# NMRA Track Centers in Inches for HO scale



## Alan (Feb 15, 2014)

What is the recommended NMRA distance for parallel straight track & curves from center to center? In O Scale it's 4.5 inches from track center to track center on straight track.

Thank you,
Al Hummel


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## johnfl68 (Feb 1, 2015)

Not sure where you got 4-1/2" for O scale, as that specific value isn't on the chart for that scale?

NMRA STANDARDS S-8 Track Centers:
http://www.nmra.org/sites/default/files/standards/sandrp/pdf/s-8.pdf

It depends on what "Class" locomotives and what your minimum "radius" curve used.

For example Class Ia (large steam) and no less than 32" radius curves, it would be 2-1/2" track centers.

Consult the HO Scale section of the PDF to look up your use case.

John


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## lajrmdlr (Apr 25, 2014)

The standard distance between two parallel HO tracks has always been 2" which roughly equates to 14 scale feet. That amount allows people to walk between cars easily. On curves it should be at least 2.25 - 2.375" to allow long engines & cars to pass each other w/o their ends hitting each other. 
Sometimes straight parallel tracks can be down to 13 feet so cars can be loaded/unloaded thru the doors. Something strong enough to handle heavy loads between the cars. A produce terminal had 12 spurs off a track at 15 degree angles. Each spur held 3 cars. With all the doors open all 36 cars could be unloaded at once.


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