by Keri Allan
24 Nov 2022
HS2’s tunnel boring machine (TBM) Dorothy has begun its second one-mile tunnel bore under Long Itchington Wood in Warwickshire.
This is the first HS2 TBM to be reassembled and reused, and marks the next construction milestone on the northern section of Phase One.
Named after Dorothy Hodgkin, the first British woman to win the Nobel Prize in Chemistry, the TBM’s inaugural launch took place last December, and became the first to complete a HS2 tunnel drive this July.
Since the breakthrough, the TBM’s 1000-tonne gantries have been brought back through the tunnel and reassembled at the north portal.
The 10-metre diameter cutterhead, weighing 160 tonnes, was moved by road during an intricate night-time operation in September, while Dorothy’s 130-tonne tail skin and eight other large pieces from the front and middle shield were also transported using specialist equipment.
Four other HS2 TBMs are currently in the ground, digging twin bore tunnels under the Chilterns and London.
When Dorothy breaks through next summer, Long Itchington Wood Tunnel will be the first twin tunnel to be completed on HS2.
“After celebrating HS2’s first historic tunnel breakthrough in July, this TBM reassembly and relaunch is another first for the HS2 project.
“One year after Dorothy launched for her first drive, she’s now set off for the second bore, and we look forward to seeing the next HS2 tunnel breakthrough in summer 2023.”
This tunnel forms a key element in how HS2 manages environmental impacts through the design of the railway, as the wood is classified as a Site of Special Scientific Interest (SSSI).
Excavation of the twin bore tunnel will produce around 500,000 tonnes of mudstone and soil.
This is being processed at an on-site slurry treatment plant and separated out before being transported by a 254-metre conveyer to be used to build embankments along the route of the railway.
HS2 workers have completed the first base slab concrete pour at the western end of Old Oak Common station, advancing progress on the key infrastructure project....
With Railtex taking place in Birmingham, we take a look at the history of Birmingham’s Curzon Street within the context of HS2.
Jonn Elledge on the absolute madness that is terminating HS2 at Old Oak Common rather than Euston for the foreseeable future.
HS2 has received design approval for Small Dean Viaduct, which will take HS2 trains across the A413 and local rail lines.
Skanska Costain STRABAG JV has launched HS2's third London tunnel boring machine (TBM), 'Lydia' to construct the Atlas Road Logistics Tunnel.
A tunnelling milestone for HS2: the tunnel boring machine Dorothy has broken through on the second bore of the Long Itchington Wood tunnel.
The National Audit Office has released a report evaluating whether the DfT and HS2 Ltd can effectively manage the delivery of HS2 Euston.
Over 40bn GBP will be invested in the UK's transport network over the next two years, with a focus on delivering the first phase of HS2.
The two tunnel boring machines (TBMs) digging HS2’s longest tunnels has passed Amersham shaft on their 10 mile drive under the Chilterns.
HS2 has proposed changes to the construction design of its Manchester route following work with the UK Environment Agency.
New plans have been put forward to improve access to the proposed HS2 and Northern Powerhouse Rail station at Manchester Airport.
The High Speed Rail Group and HS2 Ltd have both hit back at a report created by the Cheshire Wildlife Trust about HS2's environmental impact.
Birmingham City Council has granted planning permission approval for HS2's Washwood Heath Depot, north-east of Birmingham city centre.
HS2's tunnel boring machines, Florence and Cecilia have passed the halfway point on their 10-mile journey excavating the Chiltern tunnels.
HS2 Ltd’s contractor, Align JV has installed the last of 292 concrete piles, forming the foundations for the UK’s longest railway bridge.
Network Rail has upgraded Banbury train depot to keep trains moving on the Chiltern main line during HS2 construction.
The first five-metre-tall V-shaped pier for the Curzon No. 3 Viaduct into HS2's Curzon Street Station in Birmingham has been installed.
A bridge that will carry direct rail services between Oxford and Cambridge has been positioned over the HS2 route near Calvert, Bucks.
HS2 has revealed designs for the Curzon 2 bridge: a 150-metre section of viaduct on the approach to Birmingham’s new Curzon Street Station.
Huw Merriman MP, Minister of State at the Department for Transport, will give a keynote address at this year’s Rail Industry Forum.
HS2 's Euston site construction team Mace Dragados Joint Venture is trialling a hydrogen fuel cell to power a fully electric JCB telehandler.
A second 140 metre long, 2,050 tonnes tunnel boring machine (TBM) has begun its journey across London for HS2.
The West Midlands Rail Executive (WMRE) has revised its strategy on how to grow and develop the region’s rail network over the next 30 years.
