Objectives

The primary objective is to conduct comprehensive visual and thermal drone inspections of the 132kV Hercules/Phoenix 1&2 electrical transmission lines. This assessment follows recent insulator failures and aims to establish a reliable diagnostic baseline to inform preventative maintenance strategies and restore network reliability.

Scope of Work

• Inspect approximately 4.5 kilometres of dual-circuit lattice structures over an estimated eight-hour field window.
• Perform both visual and thermal assessments of critical hardware, including conductors, vibration dampers, insulators, corona rings, tower members, anti-climb devices, tower labels, compression joints, earthing systems, arching horns, and bonding conditions.
• Evaluate secondary degradation factors such as insulator pollution deposition and metal corrosion.
• Provide a detailed condition report of the OPGW fibre optic network utilising the same structural supports.
• Deliver a comprehensive technical report supported by photographic evidence, certification, and actionable maintenance recommendations.

Technical Requirements

• Supply and operate an industrial-grade drone (specified as DJI 4200 or equivalent) fitted with high-resolution zoom and thermal imaging cameras.
• Secure all necessary flight approvals, permits, and structured flight plans prior to mobilisation.
• Submit a mandatory Safety, Health, and Environment (SHE) management file before any site work commences.
• All testing and measurement instruments must hold valid SANAS calibration certificates and comply with ISO 9001, IEC, or IEEE standards.
• Upon completion, works undergo a two-week Operational Test Period (OTP); the contractor remains fully liable for rectifying any defects discovered during this phase.
• A minimum six-month warranty applies to all remedial actions or installed components.
• A Service Level Agreement (SLA) will govern performance metrics post-appointment, and contractors must present a detailed execution methodology if shortlisted.

Skills and Competency Requirements

• Valid Drone Pilot Certificate and Remote Operator Certificate (ROC).
• Practising Registered Electrical Engineer (Pr. Eng.) authorised to compile and sign off on the technical report.
• Active Public Liability Insurance and Professional Indemnity Insurance policies.
• Documented proof of completing at least three comparable drone inspection projects within the preceding three years.
• Registration with the Central Suppliers Database (CSD) and the Municipal Council Database.
• Current Tax Compliance Certificate and Letter of Good Standing.
• Strict adherence to municipal induction protocols, HSE risk management procedures, and preferential procurement equity targets.

Key Terms and Services Explained

• OPGW (Optical Ground Wire): A hybrid cable mounted atop transmission towers that functions simultaneously as a lightning/ground protection conductor and a high-capacity telecommunication fibre network.
• ROC (Remote Operator Certificate): A statutory aviation licence required by civil aviation regulators to legally conduct commercial drone operations in controlled or restricted airspace.
• SANAS Calibration: Certification from the South African National Accreditation System verifying that testing equipment meets nationally recognised accuracy, traceability, and quality standards.
• OTP (Operational Test Period): A contractual monitoring window immediately following project completion, during which the contractor retains full financial and operational responsibility for system performance before final payment is authorised.
• SLA (Service Level Agreement): A formal contract annexure detailing performance benchmarks, reporting obligations, response times, and penalty clauses for non-compliance.