PTS - Personal Track Safety Working Near Electrified Lines Flashcards

What does it mean if the stinger (third rail conductor rail) has a gap or appears discontinuous at certain track locations?

Answer: Gaps in the third rail exist at points, crossings, and transitions — adjacent sections may still be live and the entire conductor rail system must be treated as live unless formally isolated

Gaps in the third rail at points and crossings do not mean the rail is de-energised. Adjacent sections are connected through the network and remain live — treat all third rail as live unless isolated.

What is the danger of working on or near electrified lines during foggy or damp weather conditions?

Answer: Moisture significantly reduces the electrical resistance of surfaces, increasing the risk of electrical flashover and reducing the safe working distance from energised equipment

Moisture reduces the electrical resistance of ballast, sleepers, and equipment, increasing the risk of electrical flashover from OLE and reducing the effective safe distance from energised equipment.

What must a COSS verify before allowing any crane or lifting equipment to be used near overhead line electrification?

Answer: That a formal OLE isolation and earthing arrangement is in place, or that the crane's reach cannot come within the safe clearance distance from any OLE conductor under any operating condition

Before using cranes or lifting equipment near OLE, either a formal isolation/earthing must be in place, or the equipment's maximum reach must be confirmed as unable to encroach within the minimum approach distance from any OLE conductor.

What is 'step potential' and why is it a hazard near the site of an electrical fault on the railway?

Answer: The voltage difference between two points on the ground near an electrical fault, which can drive current through a person's body even when not touching live equipment

Step potential is the voltage gradient across the ground surface near an electrical fault. Current flows through a person's body between their two feet if they straddle the voltage gradient, causing electrocution.

What does the term 'bonding' mean in the context of railway electrification safety?

Answer: Electrically connecting conductive elements to ensure they are at the same voltage potential, preventing dangerous potential differences between components that workers may touch simultaneously

Bonding connects metallic structures to a common earth potential, preventing dangerous voltage differences that could cause electrocution if a worker simultaneously touches two differently-potentialled objects.

What is the correct action if a PTS holder unexpectedly finds they are within the danger zone of energised OLE equipment?

Answer: Immediately stop, keep still or move very slowly straight away from the OLE without raising arms above head height, and alert the COSS

If in the OLE danger zone, move slowly and carefully straight away from the conductors without raising arms or tools upward. Rapid movements or raised arms increase the risk of coming closer to or contacting the wire.