M4 Blagrove Railway Bridge

From the outset, CRL worked collaboratively with Skanska Infrastructure Services through Early Contractor Involvement to develop a robust methodology suited to the site’s significant constraints. Access to the bridge was restricted to night possessions, with entry only available via the M4 close to Junction 16, requiring a carefully planned logistics strategy. A temporary support structure was designed and installed to provide a stable platform for welfare, storage and plant, ensuring all facilities were in place at the start of each possession and removed safely at the end.

One elevation of the bridge was scaffolded and fitted with a protection screen, while a scaffold staircase provided controlled access from the motorway down the embankment to the railway interface. Tower access was used to reach the soffit and one side of the structure, with the tower erected and dismantled during every possession, demanding precise sequencing and strict adherence to safety procedures.

Concrete repairs were undertaken to the soffit, beams and abutments using methods appropriate to the scale and condition of the defects. Major repair areas were removed using hydrodemolition, allowing controlled breakout while minimising damage to surrounding concrete. These areas were then reinstated using sprayed repair techniques to achieve durable, well-compacted repairs. Smaller defects were broken out by hand and reinstated using hand-placed repair materials.

Galvanic anodes were installed to provide localised corrosion protection within repaired areas, supporting long-term durability. Additional works included replacement of mastic joints to wingwall movement joints and application of anti-graffiti coatings to abutments and wingwalls. All activities were delivered safely under night possessions in close coordination with Highways England, Swindon Borough Council and Network Rail.