Probabilistic assessment of risk associated with mobile telephone antennas on HV towers

Mobile telephone base stations sited beneath or adjacent to HV towers require significant risk management consideration. The paper examines the level of shock hazard associated with people moving near a HV tower, and determines the sensitivity of the risk to a range of parameters which might be expected to have significant impact upon the various shock scenarios. High resistivity surfacing materials, such as crushed rock and bitumen, are often used to limit electric shock hazards for utility operators and maintenance staff, as well as the public. This paper evaluates the performance of series impedance insulation used as an earthing system safety mitigation measure. Investigations have been made into the impact of probabilistic aspects of the shock scenario. Interference theory and Monte Carlo simulation techniques are used to statistically appraise the actual level of safety afforded by various safety criteria when compared with the benchmark body current criteria.