High Speed 2 (HS2) Ltd and the Department for Transport (DfT) face a dilemma over whether to press ahead with construction of a 7km tunnel linking Old Oak Common with Euston later this year after the station project itself was put on pause earlier this month. The £1.2bn tunnel is due to start construction in the coming months with tunnel boring machines working from the Old Oak Common station box eastwards to meet the existing railway north of the station. HS2 confirmed that some elements of the Euston Tunnels project will be paused, with critical work ongoing. It is understood that some work along this section of the HS2 route will be brought to a safe stop, and critical preparatory work continuing. Work that will continue includes the extension of Granby Terrace Bridge and associated utilities works in the Euston Approaches, and the completion of the Atlas Road logistics tunnel between Old Oak Common station site and the Atlas Road site. The preparation works for the launch of the two TBMs from the Old Oak Common Box towards Euston will also continue. Works at the Adelaide Road Vent Shaft and Headhouse, and Canterbury Road Vent Shaft and Headhouse however will be brought to a safe stop, along with non-critical works on the Euston Approaches site. A HS2 Ltd spokesperson said: “In line with direction from the Government, some HS2 work between Old Oak Common and Euston is being paused and rephased with only critical preparatory work continuing during this time. We are working with our contractors to manage the impacts of these changes. “The government remains committed to delivering HS2 from Euston to Manchester and these vital tunnels will enable high speed services into central London – creating jobs, better connecting our country and giving people more zero carbon transport alternatives.” The works are set to be undertaken by a joint venture between Skanska, Costain and Strabag (SCSJV), which has been contracted to design and construct the final 26.4km of the HS2 route from the Chilterns to the London terminus. In June last year the SCS joint venture was handed an additional £78M for its role in delivering the approach tunnels to Euston station.

The Total Contact is Valued At £1.2Bn And HS2 Stated.

at the time that the additional funding was within contingencies set aside in phase one’s £44.6bn budget. The issue for the government is that if the tunnelling aspect of the project is delayed, then it could cost millions to resume tunnelling at a later date once Old Oak Common station has become operational for Phase One of the new high speed rail line. Transport Secretary Mark Harper announced earlier this month that Euston station would be put on pause for two years while work was undertaken to find a solution to the ballooning cost of the 10-platform terminus. The cost in 2019 had been £2.6bn, however this rose by another £2.2bn to £4.8bn in the latest estimates. Euston isn’t the only part of the HS2 project which has been paused by the government with work at Crewe also halted for two years and works expected to be rephased to now complete in the middle of the next decade. At the weekend communities secretary Michael Gove told Andrew Neil’s Channel 4 TV show that he couldn’t confirm whether the Euston terminus would go ahead. However, at a select committee meeting on Wednesday prime minister Rishi Sunak recommitted to the London terminus at Euston, stating there was nothing “ambiguous” about the final southern station for the high speed line. Tunnelling specialist Bill Grose said he expected the sensible option in lieu of a firm decision on Euston could be to safeguard aspects of the route for construction sometime in the future. “I expect that HS2 will look carefully at the implications of mothballing the tunnels, and make sensible provisions to be able to complete the drives without disrupting the operating railway,” Grose told NCE. “There’s always a capital cost involved with mothballing any part of an infrastructure project – redesign, route safeguarding measures, disposal or protection of existing assets, etc, and HS2 will be working those out. “It would be hard to justify boring the tunnels if there is not a commitment to build Euston Station, straight away or at some time in the future. If there is a strategic commitment but no funding, ie mothballing, then it would be more sensible to safeguard now for construction some time in the future.” In an update on the project published in October 2022 SCSJV and HS2 said they planned to begin excavating parts of the the 7.2km tunnels in late 2023 including the Euston Cavern, a large underground structure at the eastern end of the tunnel where one tunnel splits into two. Other areas to begin construction included the Euston Portal and the Euston Throat Railway Cutting, which would allow trains to access different platforms at the station. Tunnelling was expected to take aroudn two years to complete. A National Audit Office report published earlier this week into the costs of the station called for a “reset” of the Euston terminus project and warned that any delay could worsen cost increases. Speaking to NCE one civil engineering expert questioned the wisdom of proceeding with the 7km tunnel if the station isn’t definitely going ahead. “If they’re going to do the tunnel and not the station, that is absurd,” they said. “If you’ve built the tunnel, the station [at Euston] is the least of your problems. “Why would you not build the part of the project such as the station, which at least gives you some money at some point, but you would build the risky and rather expensive tunnel?”