The Elizabeth line

From west to east:
connecting London
and beyond

The Elizabeth line is a high-frequency, high-capacity metro railway, stretching from Reading and Heathrow airport, west of London, to Shenfield in Essex and Abbey Wood in south-east London.

Play to explore
the line

+10%

increase in central London rail capacity to support a growing city

1991-1995

Initial designs and studies to support the original Crossrail Bill. This includes mechanical and electrical (ME) services, Tottenham Court Road station and eastern running tunnels design. Our studies propose solutions for signalling communications, ventilation, power supply, project management, cost control, risk and value engineering.

2000-2002

Study to extend the tunnelled route east of Liverpool Street, as well as a separate ventilation study for the future Canary Wharf station. This leads to a revival of Crossrail and the start of the scheme.

2000-2007

ME and structural engineering designs developed for central London stations as well as portals and shafts. We help design over-station developments and assess the environmental impact of the project during construction and after completion, covering water quality, contaminated land, air quality and traffic impacts. These form part of the Crossrail Hybrid Bill documents. We also help develop a new ticket hall design at Farringdon, which integrates with upgrades to the Thameslink line. We continue to support Crossrail, while the Bill is under Parliamentary scrutiny.

2002-2009

Rail systems, utilities, ventilation, ME and rolling stock designs for the Hybrid Bill and beyond.

2002-2009

Rail systems, utilities, ventilation, ME and rolling stock designs for the Hybrid Bill and beyond.

2003-2012

Business case review of Crossrail for the Department for Transport and advise on operations and land issues.

2002-2009

Rail systems, utilities, ventilation, ME and rolling stock designs for the Hybrid Bill and beyond.

2003-2012

Business case review of Crossrail for the Department for Transport and advise on operations and land issues.

2005-2011

Multidisciplinary designs for Farringdon, Liverpool Street and Whitechapel stations, as well as the complex Stepney Green junction.

2008-2018

We win a third of detailed design contracts, including Liverpool Street station, sprayed concrete lined tunnels, tunnel and shaft ventilation, tunnel ME, rolling stock and depots, signalling, traction power, overhead line equipment and platform screen doors. We also work on advance projects at Pudding Mill Lane portal and Paddington station, and work with Crossrail Ltd on the materials and workmanship contract.

2013-2022

Contractor Alstom TSO Costain appoint us as engineering consultant for tunnel fit-out. The contract involves design and installation of tunnel equipment, including 48 ventilation fans, 66 drainage pumps and 40km of walkways, fire mains and lighting. Working with Siemens, we review and test Human-Machine Interface (HMI) designs for station operation, including closed-circuit television and customer information systems. We develop detailed ME and structural designs for Woolwich station with Balfour Beatty.

2013-2022

To ensure the smooth transition from Crossrail project to the Elizabeth line, we advise infrastructure manager, Rail for London, that the commissioned railway meets operational and maintenance requirements. We also provide the detailed designs for Woolwich station, North Woolwich Portal, Plumstead Portal, and Connaught pumping shaft. Our Human Factors team helps design the line’s Route Control Centre and the Back-up Control Facility.

The line has been decades in the making. We’ve been involved since 1991.

We have worked on the Elizabeth line from its early stages under various roles, advising on the route and its structures, producing solutions for its trains and developing the rail systems that convert tunnels and stations into a functioning railway.

Use the arrows
to explore

How do you build a new railway through and under one of the world’s major cities?

This is how

Mapping the route

Designing the tunnel alignment under London and connecting 41 fixed points was a step-by-step process. It all began with a walk of the proposed route and combining the findings from our walk-through with information from historic maps, details of future developments and protected buildings, geotechnical reports and aerial photography, to understand what buildings and infrastructure would be impacted on the surface and below ground.

MobileVid

Under the streets of London

To deliver a fast rail service and reduce future maintenance, engineers had to design a tunnel alignment that is as ‘straight’ as possible, minimising the number of curved stretches, which slow trains and increase track wear. The line also had to pass through sites allocated for shaft, station and portal construction.

The tunnel depths have been kept as shallow as possible to minimise the distance rail passengers need to travel to get from the surface to the platforms. Ground conditions for tunnelling are typically better the deeper you go, so the ambition for shallow tunnels had to be balanced with what lay beneath. Existing infrastructure also dictated tunnel depths in places.

Creating enormous, elegant and easily navigable spaces

12km

sprayed
concrete lining

5

stations

3

crossover caverns/
cross-passages

3

ventilation/
emergency shafts

1

temporary shaft

Bond Street, Tottenham Court Road, Farringdon, Liverpool Street and Whitechapel stations are some of the largest subterranean spaces ever constructed under London. Each station is designed with spacious circulation routes and cladding for all five stations contain glass-fibre reinforced concrete panels that have been cast to reflect the shapes engineered from the ground by tunnellers using a method known as sprayed concrete lining or SCL.

