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OvergroundUnderground

Urban transport in the 21st century

Metros | Transit

Overground Underground I Mott MacDonald I 32 I Mott MacDonald I Overground Underground

Contents

4Metros are in our DNA

6The value of planning the economics of metros

8Going underground tunnelling in the heart of the city

14All aboard! the complex world of building metro stations

20A station in the desert Doha’s new metro

30Conducting the power space and heat challenges

28Good neighbours minimising noise and vibration

10The lie of the landcombatting settlement in New York

26Engineering real benefits knitting together the components that make a metro network work

25Rolling on down the line dealing with complexity

Metro transport started in London with the creation of the first underground railway line, the Metropolitan Line, which opened in January 1863. The line has since been extended and now carries 53M people a year. It pre-dates by only 27 years the City & South London Railway (CSLR), the first deep-tube railway, designed by our founders Basil Mott and David Hay.

Metros connected and enabled the expansion of London, opening opportunities for housing, commerce and industry, and creating value captured in robust business cases. These are timeless objectives, and they apply just as much now as they did in Victorian times. We are working on Crossrail and Crossrail 2, continuing a long tradition of playing a major role in developing infrastructure to support the growth and prosperity of London.

Some 128 years after our first involvement in metros we remain at the forefront of the technologies that support ever-efficient design, delivery and operation of new, expanded or existing rapid transit networks. From high-capacity moving block railway signalling systems to cutting-edge underground space creation using sprayed concrete construction of tunnel linings to digital design and virtual asset creation and operational planning, we continue to drive innovation in the industry through improved efficiency and productivity.

Chris Dulake Global practice leader, metros and transit

Driving growth and prosperity

1890 CSLR, the world’s first deep-level electric rail line

1900 Central Line

1900 Bank station lifts installed

1911 Earls Court station escalator installed

Mott MacDonaldmetros timeline

1920s CSLR extension to form Northern Line

1930s Central Line extended using bolted concrete tunnel linings

33From BIM to Smartrealising the value of data

34Moving Sydney Metro forward digital project delivery

38Building expertise a new generation of metro engineers

16Beneath the streets of London

Crossrail Liverpool Street

22Passenger experience getting people from A to B

36Mandatory sustainability cutting carbon and costs

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In our DNA

The timeline demonstrates that Mott MacDonald has been developing sustainable transport infrastructure for more than a century. We have helped to build metros in more than 50 cities and worked on the world’s most challenging projects.

Our design and engineering teams have constantly been at the forefront of change. The precast concrete tunnel lining pioneered on the Redbridge to Newbury Park extension to London’s Central Line in the 1930s, and now a widely used, was designed by bridge and tunnel engineer David Anderson, a partner at Mott, Hay and Anderson. In the mid-1960s, we patented the bentonite-slurry shield tunnel boring machine (TBM) for use in soft ground from which today’s earth-pressure balance TBMs originate.

Down belowMetros are synonymous with tunnels and tunnelling is in our DNA. Our founders, engineers Basil Mott and David Hay, both worked on the City & South London Railway, which opened in 1890 and was the world’s first deep-level electric railway. We are now recognised as world leaders in tunnel planning, design and construction.

Our metros inventory contains some notable firsts. We were responsible for detailed design at Beacon Hill in Seattle, a segment in the 22.5km light rail line for Central Puget Sound Regional Transit Authority. It opened in 2009 and was the largest soft-ground sequential excavation method (SEM) tunnel in North America. For the first time in India, we used slurry TBMs on the Bangalore Metro.

Expansion of mass transit networks in increasingly congested urban environments face many challenges, both above and below ground. Budget, space and time constraints, and protection of existing assets, all require innovative methods and different ways of working.

1964 John Bartlett patents TBM

1964 Toronto Subway

1935Moscow Metro

1940s LU stations used as bomb shelters

1950s Plans to link the UK and France via a tunnel under Channel

1969 Helsinki Metro

1971 Victoria Line

1980s Dublin DART

1980s Tyne & Wear Metro

1981/85 Melbourne Underground Rail Loop

1983 Caracas Metro, Venezuela

1984 Singapore Metro

1987 Docklands Light Railway

1995 Medellín Metro, Colombia

1999 Jubilee Line extension

2002 Sheppard Subway, Toronto

2002 Metro de Porto

2003 Los Angeles Metro

2004 Bangkok Metro

2008 Kaohsiung Metro, Taiwan

2006 Delhi Metro

2009 Sound Transit, Seattle

2011 Bangalore Metro

2013 Kolkata Metro

2014 Budapest Metro Line 4

2015 Chennai Metro

2016/17 KVMRT, Kuala Lumpur

2017 Victoria station upgrade

2018 Crossrail (Elizabeth Line)

2018 Silicon Valley BART extension

2019 Doha Metro

2019 Melbourne Metro Rail project

2019 Sydney Metro Northwest

2020Northern Line extension

2021 LA Regional Connector

2023East Side Access, New York

Our engineers are working on City Rail Link in Auckland, the first underground project in New Zealand, while we were consultants on Singapore’s inaugural mass transit line.

