HS2 Colne Valley Viaduct wins design award
26 Nov 2024Colne Valley Viaduct named winner in the 'engineering' category of the Royal Fine Art Commission Trust’s Building Beauty Awards - 2024
25th Aug 2022
Align JV completes first tunnel cross passages
As the tunnelling machines under the Chilterns approach the four-mile mark, our Align JV completes the first of thirty-eight underground connections between the northbound and southbound tunnels.
The construction of HS2’s longest tunnels stretching for 10 miles under the Chilterns has begun a new phase with the start of work on thirty-eight cross passages linking the northbound and southbound tunnels.
The Chiltern tunnels will carry high speed trains between London and the North at speeds of up to 200mph (320km/h). The trains will travel through two parallel tunnels linked by short passages for use in emergencies.
With the two giant tunnelling machines, named Florence and Cecilia, now almost four miles into their journeys, attention has turned to the first cross passages.
An expert team of miners used a remotely controlled excavator to break out of and excavate from one running tunnel to the adjacent tunnel. As the excavation is progressed the ground is supported using a sprayed concrete lining (SCL).
Delivered by HS2’s main works contractor, Align – a joint venture formed of Bouygues Travaux Publics, Sir Robert McAlpine, and VolkerFitzpatrick – each passage is between 15 and 20 metres in length.
Once the team had completed the SCL lined tunnel, a water-proof membrane was installed followed by a secondary concrete lining constructed by placing concrete behind formwork installed in the cross passage.
Martyn Noak, HS2 Ltd’s Head of Tunnel Engineering, said:
“HS2 is making huge progress, with 25,000 jobs supported by the project, construction in full swing between London and Birmingham and now the start of this new phase of tunnelling work under the Chilterns.
“While invisible to the travelling public, the cross passages have a key role in providing a safe operational railway. In an emergency they allow the safe evacuation of passengers into a place of relative safety in the other tunnel. Constructing cross passages is different than using a tunnelling machine as the ground is excavated in short lengths with each advance being left unsupported for a short period of time until the sprayed concrete lining is installed. It is a different set of risks and a specific skilled workforce is needed.
“It’s great to see the first one complete and I’d like to congratulate everyone involved in this important milestone, one down 37 to go.”
The completion of this cross passage is a significant milestone for the team at Align JV, delivering the first mined cross passage on HS2 phase 1. I’m proud of the team, their hard work and collaboration to get us to this point.
Daniel Altier Align Project Director
Once the passageway is complete, the safety doors can be installed at either end. These are being manufactured by Booth Industries who won the contract to provide more than 300 units for all the tunnels between London and Birmingham.
The win allowed Booth Industries to establish a new facility in the town and create up to 50 jobs over the next 10 years. The sliding doors have been subjected to rigorous fire and fatigue testing to take account of the train speeds, associated pressures and frequency of the trains.
Each running tunnel has an emergency walkway that allows passengers to safely evacuate the train and walk through the cross passages into the other tunnel where they can be rescued on a passenger train. Access for emergency services is from either the portal or one of the five ventilation/emergency access shafts.
Find out more about HS2
-
![]()
Read more about -
![]()
Read more aboutLast segment of Colne Valley Viaduct installed
06 Sept 2024The Colne Valley Viaduct becomes Britain's longest rail bridge after Align JV reaches this major milestone for HS2.
-
![]()
Read more aboutSector profile: Mike Hickson, Managing Director of Defence
01 Jul 2024Mike Hickson, Sir Robert McAlpine’s newly appointed Managing Director of Defence, shares his vision for the sector and his ambitions for the year ahead.
Latest Infrastructure news
-
![]()
Read more aboutGreen Apple award for project with sustainability at its core
27 Nov 2024The sustainable approach to delivery taken by our AmeySRM JV team on the A533 Expressway Replacement Bridge Scheme has seen the project honoured with an international Green Apple Environment Award.
-
![]()
Read more aboutHS2 Colne Valley Viaduct wins design award
26 Nov 2024Colne Valley Viaduct named winner in the 'engineering' category of the Royal Fine Art Commission Trust’s Building Beauty Awards - 2024
-
![]()
Read more aboutA19 named England’s No1 road
08 Nov 2024The Strategic Roads User Survey by Transport Focus highlights the remarkable success of the A19 DBFO Project.
Latest news
-
![]()
Read more aboutMaggie's Northampton topping out
21 Feb 2025Sir Robert McAlpine Special Projects celebrates the topping out of Maggie’s Northampton, a new cancer support centre at Northampton General Hospital, marking a key milestone in providing expert care for those affected by cancer.
-
![]()
Read more aboutCaroline Mulholland on good design in Healthcare
12 Feb 2025As IHP is Lead Partner of the EHD Champions Awards, Caroline Mulholland reflects on the significance of design in healthcare, international best practice and lessons from the Awards.
-
![]()
Read more aboutNational Apprenticeship Week 2025 with Jack Chapman
11 Feb 2025In support of National Apprenticeship week, we caught up with Trainee Quantity Surveyor Jack Chapman to hear about his experiences and progress on the path to a rewarding career.
