Expanded has been appointed by Balfour Beatty, Vinci Systra joint venture (BBVS) to deliver the reinforced concrete structure that will form the frame and base for the HS2 station building.

Construction will see Laing O’Rourke company Expanded excavate 20m below ground level removing 690,000 cubic metres of clay, before placing 32,000 tonnes of steel and pouring 190,000 cubic tonnes of reinforced concrete.

The “top down” excavation will allowsthe ground floor slab to be constructed initially with a series of mole holes allowing access for the large excavators to remove the earth from within.

The box at the east of the site allows the Tunnel boring machines (TBM) to be launched towards Euston. The west of the site is where the spray concrete lined tunnel between Old Oak Common and the Victoria Road Crossover box finishes.

Work to build the station will provide 2,300 jobs (with Expanded providing 500 of those, including 10 apprentices) and act as a catalyst for the UK’s largest regeneration project in the Old Oak and Park Royal area.

HS2’s Deputy Project Client for Old Oak Common Station, Rob Avery, said: “The start of work on the gigantic station box structure is a key milestone for the team at Old Oak Common. Work is progressing well on site and we are pleased that Expanded have now joined us on site as the programme continues to move forward.”

Expanded Business Unit Leader Peter Lyons said: “The award of this contract builds on our extensive experience in the rail sector, especially in London and will see us work on another HS2 project where we have previously delivered bridges utilising our modular bridges capabilities.

“We are proud to be joining forces with the BBVS joint venture in delivering the main station box. We began pre-construction works in May and the team are pleased to have now started this mammoth task.”

Designs for the station show that the six high-speed platforms will be situated underground with an integrated connection to the adjoining conventional station by a split-level public concourse and dramatic conventional rail overbridge to provide seamless interchange.

These are unified by a vaulted roof inspired by the site’s industrial heritage.

BBVS Project Director Nigel Russell said: “We are pleased to be working with Expanded on the delivery of the station box, which represents an integral part of Old Oak Common Station.

“The reinforced concrete box will form the frame and base for the new state of the art HS2 station building as well as the six underground high-speed platforms.”

Old Oak Common will provide high-speed rail services to the Midlands, Scotland and the North and trains to central London and Heathrow and Wales and the West of England.