Regulations for dc Railways

2 Stray Currents from dc Railways 15.2.1 Regulations for dc Railways 

Nearly all dc railways use the rails to return the operating current. The rails are mounted on wood or concrete sleepers (ties) and have a reasonably good contact with the soil in surface railway installations. The electrolytically conducting soil is 

The most important measures to reduce stray currents are  

Tracks on wooden sleepers in ballast have a relatively low leakage load that is a hundred times smaller for a ballast bed than for tracks in the street. Good electrical insulation is, however, only ensured if the rails have no electrical contact with other installations with low grounding resistance. Overhead conductor poles should in principle not be connected to the rails. Exceptions are overhead conductor poles with electrical equipment that is connected to the rails to avoid inadmissibly high contact voltages in the event of a failure. Such overhead conductor poles should be 

Parameter Rails in the street Rails on gravel ballast tunnel Unit 

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