PTS Working Near Electrified Lines 3 — Questions and Answers
Question 1: When must a worker handling long metallic tools (e.g., rail bars) be especially cautious near overhead electrified lines?
- Only when the line is known to be de-energized
- When the tool could bridge the gap between earth and the live conductor (Correct answer)
- Only during night shifts when visibility is reduced
- When the temperature causes metal expansion
Correct answer: When the tool could bridge the gap between earth and the live conductor
Long metallic tools can act as conductors and bridge the distance between earth and a live overhead wire, causing electrocution.
Question 2: What color is typically used to identify the overhead catenary wire on electrified rail systems in the US?
- Red insulated cable
- Green earthed return wire
- Bare copper or aluminum wire (no color coding — position identifies it) (Correct answer)
- Yellow warning-coded sleeve
Correct answer: Bare copper or aluminum wire (no color coding — position identifies it)
Overhead catenary wires are typically bare copper or aluminum and are identified by their position above the track, not by color coding.
Question 3: A worker sees a colleague accidentally contact a live electrified rail and fall. What should the worker do FIRST?
- Rush to pull the colleague away immediately
- Call for help and ensure the power is isolated before approaching (Correct answer)
- Throw water on the colleague to break the circuit
- Apply CPR immediately while the power remains on
Correct answer: Call for help and ensure the power is isolated before approaching
Approaching a victim in contact with live current without isolation risks a second electrocution — you must call for help and wait for power to be cut first.
Question 4: Which type of glove provides protection when handling equipment in areas where incidental contact with electrified components is possible?
- Standard leather work gloves
- Rubber insulating gloves rated for the voltage level (Correct answer)
- Anti-vibration gloves
- Cut-resistant gloves with steel fiber
Correct answer: Rubber insulating gloves rated for the voltage level
Rubber insulating gloves rated for the specific voltage level are required to provide protection against electrical shock.
Question 5: What is the significance of the 'approach distance' versus the 'no-go zone' in electrified rail safety?
- They are interchangeable terms for the same boundary
- The approach distance requires caution; the no-go zone prohibits entry without isolation (Correct answer)
- The approach distance is inside the no-go zone
- The no-go zone applies only to overhead lines, not third rails
Correct answer: The approach distance requires caution; the no-go zone prohibits entry without isolation
The approach distance is a caution zone requiring awareness and precautions, while the no-go zone is a hard boundary that cannot be entered without electrical isolation.
Question 6: How should a worker respond if their vehicle or machine makes contact with an overhead electrified line?
- Exit the vehicle immediately and run
- Stay inside the vehicle and call for help unless fire forces exit (Correct answer)
- Try to reverse the vehicle away from the line
- Open the door and step down carefully to test the ground
Correct answer: Stay inside the vehicle and call for help unless fire forces exit
Staying inside a vehicle that contacts an overhead line is safer because the vehicle acts as a Faraday cage — exiting creates a path for current through your body to ground.
Question 7: Which safety document must be in place before any planned work begins on or near electrified infrastructure?
- A personal risk assessment written by the worker
- A Permit to Work or equivalent electrical safe system of work (Correct answer)
- An informal verbal agreement from the shift supervisor
- A standard tool checkout form
Correct answer: A Permit to Work or equivalent electrical safe system of work
A Permit to Work or formal electrical safe system of work must be in place before any work near electrified infrastructure, ensuring all hazards are controlled.
PTS Working Near Electrified Lines 3
When must a worker handling long metallic tools (e.g., rail bars) be especially cautious near overhead electrified lines?