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Orphanage Road bridge

Due to an existing strong relationship, Network Rail approached MPB to re-examine the challenge under a two stage ECI process. Working collaboratively with Network Rail’s design and delivery teams, MPB developed an alternative construction methodology, refined the structural design to improve buildability, and produced detailed planning for the blockade works, including sequencing, logistics, and contingency arrangements.

Through this early engagement, MPB were able to demonstrate a safe, efficient, and deliverable solution within the 101-hour possession window, enabling Network Rail to confidently proceed. MPB then negotiated the implementation contract and successfully delivered all works within the planned blockade, validating the robustness of the ECI approach and restoring confidence
in the programme.

The successful reconstruction of Orphanage Road bridge stands as a clear demonstration of the value of true early contractor involvement. By challenging constraints, optimising design, and rigorously planning every aspect of the 101‑hour blockade, MPB delivered a solution previously deemed unachievable. The project not only restored a vital route into Watford but also reinforced Network Rail’s confidence in an innovative, collaborative delivery model, showcasing MPB’s ability to de‑risk complex rail infrastructure works and deliver precisely when it matters most.

CHALLENGES / SUCCESSES

A primary challenge was the off line construction of the 450 tonne replacement bridge deck, which demanded strict dimensional control to ensure compatibility with existing track geometry and structural interfaces. The subsequent installation using Self Propelled Modular Transporters (SPMTs) introduced additional technical risk, requiring accurate load distribution, controlled manoeuvring, and continuous monitoring to maintain stability during positioning.
The design and construction of piled retaining walls adjacent to operational railway assets required careful assessment of ground movements, vibration limits, and potential impacts on track alignment.
Track removal and reinstatement had to be completed within the possession window, with precise tolerances for ballast, rail alignment, and geometry to ensure safe hand back to Network Rail.

Collectively, these achievements showcase MPB’s skill in delivering demanding rail infrastructure works with expert management, assured execution, and dependable performance.

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