Apart from their mere static and constructive functions our MSH sections were deliberately chosen to embellish the overall design of the traffic constructions - combining good looks with sleek cross sections and robustness.
The 6- to 8-lane expansion of the German Autobahn A7 from junction Bordersholm up north to junction Hamburg Nordwest leads through densely populated areas - a situation which demanded efficient noise protection measures. Several tunnels and more than 4 km of sound barrier constructions were included in the motorway design in order to fulfil stricter legal requirements in conjunction with increased traffic volume.
Appealing constructions preferred
The project developers regarded the motorway enclosures and gantries as part of the urban development and included their special design demands already in the tender. Sound barriers and gantries were supposed to be "of high aesthetical quality, featuring a clear and uniform styling as well as a discrete coloring". Elegant and fluent component leads to the tunnel portals were demanded both from the median and from the sidewalls. In order to fulfil these exceptional demands, the design was based on our circular MSH sections of higher wall thicknesses, which allowed a substantial reduction of the sections' outer diameters and hence much more filigree threecord and lattice trusses.
The working community ARGE A7 Bodersholm consigned the manufacturing, delivery and assembly of the steel constructions to Stahlbau Queck GmbH, Düren. The steel constructors were responsible for a total of 4,050 m of sound barriers, 21 gantries and 2 tunnel portals. The units were delivered and assembled in coordination with the overall construction process, frequently on a short-term delivery basis. Stahlbau Queck was substantially supported by the Duisburg based Stahlrohr GmbH, who apart from tube logistics were responsible for processing work on the tubular constructions. With their proprietary 3D-unit for laser and plasma cutting they were able to process the MSH sections manufactured by Vallourec and deliver them to Stahlbau Queck "cut to size and ready for welding". Right now, construction work on the A7 is still in progress and scheduled to be finished by the end of 2018.
Elegant sound barriers and gantries designed with MSH sections by Vallourec are part of the highway development project on the Autobahn A7 in Northern Germany.
A construction based on our circular MSH sections of higher wall thicknesses allowed a reduction of outer diameters for a slim design of the tubular threecord and lattice trusses.
Entrance to the 2.4 km long tunnel: elegant and fluent component leads from the upper projections of the sound barriers on the median and the outer sidewalls of the motorway to the tunnel portals.
All photos: DEGES