System Uprating Johannesburg City Power
Johannesburg, South Africa
In South Africa, recent economic growth in the region had created critical demand that was outstripping the capacity of the country’s 1950s electricity transmission and distribution infrastructure. The need for infrastructure upgrades in Johannesburg was put on a fast-track for the 2010 World Cup in South Africa.
City Power in Johannesburg, contracted Quanta to re-conductor the existing 88 kilovolt (kV) network around Johannesburg to increase capacity and reliability (approximately 200 MW per circuit) and upgrade to ACCC High Temperature Lisbon conductor using Quanta proprietary LineMaster™ energized robotic arm technology. Although live line work is becoming more common in the U.S. and Canada, this was the first use of the technology in South Africa.
The project started with a complete condition assessment of the lines, towers insulators, tower footing and access roads and facilities. This was followed by line design, conductor selection and general engineering studies. Most of the tower and footing re-conditioning were done first before the energized work started. Although the sophisticated and patented LineMaster™ equipment requires the unique live-line skills of Quanta crews, the project was executed by a combination crew from Quanta and a local construction company in a highly populated urban setting in far less time and at a reduced budget than otherwise would be possible using conventional upgrading techniques and taking system outages. The other hidden benefit using this energized recnductoring technique, is the cost benefit of no outages, hence no revenue loss for the client.
The 12-person Quanta crew arrived in South Africa in August 2009 and received one month of training related to local rules and regulations. The remaining part of the crew (10 linemen) was made up of local authorized barehand linemen. The crew utilized barehand techniques to complete the projects. Phase 1 of the contract – from the Kelvin Generation Plant to Cydna Substation – began early in the summer of 2009 and involves the energized re-conductor of four 88 kV circuits on double-circuit, lattice towers. Each circuit is approximately 10 miles in length. Additional circuits to be worked were identified as the project progressed. By the end of December 2011, Quanta has installed approximately 400km of Lisbon conductor under energized conditions.
Critical system improvements were made in time for the arrival of more than 1.3 million people for the World Cup’s first round. During the 2010 World Cup, Quanta also provided emergency restoration, and was kept on standby to ensure that the event was free of disruptions or outages. During the world cup, a tower was damaged and Quanta was contracted in to replace the tower under energized conditions. In 4 hours, Quanta replced the old lattice type tower with a monopole.
Economic and Other Benefits of Energized Work
- Increase system capacity –50% target. Achieve 100%
- Mechanically harden transmission system, extended life
- Improve reliability and enhance economic performance
Emergency Support During World Cup
Scope: Reconductoring to increase transfer capacity of existing lines
Quanta Team: Quanta Technology, Allteck Line Contactors, Quanta Services Africa
Line Condition Assessment