A recent conference organised by the Institution of Mechanical Engineers (IMechE), asked “Capacity or Performance – Either or Both?” The answer, of course, is both. Capacity (more people and freight transported per hour) and performance (punctuality and reliability obviously, also journey times) are possibly the biggest challenges faced by the UK rail industry.

The more difficult question “How to deliver improvements in a cost effective manner that balances both the short and long term?” received answers from strategic to technical, local to regional and nationwide, shared in publications and at events throughout 2017 and into 2018. With rail professionals aligned on their theories and the industry delivering in practice, can they engage effectively with Secretary of State Chris Grayling’s newly appointed Rail and HS2 ministers? Could a professional consensus support renewed political will to deliver in future franchises, CP6 and beyond?

Last year – January 2017

But first, what did railway engineers do for us in 2017?

Although led by mechanical engineers, with contributions from civil and signalling colleagues, answers to “how can we enhance capacity?” and “is it worth doing?” were included in the IMechE’s report ‘Increasing Capacity: Putting Britain’s Railways Back on Track’, published in January 2017 (as reported in Issue 148, February 2018).

Despite positive messaging from the Rail Delivery Group (RDG), the non-specialist ‘popular’ news media has remained intent on grumbling about fare rises. Whilst there have been significant industry downsides of poor service, including those attributable to rail strikes, few rail passengers (or indeed members of the public) have grasped the astonishing fact that, over the past 20 years, national rail passenger-km rose 116 per cent; on London Underground by 83 per cent, and national freight was still up 34 per cent despite the sudden loss of power-station coal traffic.

Demand for rail is expected to continue to grow, given population growth, increasing road congestion and the impact of current railway infrastructure and rolling stock investments including Crossrail and HS2.

The IMechE’s report explored inter-disciplinary understanding of current railway capacity challenges and opportunities, alongside sufficient technical background to make them accessible to the general (and political) reader. Case studies of capacity improvements that have been delivered increased in complexity, starting from the relatively simple case of upgrading a self-contained system: the Victoria Line on London Underground.

Victoria enjoys the classic metro characteristics to optimise capacity and performance – identical trains in simple service patterns with managed dwell times. As built, in 1968, it was a world first in ATO (automatic train operation), delivering 27 trains per hour in 2012. As upgraded, Victoria line delivers 36 trains per hour since April 2017 – a peak capacity of 36,000 people per hour per direction.

On national railways, realisable capacity and performance fall as complexity and dependencies increase. Trackwork simplification and platform lengthening in the Waterloo area (to accommodate longer trains which accelerate faster) have been key to squeezing more people-per-hour capacity for suburban and longer-distance Wessex routes out of London, bringing 110,000 people into London during each morning peak. Building on this infrastructure and rolling stock success, signalling and train control solutions, such as closer running and enhanced route setting algorithms, are being explored.

Transport for the North’s capacity and performance improvements – such as more frequent and longer trains, electrification and new fleets – are designed to reduce local road congestion, prompting modal shift onto rail. Further, chiming with the wider industrial strategy, growing rail capacity should also encourage economic growth, attracting companies from the South, creating jobs, enabling people to access training and re-training.

Network capacity growth is core to HS2, which is extensively discussed elsewhere. In this context, suffice to say that wider rail network capacity opportunities and performance impacts are immense: interfaces, such as with flexible freight and cross-modal Mobility-as-a-Service smart concepts, are crucial to optimise transits and journeys into the next century.

Later in 2017

February’s IMechE and IRSE seminar on ATO for mainline railway systems identified why it’s hard and how much it would be worth having.

April 2017’s international biannual Stephenson Railway research conference in London provided an opportunity for the team to bring the IMechE’s ‘Increasing Capacity: Putting Britain’s Railways Back on Track’ to the attention of the political decision-makers for whom it was written. However, the snap General Election unfortunately drove the rail minister to withdraw from the VIP lunch at its launch. Meanwhile, undaunted, the technical work continued…

June 2017 saw signalling, infrastructure and traffic management system developments furthered by IRSE’s series of Digital Railway discussion workshops, building on the consensus that Automatic Train Operation and European Train Control System are not magic bullets for mixed traffic railways.

Irrespective of ATO and ETCS, performance and capacity can grow with incremental and innovative developments across the system, such as signalling better aligned to different trains’ braking potential, train braking distance reduction (and consistency) through better sanding for adhesion, conflicting train moves eliminated through infrastructure modifications and every improvement being hardwired into the timetable and operationally managed to the second.

