Construction World February 2017

CRANAGE AND HEAVY LIFTING

INCREASED HIGH-RISE INVESTMENT Enthusiastic investment in high- rise structures around some of South Africa’s most developed urban centres will lead growing

cranes in the traditional way, with a 75 m jib having to be constructed on the ground next to a building site.” There is often simply not the space available, he says, and some roads have become so busy that it is not an option to close them off for the duration of erecting a crane. Key advantages A key advantage of the flat-top crane is that its jib can be erected in short sections – usually five or 10 metres each – rather than being assembled on the ground and lifted as one piece. This makes it possible to deliver a 75 m jib in smaller segments and assemble it in the air. SA French is the exclusive Southern African distributor for Potain cranes, a global market leader for over 40 years. With an extensive range of conventional saddle jib tower cranes, hydraulic self-erecting cranes, topless cranes and luffing jib cranes, Potain has supplied over 120 000 of these units around the world. A further advantage of the flat-top design is the absence of a top tower (cathead) and jib ties, which allows it to operate with more hooks with closer working distances between jibs. “The luffing jib crane is also an increasingly popular option for contractors when faced with these tight working conditions,” says Van Breda. “In highly space-constrained cities like London, luffing

“I don’t see any shortage of development in places like Sandton – and it is taking place in an increasingly space-constrained environment,” says Van Breda. “It’s an inevitable process driven by urban migration and the pressure for living and working space; at the same time, the rising value of land has created a trend towards taller buildings.” He highlights how building under these conditions becomes more and more restrictive for contractors, who need to re-think the suite of lifting equipment that they employ on each job, according to its particular demands. “Despite the fact that conventional cranes are still being used extensively in urban centres, this does assume available space on site, and the option of closing a road over a weekend to construct and erect a crane,” he says. “We are getting to the point where we just can’t consider erecting demand for topless – or flat- top – and luffing jib cranes, according to SA French managing director Quentin van Breda.

SA French managing director Quentin van Breda.

“It is a surprisingly common occurrence for workmen to be required to walk to the working areas on the 25 th floor of a building – even though just one trip could easily waste half an hour of the working day.” jib cranes are seen everywhere, because contractors must pay for every cubic metre of space that they use outside of their building line. This ensures that crane movements are strictly controlled and do

A key advantage of the flat-top crane is that its jib can be erected in short sections.

A further advantage of the flat-top design is the absence of a top tower (cathead) and jib ties.

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CONSTRUCTION WORLD FEBRUARY 2017