HO scale NX/UR relay interlocking plant

A Labor of Learning by Dave Barraza

please note the site is currently under construction


I had been learning interlocking practice from 2 books, Railroad Operation and Railway Signalling, by Edmund Phillips, and Electric Interlocking, by General Railway Signal Company

More valuable than this was learning to render NX & UR relay plants in the outstanding NXSYS software by Bernard S. Greenberg. More on this later.

I had already resolved to build a CTC-style miniature lever controlled plant for the "Allston" interlocking on my HO scale model train set,


then a kind gift of the AAR 8025A typical relay based interlocking circuits made me instantly decide to make "Allston" a Union-Route style pushbutton plant.
 Cicruit Description (frames-long download)  Pictures