Railways | Electrification

Electrifying stories

Electrification of the world’s railways is more complex than passengers know. Behind every journey lies a story. 4 I Mott MacDonald I Electrifying stories Electrifying stories I Mott MacDonald I 5

Pantograph and contact wire Taiwan high speed rail

Bright sparks behind electrification

Railways around the world Electric trains are now To add to the complexities, Our multidisciplinary teams of rail engineers are cheaper to operate, third rail systems are used working around the world tackling every aspect have come a long way since easier to maintain and in a variety of voltages of railway electrification. Their unique solutions the Greeks invented the Diolkos are generally more reliable – 600V DC in Tokyo, range from voltage upgrades and discontinuous than diesel trains, which 850V DC in Moscow, electrification (short sections without power) paved limestone trackway, which largely replaced steam. 1.2kV DC in Berlin and to AC/DC changeover integration. was used to transport boats Electric trains are also 1.5kV DC in Guangzhou more environmentally as well as the more Clearances between live wires or rails and other across the Isthmus of Corinth sustainable and capable common 750V DC. objects or people are a major issue, particularly around 600 BC. Wooden railways of greater acceleration Overhead line supply when retrospectively electrifying legacy railways. performance resulting voltages vary too, from Meanwhile, protecting sensitive equipment in in the 16th century gave way to in shorter journey time 1.5kV DC and 3kV DC, buildings neighbouring a railway from electromagnetic steel as steam engines became for passengers. through 15kV AC to interference presents its own complexities. the more widely used the norm, dominating the world’s However, there is no 25kV AC. Pressure on operators to tackle climate change railways until the mid-20th century. standard electrification and improve sustainability requires new solutions system. From New York to powering railways. These include on-board to London, Melbourne to energy storage combined with discontinuous Japan, differing systems electrification, wayside energy storage, reversible have evolved. Third rail, DC substations, hybrid conductor rail, and high fourth rail, and overhead annealing temperature alloy for overhead contact lines have all undergone wires. New ways of getting power from the grid to their own evolutions and the railway is also a challenge. – despite commendable steps to harmonise Running the railway is more than just rolling stock, systems – engineers face stations and passengers. Powering the system complex challenges when presents multiple complexities for engineers to renewing or upgrading tackle. Here are just some of our electrifying stories. existing infrastructure. 6 I Mott MacDonald I Electrifying stories Electrifying stories I Mott MacDonald I 7

Bridge on the Ordsall Chord, part of the GNRP ®MatthewNicholPhotography

Cutting journey times goes down to the wire

With rolling stock in the north of Electrification would drawn from different allow electric trains to run substations interacting. England coming to the end of on the route, which are Identifying these locations, its life, coupled with the need to faster, quieter, cheaper to helped maintain design operate and less polluting momentum on our improve journey times on the than diesel trains. project without affecting 41km route between Manchester the interconnecting Designs for overhead line projects. With Network and Preston, in the north of electrification systems are Rail engineers working England, there was an opportunity generally set out on an on MFD in our offices, engineering drawing called lines of communication to make some significant changes. a major feeding diagram were clear and constant. (MFD). This shows the substations where current Our approach also will be drawn from and involved strategically the distances it needs to identifying where points travel. MFDs can undergo should be located, so many changes over that sections of track the course of a project, could be switched particularly when there off for maintenance, are interconnecting while key routes projects, such as on remained operational. the Great North Rail Project (GNRP). We also proposed an auto-transformer system By being flexible and on the route. This proactive, we identified balanced current flowing where changes in the in the overhead line MFD might occur and with that returning via planned how best to the track to help control accommodate them. We voltage in the overhead also suggested where to line equipment (OLE) locate the neutral sections, system, helping it function which prevent the current more efficiently. Electrifying stories I Mott MacDonald I 9

