a model 2-3m long ? Separate house for it

Edited by Nenad M
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The iron frames etc. were not rolled, to my knowledge, but bent red-hot to shape on a special cast-iron plate. This plate had square holes in a regular pattern into which stops or dogs could be set. These dogs followed the shape as lofted. The iron profile is being forced against the dogs using levers and tackles. It is secured with more dogs and wedges until it has cooled down.

 

As steel would loose its properties when heated to a red, this technique can only be used on wrought iron and is not used anymore in modern times.

 

wefalck

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Actually, I think you'll find that bending slabs were used until relatively recently, and certainly in the construction of frames in steel ships.

 

There was a bending slab still in situ in the frame shop at Cockatoo Island Dockyard in Sydney definitely in the early 1960's - although not then used.  If I remember rightly, I was told that it had been in use at least up until the 2nd World War.  H.J Pursey's 'Merchant Ship Construction', which was first published in 1942, showed a bending slab as the standard method of frame bending.  I recall that Pursey was considered a little old fashioned in his outlook, however bending slabs were recent enough standard practice in 1942 to be included in his book, which was a standard text.

 

The first illustration shows the frame bending slab still in place in the smithy's shop at Chatham Historic Dockyard in England

post-5-0-08148800-1387753341_thumb.jpg

 

The second illustration is the drawing of a bending slab from Pursey's 'Merchant Ship Construction.

post-5-0-66010300-1387753403_thumb.jpg

 

John

 

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I forgot that I had taken pictures of that in Chatham too … in the background you can see the furnace in which the bars were heated. The rails around the slab are a concession to modern visitors' safety requirements. If I remember right, the bars were pulled out of the furnace using tongs suspended from overhead rails and gantry cranes.

 

wefalck

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Hi guys, Bending the brass angle is not too bad if you get a feel for it. It tries to peak up, so to speak, and you need to sort of massage it back flat. The bevel could be put in with the frame in place fitting it to ribbands. The whole frame would actually be doable, but the cost would amaze you. Milling your own angle would be a big job if you wanted to. The modelling methods don't correlate with full size building methods.

 

I can't imaging doing the fasting of the planks, though I do know how. I dislike treenailing as it is. To do it I would need to be paid handsomely as I would need to survive the boredom Har Har! And I would have to bank on finishing it all before heading to the great beyond! I would hate to hide much of the frame after all that labor, I guess that would help with the plank fastening some. Thinking about the cost of all of that the angle though, Phew! Check this out at the Special Shapes website. Maybe I could find a wealthy benefactor!

 

I would suggest doing just an area on one side open to show the frame, doing the rest in wood with some easy method.

 

I have a model with bent angle on it on my website and U Tube site. It's the Fairbanks Morse cinder conveyor in brass.

 

Von Stetina

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