Please Help a Newbie

Discussion in 'Scratchin' & Bashin'' started by only15, Jul 17, 2008.

  1. only15

    only15 PRO:Pain In The Behind

    Hi all,
    I am looking at scratchbuilding my first locomotive from my local prototype - The 3'6" Tasmanian Rail network (Tasmania is the southern most state Australia!). I build in OO or 4mm to the foot or 1:76 (more info on the prototype can be found at

    I have a Diagram/outline drawing of the locomotive and want to scale to the gauge i am working in.

    Can anyone please help me?

  2. TinGoat

    TinGoat Ignorant know it all

    Newby Help

    Hi Nathan,

    I'd like to help you out...

    For 3'6" gauge you might be better off in S-Scale. 1:64 / 3/16" to the foot.

    Known as Sn42 or Sn3.5.

    That way, you can use RTR HO/OO track and mechanisms and scratch/bash the superstructure to fit.

    It would be easier and cheaper than HOn42 using TT scale track and mechanisms.

    Here's a list of Scale / Gauge combinations for modelling 3' 6" gauge from New Zealand Model Railway Guild:

    Scale Gauge Name Identity

    9 mm. 32mm 'O'gauge NZ34

    1:64 16.5mm Sn3.5 NZ64

    1:87 12mm HOn3.5 NZ87

    1:120 9mm TT3.5 NZ120

    OO [4mm] scale really isn't used for modelling 3' 6" gauge.

    Oops, I stand corrected, OO [4mm] scale is used, but on 16.5mm gauge track, you are looking at just over 4 scale feet, instead of 3.5 feet....

    Modelling the Railways of Tasmania

    Personlly, I'd go with Sn42...
  3. cidchase

    cidchase Active Member

    Hi Nathan, if you want to stay with 4mm how do you feel about hand-laying the track, 14mm gauge? That way you also get the ties and tie spacing you want.
  4. only15

    only15 PRO:Pain In The Behind

    i have picked OO for the same reason as it was picked by the people who built some of the layouts featured in that site, readily avaliable bogies, couplers, mechanisms, track
    all i want to know is how to scale down a diagram i have...........

    Can anyone please help me with this process?

  5. cidchase

    cidchase Active Member

    Take any dimension you have for the prototype, and divide it by 76.

    If you have a dimension on the diagram of, say, 2.50m, then in OO
    the length would be 33mm (2500/76).

    If you have a dimension on the diagram of 10'-4", (124"), then in OO
    it would scale to 1.63" (124/76)

    If your drawing or diagram does not have dimensions but you know it is a definite scale, then you can use that also. You would measure the drawing, multiply by the known scale to get the prototype dimension, then divide by 76.
  6. Squidbait

    Squidbait Recovering ALCO-holic

    If you've got plans drawn at one scale, and you want to re-size them to another, you can use the zoom/reduction feature on a photocopier. This site has a table that gives the zoom factor needed to change from one scale to another, and tips on multiple-step enlargements/reductions.
  7. only15

    only15 PRO:Pain In The Behind

    Thanks Guys,
    cidchase, that is exactly what i was after,

    Thankyou so much,

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