What is sprayed concrete lining?

12km

sprayed
concrete lining

5

stations

3

crossover caverns/
cross-passages

3

ventilation/
emergency shafts

1

temporary shaft

12km

sprayed
concrete lining

5

stations

3

crossover caverns/
cross-passages

3

ventilation/
emergency shafts

1

temporary shaft

Travelling down an escalator to platform level, along a cross-passage and onto a train, junctions merge and sightlines broaden, enabling passengers to easily navigate the surroundings.

SCL was introduced to London in the 1990s, initially only as a temporary structure. Now it is a permanent one, which compared with other tunnelling systems takes less time, and saves materials. This progress has been achieved without compromising structural capacity and durability.

Mike Savill
Tunnel practice lead for UK and Europe

The deepest point on the line – Moorgate shaft

42m

deep

35m

diameter

1.2m

thick diaphragm

Moorgate shaft at the west end of Elizabeth line’s Liverpool Street station is an irregular polygon and construction involved a combination of diaphragm walls and piles, with top-down excavation and a series of ring beams and lining walls installed at intervals. Our innovative use of real-time site monitoring data and state-of-the-art 3D numerical analysis of ground-structure interaction, ground movements and impact on nearby tunnels kept the project on track. Protecting the nearby northbound tunnel for the Northern Line – less than 5m away – was crucial and governed the design of the shaft’s diaphragm wall structure.

Find out how we kept the project on track

42m

deep

35m

diameter

1.2m

thick diaphragm

42m

deep

35m

diameter

1.2m

thick diaphragm

Space to breathe without the noise

Full height platform screens create a safety barrier between the passenger and platform edge and enable more efficient control of air flow. The screens had a major influence the ventilation system - a complex system of fans, shafts and cross passages to supply cool fresh air and extract warm, used air. Energy efficient fans and insulation in walls around ducts or between ducts and the receptor, minimise noise.

Discover how our value engineering review removed eight proposed shafts without comprising safety

Including full height platform screens created a system where air would be pushed in at one end of a tunnel and pushed out of the other. With cross passages, there would be the possibility of more routes for air to take.

David Eckford
Principal mechanical engineer

Station
to station

Paddington, Liverpool Street and Woolwich all have new Elizabeth line stations.

Each had their own engineering challenges.

Technical insight: Discover how our integration project paved the way for Elizabeth line Paddington station

Paddington:
connecting with
an historic station

The Elizabeth line Paddington station spans three levels, with two surface-level entrances into the station via a pedestrianised public realm and sits to the south of Isambard Kingdom Brunel’s iconic 19th century, Grade 1 rail station. The new station operates within a busy interchange already serving three underground lines and mainline railways.

208m

long platform

20m

below ground

Did you know?

Paddington station project achieved an ‘Excellent’ rating under the CEEQUAL sustainability standards due to its many environmental features, including a ground source heat pump, a green roof on the new station to support biodiversity, and the use of natural light and ventilation.

Designing for confined spaces… and the future: unpacking today’s equipment and planning ahead

Liverpool Street:
one of the largest
and most complex

Liverpool Street is the deepest of the Elizabeth line central stations. It is also one of the largest and most complex, stretching from Broadgate in the east to Moorgate in the west, and providing improved access to the City of London. Restrictions above and below ground required innovative solutions, and construction had to take place with minimal disruption to the daily lives of people and businesses in the heart of London’s financial district.

238m

long platform

34m

below ground

Did you know?

A 16th century burial ground was an additional complication at Liverpool Street. Archaeologists uncovered about 4000 complete human skeletons between 2m and 4m below street level that had to be reburied.

A digital twin to review progress and identify buildability issues before they cause a problem

Woolwich:
more than a station

Woolwich Station in south-east London sits at the heart of the new Royal Arsenal Riverside neighbourhood consisting of about 4000 modern homes and cultural, heritage, retail and leisure facilities set in almost 14ha of public open space. The station will ensure quicker, easier, and more convenient travel into the city for commuters, residents and visitors, as well support further economic regeneration in the area.

241m

long platform

14m

below ground

Did you know?

Dead Man's Penny was a commemorative coin given to the next-of-kin of all British and Empire service personnel killed in the First World War. It was 120mm in diameter, cast in bronze and made in Woolwich Arsenal. A new plaque commemorating the 'penny' is on an information totem outside the main station building.

