Milestone

Balfour Beatty VINCI SYSTRA completes Old Oak Common platforms

By Staff Writer  |  15 August 2026

Balfour Beatty VINCI SYSTRA has completed the six high-speed underground platforms at Old Oak Common station, each of them 450 metres long, and the station now moves into its fit-out phase.

The joint venture announced the completion on 13 August 2026. The six platforms sit within the station's underground box and will serve the new high-speed fleet running between London, the West Midlands and destinations further north.

The platform works involved the installation of almost 2,000 precast concrete platform slabs, each weighing up to five tonnes. Those slabs were laid after the construction of reinforced concrete invert walls below platform level. Teams worked simultaneously from either end of the station and connected in the centre, completing a three island-platform arrangement. Service voids were built beneath the platforms to take future operational infrastructure.

Attention now turns to fit-out. The joint venture has begun construction of equipment and staff accommodation, installation of lifts and escalators, and preparation for the final architectural finishes. Work also continues on the station superstructure, the surface-level platforms and the rail connections that tie the station into the wider high-speed network. Eight surface-level platforms are being built alongside the six underground ones.

Steve O'Sullivan, project director at Balfour Beatty VINCI SYSTRA, said: "We are now focused on the next stage of construction as the station continues to take shape."

When it opens, Old Oak Common will connect high-speed services with the Elizabeth line, the Great Western Main Line and Heathrow Express.

What the practitioner should take from this

A structural completion inside a much longer programme is a point at which commercial exposure usually shifts rather than falls away. Three questions are worth asking on any project reaching the same stage.

The first is what the completion actually releases. Where a works package has been certified as complete but the following trade cannot start, the delay sits between two subcontracts and the entitlement depends on whether the interface dates were fixed in each of them or only in the main programme.

The second is access. A station box in which platform construction has finished and fit-out has begun is a shared working area. Where several subcontractors work in the same volume, the record of who had access to what, and when, is the evidence that later decides a disruption claim. That record is cheap to keep while the work is happening and impossible to reconstruct afterwards.

The third is the treatment of works left deliberately incomplete. Service voids built now for equipment installed later create a boundary between the party that formed the void and the party that fills it. Where the later installation does not fit, the argument turns on the setting-out information issued at the time and on who approved it.

None of that is a criticism of this project, on which no dispute has been reported. It is the ordinary commercial anatomy of a station handed over in stages, and the point at which the paperwork is worth checking is the point at which a stage is signed off, not the point at which somebody complains.