Out with the old: New York’s subway challenge

New York City Transit An investigation into the TRAIN models the The proposed upgrades (NYCT) is the agency traction power system was behaviour of traction will be a once in a lifetime that operates public required to confirm the system parameters by opportunity to align the transportation in the power upgrades to support determining details of traction power network Big Apple. The city’s additional services. system performance with international subway is presently and thus confirming the standards, and we are undergoing a major NYCT commissioned suitability of a particular investigating how to move upgrade with the consultancy Henningson design. The simulator has the system from 625V introduction of Durham Richardson (HDR) been validated for to 750V DC. This will communications-based to perform the traction accuracy on London enable use of standard train control (CBTC) power system study and to Underground and has kit throughout, giving signalling and new make recommendation for been used in many transit access to a vastly more rolling stock. CBTC power upgrade. We are systems throughout North diverse supply chain and signalling is an advanced part of the HDR team and America and around the all the cost and supply automatic train control are using our proprietary world. The simulations for benefits that this brings. system that allows more simulation software known the NYCT will be centred frequent services. as TRAIN to analyse on four main routes – the NYCT’s traction power Lexington Avenue Line, electrification system. Eastern Parkway Line, 7th Avenue Line and Astoria Line.

The A$11bn Metro Tunnel will free up Melbourne’s Untangling biggest rail bottleneck by running three of the city’s busiest train lines through twin 9km tunnels, Melbourne’s creating space for more trains to run more often across the network.

City Loop The Aurecon, Jacobs and Mott MacDonald Joint Venture (AJM JV) was appointed as technical, planning and engagement advisor by Rail Projects Victoria in 2014. AJM JV is providing the full range of project support services, from feasibility to delivery.

Featuring communications-based train control technology and platform screen doors at five new underground stations, Metro Tunnel will reshape travel demand, allowing for future extensions to Melbourne’s tram and rail network as the city grows. The project will increase the capacity, reliability and efficiency of the network to cater for 39,000 more passengers during peak periods.

Major works on the Metro Tunnel are now underway with the project on track to be completed by 2025. 10 I Mott MacDonald I Electrifying stories Electrifying stories I Mott MacDonald I 11

A class 700 Thameslink train AC/DC: the breakthrough

The UK-government- as the Bermondsey sponsored Thameslink dive-under and untangles Programme, which is the tracks approaching transforming north-south London Bridge station. travel through London, is Importantly, Thameslink set to move into its final has introduced the new phase following major Class 700 train, which engineering works. is set to transform Network Rail virtually operations, but which rebuilt London Bridge has thrown up a variety station and the of engineering issues, surrounding railway as not least the need to it moved to become the operate on 25kV AC first mainline railway in north of the capital and the UK to introduce 750 DC to the south. automatic train operation All this has required a (ATO) from 2018. wide range of engineering capabilities within Network The programme, one Rail, Thameslink and of the largest civil its partners. engineering projects in Britain, and has called We are working on the “We are supporting for collaborative working, project across a range which has brought of disciplines, including the central innovation and efficiencies. systems engineering, engineering electro-magnetic The challenges have compatibility, surveying, function because been enormous, and ergonomics and human we’re flexible included major factors, and GIS. Our remodelling of Farringdon engineers are working and we have and Blackfriars as well on rail adhesion for ATO, engineering as the redevelopment of which is crucial to London Bridge, and the operating the planned resource and building of a grade 24 trains every hour skills across all separated junction at through the central London Bermondsey. This known ‘core’ during peak periods. the disciplines.” Robert Gray, Divisional director, Mott MacDonald 12 I Mott MacDonald I Electrifying stories Electrifying stories I Mott MacDonald I 13

