Ciara Walker and Marc Starmans of Arcadis look at the challenges the Digital Railway programme faces, and how they can be overcome by good management, supply chain collaboration and a strong investment case

Touch pad

Source: Network Rail

Digital in-cab signalling will expand capacity

01 / Introduction

The Digital Railway programme is the industry’s plan to tackle the UK’s capacity crunch by accelerating the digital modernisation of the railway.

Parts of the UK’s railway system are already operating above designed capacity at peak, with some services up to 200% over capacity, and passenger numbers are set to double in the next 25 years. Freight demand has also exploded, growing 100% since 2003. The benefits digitisation could provide in relieving this have been much discussed, as well as the benefits wider modernisation could bring to Network Rail, passengers and freight customers in terms of network resilience, reliability and safety.

Momentum is gathering behind Network Rail’s Digital Railway programme, and the government committed £450m to it in the Autumn Statement, giving the opportunity to get works off the ground and signalling funding and commitment to the supply chain.

However, there are significant challenges to implementation to be overcome, centred around the technology itself, as well as systems integration, co-ordination and collaboration of the supply chain and making the business case for investment.

02 / Digital Railway programme

Network Rail has created Digital Railway in order to address capacity challenges in the UK rail network, and the need for modernisation of the railways. It is a co-ordination programme for cross-industry transformation bringing together industry leaders and governing bodies and is led by an advisory group that informs and sets the programme direction.

The goal of the Digital Railway programme is the sustainable growth of the UK economy through acceleration of the digitalisation of the railway to bring forward transformational benefits in safety, capacity, cost, performance, customer convenience and positive environmental impacts.

The Digital Railway programme will touch almost every aspect of train operation, passenger experience and rail infrastructure, centred around the programme’s three main objectives:

  • More trains More space for more trains, enabled by modernising the Victorian-era block signalling with digital train control, enabling trains to run closer together on existing infrastructure
  • Better connections More flexible rail timetables able to respond effectively to changing patterns in passenger and freight demand, enabled by modernising timetable design and managing traffic in real time. Current inflexible systems often exacerbate a disruption rather than resolve it
  • Greater convenience Customers access information and ticketing services that work across all modes of transport, via web and mobile apps, enabled by an industry-wide open data approach.

Network Rail are seeking to maximise economic benefit through an accelerated deployment of digital train control. The programme covers:

  • Re-signalling and digital train control, most notably through European Train Control System (ETCS), to run trains closer together and improve capacity
  • Development of intelligent trains and infrastructure to improve monitoring of trains and data collection, as well as to reduce unplanned maintenance costs
  • Modernisation of passenger information and rollout of smart ticketing, leveraging the data created to improve outcomes for passengers and freight.

There are many inherent challenges for the Digital Railway programme, not least the complexity of the Victorian-era legacy signalling network in place and the variety of stakeholders to co-ordinate. The diversity of traffic, (varying types of passenger, freight) means challenges in making modernisation work for everyone.

To overcome these challenges in a co-ordinated and considered manner, a phased programme has been developed to deliver a Digital Railway by 2029. This will reduce deployment risks while providing time to develop technology which can maximise the economic value of the Digital Railway programme.

Table 1 Phased Digital Railway programme

Phase 1: Configuration strategic pilotsPhase 2: Technical integration and core business changePhase 3: National rollout to ETCS Level 3
Trials of the technology, including: Bringing the industry together with pan-industry collaboration Toolkits enable repeatable, scalable rollout
Traffic management trial: Romford and Wales Toolkit development leading to development of route plans, and initial industry plans for next control periods Rolling stock will gradually be upgraded to ETCS Level 3 as legacy stock expires.
ETCS Level 2: Paddington-Heathrow GSM-R specs and testing  
Thameslink: Integrated ETCS and traffic management Pathfinder – testing level 2 in one route  
  Data collection, cleansing, integration

03 / Technologies

The initial focus will be on digital in-cab signalling to expand capacity and the technology necessary to support it. Digital Railway will develop the specification of the system in conjunction with the supply chain to avoid technology lock-in and being tied to one supplier. It is also essential that a common communication protocol be developed: without one, Network Rail will always have to manage and collate the data, and opportunities for leveraging valuable insight could be lost.

European train control system (ETCS)
ETCS is a scalable digital signalling technology which allows more trains to run safely on a given stretch of track. It is the principal technology needed to expand capacity of the railway. It will see traditional line-side railway signals replaced with a computer display inside train cabs.

