28 January 2014
28 January 2014
Aerontec has designed, manufactured and installed a special composite deck on one quay of the container terminal at Cape Town, South Africa.
“As far as I know, this is the first time a project of this type has ever been undertaken in the world, and I believe it was also the biggest single composite job ever completed in South Africa,” said Graham Blyth, Aerontec’s owner.
The company says it was approached by Transnet National Ports Authority to help solve an existing problem on the main container quay. The cable tray which houses the electricity cables for the large gantry cranes along an area of over 1200m and about 3m in width, were considered a serious trip-hazard to workers on the quay.
“A first proposal was to cast a second concrete layer of 190mm thick to be level with the crane rail. However, this presented too many disadvantages: weighing in at about 1000 tons of concrete and rebar it was too heavy; too costly; too long to construct and too long to wait the prescribed 28 days for the concrete to cure, not ideal for a working quay with ships berthing all the time,” explains Blyth.
According to Aerontec, the entire project had to be completed in 12 months and the solution had to be light-weight and cost effective. It also had to allow waves to wash over and drain quickly away from the panels.
After various designs, proposals and testing, the company states a design was agreed on which made use of resin vacuum infused solid GFRP panels using woven roving and iso-phthalic polyester resin. This was then coated with a UV stabilised iso-NPG flow coat with a non-slip grip finish.
Aerontec says it partnered with South African company, MMS Technology to manufacture the composite panels. A gap was left between the panels adjacent to the rail and the panels at the water’s edge where a Panzer belt had to be installed to cover the electric crane cables. The Panzer belt is lifted by a special belt lifter attached to each crane to withdraw the cable, and to nest the cables back into the hidden cable cavity as the crane passes down the rail system. Blyth explains that the top panel is 32mm solid GFRP. This is then raised to the specified height using stepped solid feet,bonded and cored with a pultruded rod.
“There is an undulated variance of about 80mm over the existing concrete quay. We needed to be virtually level with the crane rail to eliminate any trip hazard, so countless GFRP shims had to be made and bonded in place to keep the GFRP panels level,” he adds.
The company says the project was completed within the 12 months and within the allocated budget.
Photo provided by Aerontec