Going forwardHistory has shaped Mott MacDonald and it anchors our vision for the future. We have used our extensive collective knowledge and experience to develop digital tools, from business information modelling (BIM) to train and pedestrian modelling software, to deliver faster, more sustainable projects that add value for clients.

In Kuala Lumpur, we used BIM on the Klang Valley Sungai Buloh-Kajang Line to enhance collaboration, bringing the best of our global expertise to the project.

Sophisticated computer modelling tools were used on the LA Metro to design the onboard fire suppression system for train carriages, providing better passenger protection and generating significant cost savings.

ALIGHT, our train/platform interface software, has specifically been developed to improve the layout of trains and stations by modelling passenger behaviour; ReVerb, in-house software to model and monitor train vibrations and noise levels, helps to minimise disruption in populated areas; and our simulation software TRAIN is used extensively to design and model traction systems.

Work on the CSLR, the first deep-tube railway


The economics of metros

Metros are vital to the economies of cities. Road congestion is costly. One report found the average journey in the 10 most congested UK cities is at least 30% longer by car and that being stuck in traffic jams would cost the national economy more than £300bn by 2030. Poor air quality is also increasingly an issue.

With the population of cities around the world set to rise – 70% of the world’s population is expected to live in urban areas by 2050 – the problem of clogged arteries will only worsen, irrespective of whether the shift to cleaner vehicles lessens the environmental and health impacts.

The right investmentInvesting in metros is proven to reduce congestion. It is the main reason Dubai, Kuala Lumpur, Los Angeles and Sydney are expanding their networks and why Doha and Ho Chi Minh City are constructing their first.

But it’s not just about easing traffic jams. Metros are efficient and environmentally friendly, and can move hundreds of thousands of people quickly, comfortably and affordably.

Significantly, they are also the catalyst for economic and social transformation. The extension to the Northern Line in London is forecast to boost the economy by up to £7.9bn, creating 25,000 jobs and 16,000 homes in the area.

Moving upTransit agencies around the world are increasingly looking to use over-site developments (OSD) to reduce operating or construction costs of transportation systems.

The value of planning

Transport for London says using its assets in this way brings new revenue to reinvest in the modernisation of London’s transport network. It is aiming to generate £3.4bn in non-fares revenue by 2023.

Planning is key to developing a network that realises these benefits and drives competitive advantage. Oliver Steele, one of our economic consultants, says land value capture demonstrates how metro projects can benefit from integrated land-use and transport planning. “The theory is simple: land values generally increase significantly around metro stations but traditionally this value has passed as a windfall to those lucky enough to own property when the project is developed,” he explains. “Land value capture refers to a set of mechanisms designed to optimise and secure some of this gain to fund the project’s development and construction.”

Smarter places to live Public transport also has a crucial role to play in transforming cities into ‘smart’ places, where the physical, digital and human systems integrate with the built environment to deliver a sustainable, prosperous and inclusive future for its citizens.

Technology increasingly connects different aspects of people’s daily lives and authorities worldwide are keen to leverage advances in mobile, communications and Internet of Things technologies to deliver services more efficiently and improve the overall quality of life for residents.

Smart transportation is integrated, so different modes work together seamlessly and services can be adjusted to match passenger demand.

Elizabeth Line Liverpool Street station

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Going underground

No two metro tunnelling projects are the same. Our work on India’s first bored-tunnel metro, a 6.5km long section in Delhi, and on Kuala Lumpur’s Klang Valley mass rapid transit (KVMRT) network, including a 9.5km tunnelled section, highlight the differences.

The ground conditions in the Indian capital made tunnelling difficult. The city sits in the Himalayan foothills on the water-bearing silts of the Yumuna River flood plain. Two earth-pressure balance TBMs were used, which controlled water ingress and managed

ground stability and movements. Working face conditions were tough, through a closely-spaced intercalation of very sound quartzite and disintegrating schist, while archaeological remains were a problem under Old Delhi.

The historic part of the city contains numerous large-diameter wells, often very deep, presenting a significant risk to tunnelling excavation. Navigating them was hard when most were not plotted on available documents. We were flexible in our approach. We shifted from TBM to the New

Austrian tunnelling method (NATM) to mine Chawri Bazar station. NATM requires dewatering of the ground but lowering the water table can potentially destabilise existing structures. The station is in the oldest part of Delhi – the 400-year-old ‘Walled City’ of Shajahananbad. No buildings collapsed as a result of tunnelling and dewatering.

Phase one of the 52km long Sungai Buloh-Kajang Line, one of three new planned lines on KVMRT, included an underground section in the form of two single-track tunnels.

Much of it runs through karstic limestone, known for its voids and fissures filled with water and soft material. Disturbance to these features by tunnelling or excavation works can create sinkholes, as well as surface fountains and settlement.

To counter this, the world’s first variable density slurry TBMs were employed. These allow operators to alter the pressure and viscosity of material at the cutting face to match the ground conditions, making it easier to tunnel safely through unpredictable ground.

Tunnelling in the heart of a city


The lie of

Combatting settlement in New York City

The landmark East Side Access project in New York involves the construction of new tunnels and the rehabilitation of existing tunnels. Scale and location made tunnelling challenging. The project is designed to alleviate congestion and offer easier access to Manhattan by creating a railway link between Queens and Grand Central Terminal (GCT). When it opens in 2023, new rail lines will run from Queens, connecting to the 63rd Street tunnel, which runs under the East River and will be extended by a further 1.6km, to a new terminal under CGT. Tunnelling for the project comprises 11.6km through hard rock in Manhattan and 3.2km through soft ground in Queens.