Mind the gap Goschenen station

The task of fitting electrification Engineers increasingly resort to discontinuous Natural gaps in the OLE wiring, such as where Where discontinuous electrification is potentially electrification to surmount these problems, using a separate sections of the line are supplied by different possible, the electrical performance of the system into infrastructure that was variety of methods, including onboard energy storage, feeder stations, are known as ‘neutral sections’, must be assessed to ensure it has the capacity and built up to 150 years ago keeps raising or lowering the pantograph or simply coasting and discontinuous electrification is an extension resilience to support the power demands of the trains. through a short section. of this principle. Neutral sections are usually found on engineers on their toes looking a 25kV AC electrified railway where high-speed trains Retrofitting old railway systems, built for steam days, for smart solutions at individual Coasting is a simple solution but may not always be are just one of the many modern electric rolling stock with OLE designed for modern high-speed trains an option. If there are signals a train could become types we have to accommodate. presents many challenges, but our engineers are sites. Retrofitting overhead stranded, for example, or, if the gradient is too steep, always finding clever ways to get round them, line equipment (OLE) into the train’s momentum may not be enough to propel In many cases, our engineers suggest using automatic because we mind the gaps. it through the section. Instead, onboard batteries and power control magnets to temporarily switch off the Victorian bridges and tunnels supercapacitors can store power and be accessed power supply, so that when the train passes under a presents complex challenges. as necessary. bridge or through a tunnel, the OLE can be earthed. 14 I Mott MacDonald I Electrifying stories Electrifying stories I Mott MacDonald I 15

Eliminating shocking stories

All electrified systems be required to achieve present a danger to acceptable clearances. The both passengers, tool is CAD-based and can workers and neighbours, be used with UK Network including animals. As Rail’s national gauging a result, clearances database. It can be applied play a major role in the to a single structure or an design process to ensure entire route, enabling fast electrical equipment identification of the level of is out of harm’s way. civil interventions required to electrify an existing route. We have played a key role in undertaking Our expertise has recently risk assessments to been employed by demonstrate that Network Rail to produce clearances from standing a new OCS design surfaces to live overhead handbook. It includes contact system (OCS) requirements for the equipment and pantographs design of 750V DC, are as large as practicable 1500V DC and 25kV AC and complying with the overhead contact systems, requirements of the railway while one module deals group standard for AC specifically with Network energy subsystems. Rail’s requirements for We have developed electrical clearances, an in-house design including the approach automation tool to quickly designers must take when and efficiently analyse the designing systems through clearances achievable at areas of standing surfaces overline structures or to or overline structures. identify the what would 16 I Mott MacDonald I Electrifying stories Electrifying stories I Mott MacDonald I 17

Part of the high-voltage converter for the SFC

Unlocking value through new technology in the UK

Hitachi Rail Europe is Traditional traction power We have an ongoing introducing new Class grid connections use role with Network Rail, 800/801 high-speed trains single-phase power supervising the work onto the East Coast Main transformers, each performed by the Line from 2018 onwards connected across two of contractor delivering under the UK’s Intercity the three phases of the the SFC and associated Express Programme. grid in an unbalanced infrastructure. The decision manner. By contrast, SFC to use SFC technology at The trains will be connects via all three Potteric Carr has enabled maintained at a new, phases in a balanced a faster and cheaper grid purpose-built facility arrangement, converting connection because of the

Three-phase 33kV power near Doncaster. The new the three-phase AC supply lower connection voltage. transformer undergoing depot has required the into DC and back into a The balance provided tests in 2018 strengthening of Network single-phase AC supply by an SFC connection Rail’s 25kV traction power to feed the railway. removes the undesirable supply in the Doncaster harmonic currents created area via a new feeder SFC technology has been by the traction loads, station being constructed extensively used on 16.7Hz and enables the power at Potteric Carr, south railways in Europe and factor of the load to be of the Yorkshire town. 25Hz railways in the US for controlled to suit the grid. more than two decades. In the UK, traction power However, the use of SFCs SFCs are likely to be grid connections have to directly feed railways at widely used in the future traditionally been made at 50Hz is a relatively new because of the value either 132kV or 400kV. development that has and flexibility the For Potteric Carr, been proven by projects technology unlocks. Network Rail will make in Australia only in the the connection at 33kV past few years. We used by adopting a new our experience on the first technology for the UK such project in Australia to rail network: a static develop the specifications frequency converter (SFC). for the Potteric Carr SFC. 18 I Mott MacDonald I Electrifying stories Electrifying stories I Mott MacDonald I 19

