Courtesy Jeffreys Bay Wind Farm

South Africa requires a fleet of modern cranes to meet wind-project demands, experts say.

South Africa's construction of renewable-energy capacity and coal powerplants has created new opportunities for heavy-equipment suppliers, especially crane companies, after the government recently approved 64 new projects, valued at $14 billion.

South Africa is constructing 3,916 MW of new renewable-energy capacity under the country’s 20-year energy plan, the Renewable Energy Independent Power Producer Procurement Programme. Also, in Medupi and Kusile, the country is constructing two $18.8-billion coal-fired powerplants with a capacity of 9,564 MW.

The projects have attracted a mix of international engineering-procurement-construction contractors: Vestas, Acciona, Juwi Renewable Energies, Abenga, ACS Cobra, Iberdola Engineering, Nordex Energy, Scatec, Suzlon and Temi Energia, among others.

Apart from the equipment used in site preparation, cranes have been in high demand for lifting, off-loading and installation of the wind-turbine equipment, photovoltaic (PV) modules, PV inverters and the metal structures used in PV plants.

The new wind projects call for “specialized mobile cranes to install wind turbines due to the large masses and heights the turbines will reach,” says Johan van den Berg, South Africa Wind Energy Association CEO. “Some of these cranes are approximately 18 meters long and 3 meters wide, with extendable supports to increase platform area. The booms are telescoping and can lift 600 to 700 tons at a radius of 4 to 5 meters,” he explains.

“A handful of these cranes exist in South Africa, but the country will require a fleet to meet the demand of the wind-project industry,” Van den Berg added.

Germany-based Liebherr is one of the companies whose cranes have been deployed in the new energy-project build in South Africa. Johnson Crane Hire, Burgersfort, which operates one of the largest mobile-crane fleets in Africa, sought Liebherr’s cranes for the complex lifts of wind-turbine components at Port of Ngqura, near Port Elizabeth, last year, ahead of the construction of the 138.6-MW Cookhouse Wind Farm project, a joint venture between African Clean Energy Developments and Suzlon Wind Energy South Africa, a subsidiary of India-based Suzlon Group.

A 550-tonne Liebherr mobile crane lifted and off-loaded 18 freestanding nacelles, each weighing 86 tonnes, and 28 of the wind farm’s 22-m-long tower sections, each weighing 62 tonnes. In all, the project will consist of 66 Suzlon 2.1-MW turbines.

At the 138-MW Jeffreys Bay Wind Farm, two special cranes were deployed for the installation of the wind turbines. The turbines are 80 m tall, and the blade tips rise to 132 m. Each turbine’s nacelle is the heaviest component, containing the generator and gearbox, with a total weight of 86 tonnes. Made from fiberglass-reinforced epoxy, the three 49-m-long blades are connected to the rotor at ground level before being hoisted to the top of the turbine, notes Mark Pickering, the wind project's general manager.

“This is a complicated lifting exercise in which the crane raises the assembled rotor while the smaller crane guides the rotor into the correct position. It is remarkable to watch the two cranes working together to lift the rotor, which has a diameter of over 100 meters,” explains Pickering.

At the 4,800-MW Medupi Power Station, six Manitowoc crawler cranes, three Potain tower cranes and one Grove GTK1100 mobile telescoping crane were deployed for the civil and engineering works at the project, which is expected to be completed next year. Manitowoc said the six crawler cranes were provided by international rental giant Mammoet, the GTK1100 was provided by Vanguard, and the tower cranes were provided by Kentz and SA French. Principal contractor Hitachi is running the project.

Crews are using the crawler cranes—one 756-tonne-capacity Manitowoc 21000 and five 400-tonne-capacity Manitowoc 16000s—for lifting steel beams and steel assemblies. The two smaller Potain tower cranes, a 6-tonne-capacity MDT-98 and an 8-tonne-capacity MDT-178, are employed for lifting structural-steel elements for the bag filters. A larger MD-1100 special-application tower crane has been assigned to erect the air-cooled condenser’s structure and its fans and fan rings.

Demand for cranes in South Africa has increased interest in models with less than 120 tonnes of capacity, contributing to the expansion of fleets of small cranes, according to employees at Johnson Crane Hire.

“The demand for smaller-crane hire comes from a broad range of industries, primarily transport, electrical and construction,” says Celenté Van Vreden, the company’s Johannesburg branch manager.

“Small mobile cranes are the solution when it comes to picking up anything that can’t be lifted by a forklift or a truck-mounted crane,” he added.