Mott MacDonald’s Andy Thompson was senior programme executive for the project’s construction management team. “It was a complex tunnelling project with multiple locations, which were logistically difficult,” he says.

Working under existing infrastructure was a major issue. The tunnels run under Harold Interlocking, a large, complex junction, and a railyard called Sunnyside. The junction serves Amtrak Northeast Corridor, Long Island Rail Road and New Jersey Transit networks; more than 780 trains pass through it each workday, making it the busiest rail junction in North America.

The right choiceTunnel excavation can trigger small ground movements, called settlement. This effect can be minimised by the selection of correct tunnelling and excavation techniques. Two soft-ground slurry TBMs were used to construct the tunnels, which were lined with precast concrete segments – the tunnelling equipment and lining technology had not been used before in New York City. In most locations, cover was 8-10m, but at Harold Interlocking tunnelling was only 1.8m below the surface and had to take place with

no settlement or damage to the existing railroad infrastructure. “As well as tunnelling, we had to install 9.5km of new track, 92 new switches and reconfigure the overhead and signalling systems. All this had to be done without interrupting services through Harold Interlocking,” says Andy.

Surface challengeSimilar logistical difficulties were faced on the Northern Boulevard Crossing tunnel, connecting the Queens and Manhattan portions of the project. At 38m it is the shortest of the tunnels in Queens, but it presented the design and construction teams with the biggest challenges.

The crossing had to pass just 4-5m beneath a five-track subway box. Above the subway is a six-lane highway, and above this a pile-supported elevated railway. To navigate the many foundation structures and minimise settlement risk, it was decided to construct the tunnel using sequential

the land


780+trains a day passed above tunnel excavations

38mshortest but most challenging tunnel

excavation methods, making this the first SEM tunnel to be constructed in New York City.

It is a technique that involves removing soil in carefully designed increments to maintain equilibrium in the surrounding ground, with sprayed concrete providing temporary support.

A frozen archGroundwater control and stabilisation of the soils beneath the subway box were required. Engineers were prevented from using dewatering due to the potential effects on structures and the need to minimise movement of contaminated plumes in the area.

Construction from the surface or within the subway was also not permitted due to operational restrictions. Instead they opted to construct a horizontal frozen arch. This involved installing freeze pipes around the perimeter of the tunnel to form a 2m thick arch of frozen soil. This cut off groundwater

and supported the ground to enable an initial shotcrete liner, a PVC waterproofing membrane and a 760mm thick reinforced-concrete liner to all be installed. Just a few metres separated the top of the arch and the existing railroad structure.

Drilling for the pipes was potentially risky and the freeze had to be carefully controlled to restrict the impact of volume increase and consequential ground movement. Heat pipes were installed in the upper areas to control the upward growth of the freeze towards the subway. Compensation grouting was also used to firm up the area and to mitigate settlement of overlying structures during installation of the freeze pipes and when the frozen ground thawed after tunnelling.

Minimal movement occurred to the overlying structures primarily due to careful planning to identify the risks and mitigate them during construction.

Launching the tunnel boring machineExcavation for ventilation facility at 55th Street


The spotlight tends to shine on the tunnels and elevated structures when a new metro network is constructed, but it is the stations that are often the most complex and challenging elements.

Metros are designed to move large numbers of people around congested urban areas, like arteries around the heart of the city. All the passengers see is the public realm of a station: the ticket hall, barriers, direction signs, escalators, passageways, platforms and some adverts.

Hidden from view are the electrical, mechanical, public health, communications, fire, escalator and lift engineering, and acoustics systems that enable passengers to travel safely and in relative comfort.

Metro stations can be a catalyst for investment and the regeneration of urban areas. In congested cities, where land is in short supply, they increasingly form the backbone for large-scale development.

Each design presents its own challenges, such as co-ordinating with land owners, constructing in densely populated areas and maintaining the operation of existing transport services. Work often takes place in confined and congested spaces where geology can dictate the construction processes and the extent of what it is possible to create.

The expansion of transport metro systems with improved connectivity in cities brings opportunity for investors, developers and urban residents. The increase in land value is now recognised as a legitimate way of generating the secure funding needed to initiate schemes and to stimulate interest in undeveloped land required for housing and commercial use.

All aboard!


Stretching from Moorgate to Broadgate and nestling below a busy London financial district, one of the deepest station on the new Elizabeth Line is taking shape. Liverpool Street station is akin to an iceberg, with barely 5% of the station structure visible on the surface. Some 30m below ground sits two 240m long platforms and the intricate network of equipment and systems needed to operate the railway, which is expected to serve more than 120,000 people every weekday.

During the design phase about 120 of our experts worked on Liverpool Street station, developing civil, structural, architectural, mechanical and electrical elements as well as providing construction planning, passenger and transport modelling, and rail safety assurance.

