VRIOGS 010.7 RevA - Public Transport Victoria

28 VRIOGS 010.7 Revision ASECTION 7.0NON-ELECTRIFIED TRACK IN ELECTRIFIEDAREA7.1 GeneralEven in electrified areas electric trains will not normally run over non-electrified areasof infrastructure.The additional risks due to the presence of the electric traction infrastructure can beclearly defined as:1. Electrical interference with signalling equipment due to conductive couplingfrom traction return current.2. Electrical interference with signalling equipment due to conductive couplingfrom traction fault current.3. Electrical interference with signalling equipment due to inductive or capacitivecoupling from traction harmonics.7.2 Train DetectionAny track subject to the provision of full traction return bonding shall be treated as anelectrified track as far as the requirements for track circuit traction bonding, crossbonding, and immunisation of equipment is concerned.7.3 Traction CurrentElectrical interference with signalling equipment from traction return current shouldbe minimised by ensuring that the tracks do not provide a through path for tractioncurrent to flow from one point in the electrified network to another.7.3.1 IsolationIsolation of traction current described in section 7.2 above shall be provided by theinsertion of an IRJ in each rail that abuts the rails of the electrified track. Whereelectric trains cannot inadvertently run across these IRJs (as at a diamond crossing)then only a traction supply equipment fault should lead to the track carrying tractionreturn current.7.3.2 Overruns1. Where it is possible that an electric train could be inadvertently routed ontoa non-electrified track then the train itself could bridge the protecting IRJsand inject traction return current into the rails.2. In such instances the non-electrified track for a distance at least the lengthof a normal electric train shall be provided with full traction bonding forInterstate Lines being 3000 m and for all other areas being 1200 m.(Directly related to the length of trains operating over the Network.)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.