Objectives

The primary objective of the tender is to supply, install, and commission a 3kV DC 6MVA traction transformer at Hamelfontein 3kV DC Traction Substation, ensuring compliance with environmental standards and minimizing environmental impact throughout the project lifecycle.

Scope

The scope includes:

• Delivery of a 6MVA traction transformer designed for outdoor use with specified cooling and insulation standards.
• Design, manufacture, supply, and installation of the transformer and associated 6MW 12-pulse rectifier unit at Hamelfontein substation.
• On-site testing, commissioning, dismantling, and transportation of faulty equipment.
• Provision of auxiliary power supply via a tertiary winding.
• Preparation of detailed technical documentation, drawings, and method statements.
• Compliance with environmental, safety, and quality standards during all phases of work.

Technical Requirements

The technical specifications include, but are not limited to:

• Transformer rated for 6MVA, with a primary voltage of specified levels and secondary voltage between 1220V to 1440V, configured for 6 or 12 pulse rectification.
• Temperature rise not exceeding 65°C under continuous full load; maximum winding temperature rise following overloads not exceeding specified limits.
• Voltage regulation within 5%, with manual off-load tap changers (+/- 2.5% and 5%).
• Impedance not less than 8%, with windings designed for mechanical strength and minimal harmonic disturbance.
• Insulation levels conforming to SANS standards, with windings insulated for severe lightning conditions.
• Robust tank construction with galvanised radiators, oil containment, and fittings including pressure relief, Buchholz relay, and temperature sensors.
• Compliance with environmental and safety standards, including type tests, routine tests, and commissioning procedures.

Skills and Competency Requirements

The tenderer must demonstrate:

• Design, manufacture, and supply experience with traction transformers and rectifiers, supported by type test certificates or arrangements for testing.
• Technical expertise in transformer windings, insulation, and mechanical strength, with detailed drawings and calculations.
• Qualified personnel with relevant electrical engineering qualifications (e.g., Degree or Diploma in Electrical Engineering, registered with ECSA, SACPCMP).
• Experience in installation, testing, and commissioning of similar high-voltage equipment in railway or industrial environments.
• Environmental management capability, including preparation of Environmental Management Plans, method statements, and compliance with environmental legislation and standards.
• Ability to develop and implement safety, health, and environmental procedures, including risk assessments, incident management, and waste handling.
• Provision of qualified Environmental Officers and adherence to Transnet’s environmental SOPs and specifications.