If the trailing pantograph is defective, what action is required?

If the trailing pantograph is defective, what action is required?

• A. Lower the trailing pantograph and raise the leading pantograph.
• B. Raise the trailing pantograph and lower the leading pantograph.
• C. Lower both pantographs.
• D. Raise both pantographs.

Answer: (C)

When a pantograph fault is detected, the safe action is to remove contact with the overhead by lowering the pantographs. If the trailing pantograph is defective, lowering both pantographs ensures there is no current pickup and prevents potential damage from arcing, overheating, or dragging a faulty device along the contact wire. Keeping any pantograph raised while a fault exists risks further damage to the overhead wiring and the pantograph itself, and could create unsafe conditions for the train and crew. Lowering both guarantees isolation from the catenary and allows the train to move under maintenance conditions to a facility for repair.

When a pantograph fault is detected, the safe action is to remove contact with the overhead by lowering the pantographs. If the trailing pantograph is defective, lowering both pantographs ensures there is no current pickup and prevents potential damage from arcing, overheating, or dragging a faulty device along the contact wire. Keeping any pantograph raised while a fault exists risks further damage to the overhead wiring and the pantograph itself, and could create unsafe conditions for the train and crew. Lowering both guarantees isolation from the catenary and allows the train to move under maintenance conditions to a facility for repair.