Cowford wrote:Not that this is a direct relation to "heavy rail," but Chicago's CTA el trains sport (and use) four "class" lights per side (red, yellow, green, and white). These are used in differing combinations to denote the train's route, I presume. For example, purple line trains display two white lights. Makes it easy to determine if "your" train is approaching at night long before you see the signboard!
Ditto for Philly's Broad Street subway (orange line), there are five markers; white-local, green-express, yellow-Broad-Ridge spur, blue-special, red-tail marker. Reading MU cars, diesel and electric had four colors available; red, yellow, green, and white. PRR MUs had the little red "pin hole" markers, found on all PRR passenger equipment, later replaced by Septa with larger more visable 3" lenses.
"I may not have a brain, but I have an idea!" BOB, benzoate ostylezene bicarbonate.