Partner Paul Monaghan and engineer James Cable were wide awake as the rest of the firm was fast asleep in bed recently, working through the night to witness Derby’s newest bow string arch bridge being slid into place.
The structure, located to the south east of Derby’s town centre, has been designed by HBPW and will play a major part in alleviating congestion in the East Midlands city. It replaces the former London Road over bridge which took the two lane A5194 across a total of seven railway lines and sidings, which form part of the Derby to Birmingham line.
Paul said: “From an engineering perspective this is a major step forward as well as a defining moment for the city itself.
“As part of engineering protocols James and myself had to be on site from midnight until around 3.30am as the bridge was finally manoeuvred into place. Once lowered – another engineering challenge in itself – the bridge deck and parapets will be cast and service diversions from the temporary bridge routed back along the new structure ahead of road surfacing. Hopefully normality should have returned by the end of 2014.”
James added: “Four old bridge spans have now effectively been replaced by two new superstructures. Three have been lost to the bow string arch bridge which, in turn, has also enabled two supporting piers to be removed to create a more open area beneath the new structure. In addition the vertical alignment has also been altered to increase minimum vertical clearance from the railway to 4.78m in order to allow for future electrification of the lines.”
The scheme also features a traditional pre-cast concrete bridge deck across the remaining Bombardier span.
