I am going to use the flex track. I played around with it last night and that
seems to be the way to go. The entrance to the yard will be off a curve. I am
going to Fredericksburg, va for a few days, so I will work on it when I get
back. Will also be visiting "Granddads Hobby" shop in springfield and pick up
more switches and flex track. I am adding three more turnouts.
Take a look at the NMRA standards for turnouts at
You need to deal with two issues - what radius curve to use and how many
degrees of arc of the curve are needed.
If you're using #4 turnouts, NMRA dimension #11 says the radius of the
curved diverging rails is 15", so you might think that using 15" radius
curves with these turnouts in a ladder would be no worse. But since the
length of the curved rails in the turnout is short, and is ameliorated by
the broad 43" radius (NMRA dimension #6) of the points and the straight rail
through the frog, the effective radius of the turnout is more broad, so I'd
suggest using 18" radius Atlas track. NMRA dimension #18 says the angle of
the #4 turnout is 14.25 degrees. Thus you need this much arc in the
diverging route to get the track back to parallel with the tangent route
through the turnout. This is about 15 degrees, which would be a 1/2 section
of 18" radius track (with 12 sections to a 360 degree circle, so each
standard 18" curve has an arc of 30 degrees). (But note this is all a
little off, as Atlas #4 turnouts are actually about #4.5).
If you're using #6 turnouts, the NMRA dimensions say the tightest radius in
the turnout is 43", and the effective radius with the straight frog is even
more broad, so using Atlas 22" radius Snap Track is undoing any advantage
from the broad turnouts. As another poster commented, you'd be best off
using flex track. If you do choose to use 22" radius Snap Track, NMRA
dimension #18 says you need about 9.5 degrees of arc. Atlas 22" radius
track uses 16 sections to a circle, so each section is 22.5 degrees of arc.
This then says you need to use a special cut section a bit less than half a
regular section of 22" radius track.
Since almost no one wants the limitations of a 15" minimum radius curve
layout from #4 turnouts, and since 43" radius is so generous and yard
ladders made of #6 turnouts use so much real estate (yard length, or
shortened yard tracks), I suggest you look at using Walthers/Shinohara #5
turnouts in your yard as an excellent compromise for smooth operation in a
reasonable space. Geezer
The problem/challange in model rail road yards is to get enough yard
track into the never-big-enough space available. You want long sidings,
and many of them to allow you to break up a long freight train and sort
the cars out be destination. For instance your "Hotshot
Transcontinental" with 50 cars pulls into the yard. You want to break
it up and set the cars going to Manchester on one track, the cars going
to Concord on another track, the cars for Bellows Falls and
Mechanicsburg and Ipswitch all deserve their own sidings, so they can go
out as peddler freights later on. We are splitting up 100 cars five
ways, so each siding wants to hold at least 10 cars. Plus, rolling
stock expands to fill available track, so anyway you play it, you want
as much yard track as you can squeeze in.
The sharper a turnout you can use, the more trackage you can squeeze
in. Freight cars are (mostly) shorter than passenger cars and will take
a #4 turnout, no problem. If you are using Snap-Track, the traditional
Snaptrack turnouts are equivanent to an 18" carve track section married
into a straight section. These are slightly different from true #4 and
#6 turnouts where the diverging track is STRAIGHT. Your layout design
program ought to understand the difference between the two turnout styles.
Was it me, I'd go with the sharpest possible turnout to save space.
I'd think about modeling the transition era (1950's) so I can keep my
freight cars down to 40 footers, and use a small switch engine, maybe
even an 0-4-0 steamer to handle the sharp curves. I'd allow for
uncoupling magnets on each siding. I'd allow finger clearance between
sidings to handle derailments. I'd want LED's to indicate turnout
positions to prevent confused engineers from running thru turnouts set
against them. I'd avoid any S bends. I'd want the yard lead to be
straight, no curves 'cause the yard moves are backing moves that are
more likely to derail than forward moves. I'd want toggle switches to
turn off the track power on each yard siding so I could leave
locomotives on them. I'd want to be able to reach the last and farthest
sideing in case of derailments.
Try not using a curved section. If you can squeeze in a parallelogram
shaped yard then you can run onto the diverging track and run straight
to the exit turnout.
As others have posted, available space will probably drive your design
more than anything else.
The lotto must be rigged, I should have won by now.
Modular furniture is cruel and unusual.
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