Tarcza manewrowa – urządzenie sygnalizacyjne stosowane w ruchu kolejowym
do informowania maszynisty w czasie manewrów -
http://pl.wikipedia.org/wiki/Tarcza_manewrowa------------
Low speed shunting movements such as those to or from sidings or through crossover roads are governed by shunting signals. A shunting signal, when cleared, gives the driver permission to proceed cautiously as far as the line is clear, or to the next signal -
http://www.railsigns.co.uk/sect3page1/sect3page1.html----------
Shunting signals allow a train to move forward onto a line which may already be occupied. -
http://en.wikipedia.org/wiki/British_railway_signals#Shuntin...---------
It's a shunting signal (called shunting shield in polish) that controls trains manouvers within station's limits. It's always located within a station / yard or depot boundary. Blue light says "shunting forbidden", white one "shunting allowed". On a plate, Tm stands for Tarcza Manewrowa (shunting shield). -
http://www.flickr.com/photos/fernhout/5188496228/