Mock-up of my curved viaduct

Discussion in 'Scratchin' & Bashin'' started by Biased turkey, Dec 9, 2006.

  1. Biased turkey

    Biased turkey Active Member

    I have a 25" by 36 " layout, there is no way to fit just 1 single Atlas straight track. So I have no other choice than to build a curved viaduct.
    How do I go from the mock-up to a real curved styrene stone viaduct ?
    Tia for any suggestion.
  2. Jim Krause

    Jim Krause Active Member

    You have a great start. Use your mock up and refine the pattern. I believe you can get stone patterned styrene sheets. Cut your styrene sheets for the exterior and use the mock up for a pattern. I would suggest some wood or other material as sub structure to give your viaduct strength.
    If you have a bandsaw or sabre saw you can cut the sub structrure from one piece of wood and cover it with the styrene. Other folks will have other ideas
  3. doctorwayne

    doctorwayne Active Member

    As Jim notes, you have a good start with your mock-up. I'd use styrene to build the finished model, .060" sheet for the sides and the deck, and .030" for the underside of the arches. One thing that I would change would be to extend the sides up about 2' higher than the deck, making sure that your longest cars will still clear it, particularily on the inside of the curve. That will allow you to ballast the deck, which was the usual practice with this type of bridge. To add some character, laminate two 2' high strips of .060" to the inside (track side) of each extension, and a 3' or 4' high strip to the outside top edge, then make a cap for both of these side walls out of more .060" sheet.
    To construct the arches, after you have cut the outside faces of the bridge, you'll need to provide some solid support for attaching the .030" material in place. Scraps of the .060" will work fine for that: simply cement them to the backside of the bridge sides, but set-back .030" from the edge. That way, the upper (unseen) edges of the .030" material will be glued to the edges of the .060" scraps, and the edges of the .030" styrene will be cemented to the back faces of the bridge sides. When the glue has dried completely, use a file or some sandpaper to smooth the joints.
    You could sand the entire bridge with a medium sandpaper, then paint it a suitable concrete colour and be done. Or, if you want a stone finish, you could scribe the styrene, before assembling the components, to represent cut stone. To widen the grooves, use a pair of pliers to snap the tip off an old X-Acto #11 blade, then drag the backside of the blade through the scribed lines.
    There are also many commercial "stone" sheets available. If you can find them in styrene, use the same cement to laminate them to the bridge as you used to construct the bridge. (I use lacquer thinner as styrene cement: cheap, and fast drying.) If the stone material is a different kind of plastic, such as ABS or vinyl, contact cement will work well, and is also useful for heavy embossed paper "stone" sheets.
    By the way, always nice to see another TH&B modeller. :thumb:


  4. Biased turkey

    Biased turkey Active Member

    Thanks to both of you for the encouragement.

    To Jim Krause: I don,t have the tools to cut the substructure from 1 piece. so I,ll have to go the "doctorwayne" way.

    To doctorwayne: When you say:
    "To add some character, laminate two 2' high strips of .060" to the inside (track side) of each extension, and a 3' or 4' high strip to the outside top edge, then make a cap for both of these side walls out of more .060" sheet."
    Is it to make the viaduct looks like the one ( from Kibri ) on the pic ?

    The 2nd pic is one from a real stone viaduct on the transiberian line.
    That russian link has a carload of viaducts:

    I'm fedup of seeing only N scale CP and CN locos and rolling stock in the hobby stores around Montreal, so that's why I decided to model the TH&B. Plus, their paint scheme looks good.
    Great pics ( as usual ) . Are those GP7 ?

  5. doctorwayne

    doctorwayne Active Member

    I was just thinking that a bit of three-dimensional detail would enhance the appearance of the finished product. The retaining walls, in the background of the picture below, are .060 sheet, with some extra strips laminated on to add a bit of "character", and to "bulk up" the top edge, which is visible from some viewing angles.


    Laminating on those extra strips will give your structure a more prototypical thickness, as stone structures are usually quite substantial, too.

    Thanks, B.T. Being originally from Hamilton, the TH&B is my home-town road and favourite prototype. The 403 is a GP-9, while number 76 is a GP-7. Both are modified and remotored Athearns, in HO scale, and were featured in Model Railroader's Paint Shop back in February, 1979. I shot a whole roll of b&w film on the two prototypes, to aid in detailing, and had quite a few colour photos already, to help with paint info. Mine are brush-painted with custom-mixed Polly-S paint, with dry transfer letters from C-D-S alphabet sets used as paint masks for the lettering. The heralds on the cabs were hand-painted, as none the right size or colour were available at the time.

  6. Biased turkey

    Biased turkey Active Member

    Doctorwayne: The pics of that retaining wall explains clearly what you mean by "enhance the appearance of the finished product".

    1 thing is sure: my next N scale locomotive will be the Atlas GP7 TH&B
  7. Jim Krause

    Jim Krause Active Member

    Go with what is easiest. I tend to think that everybody has shop tools, which is not the case for many folks. The styrene structure will give you a lot of strength if you do a bit of engineering, See, you're learning new skills as you go. That's half the fun of model railroading. Jim Krause
  8. hiscopilot

    hiscopilot Member

    i am glad I found this thread as I will be making a curved viaduct in my layout and this gives me more than a headstart with ideas!

    thanks guys for posting pics and explaining also/
  9. Biased turkey

    Biased turkey Active Member

    OOps, sorry people, I realize that I cleared all my uploaded pictures, included to mockup of the curved viaduct.
    I'll fix that tonight .

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