After last year suffering delays as a result of an accident that claimed the lives of six people, progress is now being made on the development of energy utility Eskom’s Ingula pumped storage scheme, located between Ladysmith and Harrismith, in the Little Drakensberg.

Once completed, Ingula, now in its seventh year of construction, would be a peaking hydropower station comprising an upper and lower dam or reservoir, separated in elevation by 480 m and boasting an underground powerhouse housing four 333 MW pump turbines 116 storeys below surface in two excavated underground caverns.

It would further boast an underground labyrinth of interconnecting tunnels and waterways, which would extend 6.5 km, while 3 km of access tunnels and several shafts would allow water to be released from the upper Bedford dam and delivered to the power-producing turbines, before being captured in the lower Braamhoek dam.

During off-peak times, the turbines would be reversed, pumping water back from Braamhoek dam to Bedford dam, in readiness for the next peak event.

Once completed, the project would have a generating capacity of 1 332 MW available during periods of peak demand and to supplement baseload when necessary.

Expected completion and operation of the first of the four pump turbines was expected by May 2015, with the remaining units coming on-stream in the following year.

Royal HaskoningDHV construction senior supervisor Jacques du Plessis said in a statement that underground work was proceeding at pace, with the concrete lining in the tailrace and headrace tunnels completed, cavity and consolidation tunnel grouting about 75% complete and concrete slip-forming at one of two 91 m high surge chambers ongoing.

Royal HaskoningDHV, along with local consultants GIBB and Knight Piésold, formed the Braamhoek Consultants Joint Venture – the team responsible for the overall design and construction supervision of the project’s various packages.

Elaborating further on the progress of the project, Du Plessis noted that all civil works in the transformer hall had been completed, while the machine hall and underground control room were nearing completion.

“The first turbine shaft and runner were taken underground recently, two generator transformers have been installed and mechanical and electrical fit-out work is under way.

“Above ground, the operations and maintenance building on the intake structure is nearing completion, as is the stop-log storage facility at the outlet,” he outlined.

The double-storey administration building, which would have direct access to the main tunnel leading to the underground power station, had also recently been completed.

In addition to office space, the building accommodated the external control centre for the power station.

Also recently completed was the visitors centre, which comprised a small office wing, a cinema, various display halls, an auditorium and a facilities wing.