HS2 was originally proposed in 2009 with the intention of removing intercity services from the West and East Coast Main Lines, and to improve capacity on the current railway to increase local, regional and freight services.
An additional benefit for passengers is that trains travelling between Birmingham and London are estimated to save around 35 minutes in journey time compared to regular services, and journeys between Manchester/Leeds and London are estimated to save almost an hour.
The Department for Transport forecast in its initial business case that HS2 will have a positive economic impact, and that quicker journey times and extra capacity will generate a shift from air and road travel to rail.
In 2012 Justine Greening, the then Secretary of State for Transport, announced that the project would go ahead in two phases. Phase One is to be built between London Euston and Birmingham Curzon Street stations, and Phase 2 was intended to be a ‘Y-shaped’ section of track from Birmingham, with one line going to Manchester and the other to Leeds.
News of the cancellation of the Leeds branch of Phase 2 was announced in November 2021 with publication of the Integrated Rail Plan. The eastern leg of HS2, also known as Phase 2b, will run from Birmingham to the East Midlands, with a stop inside Nottinghamshire at East Midlands Parkway. That station, just south of Nottingham, has links to Nottingham and Derby. The new 42-mile high-speed line is promised to cut journey times between Birmingham and Nottingham from 74 to 26 minutes, according to Nottinghamshire County Council.
The Manchester branch is now split into Phase 2a and 2b. Phase 2a will be constructed at the same time as Phase One, which will extend beyond Birmingham to Crewe. A hybrid bill for the construction of Phase 2b – from Crewe to Manchester – will be submitted to parliament in the next few months.
Permanent construction work on Phase One was started in September 2020 after delays caused by project reviews and the COVID-19 pandemic. With more detailed project planning, the cost of the project has risen from the government’s initial estimate of £55.7billion to £72bn-£98bn.
STATION TO STATION
However, initial work was already underway. Demolition began at Euston station in October 2018 in preparation for a brand-new station for the high-speed trains, as well as updating the existing station. In December of the same year, enabling work was completed by LM JV (Laing O’Rourke and Murphy) at the site of the new Birmingham Curzon Street station, andin 2021 construction companies Mace and Dragados won the contract to construct the station itself. This will make Curzon Street the first brand-new intercity terminus station built in Britain since the since the 19th century.
The Curzon Street station, designed by WSP and Grimshaw Architects LLP, is planned to be net zero carbon in operation. It will capture rainwater and provide sustainable power generation, with over 2800m2 of solar panels located on platform canopies.
As construction work on Euston station is due to take longer than originally expected, the London terminus of HS2 will be Old Oak Common, six miles to the west of central London, until work is completed at Euston. Old Oak Common rail station will be the UK’s largest new-build railway station: 850m long and contain 14 platforms.
The construction contract for this station has been awarded to Balfour Beatty VINCI SYSTRA (BBVS). Work began on 23 June 2021 on the 1.8km long underground diaphragm wall around what will become the station’s 750,000m3 ‘underground box’, where six HS2 platforms will sit.
The station’s proposed lightweight roof structure has been designed to minimise the use of materials and allow lots of natural light in, which reduces the carbon impact of the station. Its environmental credentials will be boosted by solar panels covering the roof, generating a supply of renewable energy for the station.
Nigel Russell, project director, BBVS says: “We are proud to be delivering one of Britain’s largest, connected and sustainable railway stations while simultaneously stimulating the local economy. We are providing numerous employment opportunities for local people, as well as offering 250 apprentices the opportunity to start their career on the UK’s most exciting engineering project.”
TUNNELLING THE CHILTERNS
In July 2020, a 17-metre-high headwall was built at the southern end of what will become a 10-mile twin-bore tunnel under the Chiltern Hills. These tunnels are expected to take three years to dig using two 170m-long, 2,000-tonne tunnel boring machines (TBMs), named Florence and Cecilia, which move at a speed of up to 15m per day. TBM Florence began tunnelling in May 2021 and Cecilia followed in July. Each TBM is a self-contained underground factory, digging the tunnel, lining it with concrete wall segments and grouting them into place as it goes. By the beginning of October 2021, TBM Florence has completed one mile of tunnel through the chalk and flint below the Chilterns. At its deepest, it will go 90m below surface.
The 8.5 tonne concrete segments that will support the walls of the tunnels, 112,000 in total, are being cast at a purpose-built facility at the southern end of the tunnel by Align JV, a joint venture between Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick.
These wall segments are made of fibre-reinforced concrete and are polished by a robot, which is said to provide a more consistent finish than the more traditional manual process. Fibre-reinforced concrete is cheaper and safer than traditional steel mesh-reinforced concrete, and features enhanced performance and durability. Because it doesn’t contain steel mesh, it takes less time to lay or form, exhibits no corrosion issues, reduced weight and increased crack control.
According to HS2, approximately 2.7 million m3 of material will be excavated during the construction of the tunnels, and used for landscaping around the south portal site.Four other tunnel drives complete the Phase One section.
Align JV has installed ‘Krokodyle’ robotic arms to the TBMs. They are designed to remove the wooden spacers between the concrete tunnel segments and insert connection dowels. This is a job that people would traditionally do, and is potentially hazardous.
Eddie Woods, HS2 Ltd’s head of tunnelling says: “Safety is a key priority for HS2, and the introduction of these innovations that essentially remove personnel from harm’s way is an excellent example of the sort of initiatives we are pleased to see implemented on the project.”
Didier Jacques, Align’s underground construction director, adds: “We are very proud of these innovations, which we would be happy to share with tunnelling teams working on other projects across the world, to help reduce the likelihood of accidents and injuries.”
The TBMs are kept running by a team of 17 people working in shifts as well as over 100 people on the surface. In total, there will be 10 TBMs creating 64 miles of tunnels across Phase One of the HS2 project.
Phase One is due to open between 2029 and 2033 after the stations are built, the 32 miles of tunnels are dug, 500+ bridges and 50+ viaducts built, and 44 miles of cuttings and 38 miles of embankments are made.
BOX: HS2 PLANT ECO INNOVATIONS UK’s first 250-tonne all-electric crawler crane (below)15-tonne electric road sweeperAlternative fuel trials, including hydrogen dual-fuel system in construction vehiclesRenewable energy solutions (solar and wind) trialled to replace diesel generatorsGenerator technology uses bio-LPG to replace dieselFirst infrastructure project to adopt new advanced emissions identification scheme developed in collaboration with the Construction Equipment Association