Triple track curved bridge: N scale

videobruce May 26, 2012

  1. videobruce

    videobruce TrainBoard Member

    324
    8
    14
    Here are some more pics from different angles. These were taken earlier before any track was permanently laid.
    long bridge span wide.JPG long bridge small 03.JPG long bridge small 04.JPG
     
  2. randgust

    randgust TrainBoard Member

    3,496
    504
    55
    Before anybody else catches me on this one....particularly with my ATSF herald on, I found a picture of a CURVED THROUGH TRUSS although it is only one track. It is on the west end of the original Mississippi bridge of the Santa Fe at Ft. Madison. That span has been replaced with deck girders, but sure enough, there's older shots of the previous bridge, and there is a through truss with a curve right in the middle of it.

    http://www.kansasmemory.org/item/220364

    I have the "Bridges" book on the Santa Fe, and it has the trackside angle shooting through those through trusses. It 'looks like' a wide double-track truss with just one track in it. The other incredible thing, of course, is that it was a dual-use road and railroad bridge on the same deck at this point.

    So while I'll still stand on the 'I've never seen one in the field' I'll hold this up as at least one example that they existed. As far as for multiple track???
     
  3. Pete Nolan

    Pete Nolan TrainBoard Supporter

    10,582
    180
    122
    Randy,

    Straight bridges slightly offset? I'll bet the slight curve was centered on the piling between span one and span two. Trusses are not designed for sideways forces. I wonder what the speed limit was on that bridge--perhaps 5 mph, or less?
     
  4. OC Engineer JD

    OC Engineer JD Staff Member TrainBoard Supporter

    12,745
    645
    145
    Go to Google Maps, and put in Massillon, OH. I think you will find what you are looking for there. I used to run over this bridge when I worked the passenger train and special locomotive moves on the OC. :)
     
  5. thefullgonzo

    thefullgonzo TrainBoard Supporter

    59
    0
    8
    What about a "concrete" bridge almost like an overpass on a highway. Make a form out of Formica or ?? use casting plaster, with some black paint in it to represent concrete? Curve it to match you track. You would have to put something in it for strength, like rebar in normal concrete...It probably wouldn't be prototypical....
     
  6. upguy

    upguy TrainBoard Member

    406
    23
    20
    Not sure if this will help in your situation, but I used two side girders from an Atlas HO bridge that I had to cover the plywood base on my modules. They were originally built as HO modules with 2 tracks, but I converted them to 3 track N scale modules and left the bridge as it was. The track still needs to be ballasted, but you can get the idea.
     

    Attached Files:

  7. randgust

    randgust TrainBoard Member

    3,496
    504
    55
    Pete, see your email. I can't find that picture to post and it is from a book.

    But it is 'game over' with that tip from Jerry..... holy %$##!

    http://www.flickr.com/photos/blueanalog/5951382787/

    And... I had to go in an measure it...that's 3 200' spans.

    See, this is how it is done. If you really want a photo of something, it's pretty simple. State categorically and unequivically, in a forum, that such a situation never existed. Irrefutable documentation will magically appear. It's like Newton's Fifth Law of Gravity. I've learned to leave an escape hatch....

    I haven't even tried to research it, but I'd almost bet that was done by PRR. If there was any railroad that felt confident enough in repealing laws of design and physics, it was them. The bridge local to me is every bit as odd; a curved through girder, 2-track multiple span, with a girder in the center. Probably the same design team.
     
  8. videobruce

    videobruce TrainBoard Member

    324
    8
    14
    How about that, someone that understand multiple trackage.
    That is about the length of the shorter of the two spans.

    I have some of those CV plater girders ordered and will post back when I custom 'bash' one together.
     
  9. videobruce

    videobruce TrainBoard Member

    324
    8
    14
    Ok, here is what I hope is the finished product. I used CV HO scale plate girders (per recommendation), trimmed to length. I also bought some of their trusses for the offset middle support on the longer bridge.

    I plan on getting those stone plastic 'panels' (assuming I can find what I like) for the 'walls' of the abutments to attach to the foamboard under each side of the spans. The clearance is somewhat excessive, as I seem to have a bad habit of going overboard on clearance as I did on my first layout. I decided to use 3/16" clear Plexi instead of that black, thinner ABS plastic for strength, but mostly so I could attach those plates to the side of the base. I also added strips of ABS that I cut for additional surface area to glue along the inside of the bridge for those plates. Those will be covered with ballast.
    I also sliced the foamboard so the surface of the bridge base is level with the rest of the layouts foamboard and will use cork roadbed across the spans covered with ballast so no one will see the clear Plexi.

    long bridge w support small 01.JPG long bridge w support small 02.JPG
     
  10. Pete Nolan

    Pete Nolan TrainBoard Supporter

    10,582
    180
    122
    Ditto! There is some rather massive bracing visible, but--well--I hereby state the Higgs boson does not exist!
     
  11. randgust

    randgust TrainBoard Member

    3,496
    504
    55
    Nonsense! David Smith uses Higgs Boson to power his Z-scale barber poles, and I loaded my speeder dog team with them as well as a power source. Completely practical in both N and Z. It's the design essence of T scale as well.
     
  12. Pete Nolan

    Pete Nolan TrainBoard Supporter

    10,582
    180
    122
    LOL!

    From Google satellite view, it looks like three skewed straight segments. The view is distorted: the middle of the bridge is offset, and the ends look like something out of Escher. But the bridge deck appears curved. Might just be worth the 4-hour one-way trip for me to check it out.
     

Share This Page