Crossrail / Elizabeth line Arup’s role in London’s new suburban metro system
When Crossrail, now known as the Elizabeth line, commenced operation in May 2022, it represented the culmination of more than three decades of endeavour, collaboration and tenacity.
Project in numbers
additional people will be within a 45 min trip to central London
annual passenger capacity of Crossrail
of new tunnels dug under London
Millions of passengers will benefit from the new system, which connects areas to the west and east of the capital, expanding capacity on London’s busy rail network by 10% with a fast and regular service.
Arup played a key role from the very start, working in joint venture with our partners on infrastructure, tunnelling, geotechnics, station technical design, fire engineering, acoustics and many related elements.
Crossrail offers many valuable lessons for other major metro projects around the world, from design choices to tunnelling techniques and environment, economic and social implications. We want to share what we’ve learned from this incredible scheme.
Championing a public transport vision
Every multi-decade rail project requires a compelling vision and Arup has been championing public transport schemes, such as Crossrail from the early days.
In the late 1980s we were asked by the UK government to evaluate transport options for East London.
Presented in 1989, our advice recommended more investment in rail infrastructure would ultimately be needed to address the city’s capacity and connectivity issues.
Arup believed in the potential of Crossrail from its very beginnings. The finished system demonstrates the firm’s commitment to creative collaboration on the most challenging rail schemes. Terry Hill,Former Non-Executive Director, Crossrail and Former Chair, Arup
Crossrail offers a blueprint for major metro projects around the world, from design choices to tunnelling techniques and environment, economic and social implications. A brief history of our involvement in the Crossrail project:
Where would the tunnels go? Our route-wide geotechnical investigation begins
Other options? Smaller scale alternatives to Crossrail study
Canary Wharf station design study
Appointed multidisciplinary design package 2 – preliminary design Royal Oak to Farringdon
Crossrail gets Royal Assent i.e. green light to begin
Detailed engineering design for tunnels, stations and depot begin
Construction of the route gets underway
Elizabeth line opens to the public
Tunnelling and engineering feats
We assembled a team of 200 engineers and specialists to undertake extensive settlement analysis and damage assessments, to evaluate the impact of ground movement under the central tunnelled section. This involved the assessment and mitigation of over 4,000 buildings, railway, major utilities, and other infrastructure adjacent to the route to establish how it would respond to the tunnelling and station excavation.
Arup–Atkins then designed the 42km, 7.1m external diameter bored tunnels that would run under central London. Our team had to navigate the tunnels through London’s congested subterranean world, weaving them around building foundations, London Underground tunnels and a host of other structures and utilities.
At Tottenham Court Road the team had to thread the tunnels over the Northern line and below the escalators for the London Underground station with only 700mm between the Elizabeth line and Northern line tunnels.
A quiet neighbour
A new underground rail system potentially presents serious acoustic implications for those adjacent to or above its route.
We used prediction models to identify which buildings may be affected when the 200m long trains pass underneath them. Using this data, the team optimised the design of the tracks inside the tunnels to reduce the amount of vibration transmitted into the ground and hence minimise the impact of ground-borne noise from the railway.
Under two highly sensitive parts of the route – Barbican Concert Hall and Soho, home of many of the UK’s top recording studios – the solution was to float the entire track structure on springs.
Arup structural engineers designed this special floating track slab system, to provide a high level of vibration reduction without compromising the safe operation of the railway.
Stations and developments above ground
We worked on technical design at six of the ten new central stations on the Elizabeth line, and helped shaped over-site development for commercial developer partners.
A new or developed station offers considerable opportunities to meet local needs. From developing new acoustically isolated above-station residential homes and offices in Soho, to shaping an enhanced passenger experience at Tottenham Court Road station, we took a flexible, creative and pragmatic approach to station design and over-site rail development.
Crossrail is much more than a new Tube line. It’s a fundamental, now and forever reshaping of what it means to live, work in or visit London, a reconstruction of the city’s geography that will shrink time for millions of us and become a core part of our lives. Julian Glover,Evening Standard
Benefitting cities and communities
The Crossrail scheme supports our belief that rail is transformative for communities, cities and nations.
The scheme has already provided years of economic stimulus to areas like Thamesmead, Woolwich and Abbey Wood, and by offering radically faster access to the city it has connected their populations to new opportunities for work, education and leisure.
Developing a new rail system offers many opportunities to improve surrounding communities, from external landscape to over-site developments to local skills and employment.
Our research has established that thousands of new homes have been built within one kilometre of Elizabeth line stations, with populations growing and employment opportunities increasing within 500 metres of Elizabeth line stations in some of the city’s most deprived areas.
Evaluating those benefits is complex but vital task if the right lessons are to be learned.
Learning from Crossrail
After decades of development, problem solving and sheer hard work by all involved, the Elizabeth line opens at a pivotal time for rail.
In a world now committed to net zero targets, rail offers people an efficient and affordable alternative to private cars. It remains the most sustainable, resilient and low-emission form of land transport we have for mass capacity travel.