VRIOGS 010.7 RevA - Public Transport Victoria

10 VRIOGS 010.7 Revision A5.4 Adjacent to electrified tracksWhere non-electrified tracks are in an electrified area they should not carry normaltraction currents.1. The design of the rail bonding should therefore not allow for traction returncurrent to flow through the non-electrified rails. Any bonding design whilstadhering to the normal signalling principles for track circuit series continuityshould provide only a single path between any rail and the traction returncurrent system.2. In the event of an incident such as overhead line damage or misrouting of atrain the bonding components of the non-electrified tracks could be subject totraction current return. The bonding infrastructure shall ensure that anytraction current does not lead to an unsafe situation for personnel on thetrack.5.5 Junctions with electrified tracks1. If non-electrified track runs in an electrified area there may be situationswhere electrified track has either a running connection to or across the nonelectrifiedtrack. This connection may itself be electrified to allow electrictrains to access other tracks beyond the non-electrified line or to allow forelectric trains to be misrouted and then recovered without damaging theelectrification infrastructure.2. Full traction return capability for the non-electrified line shall be provided tothe extent that an electric traction unit could travel whilst still drawing powerfrom the electrified line.5.6 ContainmentWhere the electric traction supply system terminates whilst the track continuesmeasures shall be made to ensure that the return traction current is contained withinthe electrified area. The first provision shall be an insulated rail joint in each rail inthe vicinity of the end of the electrification supply infrastructure. These joints shall benominally 15 m from any rail of an electrified track normally coinciding with the firsttrack circuit joint beyond the point of separation.5.7 Track-circuited trackThe spread of stray traction return current using the rails should be constrained ifpossible; therefore at approximately 1200 m from the point of separation a trackcircuit joint will be inserted with an IRJ in each rail.This location should be chosen to coincide with both the layout of the signallinginfrastructure and any physical features of the geography (e.g. watercourses,tunnels) that may act to contain or exacerbate stray currents.NOTE: 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.