Crossrail is very different from most metros projects as it brings mainline trains into a metro environment, says David Eastland, who was lead MEP design director on the station, responsible for developing the mechanical, electrical, public health, fire, acoustics, and escalator and lift engineering systems. “It’s essentially a mix of two railway cultures,” he says, “big rail in an underground metro environment.”

Designing for confined spacesSpace was limited. The location is also a busy area and the work had to take place with minimal disruption to the daily lives of people and organisations. Restrictions above and below ground required innovative solutions. David says physical constraints, including expensive real estate, Victorian sewers, existing Tube lines and the Post Office railway, made the station one of the trickiest to design and build: “We had to create a great space underground for travellers and all the ‘back of house’ systems and equipment, and be sensitive at the same time to the surface environment.”

4000complete human skeletons were unearthed during construction

30mLiverpool Street station is one of the deepest on the Elizabeth Line

Beneath the

Our engineers designed a corridor, a ventilated cut and cover structure, to house the tangled labyrinth of utilities at the site of the Broadgate ticket hall that could not be relocated to nearby streets because of the shallow depth of the London Underground tunnels.

Some 22 telecommunications ducts, 18 high-voltage power cables and two water mains had to be diverted before work could begin excavating the site. Co-ordinating the two-year diversion project involved careful negotiation and planning to ensure there was no disruption to services. The benefit for utility companies is that maintenance work can be carried out or additional services installed without disrupting traffic by excavating the road. An additional complication is that the site is above a 16th century burial ground for the original Bethlehem Royal Hospital. Archaeologists discovered around 4000 complete human skeletons 2-4m below street level, which had to be reinterned.

At the other end of the station, at Moorgate, designers had to realign escalator shafts to avoid a large Victorian sewer system designed by Joseph Bazalgette. “We had to adjust the design to miss the egg-shaped brick sewer,” explains David.

Height restrictions at Moorgate ticket hall required us and principal architects WilkinsonEyre to design a ceiling arrangement that doesn’t feel too oppressive. “We worked hard with the architects to co-ordinate the aesthetics and the services requirement,” says principal engineer Stuart Hill, who designed the hall’s lighting system and electrical services. “An integrated services spine, which maximised ceiling height, was preferred to ceiling voids. The exposed and fibre-reinforced white precast concrete sections, which are angular, will glow with indirect lighting, giving the feeling of space.”

streets of London

Northern Line

Elizabeth Line westbound

Elizabeth Line eastbound

Post Office railway

Central Line

Existing mainline rail station2220m² Finsbury Circus

Circle, Hammersmith & City, Metropolitan lines

The Elizabeth line Liverpool Street station has been built in a very congested underground environment, including Victorian sewers, existing Tube lines and the Post Office railway, beneath expensive real estate.

18 I Mott MacDonald I Overground Underground

It was Greek physicist and engineer Archimedes who first noted that submerged objects would float to the surface if their density were less than the density of the fluid. As massive as they are, underground concrete structures will still float if the vertical downward loads are less than the upward vertical ones. It means that to stay in the ground and not float or shift upward the combined mass of the structure and gravitational forces must be greater than the buoyant forces created by water. It is why buoyancy is important in the design of subterranean structures, such as underground metro stations and tunnels.

Until the oversite structures go up, engineers working on the Northern Line extension in London on the south bank of the River Thames must keep the station constructions down. “The earth actually pushes the stations up,” says geotechnical engineer Peter Rutty. “It’s called uplift, and it means the building essentially floats in the ground. We’re not going to see half-built stations sailing down the local high street, but they could shift in the ground. Tension piles and panels are being used to anchor the stations until the oversite developments are completed.”

Keeping a concrete box in the ground

The ticket halls will be connected to the platforms by 15 escalators to exit into Liverpool Street at one end and Moorgate at the other. Because of constraints above ground – for public lifts there were few opportunities for vertical shafts from platform to surface without demolishing existing buildings above – we proposed inclined lifts. These will glide up and down alongside the escalators.

Inbuilt resilienceDesigners must plan for the unexpected even if futuristic forecasts seem science fiction. David notes that the initial design for MEP systems at Liverpool Street were being developed at the same time in 2007 as Apple announced the launch of its first iPhone: “No-one would have envisaged that within 10 years most people on the move would be streaming all kinds of data to handheld devices. Contactless payments through a phone was also unheard of.”

Similarly, lighting in 2007 was mostly fluorescent lights, but the station was designed to be able to install light-emitting diode (LED) systems, which were then still in their infancy and have since become the default selection for all buildings wanting to meet BREEAM and CEEQUAL sustainability standards. “Resilience is crucial and the design for Liverpool Street has to ensure there will be no overload whatever new systems are installed in the future,” says David.

Liverpool Street platform tunnels

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A station in the desert

The new metro in Doha is a key element of Qatar’s National Vision 2030, which aims to transform the country into a more sustainable society. Overall, the metro will comprise four lines, 300km of tunnels and 98 stations. Phase one consists of 70km of tunnels and 35 stations, including two major stations at Education City and Msheireb. We have been working on both since 2013. Work on phase one is due to finish in 2019, with it opening in 2020.

