Rather than, yet again, post my developing layout plan on Simon Paley's thread about his book on Colour Light Signalling for Railway Modellers, I think it's time I start a new thread for my questions.   The layout below represents nowhere in particular, but is intended to represent somewhere in Central Scotland in the early 21st Century (principally in the period from around 2006 to 2009).     The Up and Down lines are fairly self explanatory and effectively just provide the