Bringing 50+ systems together to form one functioning rail line

Delivery of the Elizabeth line brought together a whole new set of technologies for operating and maintaining a railway, some never seen together before in London, the UK or further afield. Among others, our systems integration specialists had to:

connect a new metro line with services on mainline routes
ensure perfect synchronicity between stations, routeways, signalling and telecoms
manage multiple contracts, delivered by many different parties

Discover how we connected everything How enterprise and digital integration delivered operational readiness

We used to think that the single biggest risk on the Elizabeth line was the tunnelling drive – it wasn’t. The biggest risk was how to bring the systems together.

Mark Wild
Crossrail Ltd chief executive

A collaborative and integrated approach across the various contracts and stakeholders was required to test and commission the highly complex station and communications systems.

John Bettles
Head of global railway systems

All aboard the trains

70

trains

1500

passenger capacity

9

carriages per train

24

trains per hour

Elizabeth line trains feature the latest technology to support modern travel and communications but weigh about 20% less than most mainline trains and use 30% less energy.

Creating a ‘reference train’ – setting the standards for the new trains Maintaining the fleet – developing Old Oak Common and Ilford depots Human-centred design – bringing signalling, power and service delivery teams together in one central control facility

70

trains

1500

passenger capacity

9

carriages per train

24

trains per hour

70

trains

1500

passenger capacity

9

carriages per train

24

trains per hour

Lasting
legacy

300k

jobs

180k

new homes

4.4Mm²

office and retail space

Our work on the Elizabeth line has put us at the forefront of collaboration with other industry leaders and shaped the careers of a generation of engineers. The skills and experience gained on the project are being used throughout the UK and exported internationally. Already, the lessons learned from the project have influenced new metro and suburban rail systems in places such as Sydney, Vancouver and San Jose.

Discover more about the outcomes:

Learning legacy: How our experts who worked on the Elizabeth line are helping to move the industry forward

The Elizabeth line has been with me throughout my career. It was the 'next big thing' when I started in the 1990s with British Rail and formed a significant part of the work I have tackled during my time at Mott MacDonald. There have been so many enjoyable moments for me along the journey.

Mohammed Abu-Qulbain, electrical engineer
and station commissioning lead for Woolwich

Thank you to Crossrail Ltd and Mott MacDonald colleagues for sharing photos, diagrams and videos. Crossrail video and image content copyright Crossrail Ltd.

Talk to me and my team
about your rail ambitions

Neil Henderson

Mott MacDonald project director for the Elizabeth line

The Elizabeth line

From west to east: connecting London and beyond

The Elizabeth line is a high-frequency, high-capacity metro railway, stretching from Reading and Heathrow airport, west of London, to Shenfield in Essex and Abbey Wood in south-east London.

Play to explorethe line

+10%

increase in central London rail capacity to support a growing city

Explore our 30-year journey.

1991-1995

2000-2002

2000-2007

2002-2009

2002-2009

2003-2012

2002-2009

2003-2012

2005-2011

2008-2018

2013-2022

2013-2022

The line has been decades in the making. We’ve been involved since 1991.

How do you build a new railway through and under one of the world’s major cities?

This is how

Mapping the route

Under the streets of London

Creating enormous, elegant and easily navigable spaces

Creating enormous, elegant and easily navigable spaces

12km

sprayedconcrete lining

5

stations

3

crossover caverns/cross-passages

3

ventilation/emergency shafts

1

temporary shaft

12km

sprayedconcrete lining

5

stations

3

crossover caverns/cross-passages

3

ventilation/emergency shafts

1

temporary shaft

12km

sprayedconcrete lining

5

stations

3

crossover caverns/cross-passages

3

ventilation/emergency shafts

1

temporary shaft

SCL was introduced to London in the 1990s, initially only as a temporary structure. Now it is a permanent one, which compared with other tunnelling systems takes less time, and saves materials. This progress has been achieved without compromising structural capacity and durability.

The deepest point on the line – Moorgate shaft

42m

deep

35m

diameter

1.2m

thick diaphragm

42m

deep

35m

diameter

1.2m

thick diaphragm

42m

deep

35m

diameter

1.2m

thick diaphragm

Space to breathe without the noise

Including full height platform screens created a system where air would be pushed in at one end of a tunnel and pushed out of the other. With cross passages, there would be the possibility of more routes for air to take.

Station to station

Paddington:connecting withan historic station

From west to east:
connecting London
and beyond

Play to explore
the line

The line has been decades in the making. We’ve been involved since 1991.

sprayed
concrete lining

crossover caverns/
cross-passages

ventilation/
emergency shafts

sprayed
concrete lining

crossover caverns/
cross-passages

ventilation/
emergency shafts

sprayed
concrete lining

crossover caverns/
cross-passages

ventilation/
emergency shafts

Station
to station

Paddington:
connecting with
an historic station

Liverpool Street:
one of the largest
and most complex

Woolwich:
more than a station

Lasting
legacy