Project Overview
Kilnbridge is delivering one of its most complex and wide‑ranging project portfolios to date at Old Oak Common, supporting the construction of what will become one of the UK’s largest and most strategically important rail hubs.
The site spans more than a kilometre and is divided into the Western Box, Central Box and Eastern Box, with Kilnbridge delivering major structural, architectural, civil, utilities and steelwork packages across all areas.
The scale of the works, the density of interfaces and the operational constraints of the surrounding rail environment make Old Oak Common a defining project for the business, demonstrating its One Kilnbridge approach to single source service provision.
Kilnbridge is engaged under three principal contracts, covering five distinct work packages. These include ancillary buildings, station platform accommodation blocks, urban realm and utilities, bridge replacements, and a major secondary steelwork package.
Each work package carries its own technical challenges, but together they form an integrated body of work. This work is being collaboratively delivered by all four Kilnbridge operational businesses – Kilnbridge Structures, Kilnbridge Design and Engineering, Kilnbridge Structural Services and Kilnbridge Fire protection – in turn, supported by K-Plant and K-Fab, demonstrating the group’s integrated design‑and‑build resources and capability to deliver a multi‑disciplinary engineering approach.
The ancillary buildings package spans the full length of the site and includes a wide range of structures such as ventilation cores, portal buildings, accommodation and training crew buildings, canopies, substations and other specialist facilities.
These buildings incorporate reinforced concrete frames, precast elements, primary and secondary steelwork, cladding systems, glazing, louvres and multiple roofing types including green roofs and glazed systems.
Kilnbridge also holds full design responsibility for this package, taking the works from RIBA Stage 4 through to Stage 5. The scope extends to complete internal fit‑out, including raised floors, partitions, blockwork, offices, kitchens, toilets, ceilings, screeds, finishes and architectural metalwork. The envelope systems include corten steel cladding, green wall systems and a variety of façade treatments, each requiring precise coordination with structural and MEP interfaces.
An urban realm and utilities package of works covers extensive external works across the Eastern and Western Boxes, including deep drainage, utilities, hard landscaping, attenuation tanks, boundary structures and public‑realm elements.
The utilities scope alone involves more than five kilometres of cabling, potable water, fire mains, irrigation and adoptable services, installed within excavations reaching depths of up to eight metres.
Kilnbridge is also delivering multiple attenuation tanks, including two in‑situ tanks in the Western Box. This tank is a major engineering undertaking, with excavations exceeding eight metres in depth and a footprint of approximately seventy‑five metres by thirty metres. A smaller pre cast attenuation tank in the East Box.
Kilnbridge is responsible for all excavation, temporary works and final construction. Once the first stage is complete, the tank will be temporarily used as a live attenuation facility to support ongoing site operations.
The urban realm package also includes substantial earthworks and retaining structures, incorporating lightweight expanded aggregate fill to reduce loading on retaining walls and optimise structural design. These works require a combination of temporary and permanent retaining systems, in‑situ and precast walls, geogrid structures and complex sequencing to maintain access across the site.
The breadth of the package, combined with the depth of excavation and the density of utilities, makes this package one of the most technically demanding elements of the project.
A further package of work covers the station platform accommodation blocks located within the Central Box. This package includes eighteen accommodation blocks, six freestanding platform levels and twelve escalator block structures.
Kilnbridge is delivering the structural steel support systems for these areas, including beams, T‑level supports and twenty‑four V‑shaped intermediate supports that carry the escalator assemblies.
These works require precise alignment with the primary steel frame and careful coordination with architectural and MEP systems within the station superstructure.
Kilnbridge is responsible for two major new bridge structures: one spanning Old Oak Common Lane and the other spanning the London Underground Central Line.
These bridges support the realignment of the Great Western Main Line and the introduction of new rail approaches into the station. The works involve demolition, excavation, backfilling, permanent and temporary piling, sheet piling, reinforced concrete pile caps and abutments, precast beam installation, permanent formwork, reinforcement and in‑situ deck construction.
The programme for these works is exceptionally tight, with immovable possession windows and no opportunity for resequencing. A critical and time sensitive package, it requires absolute precision in planning and execution.
The bridge abutments also incorporate high‑quality architectural finishes. One abutment features a patterned architectural treatment, while the opposite abutment includes a wildlife‑themed finish with intricate fins and textured elements. The latter presents significant construction challenges due to its fragility and complexity, but both will form prominent visual features within the completed public realm.
Further demonstrates the company’s ability to work with different materials, Kilnbridge is designing, fabricating and installation secondary steelwork across the station platforms.
This includes purlins, canopy support structures and steelwork associated with the central overbridge escape stairs. All steelwork is being fabricated by K‑Fab, Kilnbridge’ fabrication team, before being installed on site. The package extends the full length of the platform zones and interfaces with primary steel, cladding systems and architectural elements that are being installed by other contractors.
Conclusion
Across all work packages, Old Oak Common represents a project of extraordinary scale, complexity and interdependency. The combination of deep excavations, major structural works, extensive utilities, architectural buildings, bridge replacements and large‑scale steelwork showcases Kilnbridge’s ability to operate across multiple disciplines with precision, reliability and technical excellence.