Construction of HS2 Victoria Road tunnel shaft completed

WORK at HS2’s Victoria Road site in Acton has taken a significant step forward, following the completion of construction for the base slab of the Victoria Road ancillary shaft.

HS2’s main works contractor Skanska Costain STRABAG joint venture (SCS JV) began permanent work in February 2021, when a 160m3 concrete collar was first poured around the site of the shaft.

The internal shaft, which is 30 metres deep and 25 metres in diameter, was then built using precast concrete segments and using a sprayed concrete lining technique.

A team of around 30 engineers and operators have now completed the shaft, with a 3.3-metre-thick base slab constructed in three different pours.

The site at Victoria Road will be used by SCS JV to assemble and launch two tunnel boring machines that will dig the 3.4-mile eastern section of the Northolt Tunnels.

The tunnel boring machines are due to arrive from Germany in early 2023 and will begin the 12-month tunnelling programme later that year.

The ancillary shaft will then eventually provide ventilation and emergency access to the Northolt Tunnels when they are in operation.

SCS JV is also building a crossover box at Victoria Road that will allow trains to switch tracks on the way in and out of Old Oak Common station.

The site is due to be connected to the logistics hub at Willesden Euroterminal by a conveyor system that will remove spoil excavated for the tunnels for onward movement by rail.

“We’re constructing eight ventilation shafts along our 13 miles of twin bore tunnels in London, and this vent shaft is the first to advance to this stage,” said SCS JV Managing Director James Richardson.

“Work is progressing well at all our other shaft sites, so that they are ready for tunnel boring machines to travel through them as our huge tunnelling programme progresses over the next three years.”

The Victoria Road ancillary shaft in Acton is the first of eight in London where base slab construction has been completed.