HEAVY LIFTING Vanguard loads a 230 t generator with its 800 t hydraulic lift system
International heavy-lift, abnormal transport and installation specialist Vanguard has been active in two vital power generation projects in the Eastern Cape and KwaZulu-Natal, which are set to supply South Africa with more than 1 000 MW of power during times of high electricity demand or supply shortfalls.
Vanguard was subcontracted to provide the warehousing, transportation and installation of heavy equipment – including accessories – to both the Dedisa and Avon open-cycle gas-turbine peaking power projects, developed by international energy group GDF Suez.
The company has completed five of the six lines of the handling, transportation and positioning of the generating plant.
The joint project is an R11-billion investment comprising six power generation lines, with each line comprising a 191 t gas turbine, a 231 t generator and a 140 t transformer. The last line at Avon was set to be completed by the end of last month.
Vanguard project manager Dale Huddy says the port handling elements for the Avon project required the company to have a full operation at Vanguard’s yard in the Richards Bay port.
“There, we set up one of our 800 t hydraulic lift systems to transload the heavy units from our self-propelled modular trailers onto our multiaxle trailers, ready for transportation.”
Applying its specialised transport experience and equipment, Vanguard transported the loads for 144 km to the project site, using a 20-axle, three-file trailer combination for the generator and turbines, and a 16-axle, two-file combination for the transformer.
“The trailer configuration that Avon required was bigger than the one for Dedisa, resulting in an increased gross combination weight, which meant we had to use more horses to move the loads.
“For the generator and turbines, we pulled with two horses and pushed with one, but for the transformer we pulled with one horse and pushed with a second horse,” explains Huddy. This ensured optimal road safety and efficiency for the 66-m-long horse and trailer combinations.
Adding extra administrative capacity to the project, Vanguard’s head office arranged the applications for abnormal permits, organised the necessary police escort assistance and undertook the crew deployment – leaving on-site managers to focus on the task at hand.
Huddy explains that Vanguard’s engineered project solution for Avon had to accommodate the access routes on site, where the company applied its on-site lifting and moving expertise.
“As with Dedisa, the on-site lifting and moving solution included lining up each generator with its foundations. However, this time we had to do so from the opposite side of the site, followed with the turbine.”
Moving and placing the transformer on site posed certain navigational challenges. Therefore, Vanguard offloaded the transformer using a different approach.
“A sharp turn was managed by enabling the manual hand- steering function on the trailer, which was then lined up parallel with the transformers’ foundations. We lifted the transformer off the trailer and lowered it onto jack-and-slide rails, slid it across in between the foundations, lifted it with the 500 t Power Towers and carried it forward onto its final resting place,” says Huddy.
Coordination of the project was complex, with teams working in the port and teams on site to ensure efficient on- and off-loading cycles. The port crew comprised truck drivers, load escort drivers and riggers, while the on site crew included a dedicated four-man team to set up and dissemble the Power Tower system, and to offload and position each heavy unit.