June 25 - In South Africa, Johnson Crane Hire has completed the first two projects of a 12-month contract signed with Vestas in September 2014 to find and institute the most appropriate lifting solutions for the wind turbine manufacturer's involvement in
Active in South Africa for 11 years, Vestas is providing wind turbines to wind farm projects at Grahamstown, Saldanha, Great Kei Municipality, Tsitsikamma and Grassridge.
Johnson Crane Hire's involvement on the West Coast 1 project in Saldanha entailed executing the lifts for 27 of the 80-m high 2 MW capacity V90 turbines, including the 96-tonne nacelles and 13-tonne blades, as well as relocating the crane components between each turbine pad.
The Chaba heavy lift contract in the Great Kei Municipality, adjacent to the N2 near Komga, involved the lifting of seven V112 3 MW turbines, each with an installed height of 84 m.
Cornelis Grotius, general manager of Johnson Crane Hire's heavy lift division says that typically for heavy lift solutions such as required by Vestas, Johnson Crane Hire would be contracted on a project by project basis. However, the company was able to offer a long term sustainable heavy lifting solution to Vestas, which was accepted in September 2014.
Grotius says that the benefits of the long term lifting solution accrue to each of the parties. Vestas received preferential long-term contractual pricing, is also assured of constant service delivery levels in-between each of the four contracted projects while each project can proceed without delay as the crane, a Liebherr 750-ton LG1750 lattice boom truck mount crane, has been requisitioned for sole use at the Vestas wind farm sites.
He adds that Johnson Crane Hire benefits from the constant use of its crane over the 12-month period and the elimination of time-consuming renegotiations between contracts.
The design of the Liebherr LG 1750 allows for easy relocation between sites with increased mobility on sites with varying terrain.
Grotius says that preparatory work for the two completed lifting projects was complex, with intricate lift design and planning being the order of the day. "Since each installation was undertaken in an area chosen for its constant, consistent and high-speed winds, we had to carefully calculate the effect of the wind on the lifting of each wind turbine component. Extensive rigging studies and methodologies were required not only for the shipping, but also for the building and installation of the crane. Safety of all on site during the lifts was a primary concern," he says.