Key characteristics are:

  • Automatic train protection (ATP) ensures trains operate within safe limits and speeds. Cab signalling provides safe movement authority directly and continuously to the driver through cab desk display
  • Gives movement authority to a train, allowing a maximum point to progress to safely, given occupation of the line by other trains ahead, and setting the speed accordingly
  • Permits the driver to drive the train but, should distance or speed limit be exceeded or in danger of being exceeded, then ETCS intervenes to control the train, bringing it to a standstill if necessary.

ETCS can be configured to operate in one of the following application levels:

  • ETCS Level 1: Movement authority is passed to the train via a switched balise or transmitter on the track, while a conventional signalling system continues to be used. Though cheap to convert the current system, only the interoperability and improved safety benefits are achieved
  • ETCS Level 2: Movement authority is passed by GSM-R radio network from a Radio Block Centre to the train. Conventional trackside detection systems are used in conjunction with the interlocking signalling system. This is the level proposed across the UK network and provides capacity benefits with increased track sections to move into
  • ETCS Level 3: Builds on level 2, but uses critical data from the train rather than conventional train detection systems trackside. This allows a system of moving “virtual blocks” around the trains as they travel, which will allow for calculation of a minimum safe braking distance behind them. This means that track capacity isn’t defined by track sections broken up by signalling, but by the maximum number of trains which can operate subject to a safe braking distance between them. In the long term the UK will strive to reach this level and the capacity benefits it provides.

Global system for mobile communications – railway (GSM-R)
GSM-R ensures digital, secure and dependable communications between drivers and signallers using radio technology and will form the backbone of any ETCS system in the UK. However, the diversity of data it can support is not wide and there are challenges ensuring coverage so infill sites will be needed to ensure dual coverage. Advanced systems are being considered to overcome this limited capacity, such as Long Term Evolution with a 4G service. These are some way off being ready to use.

Traffic management (TM)
Where ETCS allows more trains on the tracks, the traffic management technology maximises network performance by allowing trains to run together as effectively as possible, optimising the throughput the existing track can support. The traffic management software allows real-time train planning to cope with short notice needs or disruption, as well as allowing more flexible timetables, to cope with school holidays or other annual changes in demand.

Automatic Train Operation (ATO)
To support drivers in implementing ETCS and TM systems, ATO provides in-cab digital decision support tools to give drivers the information they need at the right time to boost performance and safeguard safely.

ETCS Robust Level 3

ETCS Level 3 technology relies on the trains assuring their own integrity to guarantee they haven’t left a carriage on the track for those behind to hit. Not all trains have this capability, and in particular, freight trains are far less likely to. As such Level 3 presents a technological challenge to tracks with a variety of traffic on them. A solution presented by Arcadis in the Netherlands is ETCS Robust Level 3, where trackside detection equipment is used to assure a safe distance behind trains which cannot assure their own integrity (such as freight trains) and Level 3 is used for trains which can. For lines with a lot of passenger trains the big gains of Level 3 can be achieved without having to solve the problem of train integrity for freight trains. With gradual introduction of trains equipped with train integrity monitoring, track capacity could be increased without needing to modify trackside train detection equipment, and eventually legacy trackside equipment could be removed. This thinking has already been put to the test by Arcadis, ProRail, Bombardier and Alstom in the Netherlands in a successful proof of concept. The principles of this solution, “Hybrid ETCS Level 3”, have now been jointly approved by several European rail infrastructure managers, Unisig, and the majority of the ETCS industrial parties.

Freight rolling stock

Source: Tylinek /

Freight rolling stock will need to be upgraded

Table 2 ETCS implementation programme

2013 Testing began at ETCS National Integration Facility (test track on Hertford Loop)
2017 ETCS level 2 installed Western Paddington-Heathrow allowing Crossrail ETCS to run
2018 ETCS Level 2 overlay Kings Cross-Wood Green area (signals removed 2020)
2018 ETCS level 2 with no signals Moorgate-Drayton Park
2019 ETCS level 2 Western Paddington-Bristol (signals removed by 2025)
2020 ETCS level 2 with no signals on East Coast Main Line Kings Cross-Doncaster

04 / Stakeholders

Given the complexity of the Digital Railway programme and the many stakeholders involved, success will depend on the strength of co-operation.

It is beneficial to have a programme management and systems integration function involved which can ensure integration and smooth delivery of all the moving parts, and co-ordination between the stakeholders.

A whole industry approach is needed, which includes:

  • Investment by owners and operators in upgrading rolling stock, or retrofitting newer stock, as well as re-skilling the workforce to deliver more flexible working practices
  • Investment by the infrastructure operator in communications, command and control information, power infrastructure, and re-skilling operational and maintenance staff to work with digitally enabled processes and tools
  • Investment by government to change regulation and franchising frameworks to put necessary enablers and incentives in place to accelerate the pace of change
  • Investment by the supply chain in technology solutions and in building the required skills base to deploy them.

