SYSTEM OVERVIEW

London Electricity’s 132KV high voltage power supply tunnels criss cross the city from central to outer London. GAI-Tronics have already supplied 4 systems to London Electricity following successful field trials, and this latest addition is in keeping with London Electricity’s policy to increase safety and productivity underground through increased communications, for which a further 20 systems (through new build and refurbishment) covering the capital’s power supply tunnel system is anticipated.

SYSTEM FUNCTIONALITY

The RFM 2000 Radio Base, has the capability for the connection of up to 4 radiating cable outputs, carrying both r.f. signal and d.c. line supply. The signal is boosted at 500m intervals by use of an in line repeater powered from the superimposed d.c. supply. The system can be split to enable coverage at junctions giving a “Christmas tree” coverage with the ability to add in d.c. line supplies as required.

For London Electricity the ability to use the system as a local communications system with remote access via the Public Service Telephone Network, enables both in tunnel communications between crew, and the ability to access the PSTN in the event of an incident via I.S. hand portable radios. This together with the proven non-interference from the surrounding high tension supply lines, battery standby and low maintenance make the GAI-Tronics RFM 2000 radio system the ideal communications system for this application.

SYSTEM DIAGRAM



This illustration shows the basic Radio Communication System Layout