Complex and deepAt 37m deep, 350m x 55m in one direction and 190m x 35m in the other, Msheireb is the more complex of the two. It will be the hub of the new network. When complete, the station will be spread over five levels – five entrances at ground level, six platforms over the bottom two levels, as well as separate mezzanine and concourse levels. It will be one of the largest subterranean stations in the world. The terminal will also provide the

foundations for buildings up to 25-storeys high that will regenerate the area.

Excavating Msheireb was challenging. It was the first deep excavation in Doha. “There was no precedent and no experience,” says Christina Mavrommati, UK geotechnical design team lead on Msheireb. “The ground conditions in Doha comprise of medium soft rock (limestone and shale) that had never been exposed in the past to such extents. Within these formations there was also the risk of encountering karst features, such as sinkholes and caves.”

Although the medium soft rock in Doha is relatively strong and the earth pressures low, the high water table and the mostly saline groundwater posed some problems. Water only a few metres below the surface generates very high pressures behind any type of retaining structure as well as challenging levels of buoyancy, while the high concentration of salt and sulphate in the groundwater has

implications for concrete performance and durability. Added challenges were the client’s desire for vast, open-vaulted spaces, for the terminal to effectively serve as the foundation for a multi-storey building, and its close proximity to existing structures.

A total of 21 tunnel boring machines have been employed, the highest concentration on one project anywhere in the world, with Msheireb receiving a record 12 TBMs.

Money-saving solutionsSome of the design opportunities embraced on the stations include replacing more than 1000m of diaphragm walls (about 300m at Msheireb and 800m at Education City) with open cut excavations, providing a more sustainable and economical solution. Meanwhile, to counter aggressive groundwater conditions the design includes bored tension piles and thick reinforced (2-3m) elements with large concrete cover.

Msheireb station construction site in Doha


Analysing how people typically move in a building or rail station is crucial for architects, planners, fire engineers and security advisers.

People move at different speeds depending on their level of mobility, knowledge of the area and urge to get somewhere, while others, including carers pushing children in buggies and travellers trundling suitcases, require more space. Individual behavioural characteristics dictate how people react in an emergency, including their perception of risk, response to alarms and instructions, and how they interact with others fleeing a hazardous situation, such as a fire.

Passenger experience

Our STEPS pedestrian modelling software is a microsimulation tool to predict pedestrian movement through a 3D space, such as stations. It employs an agent-based approach to provide a realistic representation of pedestrian movement. The software allows individual agents (virtual people) to be assigned characteristics, such as free walking speed, patience level and familiarity with the space, to reveal how they move through the model under both normal and emergency conditions. STEPS can model interactions between people and 3D moving vehicles, such as trains, enabling users to model vehicle arrivals and departures, as well as people boarding and alighting.

The ALIGHT train/platform interface goes further than STEPS. Commuters around the world often experience congestion on platforms and when boarding or alighting trains, resulting in dwell time and safety issues. ALIGHT is a validated tool to assess rolling stock capacity and performance, with respect to timetables, dwell times and future passenger growth. The 3D models offer a detailed simulation of the interior space of vehicles, with built-in passenger behaviours defining their interaction with the vehicle layout. These are based on research by our human factors team and studies by the Accessibility Research Group at University College, London.

City Rail Link Auckland


Rolling on down the line

Metro systems are complex and include rolling stock, tracks, signalling, communication, power supplies, ventilation, lighting, fire protection and security, operational controls, depot equipment and maintenance, and asset management.

We have world-class in-house expertise in all these areas, and this was one reason the governor of Jakarta chose us to develop a metro rail network for the Indonesian capital, which in 2015 was named the most congested city in the world.

The first phase, a 6km stretch between Kelapa Gading and Velodrome, is under construction. It includes six stations and a depot, which will eventually service the whole network,

with housing and retail developments above.

Our work on the metro network has evolved from feasibility study and preliminary design to tendering and project management for phase one. The programme and project management role includes advising on the interface between rail systems as well as developing the design criteria for rolling stock and associated systems, such as signalling and train controls, traction power and conductor, communications, control and information, and automatic fare collection.

The signalling system we designed is worthy of note. It’s an enhanced version of the ‘line of sight’ approach used widely on metros and was developed to meet the client’s

requirement that trains are fully protected during transit, not just when stationary in terminals.

TRAIN, software developed in-house, supports our systems work by producing simulations under a variety of conditions. It has been used around the world, including the metros in Calgary, Dublin, Kuala Lumpur, Melbourne and Warsaw.

Technical inputs range from train characteristics, including number of motors and electrical storage systems, to track conditions, such as gradients and curvature, and signals. Output graphics can be produced for rolling stock, substations, track, wire temperature and all systems, including overall efficiency.

Dealing with complexity


Engineering real benefits

The role of our systems integration engineers is crucial to knitting together components and ensuring they work. They are involved from project conception through to asset operation and beyond.

They are responsible for everything from ensuring power supplies are adequate to doors and racks fitting. Many components generate heat, so they must also communicate with the ventilation design team. Understanding the needs of the client and ensuring all parties are aware of these is a prerequisite for the job.

We have had numerous systems engineering commissions for Crossrail, which is delivering the new east-west Elizabeth Line under London. This

work includes: designing Liverpool Street station, among the largest and most complex of the stations; integration of new line with the existing mainline railway at Paddington; aerodynamics and ventilation of tunnels and shafts; in-tunnel mechanical and electrical works; two depots; traction power; rolling stock specification; and signalling.