Some of the principal stakeholders involved are outlined here:

  • Network Rail is the infrastructure owner and is responsible for introducing Digital Railway across the national railways
  • Implementation will require a broad range of suppliers to integrate in order to deliver the full system. This will include supplying the GMS-R backbone, the ETCS/TM technology as well as power supply, infrastructure civils and demolition works
  • Train operating companies and freight operating companies will be impacted by many of the planned changes. They will need to update rolling stock to ETCS-enabled trains, and implement other elements of the programme, such as digital ticketing. Rolling stock owners will also be impacted when trains are leased by franchise holders
  • Passengers have increasing information and flexibility needs which will be answered by modernising data collection. They will see the most capacity gains
  • Demand by freight users is growing, and the current system is not meeting customer needs. Improvements to timetabling, capacity and safety will benefit the industry, and provide an economic boost by facilitating commerce
  • Rail unions need to be taken into consideration to ensure minimum strike disruption.

05 / Economics

Capacity benefits include:

  • Up to 40% more capacity, delivered at about 30% lower cost than normal line construction
  • Increased number of reliable train paths, enabling more people to travel and more goods to be transported
  • Improved performance as a result of reduced lost track space
  • Faster recovery from faults when they occur
  • 35% reduction in primary delay caused by signalling asset failures
  • Safer operations, with 80% fewer signals passed at danger (SPADs) and less trackside maintenance danger.

Flexibility benefits include:

  • Agile timetabling to optimise supply to meet demand, including freight and passenger mix
  • Reduced journey times due to better connectivity
  • Better connected intermodal freight nodes
  • Fewer line closure by exploiting bi-directional network capability
  • Scope for turn-up-and-go style travel similar to underground systems
  • Optimised train management during disruption.

Open data benefits include:

  • Clear real time multi-modal journey planning information and ticketing for passengers
  • Helpful passenger information during disruption
  • Intelligent passenger guidance from one mode to another
  • Electronic ticketing with open interfaces for ticket/token validation
  • Greater scope for service differentiation.

Additional benefits to be considered include:

  • Safety: A 50% reduction in trackside signal and control maintenance reduces risks to workers
  • Resilience: Removing equipment from the trackside, which is vulnerable to damage by adverse weather and vandalism improves the resilience of the railway
  • Environmental: Eliminating start/stop traffic reduces equivalent energy consumption up to 15%.

Business case
The benefits of the Digital Railway programme are clear, but do they provide value for money? Although the ETCS technology can be marginally more costly than traditional signalling updates, the additional capacity provided makes this comparison invalid. When compared against similar expansions of capacity such as building significant infrastructure, investment in ETCS is notably cheaper. In addition, with reduced amounts of trackside equipment there will be lower maintenance costs, so whole-life costs get progressively lower as the system gets closer to ETCS Level 3, a relatively cheap boost to capacity.

An analysis of the demands and constraints on the South West main line into London for example shows a value-for-money case for accelerating digital modernisation alongside conventional measures. The technology is forecast to deliver significant reliability and capacity benefits from a configuration comprising traffic management and ETCS Level 2 without the need for a major and costly move to build a fifth track between Surbiton and Waterloo. Capacity for up to 30,000 additional passenger journeys a day would be delivered four years earlier than with conventional upgrades, and at £60m lower capital cost.

Business cases are being developed for eight pilot routes identified as representative of the constraints and characteristics of the network as a whole, in order for Network Rail to move to targeted deployment through Control Period 6 and Control Period 7.

However, there remains a challenge around the business case for implementation of Digital Railway. The benefits of Digital Railway to the infrastructure owner do not always feed through to train operating companies and freight operating companies, and they risk taking on the cost of investing in technology without a guaranteed share of the benefits. Newer franchises may have already been priced in the cost of updating to ETCS, but most have not.

As technology is brought onto the train and away from trackside, signalling risk and cost is transferred from Network Rail to the train operating companies and freight operating companies. Ensuring they benefit is essential in making the business case work for them, most likely through changes to the train operating companies service contracts to reflect the shift in risk patterns and incentivise updating the rolling stock.

With the process of “Network Change” in the UK, where all franchises need to agree to any infrastructure changes, implementation of ETCS may be held up until financial compensation is sorted out.

06 / Procurement and supply chain

Digital Railway has engaged the supply chain through an early contractor involvement workstream, ensuring the expertise of the global supply chain is taken into consideration when forming specifications and plans. This also gives suppliers early visibility of the pipeline, increasing confidence in the funding of and commitment to the programme.

