Scratch Building a small NSWGR Trestle Bridge

Discussion in 'Specifically for scratch builds' started by Gary, Jan 26, 2018.

  1. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    Another project for my NSWGR exhibition plank is a small trestle bridge which crosses the creek. Again, this was constructed from balsa wood and some small diameter dowel.

    A few lengths of stick tape was wrapped around an old piece of track with the sticky side out. This allowed me to align the bearers of the bridge, with the outer bearers directly under the rail. I then glued individual sleepers to this. The bearers are 3mm square balsa and the sleepers were sliced from a sheet of 1mm balsa approximately 3mm wide and cut wider than the standard Peco sleeper.

    [​IMG]

    Next up was to cut and glue the corbels, once the sleepers and bearers were cured.

    [​IMG]

    Piles were made from some 4mm diameter dowel that I found in my scratch building box of tricks. The tops of the four outer piles were notched out to fit around the corbels and bearers.

    [​IMG]

    These were let to cure whilst I cut some 1mm balsa sheet to form the retaining walls. The tops of the walls project 3 scale feet (10.5mm) out from the edge of the sleepers. The angle of the returns were cut and the sheet was scribed at 6" intervals. The two walls were glued to the piles.

    [​IMG]

    Looking from above.

    [​IMG]

    Next up was to cap the wall tops and add posts to the face of the wall. Left over sleepers were used for this purpose. Also two headstocks were added to the piles under the corbels.

    [​IMG]

    A close up view of the walls, posts, piles, headstock, corbels, bearers and sleepers.

    [​IMG]

    The whole model will be given a wash or paint to complete before installing on the layout. The sleepers that are currently fixed to the Peco track will be removed and the trestle will be glued directly to the base of the rail..
    Now, I need to make some chairs for that authentic look... :scratchchin:

    Cheers, Gary.
     
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  2. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    I have given the bridge a wash of thinned down black and also added chairs/sole plates to the sleepers. The chairs were made from some 2mm x 0.25mm styrene strip, cut to 5mm lengths. These were glued to the sleepers and then painted.

    [​IMG]

    [​IMG]

    They don't look too bad considering and will look better once the bridge is installed on the layout.

    Cheers, Gary.
     
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  3. Vinylelpea

    Vinylelpea Full Member

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    Thanks for going to the trouble of showing and explaining the steps involved in the build. Much appreciated.

    Phil 🤓
     
  4. Dr Tony

    Dr Tony Full Member

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    Some might say that those posts are not upright...
    Well after surveying many of those sort of structures around here on the railways, it's pretty rare to get anything dead vertical.
    I do have a few scans of that sort of bridge hiding about the place, maybe not that small though, maybe a little bigger.
    Cheers
    Tony
     
  5. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    No worries Phil, that's what P1MRC is all about ! :thumbs:

    You're right Tony, they are not vertical. Apart from the centre pile, the others were always at slight angles to spread the weight. These bridges were constructed similar to the timber trestle road bridges.

    This is taken from a Data Sheet...

    [​IMG]

    Cheers, Gary.
     
  6. Ron

    Ron Full Member

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    No Scalescenes brick paper in sight, so I can rest easy, :avatar::avatar:
     
  7. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    True Ron, but this isn't for the competition... ;)

    Cheers, gary.
     
  8. Charost

    Charost Guest

    :thumbs: :thumbs: :thumbs: A very interesting and helpful topic. Thanks.
     
  9. Matt

    Matt Full Member

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    Looking good Gary! When will you install the track?
     
  10. Toto

    Toto I'm best ignored Staff Member Founder Administrator

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    Nicely done Gary. Very rustic.

    Toto
     

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