| Archive for thecentralstation.myfreeforum.org Railway modelling for all Scales and Gauges |
| poliss |
US SignallingLots of useful information on American signal practice, such as " A route may be indicated by the vertical arrangement of aspects, so that Green over two reds indicates the main route whilst red over two greens means diverging route."Interesting links section too. http://www.railway-technical.com/US-sig.shtml#Types-of-Signals |