Assessment of Safety Management Systems at Electrical Substations of the Transmission Company of Nigeria

This study assesses the safety management systems in place at electrical substations operated by the Transmission Company of Nigeria across the North Central and South West regions. Electrical substations present significant occupational safety hazards including electric shock, arc flash, and high voltage exposure, and the quality of safety management systems determines the frequency and severity of workplace incidents. A cross-sectional assessment was conducted at 12 TCN substations, combining documentary review of safety management system records, on-site safety inspections using a standardised checklist aligned with IEC 61511 and OHSAS 18001 requirements, and structured interviews with 36 substation operations and maintenance personnel. Assessment results are scored against a five-level safety management maturity framework. Findings indicate that none of the assessed substations achieves above Level 2 (managed) on the maturity scale. Critical deficiencies identified include absence of current arc flash hazard assessments, inadequate personal protective equipment availability and enforcement, lack of formal lock-out tag-out procedures at six of the 12 substations, and insufficient induction training documentation for contract maintenance personnel. Three substations lack updated single-line diagrams reflecting recent equipment changes, creating conditions for switching errors. Incident reporting culture is weak, with underreporting of near-miss events preventing the accumulation of learning that underpins a proactive safety system. Recommendations include a mandatory TCN-wide arc flash study, a standardised lock-out tag-out programme, and the appointment of dedicated safety officers at all substations above a defined equipment value threshold. Keywords: safety management, electrical substation, arc flash, TCN, occupational safety.