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S-7 Clearances

S-7

(S-7.1)
Note: For Help with NMRA Gauge letter definitions and the AAR Plate diagrams on which it's based see Standard S-7 Clearances and the NMRA Gauge

This Clearance Diagram and its dimensions produce the Preferred "M" Track Centers shown in STANDARD S-8, which also shows the additional side clearance and Track Centers required for curved track.

BRIDGE AND STRUCTURE CLEARANCES - TANGENT TRACK

Scale A B C D E F G H P
1" 6-1/2"
165mm
O(17) 2" 1-1/16" 1-19/32" 3-3/16" 1-1/16" 11/16" 1-19/32" 5-27/32" 1-19/32"
50.8mm 27.0mm 40.5mm 81.0mm 27.0mm 17.5mm 40.5mm 148mm 40.5mm
O Scale 1-7/8" 1" 1-1/2" 3" 1" 5/8" 1-1/2" 5-1/2" 1-1/2"
47.6mm 25.4mm 38.1mm 76.2mm 25.4mm 15.9mm 38.1mm 140mm 38.1mm
On3/On30 1-1/2" 3/4" 1" 2-1/2" 3/4" 1/2" 1-3/8" 4-1/4" 1-3/8"
38.1mm 19.0mm 25.4mm 63.5mm 19.0mm 12.7mm 34.9mm 108mm 34.9mm
On2 1-7/16"     2-1/2" 5/8"   1-1/8" 4-1/4"  
36.5mm     63.5mm 15.9mm   28.6mm 108mm  
S Scale 1-13/32" 3/4" 1-1/8" 2-1/4" 3/4" 15/32" 1-1/8" 4-1/8" 1-1/8"
35.7mm 19.0mm 28.6mm 57.2mm 19.0mm 11.9mm 28.6mm 105mm 28.6mm
Sn3 1-1/8" 9/16" 3/4" 1-7/8" 9/16" 3/8" 1-1/32" 3-3/16" 1-1/32"
28.6mm 14.3mm 19.0mm 47.6mm 14.3mm 9.5mm 26.2mm 81.0mm 26.2mm
OO Scale 1-3/16" 5/8" 15/16" 1-7/8" 5/8" 3/8" 15/16" 3-7/16" 15/16"
  30.2mm 15.9mm 23.8mm 47.6mm 15.9mm 9.5mm 23.8mm 87.3mm 23.8mm
HO Scale 1-1/32" 9/16" 13/16" 1-5/8" 9/16" 11/32" 13/16" 3" 13/16"
  26.2mm 14.3mm 20.6mm 41.3mm 14.3mm 8.7mm 20.6mm 76.2mm 20.6mm
HOn3 Scale 27/32" 13/32" 9/16" 1-3/8" 13/32" 9/32" 3/4" 2-11/32" 3/4"
  21.4mm 10.3mm 14.3mm 34.9mm 10.3mm 7.1mm 19.0mm 59.5mm 19.0mm
TT Scale 3/4" 13/32" 19/32" 1-3/16" 13/32" 1/4" 19/32" 2-3/16" 19/32"
  19.0mm 10.3mm 15.1mm 30.2mm 10.3mm 6.4mm 15.1mm 55.6mm 15.1mm
TTn3 Scale 5/8" 5/16" 7/16" 7/8" 5/16" 3/16" 9/16" 1-23/32" 9/16"
  15.9mm 7.9mm 11.1mm 22.2mm 7.9mm 4.8mm 14.3mm 43.7mm 14.3mm
N Scale 19/32" 5/16" 7/16" 29/32" 5/16" 3/16" 15/32" 1-21/32" 15/32"
 15.1mm 7.9mm 11.1mm 23.0mm 7.9mm 4.8mm 11.9mm 42.1mm 11.9mm

NOTES:

  1. Narrow Gauge locomotives with extra-wide cylinder spacing such as "K" types, require standard gauge dimensions for A, B, G and P.
  2. For increased clearances in curved track follow rules of STANDARD S-8.