May 27 - Vanguard was contracted to provide the warehousing, transportation and installation of heavy equipment for the Dedisa and Avon open-cycle gas turbine peaking power plants in South Africa.

The Dedisa and Avon power projects, which are located in the Eastern Cape and KwaZulu-Natal province respectively, are being developed by GDF Suez and are set to supply South Africa with over 1,000 MW of power in times of high electricity demand or shortfalls of supply.

Vanguard says that it has now completed the six lines of handling, transportation and placing into position of the generating plant. The six power generation lines are each made up of a 191-tonne gas turbine, 231-tonne generator and 140-tonne transformer.

"The port handling elements for the Avon project required us to have a full operation at Vanguard's yard in the Richards Bay port," explained Vanguard's Dale Huddy. "There we set up one of our 800-tonne capacity hydraulic lift systems to move the heavy units from our self-propelled modular transporters (SPMTs) onto our multi-axle trailers ready for transportation."

Vanguard transported the loads over a distance of 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 required for Avon was bigger than for Dedisa, resulting in an increased gross combination weight, which meant we had to use more horses to move the loads," said Huddy. "For the generator and turbines we pulled with two horses and pushed with one, while for the transformer we pulled with one horse and pushed with a second horse."

Vanguard's head office also arranged the applications for abnormal permits, organised the necessary police escort assistance and undertook the crew deployment.

Huddy explained that as with the Dedisa plant, at the Avon site the onsite lifting and moving included lining up each generator with its foundations, but this time it was from the opposite side of the site. The transformer was also moved and positioned at the site, which posed certain navigational challenges, and the unit was offloaded using a different approach, said Vanguard.

"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," said Huddy. "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-tonne capacity Power Towers, and carried it forward onto its final resting place."

At the Dedisa and Avon sites, Vanguard utilised a 500-tonne capacity hydraulic lift system to place the units into their final position, with an 800-tonne capacity hydraulic lift system for the port works for both projects.