The Ingula pumped storage scheme located 23 km northeast of Van Reenen, within the Little Drakensberg mountain range on the border between the Free State and KwaZulu-
Natal saw conditional approval of the Section 54 safety work stoppage lifted at the end of February 2014. The Section 54 was imposed after an accident and fatalities in the incline shaft.
Ingula, with a planned output of 1,332MW, comprises two dams − one at the top and the other at the bottom of the escarpment − underground waterways, an underground powerhouse complex, access tunnels and access roads. The station is 350 metres underground.
At this stage in order of priority the top four critical paths for the completion of the project are; completion of the upstream waterways (inclined high-pressure shafts (IHPS)); completion of the downstream waterways (surge chambers); completion of the control room; and completion of the transformer hall.
Due to the fatalities in the IHPS, all work on the project as a whole and particularly in the IHPS was stopped. Further delays could arise as new equipment is manufactured, installed and licensed for construction in these shafts and safer methods of construction are implemented in all shafts, including the surge chambers.
In the transformer hall outstanding work to be done includes the completion of civil construction to Blocks 3 to 5 and the battery room to Block 2. In the control room the east walls construction up to intermediate level, the transversal walls are complete and the west walls up to roof level. In the tailrace tunnel outstanding work includes construction of bifurcations, drilling and grouting and finishing works to tunnel and construction of plugs.
In the main underground works excavation and rock support works have been completed and civil works together with the installation of the turbine units and other mechanical items are under way. Civil works include the placement of approximately 500,000 cubic metres of concrete. The civil works activity remains critical in terms of the overall project completion due to access requirements for the transformer and electrical packages. The intake and outlet structures have been completed.
The generator motor transformers 3 and 4 are in their final position in the transformer hall.
The facility’s administration building is a double-storey, concrete-framed structure with a large basement that will have direct access to the main tunnel into the underground power station. Apart from providing office space, the building will also accommodate the external control centre for the power station. Concurrently under construction is a single-storey visitor centre, which includes a small office wing, a cinema, various display halls, an auditorium and facilities. The current completion date for this part of the project is June 2014.
The Ingula scheme will see 15,000 tonnes of steel lining in the waterways, the quarry associated with the project has produced 2.44 million tonnes of aggregate, and 3,600 tonnes of steel reinforcement will be used. The pumped storage scheme will have 16.07 km of tunnels and 8.28 km of waterways. It feature the largest span of underground cavern in Africa, in mud rock; 187 m long, 26 m wide and 54 m high. Three million tonnes of rock have been excavated from tunnels, waterways and the powerhouse complex.