Previous rail experience played its part in bringing HBPW and AmcoGiffen together when a Victorian bridge in the Peak District National Park began showing signs of age.
The under bridge on Ashopton Lane near Hope in Derbyshire, began life as a stone structure in 1894 before a brick extension was added around 100 years ago, so that more lines could be accommodated.
Since then, it has served the rail and local communities faithfully but, as Partner Jon Livesey explains, time got the better of the bridge as water began to percolate through the stone arch barrel, loosening mortar and gradually compromising the structure.
“AMCO-Giffen asked us to work with them in the reconstruction of the stone arch which worked brilliantly because we had successfully delivered on a very similar project just 12 months earlier: the reconstruction of the MBW2/44 Diving Duck bridge at Whitby, North Yorkshire.
“That experience was crucial in ensuring the project went well because both parties knew exactly what to expect from the other – there was, effectively a technical template already in existence.”
Jon added “Network Rail had approached AMCO-Giffen after a routine inspection had identified that the bridge was showing signs of distress, indicating that part of it needed reconstructing urgently. Since we had the template, we were in a perfect position to accelerate the design process, using the SPEED & PACE principles. As a team, we promptly delivered a great outcome and a bridge that is now fit for purpose for at least another century.
“We were asked to retain the brick parts of the structure which were in good condition,” he added, “minimising disruption to the rail lines running into nearby sidings and a local quarry – all in regular use.
“We also had to turn detective, using archive records to demonstrate that the brick section of the bridge and the track bed it supports would be stable when the stone arch was demolished. “We used 3D models to help convey this and adjusted the design of the new bridge to minimise the demolition required in the blockade, which saw the installation of new cill units, a new pre-cast concrete deck and concrete robust kerbs.”
Location was also a key factor because of the heritage nature of the structure.
“The bridge is in the Peak District National Park and Park authorities asked us to maintain, as far as possible, the aesthetics of the original structure.”
To that end the bridge design was adjusted and the original bridge and parapets were carefully dismantled so that they could be reused as cladding and, as a result, the ‘new’ bridge continued to look distinctly ‘old’!
“It was a carefully managed and well implemented job,” added Jon, “requiring a substantial possession period but, thanks to some considerable planning, the bridge was successfully replaced and the overall look of this historic structure was maintained. A real triple result for ourselves, AmcoGiffen and Network Rail.