All national road bridges are inspected to a planned programme coordinated through the TII EIRSPAN Bridge Management System (BMS) thereby ensuring the integrity, resilience and reliability of the national road network.
Blackglen Bridge is one such bridge and carries the R113 over the M50 near Junction 13 in the Dún Laoghaire Rathdown region of south county Dublin. The bridge is distinguished by its pronounced skew and curvature and facilitates vital connectivity between the surrounding residential and commercial areas.
During a principle inspection of Blackglen bridge several structural cracks were observed in the upper portion of the central pier. Following a more detailed special inspection to determine the cause of the cracking and to appraise the capacity of the pier it was determined that a structural strengthening solution would be required.
This led to the detailed design of a stainless-steel strengthening ‘collar’ along with 8 No. stainless steel post-tensioned bars. Given its proximity to the M50 and its role in regional traffic flow a stainless-steel retrofit system was deemed most appropriate in terms of a long-life solution with low lifecycle costs.
Thanks to Leinster Bridge Management; the MMaRC Contractor GlobalviaJons; the main works contractor Jons Civil Engineering; the MCAAS consultant Atkins; the designer ROD; the original inspector and designer RPS and the fabricator Thompsons Steel for bringing the retrofit of this critical piece of national road infrastructure from concept to reality thereby ensuring ongoing resilience of the national road network with minimum disruption to the operation of the M50.
Explore photos and videos showcasing the works below:
Date published - 05.05.2026