THE POWER TO MOVE BRIDGES

Power Team recently supplied high tonnage jacks and high pressure power packs to safely lift a bridge running over the Johannesburg N14 highway. The lift required extremely precise and reliable equipment to ensure the safety of traffic below, which continued to flow as usual.

“Bridges are being lifted in both Johannesburg and Cape Town to bring them into compliance with newly implemented legislated heights. By lifting the bridges an economically viable alternative to demolishing and rebuilding them is achieved. Highways in and around major metropolitan areas are the lifeblood of commerce. So closing a highway, for any period of time, is a less than favourable option. Rebuilding a bridge also costs in the region of seven million rand, so a safe, cost-effective alternative is always preferable,” says Ian Bennett, General Manager, Power Team SA (Pty) Ltd.

A total of twenty seven double acting jacks, providing a combined lifting capacity of 5049 tons, have been supplied. Each jack has a lifting capacity of 187 tons. The jacks are powered by three high pressure power packs. Each power pack has nine outlets, individually controlled using adjustable shut off valves.

“The process of lifting a bridge requires a high degree of precision to accomplish successfully. The bridge is first lifted using hydraulics. Steel and concrete spacers are then inserted to maintain the height. This process is repeated until the required height is attained,” says Bennett.

As a result of the harsh environment that the jacks are exposed to in the general construction industry, the Power Team jacks feature heat treated hard chrome plated piston rods, to reduce wear caused by abrasion. In addition, the jacks are supplied standard with a swivel load cap to reduce the effects of off-centre loading. The jacks also feature a built in relief valve on the retract side, which prevents over-pressurisation of the retract circuit and ensures that the hydraulic jacks provide a long and reliable service life.

“The supply of high tonnage jacks for a project in which the safety stakes are so high demonstrates the faith that the market places in Power Team products to provide effective solutions which can be used under the most demanding conditions,” concludes Bennett.