Most of our systems engineering work on Crossrail was undertaken by having our specialists embedded in co-located design teams at the project or contractor offices. Their role included creating a programme functional requirements document and the design package specifications. These helped to shape the Crossrail requirements management regime.

Meanwhile, our interface process identified and defined the connections between design contracts. We developed a so-called ‘Give & Get’ list, which was successful in managing interfaces through review meetings. The list captured the interface needs across the design teams and all suppliers.

In terms of human factors integration, the team worked closely with Crossrail to ensure human requirements were always considered and verified during the design process.

1. Right solutionsInterrogates problems/challenges and examines all potential solutions.

2. Manages complexity Provides a structured approach to data management, ensuring the right information is available to the right people at the right times.

3. Transparent decisions Establishes rigorous systems for making and recording decisions to provide a clear audit trail at any stage in the project’s lifecycle.

4. Cost certainty Pins down technical, operational and performance requirements, reduces the risk of changes during design, specification, procurement, construction, commissioning and operation.

5. SavingsIntegrates the supply chain so that every player can influence the design and schedule, enabling seamless project delivery and smooth handovers, and ensuring all disciplines contribute at the optimum time, reducing waiting time and rework.

6. Sustainability and wasteCombines with lean thinking to strengthen project performance, enhancing value-adding activities and eliminating waste, saving resources, time and money.

7. Safer Takes an integrated, whole project view to help identify potential technical, procedural and behavioural risks.

8. Continuous improvement Records information about performance through the project lifecycle, enabling refinements to be made where and when necessary.

9. EfficienciesCreates rigorous test and acceptance criteria allied to the client’s initial requirements, and linked to structured risk and reward mechanisms to drive performance.

10. DecommissioningEnsures initial project planning takes account of the final winding-up of operations and the safe storage, removal or rehabilitation of the asset.

Need

Concept

Validate

Operation

Design Integrate

Requirements

System integration

Verify

Specify Accept

Detailed design Construct

System partitioning

10 ways systems thinking adds value


Good neighbours Transport is a major source of noise in urban environments. It’s not a new problem, however; horse-drawn carriages were banned at night in many places because of the noise they made on cobbled streets.

With increasing urbanisation and the need for people to move around cities, noise and vibration must be carefully assessed when designing transport infrastructure.

Metro trains produce little direct air-borne noise, although they can cause ground-borne noise and vibration, while fixed

infrastructure, such as stations and ventilation shafts, tend to generate air-borne noise.

With buildings above or close to most networks, mitigating noise and vibration is important. Our in-house ReVerb software models and monitors train vibrations and noise levels.

Keeping the noise downNoise from railways differs with speed. Up to 80km/h, the dominant noise comes from the traction system together with ancillary equipment such as air conditioning. Unavoidable rolling noise comes at 80-200km/h and is generated

by the roughness of the surface of both wheel and rail, forcing the two apart and then back together.

Aerodynamic noise becomes dominant at around 200km/h. Because of the relatively slow speed of metros – the average on the London Underground is 33km/h – traction and rolling noise are the dominate sources of sound.

Significant ground-borne noise is rarely transmitted more than 100m, but if a building is within that range it is inescapable without designed mitigation measures.

Energy from the railway propagates through tunnel lining, the ground and into the building structure.

Solving the problemDifferent solutions have been employed to overcome the noise and vibration created by wheels on rails.

One is specialised trackforms, such as rubber-booted sleepers, which are being used on the Northern Line extension in London.


Conducting the power Minimising heat is a key goal

Heat and space present challenges when it comes to powering a metro network. Clever design and use of new technologies can overcome these.

In deep-lying metros, the soil surrounding the tunnels tends to absorb most of the heat, but its capacity to do so declines over time. On parts of London Underground (LU), the temperature of tunnels has increased from about 14°C in the 1900s to as high as 30°C because the clay through which they were bored can no longer soak up heat generated by the trains.

Cool brakingAbout half the heat generated is through trains braking mechanically. Regenerative braking converts mechanical brake power that would otherwise be dissipated as heat into electrical power for use by nearby accelerating trains.

Inverting substations can send any surplus power from regenerative braking back to the grid, turning it from direct current (DC) to alternating current (AC). Installed across a network, this technology can unlock significant energy and carbon savings as well as lessen the amount of heat generated by trains. After trialling the technology Transport for London calculated that the energy sent back

to the grid would be enough to power Holborn station for more than two days a week and save LU as much as £6M a year in energy costs.

Capturing the energy generated by decelerating trains and returning it to the grid, or storing it in a wayside system for reuse across the network, creates a more energy efficient system. “Reversible DC substations equipped with modern power converter technology not only saves energy but also improve voltage regulation at the trains,” says transport project director Sébastien Lechelle.

Imitating real lifeOur TRAIN simulation software has been used to verify, optimise and validate traction power system designs as well as model the energy consumption of rail systems, including energy savings from regenerative braking and other technologies, such as DC reversible substations. For LU, we modelled the traction power network to support the organisation’s Cooling the Tube programme to improve thermal comfort for passengers. This involved evaluating electrical losses in the traction power system and rolling stock, and calculating the predicted increase in loading on power equipment.

