NG TS 3.08.02 PDF

All underground sites are covered by this specification, however most locations will be cable tunnels which carry high voltage transmission cables. Each site has its own specific communications requirements, with safety, efficacy and overall lifetime cost being the main concerns at all sites. Site specific requirements are detailed in the invitation to tender document.

For long tunnels a leaky feeder aerial system is the most likely solution. Shorter straight tunnels may be equipped with directional aerial systems, and very short tunnels may have no permanent communications facility. Fibre optic connected telephone systems may be considered in due course.