International heavy-lift and plant relocation specialist engineering firm Vanguard provided the transportation and erection services for nine 3 MW Sinovel wind turbines for the Van Stadens wind farm project, in the Eastern Cape, says Vanguard MD Bryan Hodgkinson.
The project forms part of the roll out of wind energy projects by government as part of the Department of Energy’s Renewable Energy Independent Power Producer Procurement Programme.
“The R550-million Van Stadens wind farm project, developed by MetroWind, is just one of the wind farm sites to which we have offered our engineered solutions,” says Hodgkinson.
“Civil construction started on site in November 2012 and the nine foundation rings were delivered by Vanguard between December 2012 and March last year, as the site developed,” says Vanguard sales manager Steve Francis.
Vanguard was responsible for the discharge, storage and transportation of nine nacelles, nine hubs, 27 blades and 36 tower sections from the Port of Ngqura to the wind farm site, which is 57 km away. It was also responsible for the mechanical and electrical installation of the turbines on site, says Hodgkinson.
He explains that the main shipment of turbine components arrived in the port in early June last year. After discharging the vessel, delivery of the abnormal turbine components began. “The transportation of the 56.5 m blades and the 120 t nacelles was achieved through Vanguard’s custom fleet of heavy-capacity, multi-axle trailers. We also employed two sets of specially imported tower clamp attachments to lower the overall height of the load, which enabled the transportation of the 4.7-m-diameter tower sections on the routes, which would not have been possible using standard trailers.”
The nacelles were lifted to a height of 90 m and positioned to be secured to their respective towers. “Despite challenging weather, the goal of erecting one complete turbine per week was achieved,” says Hodgkinson.
One turbine a week was erected, over three months – from August to October last year. “The electrical installation of the turbines was completed in November last year, with the commercial operations of the wind farm starting in February this year.”
At the peak of the project, Vanguard employed about 120 people, including subcontractors. “In keeping with government’s requirements, wherever possible, we employed local labour to assist with installation work and also used local contractors and suppliers,” says Francis.
He adds that one of the major challenges of the project was the transportation of more than 90 loads of abnormal equipment. However, Vanguard “spent a lot of time carefully planning every aspect of the project. Various routes were checked, and specialised equipment had to be brought in to reduce the heights of loads to cross under certain bridges”.
High-level engineered project management ensured that the various disciplines involved in transporting, erecting and installing the wind turbines were carried out efficiently and safely, says Francis.
“Lifting heavy equipment to great heights has to be planned and executed extremely carefully. The project team planned every lift in such a way that downtime was reduced,” he notes.
The large scale of the turbine components requires specialised expertise and equipment to transport and install. The towers for the turbines on average measure more than four metres in diameter at their base and are 80 m to 90 m tall, depending on the model and generating capacity, which required their being transported in three segments of about 30 m each, explains Hodgkinson.
“The nacelle, with the generator, gearbox, drivetrain and brake assembly, typically weighs more than 100 t, while the hub weighs about 40 t and the turbine blades – three per turbine – are about 55 m in length,” says Hodgkinson, adding that, after the tower segments are assembled on site, the nacelle components, the hub and the blades are lifted to the top of the tower and installed by expert technical teams.
Hodgkinson adds that Vanguard has been working on wind energy projects where services have included port discharge, transportation and lifting, as well as the assembly of more than 80 turbines at several projects in the Western Cape, the Eastern Cape and the Northern Cape.
Vanguard met all the requirements of its projects as “it is the only South African-owned company with the expertise and capacity, including fully licensed and registered equipment, to offer a full turnkey project solution to the growing wind-energy market,” he says.
He adds that the company’s skilled experts produce high-quality workmanship that is required for each project “to stay within budget and time constraints, without compromising safety”.