TRAIN was also used to develop plans to upgrade the Metropolitan, Circle, District and Hammersmith & City subsurface lines to raise capacity, reduce journey times, install air conditioning and improve the resilience of the existing infrastructure. The project team concluded that 62 traction power substations would need upgrading, and that six new substations and one new bulk supply point would be required.

For the Dubai Metro Route 2020 extension, electrical power system analysis software was used to verify the 33kV medium voltage AC distribution system design. We assessed loading on the main power substations, busbar voltage and feeder current for 124 normal and outage operating scenarios, enabling the local authority to finalise its plans to upgrade the power network infrastructure to meet future demand.

“TRAIN enables us to optimise traction power system designs and assess new technologies and lifecycle costs,” says Sébastien. “Because we can model various scenarios, it also helps us answer our clients’ ‘what if’ questions and provide evidence to support their business cases.”


From BIM to Smart

We set out our global building information modelling (BIM) strategy in 2010, having used the technology widely for the first time for our work on upgrading the underground terminal at Victoria station in London, which started in 2007.

Our digital delivery has expanded greatly since and we firmly believe that BIM is all about adding value to information, and that the greatest potential value can be realised over the lifecycle of an asset.

Smart infrastructure is where digital meets physical. By developing and maintaining a digital representation of assets and systems, and combining live data from diverse sources, a new level of value can

Realising the value of data

be generated, leading to predictive modelling, risk-based maintenance and adaptability to social demand – all of which can be converted into economic benefit.

We have a complete and integrated set of services to optimise the performance of new and existing assets over their whole life, including information advisory, asset performance optimisation, digital infrastructure and technology solutions.

Better information enables better decisions, which can lead directly to increased reliability and reduced through-life cost. We provide the information architecture that enables asset owners to make sense of their data. Through Moata,

our predictive modelling service, we combine asset data with new data sources – such as the Internet of Things and social media – and add our bespoke layer of analytics to provide unique insights.

We are applying this methodology to new asset creation. On the Northern Line extension in London we are working directly with developers and operators to structure data for the future. For Crossrail 2, the proposed north-south rail line under London’s streets, our team is developing a world-leading information management methodology for the start of the project. It will ensure data is used throughout and beyond the construction phase to optimise performance.

Northern Line extension, London


Moving Sydney Metro forward

Sydney Metro is a huge step forward for digital engineering on major infrastructure projects.

Our role on the underground stations design and technical services contract for the 30km Sydney Metro City & Southwest section builds on our digital delivery of metros. We are also detail designers in a joint venture for stage one, Sydney Metro Northwest.

Sydney Metro City & Southwest, from Chatswood to Bankstown, passes under Sydney Harbour and through

the city’s central business district. It is due to open 2024.

Leading on digitalWe are part of the Metron joint venture with Arcadis. As digital lead, our objectives include applying sound information management principles, creating a best practice virtual environment, and dramatically improving use of technology by the client, principal contractors and suppliers.

Potential benefits from making the project digital by default include significant programme

and cost savings from using a co-ordinated 3D model across all subcontracts and with the client, eliminating the need for unnecessary drawings.

Global collaborationCollaboration has reached a new high on Sydney Metro. We have established a BS 1192-compliant common data environment (CDE) with groundbreaking ProjectWise functionality, accessible by every member of the project team. BS 1192 is a code of practice for the development, organisation and management of

production information for the construction industry.

On Sydney Metro, more than 300 people have been trained in BS 1192 processes. All 24 organisations working on the contract use the CDE to co-ordinate design inputs in 3D. Reviews of intermediate designs are model only, eliminating the need for about 900 drawings – at around AU$1500 each that’s an overall saving of AU$1.35M.

Model exchangeModels are exchanged weekly with other contracts to ensure continuous co-ordination across the whole metro, and updates to the design are imported directly to cost schedules to provide ‘live’ cost forecasting. The federated or single complete model is the central focus for collaboration.

Comments by client reviewers feed directly into the design CDE, although the number comments at each design review phase is much lower than on previous comparable

projects because the client has a better understanding of the ongoing design. Federation and clash detection is automated. This saves about 40 staff hours a week compared with previous projects.

No time differenceSydney has a truly global network of people working on the design. Synchronised dual data-sources are being used across five countries – Australia, the UK, France, Singapore and the Philippines – to minimise lag, while streamlined workflows, including digital approval of all

documents, is pushing the boundaries for a CDE.

The management information delivery plan is simply a dashboard of live project data. Rigorous model requirements have been set for Uniclass 2015, the universal classification system for the construction sector, and Construction Operations Building Information Exchange (COBie) asset data deliverables.

In realityModels are used as evidence of compliance and to justify deviations from the design. End-user

engagement was through virtual reality (VR).

The technology has been used to put 100 volunteer Sydneysiders in a virtual station, with their insights on wayfinding and safety, for example, feeding early into the design process.

The aim is to improve the connection between the structure and its end users, and save costs by eliminating the need for future changes. VR is also being used by the client and project staff to visualise the stations.

