Minimal Clearance On Rail Interior

[TrainCat2]

All, as most know, I am laying tracks in the street. The cobblestone I will be using can be easily cut & shaped to get a good fit. So the question at hand is what is the minimal clearance on the interior of the rail. I can actually cut within very close tolerances to make the effect realistic. Most of my rolling stock is out of the box 40ft MTL, ATL, BLI & Buford. I have not begun the upgrade process to metal wheel sets. Thanks in advance.

Bob

[CRR Chase]

measure the gauge of your wheel sets, allow for a few hundreths tolerance if in a curve. cut to fit the inside gauge of the wheels you use.. if not, it will ride up when going over the grade.. where the "cobble stones" are

[nickelplate759]

You probably know this already, but the NMRA track & clearance gauge includes a flangeway check at the top of the gauge:

[Point353]

All, as most know, I am laying tracks in the street. The cobblestone I will be using can be easily cut & shaped to get a good fit. So the question at hand is what is the minimal clearance on the interior of the rail. I can actually cut within very close tolerances to make the effect realistic. Most of my rolling stock is out of the box 40ft MTL, ATL, BLI & Buford. I have not begun the upgrade process to metal wheel sets. Thanks in advance.

Bob

If you go by the NMRA standard for the flangeway dimension between a stock rail and a point rail, the minimum clearance is 0.039".

[peteski]

Make sure to place the outer and inner road surface slightly below the railhead, or the track cleaning process will scrape against it, eventually damaging the surface. even 0.010-0.020" should work. Also, N scale wheel treads are wider than the railhead, so if the road surface is even with the railhead the wheels might ride on the road surface, not the rail, causing electrical pickup issues.

[chessie system fan]

Do you plan to run Bachmann steam engines? Those tender wheels are wider than typical and probably should be your benchmark. 

[TrainCat2]

Thanks all. Locos at the moment are ATL and BLI diesels with possibility of a BMann steamer if I get the gumption to get it DCC’ed. I did know about the NRMA gauge, but I was hoping that someone might have pushed the limits a little farther. Even .040 looks like parallel canyons with three tracks in the street.

Pete, we did talk about the street level and cleaning awhile back in my build thread, but thanks for the reminder. My intention is still having the street .010 -.015 below the rail head.

[peteski]

Thanks all. Locos at the moment are ATL and BLI diesels with possibility of a BMann steamer if I get the gumption to get it DCC’ed. I did know about the NRMA gauge, but I was hoping that someone might have pushed the limits a little farther. Even .040 looks like parallel canyons with three tracks in the street.

Pete, we did talk about the street level and cleaning awhile back in my build thread, but thanks for the reminder. My intention is still having the street .010 -.015 below the rail head.

Sure thing.

I suppose that if you know all the wheels you will ever use in that area you could make the width and depth tighter (according to the wheel specs), but remember that even if everything is to NMRA specs, the flanges don't ride directly against the inside of the railheads.  There is some lateral play. That is why the flangeway is as wide as it it.

[Ed Kapuscinski]

Thanks all. Locos at the moment are ATL and BLI diesels with possibility of a BMann steamer if I get the gumption to get it DCC’ed. I did know about the NRMA gauge, but I was hoping that someone might have pushed the limits a little farther. Even .040 looks like parallel canyons with three tracks in the street.

Pete, we did talk about the street level and cleaning awhile back in my build thread, but thanks for the reminder. My intention is still having the street .010 -.015 below the rail head.

There's another reason it matters too. Unlike the prototype where wheels don't overhang the rail by much, in N scale they VERY MUCH do.

I ran into the issue with the @RAIL N SCALE pavement rollers and made this image to illustrate the issue for him.

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