Current Rail Indicator Device, used to show if current is on. Not to be confused with Rail Gap Indicator which shows where current is off. CRIDs have small orange lights and are located at the end of some station platforms, just inside the tunnel. Found on http://www.trainweb.org/tubeprune/dictionary.htm
Current Rail Indicator Device, used to show if current is on. Not to be confused with Rail Gap Indicator which shows where current is off. CRIDs have small orange lights and are located at the end of some station platforms, just inside the tunnel.