INDICATION LOCKING by Metro Digital Resources Librarian • April 14, 2016 Electric locking of control circuits which prevents actions that would result in an unsafe condition for a train movement if a signal, switch, or if the operative unit fails to make a movement corresponding to a control command. (NTSC) Share:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Tumblr (Opens in new window)Click to share on Reddit (Opens in new window)Click to email this to a friend (Opens in new window)Click to print (Opens in new window)Like this:Like Loading... Related