Digital Railway’s Early Contractor Involvement Report demonstrates that to achieve the goals of the Digital Railway programme a fundamental change to the way the industry works with the supply chain is required. The industry reform programme will focus the supply chain on delivering outcomes and whole life costs and performance. Collaboration will allow suppliers to develop the right solutions together with Network Rail and tap into lessons learned from other countries. Conservative estimates suggest that cost savings could be as much as 10%, growing to 30% over time. In addition to this, disruption could be minimised by co-ordination across the supply chain, and risks could be identified and addressed earlier.

As such, Digital Railway will work with the Rail Supply Group to continue early contractor involvement, further developing the initial findings of the benefits of Digital Railway and embedding those into the targeted set of business cases being developed.

The findings will also inform ongoing work to develop the integrated industry plan. Early contractor involvement will also look to:

  • Explore alternative funding mechanisms
  • Develop a whole life commercial strategy which rewards and incentivises successful collaboration and delivery
  • Develop a Digital Railway industrial strategy focused on suppliers and skills development
  • Review restrictive legacy specifications
  • Exploit opportunities from intelligent infrastructure
  • Work with telecoms supply chain to ensure integration of requirements into digital train control specifications.

The overall aim is to develop a whole-life relationship with suppliers that takes them not just through first cost but through performance, reliability, availability, upgrades and obsolescence management.

A procurement strategy will be created emphasising engagement, information sharing and collaboration with industry. Commercial innovation will be required as well as enabled by the programme, making it an important driver for increased affordability, efficiency, performance and sustainable risk transfer.

Supplier consensus has been reached that the NEC3 suite of contracts would support the collaborative arrangements required to enable multi-party deliver of individual schemes. Rather than developing a specification in-house and then putting contracts for digital technologies out to competitive tender as before, Network Rail aims to involve suppliers in writing the specifications, ensuring engagement and clarity from the start.

Amsterdam Centraal

Source: Evannovostro / Shutterstock

Amsterdam Centraal station

07 / Case study: Digital Rail in the Netherlands

Arcadis, together with ProRail, the Dutch railway infrastructure owner, has been working with the Dutch government to implement Digital Railway across the whole of their network.

The Netherlands started the national implementation of Digital Railway in 2012 and Arcadis has been working with them since the beginning, from business cases and developing reference designs for converting existing railways nationwide, to testing and commissioning live systems.

The challenges faced in the Netherlands were similar to those of the UK: both networks are large and intensively used, and have legacy signalling systems which need to be phased out. However, the Netherlands decided on a different route to Network Rail, focusing on equipping the entire train fleet with ETCS Level 2 by 2022. In the meantime, ETCS will be rolled out trackside, with a plan to equip 2,500km of track by 2028.

Four lines have already been implemented and are now active ETCS lines. This strategy is building momentum behind the solution faster, and reflects the lack of alternatives in the Netherlands: there is simply no space to build more track to enhance capacity, so Digital Railway is the only option to address growing demand. This solution was possible in the Netherlands because one train operating company owns 90% of all passenger trains and could be encouraged to invest in ETCS. In the UK, with 30+ train operating companies and freight operating companies and a much more fragmented market this path would be more challenging.

One line Arcadis worked on was the Zevenaar line connecting the network to Germany. The migration strategy was:

  • December 2014 ERTMS (European Railway Traffic Management System, combines ETCS and GSM-R)
  • 2015 change of track layout
  • 2016 25,000V overhead voltage
  • 2017 third track to German border
  • 2022 earliest, ERTMS and third track on German side.

Dynamic testing was undertaken to ensure safety and prove that the system works. Given there was no framework in the Netherlands to perform these tests, Arcadis defined the framework on behalf of ProRail, applied for permission from the regulatory body, and created a test area with buffer zones and markings. With instruction and education, and collaboration with traffic control, extensive tests were carried out ahead of implementation. Overall 54 live tests were conducted, 186 simulation tests and a full six months of simulation testing. Lessons learned from these tests and from the experience of developing this system will be essential for any future implementation in the UK.

08 / Conclusion

One of the main challenges the Digital Railway programme faces right now is simply one of momentum, and momentum will only come with the first deployment of works. With funding set aside, pilot schemes identified and an industry plan and commercial strategy coming together, Digital Railway must now push forward into implementation, and demonstrate the benefits to the UK, justifying the programme as well as giving confidence to the supply chain.

We would like to thank Chris Pike, Martijn Huibers and Martin Zweers of Arcadis for their contribution to this piece.