The Independent Transport Commission (ITC) similarly developed its own April 2017 report ‘Classic Rail and Connected Cities’, with a seminar in July addressing ‘Overcrowding on Public Transport’. Grounded in rail infrastructure improvement and innovation deployment, the discussion broadened into multimodal transport planning for capacity solutions, acknowledging the need to resolve behavioural and disability challenges faced by travellers.

In November, the headlined IMechE conference asked: “Capacity or Performance – either or both?” After acknowledging the apparent contradictions, consensus built on how they are jointly being addressed and improved. Successive presentations from rail industry professionals (not just engineers and operators but geographers and economists too) robustly affirmed that the best railways need, and can deliver, both – there shouldn’t be a trade-off between capacity and performance.

The railway should meet passenger priorities. Network Rail’s Simon Reay reminded the conference of Transport Focus’ research findings, which affirm that reliability is key and criticise industry’s reliance on punctuality measures such as PPM and CaSL. Arguably, PPM and CaSL implicitly endorse thresholds of ‘acceptable’ lateness, whereas every minute late reduces satisfaction, and it’s “my journey” that matters, not whenever the train gets to wherever is its destination.

Further, PPM treats all trains as equal, whether they contain one passenger or 1,000. In reality, the direct impact of delay on passengers’ journeys can be captured by applying the Capacity Report’s ‘people per hour’ measure. And, fundamentally, the impact of any delay can ripple across the connected network, eating into both capacity and performance elsewhere.

Measures of train performance

Public performance measure (PPM) is the established official measure of national rail punctuality in Britain. It records the number and percentage of trains that arrive at their terminating station within five minutes of the published time for commuter services and within 10 minutes for long distance services. Punctuality is measured for all trains across the whole network, including cancelled services and delays caused by external factors (such as vandalism, extreme weather and suicides). It is a holistic measure of how the railway performs for passengers.

Recognising the impact of serious delays on passengers’ plans and on service recovery, the cancellation and significant lateness (CaSL) measure was introduced in 2009, to supplement PPM. CaSL counts a train if it is cancelled at origin or en route, if the originating station is changed, if it fails to make a scheduled stop at a station and is significantly late (arriving at its terminating station 30 minutes or more late).

Right-time performance measures the percentage of trains arriving at their terminating station early or within 59 seconds of schedule. This measure is increasingly being adopted as the quality of this information improves to make right-time data more reliable.

Source: Network Rail

Myths exploded

Inspiring as the case studies of individual projects like Crossrail and HS2 are, one ‘take home’ from the conference was the myths of performance and capacity conflict that were exploded and the approaches shared for improving both: through planning, industry structure and change management.

Myth 1 – Don’t plan accurately: pad out for performance and let capacity suffer!

Some suggest padding out the timetable to ensure technically ‘on-time’ arrivals at terminal stations. This is sub-optimal as a customer concept, because it elongates scheduled journey times and doesn’t address journeys to intermediate stations. Accurate timetabling not only sharpens punctuality throughout a route and shortens journey times but also drives on-time arrival at key nodes and junctions, unlocking maximum capacity (not to mention minimising energy use and carbon impact).

Perhaps surprisingly, run-times are not universally accurate: a bigger data haystack can help otherwise-invisible unreliability needles to be identified. For example, Paul Naylor of CPC Systems described TfL’s Jubilee line software drill down below threshold reporting and beyond levels noticeable to staff, finding systematic delays of 10 or 15 seconds on almost every train approaching West Hampstead which, once known, could be addressed and removed, improving effective capacity and performance.

Even today’s computing power, informed by expert judgement, does not produce perfectly resilient timetables. Chris Rowley’s Network Rail drone sample found that 39 trains were brought to a stand in the Norwood Junction area over less than two hours on a non-perturbed day because of small variations in right-time presentation, constrained by the conflicting moves timetabled. Larry Fawkner of Cogitare is integrating performance measurement and simulation to close the feedback loop from real day-to-day variability into planning.

Like any process, narrowing the spread of results will optimise results, close to Oliver Bratton’s MTR heart as the Elizabeth line’s performance will critically depend upon right-time presentation of trains into the central CBTC-controlled area.

Myth 2 – Industry structure needs overturning: re-privatise/ re-nationalise!

Chris Gibb (of recent railway performance investigation fame) asserted that the whole system is under strain, both from traffic and demand growth, and from the industry structure, where it can be hard for individual companies to make collective decisions or to work for the best long-term outcome. But no one at the conference advocated embarking on wholesale structural change and Chris asserted that teamwork was key, irrespective of control.

