Line upgrade

Drone technology to be utilised in line upgrade project

Babcock has commenced a 15-month contract awarded by the Zambia Electricity Supply Corporation (ZESCO), to upgrade Zambia’s 342 km Kafue Town-Muzuma-Livingstone high voltage transmission line from 220 kV to 330 kV. The contract includes the in situ condition assessment of the line, supply of materials, installation of new section strain structures and restringing onto the new and existing structures.

This is one of the oldest high voltage transmission lines in Africa and the upgrade became necessary to increase the transfer capacity of the line to accommodate the input of new Independent Power Producers coming into the grid. The project will effectively accommodate a life extension of a minimum of 25 years on this line.

On this project Babcock will utilise drones to perform in-situ tower inspections ̶ one of the first applications of this technology in Africa. These remotely controlled aerial craft, equipped with photographic equipment, eliminate the need to deploy climbers on the towers to conduct inspections, which represents a true safety innovation.

“The upgrade is Babcock’s first project of this magnitude in a SADC country and we’re looking forward to showcasing our unique upgrade capabilities with a view to expanding our project capacity into other countries in the region,” says Gary Whalley, managing director of Babcock’s Powerlines business. “In a very cost competitive environment, upgrade projects are becoming increasingly popular to meet Africa’s burgeoning energy demands.

“Although international competition for this contract was stiff, Babcock ultimately secured the contract on a very tight differential. We identified this as a project on which we could offer a potential cost advantage, owing to the low content of steel required, as this was a rebuild. We also brought to the table a robust combination of engineering expertise and historical knowledge of this transmission line, as it was originally built in the 1960s by the Italian utility company SAE, the founders of the Powerlines business which Babcock acquired in 2006.”

Whalley adds that Babcock has been strategically expanding its engineering capabilities to re-establish its full EPC contractor capacity and this will be the Powerlines business unit’s first engineering-led project since its acquisition by Babcock.

Another first for Babcock on this project is its utilisation of PLS-CADD, the most powerful overhead power line design programme on the global market. PLS-CADD is based on a sophisticated 3D engineering model that includes the terrain, structures and all the wires. The project offers the unique opportunity of re-assessing the original line design, using state-of-the-art engineering methods.

The Kafue Town-Muzuma-Livingstone line will remain on load throughout the upgrade project and the Babcock team will build by-passes to enable them to reconstruct the main line, within a very challenging time period. This will be achieved using a repetitive model of four bypasses down the line. At the end of the project the bypass equipment will be given to the client for the construction and upgrading of other powerlines.

Leader in transmission lines in southern Africa

Established in the 1950’s in South Africa, Powerlines has become the largest supplier of transmission lines in southern Africa. Today Babcock is a leader in this field, trusted to deliver major network infrastructure projects safely, on time and within budget, providing an end-to-end service, from full turnkey EPCM to in-situ maintenance, focused on high-voltage overhead lines and steel lattice towers for electricity transmission infrastructure throughout the African continent.

With a world class health and safety culture, the company operates in a safety critical environment and adheres to the strictest health and safety guidelines from day one of every project, effectively enabling the transmission of the safe, reliable and secure power essential to the development of Africa’s critical infrastructure. Babcock’s Powerlines business unit is ISO 9001, OHSAS18001 and ISO14001 accredited and its comprehensive electronic quality, safety and environmental management system is world class. All hot-dip galvanised items carry the ISO 1641 stamp.

The transmission line business operates from an extensive manufacturing facility in Nigel, Gauteng, with 30 000 square metres under roof and another 19 000 square metres of loading and sorting bays under overhead cranes.