The Great Western Main Line is one of the country”s most important arterial routes, linking London and the south-east to Bristol, Wales and the west. Network Rail is currently electrifying the line by installing 25kV AC Electrified Overhead Line Equipment (OLE).
As part of this upgrade work, two road bridges spanning the line in Newport were scheduled for demolition and subsequent immediate replacement. The B4237 Somerton Road overbridge (a 3 span, 35m long steel girder and brick arch construction) and the B4237 Cardiff Road overbridge (2 span, 25m long, steel and brick arch construction), both crossing the South Wales Main Line, were designated as requiring reconstruction to accommodate the OLE.
In order to minimise disruption to passengers, both bridges were scheduled to be demolished at the same time during an abnormal track possession over Christmas Day and Boxing Day. Walters would have just 48 hours to completely remove both bridge structures, in different parts of the city, in order to free up the track for our customer, Carillion, to commence work on the replacement bridge structures.
This delicate and time sensitive job signified Walters”s first major venture into working “on-track” in the rail sector.
Engaging with a trusted, specialist, temporary works design partner, Walters studied historical records of the construction of both bridges and developed a safe demolition sequence for each. A bespoke rail track protection system comprising polystyrene blocks and hardwood timber mats, was placed onto the track to allow Walters access to demolish the structures to the agreed sequence. All arisings from the demolition were removed from site by Walters to allow the bridge reconstruction works to continue.
Walters undertook the removal of the bridges using a combination of demolition specific machines and attachments ranging in weight up to 50t. Over 60 directly-employed demolition operatives, all of whom had received rail specific training, worked at the two sites on Christmas Day and Boxing Day 2015.
The works were completed safely and successfully within the allocated abnormal possession period, allowing Carillion to commence reconstruction works.