On30 track spacing

[Jim Hornaday]

Staring in On30 and I am wondering what the track center spacing should be for proper clearances. Any other On30 tips anyone has would be greatly appreciated!!

[mlehman]

Gauge is exactly the same as HO scale..649" min, .672" max. After that it gets complicated with On30.

You can find lots of such info here:

https://www.nmra.org/index-nmra-standards-and-recommended-practices

Thhere is a difference in the NMRA gauges beyond this. Since On30 had a much wider loading gauge, you shouldn't use the HO gauge for anything much beyond direct measurement of the track in a pinch. That's the same, but once you get about railhead height, most of the rest is different, so the NMRA has a special On30 gauge to measure clearances, overall height, etc.

EDIT: I came in from work and only half read the question, so only haltway answered it. Track Center Spacing gets complicated and with On30 sometimes depends on your prototype, given the range of things modeled. Try this newly updated RP info:

https://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-7_track_centers_and_obstacle_clearances_july_2017.pdf

[hminky]

3" cl to cl.

Harold

[BroadwayLion]

The rulling factor is the width of your fingers.

 

 

ROAR

[DSchmitt]

Clearance Diagrams

https://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-7.1_tangent_track_centers_and_clearance_diagrams_july_2017.pdf

 

Chart of mininum track centers:

https://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-7.2_curved_track_centers_july_2017.pdf

from chart

Tangent track: spacing 3"

131' prototype radius: 32.75" model radius spacing 4-3/8"  

For O scale Prototype radius x .25 = model radius

 

 

Chart for clearance of obstacles

https://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-7.3_curved_track_obstacle_clearances_july_2017.pdf

 

All RP's on Track Centers and Clearance

• TN-7 Track Center and Obstacle Clearance Methodology (7/2017) 
• ​​RP-7.1 Tangent Track Centers and Clearance Diagrams (7/2017) 
• RP-7.2 Curved Track Centers (7/2017) 
• RP-7.3 Curved Track Obstacle Clearances (7/2017) 
• RP-7.4 Interurban Track Centers and Obstacle Clearances (7/2017) 
• RP-7.5 Modifying Tangent Clearance Diagrams for Curved Tracks (7/2017) 
• RP-7.6 Using the NMRA Curved Track Center and Obstacle Clearance Assistant (7/2017) 
• ​Curved Track Center and Obstacle Clearance Assistant (tool link)

[hminky]

Have used less than 3" track spacing on parallel tracks on a temporary HO Kato Unitrack with 19-1/4R and 21-5/8R.

All the available On30 Bachmann equipment had no problems including both articulateds and passenger cars clearing each other.

Harold