Senior Engineer Damianos Bouklas got more than he bargained for when he was asked to be part of a major Network Rail (NR) demolition and bridge upgrade team.
HBPW’s man is one of the professionals playing his part in the wider Midland Main Line Upgrade, which has seen an additional line constructed between Bedford and Kettering, as well as the electrification of the line to Corby; it is the biggest engineering shake-up to the route since Victorian times.
And whilst he fully expected a range of engineering challenges, Damianos didn’t quite anticipate what he and colleagues discovered at Irchester’s Station Road overbridge in Northants…nesting brown long-eared bats living in the remnants of an old railway station which had been earmarked for demolition.
He said: “The Irchester overbridge, along with another similar structure – the overbridge at Isham, also known as Station Road – had been identified for a range of demolition and / or upgrade work to pave the way for electric trains.
“My initial job was to present a series of design proposals; did we lower the track level or raise the height of the bridges to make way for power lines?”
Specifically at Irchester there was a key challenge. Whilst the track level could have been lowered – half a metre was needed – the necessary engineering would have implicated structure foundations as well as a 1,000 metre stretch of line. The area was also prone to flooding and lowering the track at such a late stage, might have affected engineering work already completed to support an additional rail line planned for span four of the five span structure.
“In the event, the decision was taken to demolish and re-build arch four whilst raising the height of the entire bridge, not because it was a ‘cheaper option’, but simply because that approach had fewer implications for wider engineering disciplines. It was the easiest of two complicated engineering solutions,” said Damianos.
It was decided that the new bridge at Irchester would be a composite structure with integrated steel beams and pre-cast concrete segments.”
However, some would argue that the engineering part finished up being the easy bit!
“We always knew about the remnants of the old railway station adjacent to the original bridge, however, what we didn’t anticipate was bats which rapidly shifted our engineering thinking
All works eventually went ahead but only after a string of surveys and detailed planning, lasting months, had taken place, enabling the endangered creatures to be carefully moved.
“Bats are heavily protected in the UK,” added Damianos, “so this was no mean feat. In the final event – following the demolition and re-build of arch four at Irchester – the remaining four spans were upgraded courtesy of a concrete overslab which waterproofed the structure from above.
“I think it is fair to say that this was one of my more challenging assignments for a variety of reasons!” Work on Isham Road continues.
Rob McIntosh, Route Managing Director at Network Rail, said: “We are doing a huge amount of work to railway infrastructure on this stretch of the Midland Main Line to allow overhead wires to be installed.
“(And) we’re investing over £1billion in this project which will help to deliver the railway of the future, one which meets the needs of the communities and economies which our railway serves.”