NMRA Clearances for N Scale

By | March 9, 2017

Introduction

These are the clearances for bridges, structures and tangent tracks for Old Time (pre-1920), Classic I (1920–1969), Classic II (1969–1983), and Modern (post-1983) eras.

The numbers here are for N scale (1:160). The prototype (1:1) dimensions are given for conversion to other scales or you can check the NMRA standard to get information for other scales. The numbers in the following tables were taken from NMRA Standard S-7 Clearances (February 2012), except for dimensions C and D in Classic II (1969–1983) Clearances, which were calculated. All fractional inches are rounded off to the nearest 1/32 inch.

Old Time (pre-1920) Clearances

NMRA Clearances: Old Time (pre-1920)

NMRA Clearances: Old Time (pre-1920)

Scale N (1:160) Prototype (1:1)
inch inch mm inch mm
A 14/32 inch 0.438 inch 11 mm 6 feet 1828.8 mm
B 7/32 inch 0.219 inch 6 mm 3 feet 914.4 mm
C 10/32 inch 0.313 inch 8 mm 4 feet 1219.2 mm
D 24/32 inch 0.750 inch 19 mm 10 feet 3048 mm
E 7/32 inch 0.219 inch 6 mm 3 feet 914.4 mm
F 5/32 inch 0.156 inch 4 mm 2 feet 609.6 mm
G 13/32 inch 0.406 inch 10 mm 5 feet 6 inch 1676.4 mm
H 1 9/32 inch 1.281 inch 32 mm 17 feet 5181.6 mm
P 13/32 inch 0.406 inch 10 mm 5 feet 6 inch 1676.4 mm

Classic I (1920–1969) Clearances

NMRA Clearances: Classic I (1920–1969)

NMRA Clearances: Classic I (1920–1969)

Scale N (1:160) Prototype (1:1)
inch inch mm inch mm
A 18/32 inch 0.563 inch 14 mm 7 feet 6 inch 2286 mm
B 10/32 inch 0.313 inch 8 mm 4 feet 1219.2 mm
C 14/32 inch 0.438 inch 11 mm 6 feet 1828.8 mm
D 29/32 inch 0.906 inch 23 mm 12 feet 3657.6 mm
E 10/32 inch 0.313 inch 8 mm 4 feet 1219.2 mm
F 6/32 inch 0.188 inch 5 mm 2 feet 6 inch 762 mm
G 14/32 inch 0.438 inch 11 mm 6 feet 1828.8 mm
H 1 21/32 inch 1.656 inch 42 mm 22 feet 6705.6 mm
P 14/32 inch 0.438 inch 11 mm 6 feet 1828.8 mm

Classic II (1969–1983) Clearances

NMRA Clearances: Classic II (1969–1983)

NMRA Clearances: Classic II (1969–1983)

Scale N (1:160) Prototype (1:1)
inch inch mm inch mm
A 18/32 inch 0.563 inch 14 mm 7 feet 6 inch 2286 mm
B 10/32 inch 0.313 inch 8 mm 4 feet 1219.2 mm
C 10/32 inch 0.313 inch 8 mm 4 feet 1219.2 mm
D 1 2/32 inch 1.050 inch 27 mm 14 feet 4267.2 mm
E 10/32 inch 0.313 inch 8 mm 4 feet 1219.2 mm
F 6/32 inch 0.188 inch 5 mm 2 feet 6 inch 762 mm
G 14/32 inch 0.438 inch 11 mm 6 feet 1828.8 mm
H 1 21/32 inch 1.656 inch 42 mm 22 feet 6705.6 mm
P 14/32 inch 0.438 inch 11 mm 6 feet 1828.8 mm

Modern (post-1983) Clearances

NMRA Clearances: Modern (post-1983)

NMRA Clearances: Modern (post-1983)

Scale N (1:160) Prototype (1:1)
inch inch mm inch mm
A 22/32 inch 0.688 inch 17 mm 9 feet 2743.2 mm
B 14/32 inch 0.438 inch 11 mm 6 feet 1828.8 mm
C 7/32 inch 0.219 inch 6 mm 3 feet 914.4 mm
D 1 6/32 inch 1.188 inch 30 mm 16 feet 4876.8 mm
E 10/32 inch 0.313 inch 8 mm 4 feet 1219.2 mm
G 14/32 inch 0.438 inch 11 mm 6 feet 1828.8 mm
H 1 23/32 inch 1.719 inch 44 mm 23 feet 7010.4 mm
P 13/32 inch 0.406 inch 11 mm 5 feet 7 inch 1701.8 mm

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