Sydney Metro City & Southwest will include five new stations

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Mandatory sustainability

Sustainability underpins our work. From the start of a project we aim to turn it into an opportunity for growth, and to maximise sustainable outcomes for the environment and the local community. By taking cars off roads, metros are essential to reducing greenhouse gas emissions and improving air quality in urban areas.

But building infrastructure in already congested cities can generate a huge carbon footprint and environmental damage.

Concrete is the major source of carbon on tunnelling projects. Our engineers work continually to make tunnels more sustainable.

On the Northern Line extension (NLE) being built in London, our engineers worked with

contractors FLO – a joint venture between Ferrovial and Laing O’Rourke – to identify potential resource and carbon savings.

They found that reducing the thickness of the segments lining the walls of the tunnels between the two new stations by 30mm, from 280mm to 250mm, would save about 2700m² of concrete and 1500t of carbon. This outcome followed a re-assessment of the geology and refining the structural design of the segment lining by the design and construction teams.

Reusing furnace slag Replacing ordinary Portland cement with alternatives, such as ground-granulated blast furnace slag (GGBS) from steel manufacturing, produces concrete with

lower embodied carbon. On the NLE, we used concrete for secant piling with 95% GGBS – much higher than the norm. It reduced embodied carbon by 80% compared with conventional Portland cement.

The slag-based concrete was carefully designed to optimise the performance of fresh and hardened concrete, including its long-term durability, and minimise the environmental impact.

Financial savingsAdopting a more sustainable approach has financial as well as environmental benefits. As part of our multidisciplinary design role for Crossrail on the Elizabeth Line in London, we collaborated with manufacturers and future asset operators on LED lighting for new

underground tunnels and stations in the central section. LEDs will produce significant whole-life cost and carbon savings compared with conventional lighting – £2.4M in energy savings and 23,400t of carbon.

To ensure sustainability initiatives are captured, we have developed a sustainability and innovation database. It includes the estimated cost, time and carbon savings achieved on a project.

Meanwhile, our Carbon Portal tool is the first calculator to measure the lifetime capital and operational carbon footprints of BIM-designed assets.

80%embodied carbon saving for concrete on the Northern Line extension


Building expertiseYoung professionals maintain our standards

Mohamed Abdalla Using BIM to resolve clashes is just one of the roles graduate engineer Mohamed is performing as part of the Mott MacDonald team working on NLE. “A structural element, such as a column, may clash with an electrical or mechanical element, and it is my job to act as the ‘middle man’ in discussions to resolve the issue between the disciplines,” he says.

He is also managing and co-ordinating requests for information, specifications, early warning notices, progress reports and drawing register processes.

His interest in civil engineering stems from an experience as a youngster in his home country, Kenya, when a building collapsed killing several people. “I’d travelled and seen skyscrapers and buildings elsewhere, and what civil engineering can do to help people and communities. But the disaster was a warning that construction must be done properly. It prompted me to become a civil engineer.”

Jie Tang Jie is leading on the electrical design for the NLE station being constructed at Battersea Power Station. After studying electrical engineering and automation control at Xi’an Jiaotong University in China, she did an MSc in sustainable energy systems at the University of Edinburgh. Family influence – her father was an engineer – and a predilection for mathematics were behind Jie’s decision to build a career in electrical engineering.

Her role on the NLE is to manage resources and provide electrical design for the station through the RIBA workflow stages – 3 (developed), 4 (technical) and 5 (construction). This involves working with disciplines internally, such as mechanical, public health, HV, structural, risk management, human factors and tunnel ventilation, as well as external architects and IT specialists. “It is a role that requires effective communication and negotiation skills as well as good technical capabilities,” Jie says.

Haydn BrownHaydn has been working on the Sydney Metro Northwest project. It is scheduled to open in 2019 and will be the first fully-automated metro rail system in Australia. Eight new stations are being constructed and Haydn has been responsible for the design of the large canopies that will become the architectural centrepieces of the new stations. The largest spans 48m. His work on the canopies was recognised in 2016 by the Australian Steel Institute, which awarded him with its young designer, detailer, tradesperson accolade. He says working on the canopies was both exciting and challenging. “Engineers led the design of the canopies and the architects were pushing us for innovative solutions. I worked in a team that brainstormed ideas. We collaborated with steel fabricators and the architects to push the boundaries of what was possible.”

Several reasons lie behind his decision to choose a career in civil engineering, including a desire to discover solutions to unique problems and seeing those ideas turned into something tangible. “It is so satisfying to see big steel structures you’ve designed and modelled come to life,” he says.

Cremona (Keke) MakaginsarKeke is deputy team lead for the detailed design of Doha Metro’s flagship station, Msheireb. The 37m deep cut and cover station is scheduled to open in 2020. Her work on the project includes: designing the bored tension piles and other structural elements in the station; managing the civil and structural design team for all permanent works; co-ordinating with other disciplines through BIM; and interfacing with external stakeholders.

Keke studied civil engineering at the University of Bristol and joined Mott MacDonald full time after graduating, having worked for us during the summer in both her second and third years. Both her parents are civil turned aeronautical engineers, although it was a visit to the Jatiluhur Dam on the Citarum River in west Java that inspired her to follow them into the profession. “I visited as a 10-year-old and it appeared massive. I knew then I wanted to build something similar.”

Opening opportunities with connected thinking.

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