What size radius...

Discussion in 'N / Z Scale Model Trains' started by nolatron, Jan 17, 2005.

  1. nolatron

    nolatron Member

    hi all,

    Got a quick question.

    On the n-scale (code 80) layout I built I used mainly 9 in radius turns on it. I noticed with this one kato loco I have, a SD90 (6 wheel trucks), it throws any stock cars attached to it off the track because of the tight turns (oops.) My atlas (4 wheel) have no problems.

    So, I'm already starting to brainstorm a new layout before this one is even done for the future, and curious what's the recommended turn radius for large locos like this? I know bigger is always better, but what would oyu say is the minimum you could use and still make a turn safely (mainyl for space reasons).

    I love the Kato line and would like to use many more 6wheeled locos next time.

  2. LIRR

    LIRR Member

    11'' is the bare minimum for those big N scale locos, If you can go 19'' it would take care of any unslightly overhang.
  3. sams

    sams Member

    if you're gonna stick with atlas c80 sectional...
    ditto what LIRR said...
    11" min., 19" preferable...
    on the other hand....if you decide to go with other types of track or flex-track, try to keep your radii above 15-16" if you plan to use really large loco's and cars and don't want that unsightly overhang.
  4. nolatron

    nolatron Member

    thanks for info. I'll probably switch to Atlas 55 or Peco 55 (for their large selection of turnouts) for the next layout. Probably won't happen for a long time but always good to start planning ahead to avoid mistakes like this one :)
  5. brakie

    brakie Active Member

    Shaun,N Scale like any scale one should use the largest radius curves possible for better and smoother operation.Also a easement into a curve helps our locomotives and cars enter a curve without a sudden turn while entering the curve.
  6. nolatron

    nolatron Member

    stupid question: what do you mean by easement? Angling the track a little going into a curve? (ie: like a race track turn)
  7. LIRR

    LIRR Member

    Now that i've answered a question I have to ask you more experianced types, I designed my little brothers future layout using 11'' sectional because of space woes, also the turnouts are #4s would his horizon fleet amtrack coaches and his Dash-9's make it through these turnouts? If so the crossovers are for show and the GP-20 will be the only one allowed in sidings and yards (That was the plan anyway but...)
  8. LIRR

    LIRR Member

    Nol, an easement is starting the curve with say, a 19'' curve peice and "easing" into 11'' or something along those lines. Its less intensive on the poor SD90's trucks.
  9. nolatron

    nolatron Member

    Ah, makes sense. Thanks.
  10. Matthyro

    Matthyro Will always be re-membered

    Nolatron, remember here there is no such thing as a stupid question. We all have something to learn. Regarding easement, it is like you say, a gradual increase in radius until it reaches the set radius. This allows locos and cars to get ready for the curve and is easier on the couplers. Makes the trains look more realistic too going into and out of the curve. The easement doesn't have to be much to be effective.
    LIRR your question about #4 turnouts. Most equipment I know of will take #4s if speed is kept low. Of course going straight through doesn't require any slowdown. Some locos like a ten wheeler may find it physically impossible to take the curve but I haven't tried that myself so others may be able to tell you of their experinces.
  11. sschaer

    sschaer Member

    as big as possible ! with locos like sd90 i'd recommend 18" as a minimum. tightest curves on my current layout are 15". no reliable operation with long trains. next layout will have at least 30" minimum
  12. Will_annand

    Will_annand Active Member

    30" in N Scale Might be overkill. I would say 19" R minimum.

    Although on my layout it is 11" radius, but I am in 1880-1900 the biggest steamer I will have will be a 2-8-0 and the longest car a 50'
  13. sschaer

    sschaer Member


    i intend to run full-size trains (100 cars and up). 30" radius will definitely help to have reliable operations
  14. Will_annand

    Will_annand Active Member

    100 cars and up. :eek: I hope the couplers will hold. :thumb:

    In my era a full sized train is about 10 cars. :D

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