The construction of two new power plants in South Africa is helping to remedy a major energy shortage. In Nkangala, seven Wolff cranes, including four Big Wolff 1250 B models, owned by Mitsubishi Hitachi Power Systems Africa, are at work.

The new coal-fired Kusile Power Station will comprise six 800MW units and produce 4,800MW of electricity per year, making it the fourth-largest coal-fired power plant in the world.

During construction steel and concrete elements weighing around 60t have to be moved; around 115,000t of steel will be installed.

"Working together with MHPSA, our technical support department developed special collar frames for the stair towers to enable simple and yet stable anchoring of the crane to the structure", explained Andreas Kahl, managing director at Wolff. "The crane concept envisages that one of the 1250 B cranes will be relocated to Unit 6 as construction progresses."

The four 1250 B systems are complemented by a trio of Wolff 355 B luffing cranes with 50m jibs. These were erected directly on top of the 122m high boiler plants.

"This saves on space on the ground as well as costs for the customer, because fewer tower elements are required and the assembly, using a mobile crane, is much faster," added Kahl. Mounted on the mobile Wolff undercarriage UW 260.3, the luffers can operate back and forth along rails on the roof of the boiler plants, giving them a movement radius of around 40m.

"The space on the site is not only very restricted, but it also appears quite chaotic to the untrained eye. In addition to the seven Wolffs, numerous crawler and lattice-boom cranes are also in use to move very heavy and large components. That is why safety has top priority at the site," said Kahl.