2006 – July – Warhurst & Keys – Epping – Chatswood Rail Link – Radio System

Peter WarhurstJohn Keys United Group Infrastructure The aim of this paper is to highlight the unique aspects of the design and engineering required to implement radio communications within the Epping-Chatswood Rail Link. The project was unique in that the tunnel sections were much longer than other tunnel projects in Australia and therefore presented some challenging problems for the design. Although our scope includes the provision of radio coverage for both UHF and mobile telephones, the challenges for UHF (train radio and emergency services) were the greatest and so this paper will focus on that aspect. To meet the radio MTTR specification, it was necessary to locate repeaters in the station and service buildings (rather than the normal tunnel cross-passages), which necessitated some extremely long tunnel sections to be served by certain repeaters. The maximum tunnel section span of 3750 metres required the design of specially engineered radio repeaters and customised leaky feeder cables. The paper describes the processes followed to evolve the UHF radio design and specifications for the radio repeaters and leaky feeders, highlighting the limitations of each of the technologies involved.