Industrial rope-access company Skyriders Access Specialists installed temporary access platforms to allow for critical routine maintenance on the Crocodile river bridge, in Mbombela, Mpumalanga.
The maintenance, which took place in October last year, was carried out in difficult conditions, including rainy weather, constant traffic and challenging access specifications, and entailed the replacement of bridge bearings that allow for the deck of the bridge to move and expand on account of vehicle movement or thermal variations.
An active beehive, uneven ground conditions and the moving body of water under the Crocodile river bridge further complicated the project, and meant that technicians had to deploy rope access to abseil from the bridge structure to erect access platforms about 15 m from the ground – as opposed to the more traditional ground-up approach – using scaffolding.
The eight-span configuration bridge over the Crocodile river had each individual pier (column) to replace the old bearings with 80 elastomeric bearings.
However, prior to the ‘bridge-jacking’ operation, Skyriders was required to assist with the installation of temporary access platforms around each of the eight piers, which was followed by the installation of jacking brackets.
“Only one span (deck section) could be jacked at a time, whereupon the bridge bearings were replaced, enabling the team to move onto the next span,” Skyriders marketing manager Mike Zinn notes.
An eight-person team – which worked twelve-hour shifts, under the supervision of a Level 3 rope-access technician – oversaw the project, which took 20 days to complete.
“We have worked with construction engineering company and main contractor Stefanutti Stocks before, on power station maintenance projects, which made us a logical choice for this specialist undertaking,” he explains.
The Crocodile river bridge forms part of a larger rehabilitation project, which encompasses eight bridges and seven culverts along the 400 km stretch of the N4 freeway, in Mpumalanga, for main client concessionaire Trans African Concession.
Other projects and contracts being undertaken by Skyriders include ongoing work on new power station builds, inspection and maintenance of industrial smokestacks in Indonesia and a gold mine in West Africa, telecommunications tower maintenance in Johannesburg, and ongoing maintenance and inspection work at a large petrochemicals company, in Mpumalanga, in addition to work at State-owned power utility Eskom’s existing fleet of coal-fired power stations.
Skyriders offers a variety of rope-access-aided services – including nondestructive testing and inspection, concrete inspection, maintenance and repairs, application of coating systems, working-at-height safety systems and welding, all within confined-space – to industries such as power generation, petrochemicals, mining, heavy industry and facilities management.