Pantograph Inspection: Why and How

Pantograph inspection reduces repairs and prevents loss of rail service. Automatic pantograph inspection is cheaper and more effective than manual inspections.

Locomotive pantographs make continuous contact with an overhead wire from which they draw electric power. To reduce wear on the wire, the pantographs incorporate carbon blocks that contact the wire. The carbon blocks can become worn or damaged and must be replaced before they cause damage to the overhead wiring. Serious damage, called dewirement, renders the track unusable until repairs are completed.

Manual inspections are costly in labour and lost service time of the locomotive. To manually inspect the pantograph, the locomotive must be taken to a service depot and electrically isolated before inspectors access the top of the train. Such inspections are insufficient to prevent damage to the overhead wiring including dewirements.

Pancam uses machine vision technologies to inspect pantographs of locomotives in normal service as they pass an inspection point. Pancam has prevented all pantograph-related dewirements since its deployment in QR National's Mackay coal transport network.