Classification yard dimensions

[sailor38]

I am planning to add an Ell to my 4X8 layout for a yard. I will be using Atlas #4 Snap Switches for the turnouts. I know the length of the straight section is nine inches; but, since they will all be running at an angle, how much width will I need for four turnouts on the ladder track? (The last track will simply be a curve off the last turnout.) I have some latitude on width except that it will be a duckunder. No, I didn't have any geometry in school, heh heh. Also, do the higher number turnouts have the same length of straight and what advantage would there be to using them? You folks are always wonderful with your knowledge and experience, so thank you in advance for all your help![:D]

[Anonymous]

Higher number turnouts are longer, because the number is actually a ratio of how far apart the tracks diverge over how many inches. So a #4 is 1" divergence over 4" of travel, while a #6 is 1" over 6" of travel. Higher numbers are better for mainlines or for longer equipment like passenger cars -- the transition to the diverging track is smoother. For a freight yard, #4s are fine, since your trains won't be traveling over them very fast anyway.

Not sure about the "snap switches", but the regular Atlas #4 switchs put the tracks just about 2" from center to center. So a 4-switch ladder will be about 7-8" wide.

[Anonymous]

So, what is the current thinking on track spacing for yard ladders? I looked up the NMRA standards for spacing. On a tangent, I believe it was 1-13/16". I remember reading that you want to space your yard tracks a bit wider for access. What is the typical spacing for model railroad yards?

[DigitalGriffin]

QUOTE: Originally posted by sailor38

I am planning to add an Ell to my 4X8 layout for a yard. I will be using Atlas #4 Snap Switches for the turnouts. I know the length of the straight section is nine inches; but, since they will all be running at an angle, how much width will I need for four turnouts on the ladder track?[:D]

okay a curve on a #4 turnout is the same as a regular R18 section of track. Each section/turnout is 30 degrees, about 9.4" measured across the arc, and 9.317" inches with the chord. So you have 120 degrees of a R18 track.

The arc on a 120 is 37.7". The chord that cuts across the arc is 31.18". With an angle of 60 degrees, this makes 15.59" right, and 27" up from your start position. (Providing the ladder started horizontal to the right and is in a pinwheel formation.)

If you do a straight "traditional" ladder, the 3, 9" sections will be 13.5" high, and 23.38" to the right from the end of the 1st turnout track.

~Don

[MisterBeasley]

I have some old "3-way" turnouts that I plan to use for my yard. They are about the same as #6 turnouts, but they've put 2 turnouts (a left and a right) on a single base, spaced only a couple of inches apart. This is a real space-saver. Atlas does not make these, but they are fully compatable.

[Anonymous]

QUOTE: Originally posted by TopekaRailfan

So, what is the current thinking on track spacing for yard ladders? I looked up the NMRA standards for spacing. On a tangent, I believe it was 1-13/16". I remember reading that you want to space your yard tracks a bit wider for access. What is the typical spacing for model railroad yards?

Most folks here (including me) use 2" - 2 1/2" center-to-center spacing. Gives you enough room to get your hand in between the tracks to remove cars if necessary, hand-uncouple, or mount and move manual switches. Unless you have really fat fingers, I don't think you need much more than that.[:D]

[IRONROOSTER]

Atlas Snap switches are not the same as Atlas #4 switches. The snap switch has an 18" radius curve for the diverging leg. This type of turnout is not suitable for normal yard tracks because of the curve. Use the Atlas #4 switches for the yard ladders. If your yard will handle long cars use Atlas #6 switches - if you have the room, these look better for any yard. 2" track spacing is usually the norm, but you can go a little narrower or wider if needed. Narrower will require trimming the ends on the Atlas switches, just be careful to leave enough for the points to operate correctly.
Enjoy
Paul

[wcb4soorr]

Sometimes the simplest method is the best method . After designing track arramgements to "Nth" degree on AutoCAD, I buy a few essential components and draw the arrangements out full scale. A cheap way to do this, is save paper grocery bags, cut and tape them to form your full size yard space. Using actual components, lay out your yard. Place several strings of freight cars on the "layout" to get feel for what it looks like. More important, check your clearances for coupling, uncoupling. I model in N-scale. I use dental picks to ucouple my cars. This allows me to keep closer track centers. This works for me. It doesn't work for others. There isn't one foot of my layout that didn't change some what when I went from the AutoCAD design to the track laying stage. I find building a scene to be more art than science. I use the science of design to get me started, but the art is what governs the final placement. If it doesn't look right and feel right, it isn't going to be satisfying in the long run for me.

[dehusman]

Straight track spacing depends on what you want. Prototype track spacing it 13-15 ft center to center. 2 1/2 in spacing is over 18 ft. If you are for prototype appearance you will be going for a narrower spacing. If you have a fiddle yard (a staging yard where you rearrange the cars by hand) then you will want wider spacing so you can reach between the tracks. If you are using snap track you are probably going to be stuck with whatever spacing Atlas or Bachmann has decided on.

Dave H.