Category Archives: Layout Design

NMRA Clearances for N Scale

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… Read More »

Kato Unitrack #4 Turnout Geometry

Kato Unitrack is designed around a 33 mm (1.2992 inch) track center-to-center. Using various changes in geometry you can also make 49.5 mm (1.9488 inch) and 66 mm (2.5984 inch) centers. You can see the 33 mm center-to-center in the curved track segment radii which increase in 33 mm increments, the double crossover tracks having… Read More »