VRIOGS 010.7 RevA - Public Transport Victoria

6 VRIOGS 010.7 Revision AFigure 2 Point of Separation and extent of Immunisation4.3 Non-Electrified AreaThe non-electrified area is defined as any part of the rail corridor outside theelectrified area.Where non-electrified tracks cross directly over or under electrified tracks they areconsidered to be on separate rail corridors. However, the section of the rail corridorimmediately above or below an electrified track is to be considered as an electrifiedarea.4.4 Immunised Areas1. The signalling infrastructure installed in the vicinity an electrified area issubject to a harsher environment than that installed on the non-electrifiedareas due to traction currents and the stray currents induced.2. The design of the signalling must consider the effects of operating in thisharsh environment in order to assure that a similar level of safety andreliability to that required anywhere on the Network has been achieved. Thearea within which additional precautions shall be taken is known as theImmunised Area.Note: Both electrified and non-electrified areas may be contained within theImmunised Area.3. Any electrical interference, which has entered the infrastructure within theelectrified area, will flow along any metallic conductor (track, pipe work,cables, bridge structures, etc) but the rail bed and ballast and ground alsoprovide paths for stray currents. This means that if an electrified track isclose to a non-electrified track there may also be interference effects even ifNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.