The more I learn the more I don't know.

Discussion in 'G / O / S Scale Model Trains' started by raybanduchi, Dec 13, 2006.

  1. raybanduchi

    raybanduchi New Member

    You guys have been great and patient and I appreciate it, but I just saw something about codes in O trax. It seems like they were 100 and 128 or 142 or someting like that there. What's that all about?
    Is it important?
  2. pgandw

    pgandw Active Member

    There are 2 sets of numbers used with O track. The key number for the 3 rail O users is the circle diameter - usually expressed in inches as something like 027, 031, 036, 042, 054, 072.

    The other number, the rail code, is the same as in HO or N. It is the height of the rail in thousandths of inches. Code 100 rail is 0.100 inches high, code 83 is 0.083 inches high. In scale O (2 rail) common rail sizes range from code 148 downwards. Code 148 rail represents 132 lb rail in O, just like code 83 represents it in HO. Commonly used rail sizes in scale O include code 148, 125, 100, and 83. By the way, scale O and smaller scales refer to curve radius, not diameter (just to confuse us all)

    The 3 rail O guys generally need code 215, 225, or 250 rail to provide enough clearance for their much deeper flanges. Of course, a lot of 3 rail O track does not have anything like a prototypical cross section, but neither does the smallest rail, the code 20 and 30 used by some N and Z guys.

    hope this makes a little sense
  3. Cannonball

    Cannonball More Trains Than Brains

    Holy carpe' diem!
    I never realized track was so varied.
  4. Gil Finn

    Gil Finn Active Member

    Not even I knew that about codes. When I run into differmt rail hieghts in HO, I just file them down for a smooth rail joint.
    In the future I will match them up better, thanks for all that info.
  5. fsm1000

    fsm1000 Member

    For instance. I use code 83 when I handlay my track because I also model narrow gauge and old steam so it looks more real because it is a 'lighter' rail commonly used then.

    Hope that helps:)
  6. Jim Krause

    Jim Krause Active Member

    Gil: There are rail joiners and transition rail sections that will take care of that mismatch for you. The real prototype railroads even use transition rail sections between mainline and sidings or whereever they need to change rail sizes. Theirs are tapered.

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