Bigger than O27, Fits inside O42

I was going to suggest you might try Marx 034 (identified by its five vs. three ties,

as it has O27 profile, but am not sure what you are doing....

Did this get moved? I distinctly remember posting this to the track layout forum...

To get right down to brass tacks, my inner loop and switching yard suck. Too many crossovers and switches. 27" curves are just too herky-jerky for me now, and the inner loop is just plain too short.

The plan is to tear up everything in the middle and start over, possibly turning it into a grade and elevated section, with wider curves.

I've considered Marx O34 but the problem is going to be finding enough of it.

Track type really doesn't bother me, as I currently have a random mix of O27 tinplate and Fastrack using homemade transition pieces.

I'm just laying down whatever is handy when the mood suits. That's how the center section got the way it is.

Playing with SCARM and doing some measuring on the bench, I can see that it's going to be TIGHT, if not impossible with O36 Fastrack inside O42, but I really don't want to go to O31.

Maybe I'll look into some Gargraves flex track or something.

Matt Kirsch,
   I would stay away from trying to use Ft 036 inside 042 (027 profile).  What does work and work well is the RealTrax 031 inside of the 036 FasTrack, set up correctly the trains look real cook flying past each other in opposite directions.  The draw back is the RealTrax switches, my Tin Plate does not like them very much, so I just use a simple oval of 031 RealTrax inside the FasTrack with my Command Control 072 FT switches.  The 031 RealTrax is kind of tight for some of my larger Tin plate engines & rolling stock, so I run the 2600 series rolling stock along with engine like the 249E or 259E and everything runs perfectly.  The 031 will also accommodate the 263E engine & tender with some of the original rolling stock, Ofcourse you can always use the 048 and larger Ft track instead of the 036.
PCRR/Dave



With the 072 Y CC FasTrack Switches

Other than the fact that it won't fit, any particular reason? Is there an issue with O42?

I really want to stretch the layout out as much as possible and leave the 27" and 31" curves behind as much as possible

Playing with SCARM a little, I think a combination of O31-O36-O36-O31 would narrow the curve enough to squeeze it inside an O42.

Matt:

FasTrack curves measure 36” center rail to center rail but what’s more important in your case since you are trying to put the FasTrack inside the O42 is the OUTSIDE or overall diameter of the FasTrack AND the INSIDE diameter of your Lionel O27 profile O42 curved track. 

The overall diameter of a circle of Lionel FasTrack O36 curves measures 39¼” from the outside edge of the roadbed to the outside edge directly across the circle from it.  But I don’t have any O42 curved track so I don’t know how it’s measured. 

The two different and often confusing traditional methods of identifying 3-rail O gauge curved track are either calling it by its overall diameter or calling it by its center-rail diameter.  As it turns out how it is measured will determine whether or not FasTrack will fit inside of the O42. 

If your O42 curves are measured like tubular Lionel O27 and O track have been measured for decades, then 42” is the approximate OUTSIDE diameter from the outer edge of the track ties across the circle.  But again what’s important in your case is the INSIDE diameter which would then obviously be much less than 42”.  Subtracting the width of the ties (1 15/16") on each end of the circle you get 38 1/8” which is shorter than the outside diameter of the FasTrack so the FasTrack would definitely not fit. 

OTOH if Lionel O27 profile O42 curves are measured like FasTrack O36 or Lionel Super O track is measured, then you’re in luck.  In that case 42” would be the center rail-to-center rail diameter.  To get the inside diameter now you need to subtract the distance from the center rail to the edge of the ties (which is exactly half of the width of a tie) on each end of the circle which gives you 40 1/16”.  So in that case the FasTrack would fit inside the O42 with less than an inch to spare.  With 6” spacing between the center rails that should be more than adequate for clearance of rolling stock between the two tracks.

Can you measure your existing O42 and let us know for future planning purposes?   

Because this type of question comes up often I have been putting together a table of measurements for the various commercially available track types and I don’t have tubular O42 in my table yet.

HTH,

Bill