HS2’s workforce has almost hit the 30,000 mark. This is down to the recruitment of 2,300 new employees in the last three months.
HS2’s main works contractor, EKFB, has started working on two of the project’s longest cuttings in Buckingham and Oxfordshire.
HS2 has launched the first of six tunnel boring machines (TBMs) that will dig more than 26 miles of tunnels under London.
HS2 Ltd has opened applications for tech start-ups and SMEs to join the fifth group of its Innovation Accelerator programme.
HS2 has commenced work on the thirty-eight cross passages that will link the northbound and southbound Chiltern tunnels.
Dorothy, HS2’s 2000-tonne tunnel boring machine, has made its first breakthrough on the UK's high-speed rail line from London to Birmingham.
HS2 Ltd has contracted Laing O’Rourke to build the HS2 Interchange Station in Solihull at the heart of the high-speed rail network.
The first design images have been revealed for HS2’s maintenance and control centre at the Washwood Heath Depot in Birmingham.
Transport companies have to have resilient cybersecurity systems in place so they can protect their assets and detect and respond to incidents.
Birmingham City Council has granted planning permission to HS2 Ltd to construct two viaducts in Birmingham.
HS2 has begun construction of the first of five ‘green tunnels’ that have been designed to blend into the landscape.
Balfour Beatty VINCI Joint Venture is trialling an electric, high-capacity drilling rig for construction in Warwickshire.
HS2 has announced that OpenSpace Group Ltd is using artificial intelligence (AI) and LiDAR sensors to develop future train stations.
Construction of the Colne Valley Viaduct has now started, overseen by HS2’s main works contractor Align JV.
HS2 has reached an agreement to purchase Square One on Travis Street, Manchester from property provider Bruntwood.
Jonn Elledge looks at the story behind Andy Burnham's pointed comments about the exorbitant costs of rail fares in Britain.
HS2 has unveiled updated environmentally-friendly designs for the Cubbington, Warwickshire section of the new high speed line.
HS2 has unveiled the final designs for the Thame Valley Viaduct, which will cross the River Thame’s flood plain near Aylesbury.
HS2 has unveiled designs for Chiltern Tunnel’s north portal, which focus on cutting noise from trains as they enter and exit the tunnel.
A new report highlights the role of HS2 and high speed rail in general in reducing emissions and ultimately achieving net zero.
The two tunnel boring machines digging the HS2 twin tunnels under the Chilterns have reached the ventilation shaft at Chalfont St Peter.
HS2 has shared updated designs for its high speed railway terminus station at London Euston, which will be set across three levels.
The Mace and Dragados joint venture (MD JV) – HS2’s construction partner for Euston station – is ramping up procurement this month.
A new piling technology, known as hollow impressed precast energy reusable pile (HIPER), is being trialled at HS2’s Euston station site.
HS2 has signed the Rail Supply Group’s Work Pipeline Visibility Charter and will share its rail systems' technical specifications publicly.
The ‘High Speed Rail (Crewe-Manchester) Bill’ – HS2 Phase 2b Western Leg – will be introduced in parliament today (24 January 2022).
HS2 has chosen TK Elevator to manufacture and install approximately 160 lifts and 130 escalators at its four main stations.
HS2 archaeologists have excavated a vast roman settlement in Northamptonshire - one of over 100 sites HS2 has examined since 2018.
HS2 has published its Net Zero Carbon Plan, which sets out how it plans to make the project net zero carbon from 2035.
HS2 has revealed the first images of its 1.5 mile-long Greatworth tunnel - one of three ‘green tunnels’ to be built in Bucks and Notts.
Balfour Beatty VINCI (BBV) has launched a recruitment drive to support HS2 construction works planned for 2022 and beyond.
Jonn Elledge gets into the Christmas spirit and does some finger-pointing as to who is really to blame for the state of Britain's railways.
The first of 56 giant concrete piers for the Colne Valley Viaduct has been cast. Once complete, this will be the UK's longest rail bridge.
The contract to design, build and maintain the HS2 rolling stock fleet for Phase 1 London-Birmingham has gone to the Hitachi Rail-Alstom JV.
The first tunnel boring machine working on HS2 in the Midlands launched on 2 December, excavating a one-mile tunnel in Warwickshire.
As part of Alstom's acquisition of Bombardier Transportation, the companies agreed to divest a number of assets, including the V300 ZEFIRO.
Stanton Precast has been awarded the contract to deliver three 'green tunnels' for HS2 by the main works contractor EKFB.
Work on HS2’s Old Oak Common 850-metre-long station box has begun. The reinforced concrete structure will form the station's frame and base.