A Siemens-Duewag Supertram in Sheffield

To reduce carbon environmentally-friendly Bring on the The hydrogen emissions several option. In some places, countries are trialling the underground pipes may use of trains powered be part of the solution. Supertram challenge by hydrogen. Although In Germany, hydrogen there are no direct carbon trains are running close emissions, hydrogen to the major chemical trains need recharging plants that generate the regularly, so there are still gas, making supplying Sections of the Supertram in Sheffield run on the existing indirect emissions. The them economical. rail system. The challenge was matching the different scale of these emissions tram and rail standards, and connecting Supertram’s depends on the power We use our in-house existing 750V DC overhead line equipment with generation source to TRAIN software to simulate Network Rail’s newly converted 25kV AC OCS produce the hydrogen railway systems and running at 750V DC. as well as its delivery. calculate the mechanical power required by each Using standard catenary and contact wire was not Transport engineers individual train in real an option with the proposed traction power system are grappling with time to complete its because conductor temperatures would exceed the the task of estimating journey. This enables us to limits. Instead, a new conductor was introduced to the real financial and calculate the real cost of reduce temperatures. environmental costs running hydrogen trains. of trains running on A correlation can be made Our engineers validated the existing system parameters hydrogen compared with between the amount of and basic design arrangements to operate within the other energy sources. power required and the new environmental conditions, introducing a new Transporting hydrogen associated hydrogen parallel feeder and associated jumpering and around countries to consumption. This informs terminations that could be operated within the new refuel trains, either in decisions on fuel cell system. Double insulation was also incorporated liquid or gas form, may capacity requirements, into the design along with an amended earthing not necessarily be cost- refuelling cycles and and bonding regime, and new in-feed arrangements. effective or the most hydrogen consumption. Alstom’s Coradia iLint hydrogen train Ubahnverleih/CC0

“You should be very, very proud of this achievement and I am personally very grateful for all of your individual and collective efforts – thank you.” Rob McIntosh, Network Rail 20 I Mott MacDonald I Electrifying stories Electrifying stories I Mott MacDonald I 21

Manchester Metrolink tram Cutting overheads through innovative thinking

Prototype densified Every rail engineer is wood laminate cantilever looking for ways to cut the cost of erecting and maintaining overhead line equipment. Now, together with Moxon Architects, we have designed an integrated overhead line structure that is cheaper and easier to install, requires less maintenance, and is lightweight and visually more appealing Fields of influence than structures currently used on conventional and high-speed rail projects.

The design achieves this through the use of Electrified railways can 0.5 milliGauss (mG) – This innovative solution a densified wood laminate generate electromagnetic a measure of magnetic considered a complex web in the cantilever arm. interference, which is field – 50m from the track. of operational scenarios, Its intrinsic electrical potentially a problem if the Usually, we would expect including passing trains, insulation properties line runs close to buildings the level at this distance some drawing current and mean that conductors containing sensitive to be about 3mG, so this others using regenerative and supply cables can electric equipment. Over was a challenge for our braking. It enabled us to be fixed directly onto the the years, engineers engineers. We needed optimise the location of all structural arm without have come up with a to find a smart way of the conductors to reduce the need for bulky variety of ways to mitigate arranging the conductors magnetic fields as much and visibly obtrusive such interference, to reduce induction as as possible and achieve ceramic insulators. but new forms of rail much as possible. the required target. electrification and traction This also design reduces mean increasingly novel We used our in-house It was the first time in embodied carbon solutions must be applied. TRAIN software to the UK such complex compared with typical simulate the level of simulation, ahead of alternatives by 32%. The new Manchester currents flowing in the design, had been used. Metrolink Trafford Park traction power system, extension in the UK runs under all possible on a 750V DC overhead operating conditions, line system, so there was including operational a potential issue with disruptions. We then DC magnetic fields. Our used the information to client asked us to find a calculate the magnetic way of reducing magnetic fields produced by fields to no more than all the conductors. Opening opportunities with connected thinking.

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