Federal-Mogul Corporation has announced the development of maintenance-free bearings for one of the world’s longest suspension bridges. Upon completion later this year, the Hardanger Fjord Bridge in southwest Norway will be one of the largest in the world, spanning 1,310 meters (4,297ft) between pylons.
A total of 128 spherical plain bearings using Federal-Mogul’s DEVA® self-lubricating material technology will accommodate the small but essential movements that occur between the bridge and its supporting cables.
The complete bridge includes 120 spherical plain bearings with a shaft diameter of 160 mm and eight with a shaft diameter of 300 mm, used for the main retaining cables adjacent to the two bridge towers. The joint balls are made from stainless steel, which is pressed into a plain bearing made from deva.bm. A low-friction sliding bearing consists of a backing comprised of steel, stainless steel or bronze, with a deva.metal® surface layer. This surface layer is a bronze material manufactured using powder metallurgy – it is not porous and oil-impregnated, but rather highly compressed and coated with a layer of solid lubricant material, such as graphite or PTFE.
“Wind pressure, load and vibrations from traffic flow and temperature changes are all contributors to road movement on suspension bridges,” stated August Stadlmayr, managing director of Federal-Mogul DEVA GmbH. “The Hardanger Fjord bridge was particularly challenging because of its length and the loads generated, so we are pleased to have developed such a low-maintenance, yet highly effective solution.”
Conventional roller bearings were not well-suited for the prolonged, minute movements of the bridge while under constant heavy load and could potentially suffer from surface failures called ‘brinelling.’ Federal-Mogul’s thin-walled, self-lubricating sliding material, deva.bm®, addresses this issue by providing a larger load-carrying surface, providing sufficient durability for the life of the bridge without repair or replacement.
This is not the first time that DEVA plain bearings have provided reliable, low-maintenance solutions for bridge construction projects. A number of bridges around the world benefit from this Federal-Mogul technology, including the flap bridge in the port of Valencia, Spain over which the Formula 1 race circuit passes; the bridge over the Peene near Anklam, Germany; and the Rethe Bridge in Hamburg, Germany.
Posted by: Paul Whittaker, Editor ipmd.net, [email protected]