The Integrated Rail Plan published today, 18 November 2021, announces a huge slash in new railway lines being built in England.
HS2 has published a shortlist of bidders for the Phase 2a Design and Delivery Partner contract. The winner will be announced next summer.
In this month's column, Jonn Elledge muses on the future of HS2's eastern leg and the political tug of war taking place behind the scenes.
HS2 tunnel boring machine ‘Florence’ has passed the one mile mark, cutting through a mix of chalk and flint beneath the Chiltern hills.
HS2 has invited six bidders to tender for a major two-part enabling works contract for its recently approved Phase 2a section.
One year on from the start of phase one's construction, HS2 has announced that 20,000 people are now working on the high-speed rail project.
HS2 has confirmed the shortlist of bidders to build its control centre and rolling stock maintenance depot.
HS2 Ltd has published revised images of the Adelaide Road headhouse in Camden, after changes were made to the design.
Images of HS2’s Chesham Road rural headhouse, which will provide emergency access to the 10-mile-long Chiltern tunnel, has been unveiled.
The companies shortlisted to build HS2's Interchange Station in Solihull have been named by HS2 Ltd. The contract is to be awarded in 2022.
Leaders from across Yorkshire and the North East of England have contributed to a report demonstrating the importance of HS2's Eastern Leg.
SCS JV has signed the first of two contracts for the production of tunnel segments that will be used to construct HS2’s London tunnels.
In a UK first, on-site 3D reinforced concrete printing will be deployed by HS2's London tunnels contractor SCS JV.
Excavation of the vent shaft at Chalfont St Peter has begun in Buckinghamshire. It is the first of five on the HS2 Chiltern tunnels section.
HS2 designers are set to more than halve the amount of embedded carbon used in one of the high-speed rail project’s viaducts.
HS2 has begun its search for a team of specialist ground investigation contractors for the western leg of Phase 2b from Crewe to Manchester.
HS2 has launched Cecilia, the second of two 2,000t tunnelling machines that will excavate ten-mile-long tunnels beneath the Chiltern Hills.
Permanent works on HS2's Old Oak Common station have got under way today with phase 1 seeing the construction of a 750,000m3 underground box.
HS2 has obtained approval for a scheme that will use excavated material to create new chalk grassland, woodland, wood pasture and wetland.
HS2 begins search for a construction partner to build Interchange Station. This will be at the centre of the new high speed rail network.
HS2 Ltd has revealed a new vacuum excavation technique for piling which could have massive benefits for the wider construction industry.
HS2 has deployed the first of 10 tunnel boring machines (TBMs) that will be used during phase one of the UK’s new high speed railway.
HS2 has confirmed that a team made up of Mace and Dragados will build Birmingham’s new city centre high speed railway station.
HS2 has presented its design of the Oxford Canal Viaduct that will measure 62.5m and span the canal and towpath between Banbury and Daventry.
HS2 Ltd has published its shortlist of companies it has asked to tender for the high-speed railway's high-voltage power supply systems.
HS2 has cast the first of 112,000 wall segments for the high-speed railway's 10-mile Chiltern tunnel outside of London.
Work has begun on what will be the UK's longest rail viaduct – the Colne Valley Viaduct to the northwest of London, measuring 3.4km.
HS2 will use retired wind turbine blades originally destined for the incinerator to make reinforced concrete that is carbon-friendly.
HS2 Ltd has started its search for a specialist contractor to deliver the high-speed railway's engineering management system (EMS).
Following the formal handover of the Heathrow Express depot to Network Rail, NR will begin its decommissioning work in preparation for HS2.
Collins Earthworks has completed the preparation of the HS2 site in Warwickshire in readiness for tunnelling to start this summer.
HS2 Ltd has started its search for a contractor to build the rolling stock depot and control centre at Washwood Heath in Birmingham.
HS2 Ltd has revealed the design of the Euston tunnel headhouse that will sit alongside the West Coast Main Line in London.
HS2 Phase 2a, connecting the high-speed line from London to Crewe via Birmingham, has received royal assent in parliament.
HS2 has revealed its final design for the headhouse and vent shaft at Chalfont St Giles which will provide ventilation to the Chiltern tunnel.
Comments in the Commissioner's report stating the government is exploring cutting down platform numbers at HS2 Euston have sparked concern.
The first of five headhouses that will provide ventilation and emergency access to the HS2 Chiltern tunnel has gained planning approval.
The designs for the HS2 viaducts at Water Orton in Warwickshire have been unveiled following a public consultation in spring 2020.
Please fill in the contact form opposite. A member of the team will be in touch shortly.