DfT should define franchises to incentivise the best use of paths by the busiest trains (such as when Gatwick Express was consolidated into GTR) to maximise route capacity. Industry should promote the use of full train lengths, spreading passenger loading by extending platform roofing and carefully locating waiting rooms. Ticketing and fares are not simply a commercial issue but critically impact on capacity and performance.

Passengers don’t look at PPM when making choices between modes; few non-rail users want faster services but most want convenience, although adding new stations will make end-to-end services slower and soak up capacity, precluding more frequent services.

Conversely, Rob Warnes of Northern Rail explained that, sometimes, performance straightforwardly drives better connectivity. Northern has created capacity and a more robust timetable for May 2018 by increasing through running, for example across central Manchester. Reversals on the other side of the central area are enabled by relatively small infrastructure investments, such as an extra bay platform at Bolton, which also allows signallers to re-order trains and reduce conflicting moves.

Myth 3 – Competing companies can’t cooperate, so performance and capacity are suboptimal.

Much is made of the negative impact of competing rail companies, but Rob Warnes cited capacity and performance improvement by cooperation, explaining how TPE and Northern dispatchers support each other at Piccadilly’s through-platforms to reduce station dwell. Simple physical changes, such as re-siting the train-ready-to-start buttons, facilitate staff coordination, whilst overall passenger flow is improved (and crowding limited) by removing platform clutter and re-locating information screens. The Northern Hub scheme originally included building additional through-platforms for greater capacity: however, this was on hold pending Department for Transport evaluation of a digital signalling alternative.

Dick Fearn, independent chair of the new Western Route Supervisory Board, has no executive authority but brings managing directors of track and train companies (freight and passenger) together with Transport Focus to optimise strategic priorities.

They are exploring how to realistically accommodate traffic growth, managing emerging risks to deliver performance now and into the future while coordinating across a system to deliver customer expectations.

Several train company directors and managers who took part, and who do have executive authority, asserted the undoubted value of experience yet acknowledged that, to make the most of the existing railway, they need to make best use of new technologies and new thinkers.

Lessons to be learned

Presenters shared today’s mix of high-tech drones and big data, sophisticated software and bold management, to help enable empathic and engaged employees to deliver high-performance, high-capacity services with “vim and brio”, as Geoff Hobbs of TfL put it.

The conference invited government to heed professional advice from industry to funders, particularly regarding incentives and investment.

In conclusion, the IMechE pointed to the future, how to enable the next step change in capacity railways to help shape a better world. It highlighted the continuing modal shift from road to rail (future-proofing Autonomous road vehicles and embracing the emerging Mobility-as-a-Service culture), the economic benefits (national and regional, shifting growth north from the overheating southeast) and the reduction of CO2 and other harmful emissions, particularly as air quality consciousness rises.

In return, the industry looked to government to hear what is needed to get the most out of the current rail system, supporting Network Rail and operators to unlock these opportunities. Government should recognise the need for significant enhancements to unlock big capability improvements, supporting the development and evaluation of schemes and technologies that the rail industry, devolved authorities and the National Infrastructure Commission (NIC) will bring forward, including a truly robust electrification programme.

But this was not to be. In February 2018, while rail engineers were digesting the aspiration of the new rail minister, Jo Johnson, to phase out diesels by 2040, Transport Secretary Chris Grayling confirmed cuts to electrification plans.

Then, in March 2018, speaking at the Westminster Energy, Environment and Transport seminar entitled ‘Next Steps for the UK’s Railway Infrastructure’, I asserted that the challenge to government is investment. Public money will deliver more railway capacity and performance if more private sector funding can be unlocked, with:

A transport-wide, future-proof vision (integrating rail for sustainable mass transit, freight and long-distance trunk routes);

A long-term, committed plan (beyond 2040, including electrification);

Stability, for optimum delivery (stick with the industry structure, but speed-up performance and capacity improvements by engaging customers and the public).

Could 2018 become a year of real political opportunity for rail engineers?


This article was written by Rebeka Sellick, lead author of the IMechE’s Railway Capacity Report and a member of the ‘Capacity or Performance – either or both?’ conference organising committee. Thanks to all fellow contributors to IMechE’s work, especially conference presenters and IMechE staff, Francis How (Institution of Railway Signal Engineers’ chief executive), the current IMechE Railway Division chair Richard McClean, and past chairs Richard East and Chris Kinchin-Smith.


Read more: The Railway Industry Association’s Innovation Conference