Construction World April 2017

PROJECTS & CONTRACTS

LIFTING De Aar wind farm TURBINES

Challenging conditions are considered normal for Johnson Renew, and its contract at De Aar 1 Wind Farm showcased how this subsidiary of Johnson Crane Hire overcomes these with ease.

Cornelis Grotius, general manager Johnson Renew, says that the current contract to supply cranes and support services for installation of 67 wind turbines started in May 2016 and is expected to have an eight month duration. Being constructed by EPC Longyuan Engineering South Africa, the Longyuan Mulilo De Aar Maanhaarberg Wind Energy Facility project is a 96,5 MW wind energy facility. Longyuan Engineering South Africa, of which a local Community Education Trust

has a 30% shareholding, is a subsidiary of China Longyuan. The wind turbine generators are being supplied from China by Guodian United Power Corporation. Grotius says the wind turbine components are offloaded on the installation pads ready for the heavy lift programme to begin. These lifts are done using a 250 t mobile crane. The heavy lift programme starts with the pre-installation of the bottom tower sections using a combination of a 550 t crane and a 100 t crane. The main installation lifting will be done with a 1 200 t hydraulic crawler crane used in combination with a 100 t crane. “As a subsidiary of Johnson Crane Hire, Johnson Renew has ready access to the depth of its parent company’s crane fleet which allows it to supply these different crane combinations,” Grotius says. “This is a major differentiator in the market and allows us to customise lifting packages for individual projects.” Significantly, the LTR 11200 is the fleet’s newest crawler crane and was selected to undertake the main installation lifts due to its narrow track crawler undercarriage and 100 metre hydraulic boom. This technology allows the machine to move and set up ABOVE: Johnson Crane Hire’s LTR 11200 crawler crane in action. LEFT: Johnson Crane Hire's new LTR 11200 was selected to undertake the main installation lifts due to its narrow track crawler undercarriage and 100 metre hydraulic boom.

relatively rapidly between installation pads with the added advantage of travelling on narrow access roads. This will assist in increasing the productivity on the project. Commenting on the challenges on this particular site, Grotius says that there are a number of very steep hills resulting in potentially difficult terrain in which to work. Undertaking heavy lifts difficult conditions is not new for Johnson Renew. “We have an established track record with challenging conditions and will be able to leverage our resident expertise in heavy lifting and wind farm project experience to ensure that we meet the construction programme safely,” Grotius says. Preparing for any lift includes a full assessment of the on-site conditions as well as route surveys. All this is done in close collaboration with both the client and the crane OEM to ensure all aspects are factored into the lifting solution. “Upfront planning enables our heavy lift team to select the most appropriate crane configuration for the task at hand which in this case is the new LTR 11200 crawler crane,” he says. “It is by understanding our crane fleet and how these machines can be adapted for specific site conditions that we are able to optimise the lifting solution and produce the results we do, and with an impeccable safety record.” This knowledge comes with years of experience, and ensuring that all operators are skilled and competent. “Ongoing operator training also plays an important role in adapting the lifting operation to site specific conditions,” he says.

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CONSTRUCTION WORLD APRIL 2017