Demolition of Somerton Road Bridge
Client: ABC Electrification, Network Rail
- Road over rail
- 35m long, steel girder and brick arch bridge
- On track demolition
- 52hr railway possession
- 30 operatives working 2 shifts over Christmas Day
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 project, the B4237 Somerton Road overbridge (on the South Wales Main Line in Newport) was designated as requiring reconstruction to accommodate the OLE. Walters were faced with the difficult task of removing the three-span bridge deck under a blockade of the railway line on Christmas Day and Boxing Day 2015, without causing any damage to the railway infrastructure.
This job, along with the Cardiff Road bridge demolition project (which was undertaken concurrently with Somerton Road Bridge), signified Walters’s first major venture into working ‘on-track’ in the rail sector.
Walters engaged with a trusted, specialist temporary works design partner, to study historical records of the bridge construction and jointly develop a safe demolition sequence for the Somerton bridge structure. Once finalised, the demolition sequence was submitted to Carillion and Network Rail for review and design checking.
Walters undertook the removal of the bridge using a combination of demolition specific machines and attachments ranging in weight up to 50t. Over 30 directly employed demolition operatives, who had all received rail specific training, took part in the scheme over a 24hr period on Christmas Day 2015.
Railtrack protection system
A bespoke rail track protection system was designed and laid in the form of polystyrene blocks and hardwood timber mats, allowing Walters specialist demolition plant to access the rail to demolish the structure to an agreed sequence.
All arisings from the demolition were removed from the track protection deck to local off-track storage areas by trucks. Due to the size of the main steel span, a 1000t crane was also used to assist with the removal. Once the ‘on-track phase’ of the work was completed, Walters removed all rubble, soil and steel arisings from site to allow the bridge reconstruction works to continue.
The works were completed successfully within the allocated abnormal possession period, allowing Carillion to commence reconstruction works on Boxing Day.
Follow the link to view a short timelapse video of this contract.