Seven bridges for motorway widening
Rowecord Engineering has fabricated, supplied and erected a total of seven new steel bridges over the M1 motorway, as part of the on-going widening scheme taking place between junctions 6A and 10.
Main contractor Balfour Beatty/Skanska joint venture is widening the motorway to four lanes, with continuous hard shoulders, in both directions on a 17km-long stretch of highway from the M25 through to Luton.
The seven new bridges are all replacement structures and include three accommodation single lane access bridges, two double lane bridges at J10, one double lane structure at Slip End and the four-lane wide Breakspear overpass at J8.
The J8 bridge was the last structure that Rowecord fabricated and erected. This 115m-long bridge was lifted into position in four main sections per span, each weighing 35t.
All of the bridges are supported on mid-carriageway concrete pillars and concrete abutments.
“We lifted all the bridge sections in pairs of braced girders,” said Wayne Powlesland, Rowecord Contracts Manager. “This reduces installation time and provides better overall stability.”
The erection programme involved a number of nighttime closures of the M1, as well as some rolling block closures. Rowecord estimated that the majority of lifts were completed in six hour possessions.