Delivering future rail capacity

On 23 March 2016, the House of Commons passed the High Speed 2 (HS2) Hybrid Bill by 399 votes to 42, paving the way for Royal Assent. This cross-party political support for HS2 reflects its strong case. Yet the scheme remains controversial. Although scepticism about high-cost projects is understandable, it is not generally understood that when complete in 2033, HS2 phase 2 will double the capacity of all UK north-south inter-city rail routes.

Additionally, taking inter-city traffic off Euston’s main line will provide an additional 13,000 commuter peak period seats. Even with pessimistic assumptions, HS2 is expected to return more than two pounds for every pound invested, boosting annual productivity by £8-15 billion.

Twenty years ago, few would have predicted that rail passenger journeys would have doubled by now. Network Rail’s long-term planning process is now considering future demand and has concluded that rail traffic will continue to grow in the coming decades. Hence the need to build HS2 and ensure that poor rail capacity elsewhere does not constrain economic growth.

To develop the capacity enhancements needed to meet predicted long term growth up to 2043, Network Rail is producing twelve route studies. These build on the previous route utilisation studies which considered requirements up to 2031.

Getting back on track

The Institution of Mechanical Engineers (IMechE) recently published its report “Increasing Capacity: Putting Britain’s railways back on track” to highlight this issue. It demonstrates the need to invest in HS2 and other rail projects as well as accelerating the implementation of innovations.

The intention is to provide politicians and other decision makers with a professional engineering institution’s perspective on this issue. A further aim is to help the supply chain understand the issues and encourage innovators to generate new ideas and transfer emerging technology into rail.

The report was led by the Institution’s Railway Division and produced in association with TRL, whose head of rail, Rebeka Sellick, was one of the lead authors. In the report’s foreword, Rebeka shows her enthusiasm for this topic by stating: “We want all to share our excitement in the opportunities for railways to reduce road congestion and deliver joined-up journeys using the best sustainable transport.”

It derives its conclusions and recommendations from case studies of four railways which are all quite different: London Underground’s Victoria line; Wessex routes out of London Waterloo; Northern England and HS2.

ATO-on-ATO upgrade

The Victoria line opened in 1968 with Automatic Train Operation (ATO), a world first. It has one 21km long route, 16 stations, and carries 650,000 passengers each day. By one metric it is London’s busiest tube line, with average station usage more than twice that of any other line.

Between 2006 and 2013, London’s overall travel demand increased by 12 per cent, whilst the increase on the underground was 36 per cent. On the Victoria line, a recent upgrade enabled the service frequency in peak periods to be increased from 27 to 33 trains per hour (tph) in January 2013. Later this year, there will be a further increase to 36tph.

Successfully delivering such a high capacity railway required a system approach which had to consider issues such as station dwell times, the passenger train interface and passenger station flows as well as trains, signalling, track and power systems. It required a meticulous study of each operational factor that influenced the design of trains and signalling.

This in-depth application of systems thinking, with careful and disciplined attention to detail, has produced Britain’s most frequent train service which can carry up to 48,000 passengers per hour (pph) in, albeit uncomfortable, crush- loaded conditions. It has also resulted in a more reliable service with customer hours lost due to signalling and train failures reduced by 75 and 84 per cent respectively since 2006/07.

The upgrade included the introduction of a new ATO and signalling system, provision of a new service control centre and supporting ventilation, track, power and depot works. 43 trains were replaced with 47 new Bombardier-built eight- car units which have higher performance, bigger doors to reduce station dwell times and more room. They are also three metres longer as they use the extra platform length provided due to uncertainty about the original ATO stopping accuracy. They are 40mm wider than normal tube trains, as the line has wider tunnels.

A good example of the line’s ‘to the second’ operation is the 218-second Brixton turn around. In this time a driver shuts down his cab, a different driver opens up the other cab, crossovers are set and the train is driven clear of the platform. Currently, this is assessed to require 203 seconds – it will have to be reduced by a few more seconds for the 36tph service.

The Victoria line upgrade demonstrates what can be achieved when trains are of one type, all have a consistent stopping pattern and careful attention is paid to station dwell times. This ‘metro’ type of train operation maximises line capacity and offers lessons for the main-line railway and high-speed railway networks.

A high-speed metro

The IMechE considers that “HS2 is essential both of itself and to free up capacity for passengers and freight on the West Coast, East Coast and Midland main lines”. With 18tph out of London, each with 1,100 seats, HS2 phase 2 will carry up to 20,000pph in each direction compared with 7,100pph for the current Euston peak-hour departure inter-city services.

Carrying this number of people requires a whole-system design which considers passenger flow from the outset. New HS2 stations will have wide step-free, gap-free platforms which will be accessed by lifts and escalators spaced every 100 metres with special facilities for luggage. Effective passenger information and signage will be provided using techniques that direct large crowds in theatres and stadiums.

Eighteen trains an hour is a demanding requirement and compares favourably with the maximum of 14tph on Japan’s Shinkansen network. Allowing for variations, this requires a minimum of 150 seconds between trains. For this, HS2 has specified Automatic Train Operation and European Train Control System (ETCS) Level 2 which offers in-cab signalling to eliminate the constraint of lineside signals.

In addition, the network needs to be engineered to avoid following trains having to slow down as preceding trains reach junctions or stop at intermediate stations. This requires 230km/h turnouts and intermediate stations on loops which are six kilometres long.

To be a success, HS2 will require a metro-style operation with careful attention to passenger flow and station dwell times as well as running trains with the same performance characteristics. To illustrate this point, if a 200km/h Pendolino was to run on HS2, it would destroy three quarters of the train paths.

Northern Powerhouse

The Northern Powerhouse aims to shift growth from the constrained south of England to areas of unfulfilled potential in the north. To achieve this, Transport for the North (TfN) has been set up which is intended to have powers similar to Transport for London.

This requires better links between Liverpool, Manchester, Sheffield, Leeds and Newcastle. Journey times between these cities are poor compared with other UK inter-city journeys. For example, the fastest trains between Manchester and Leeds only average 53mph. TfN has been granted £60 million to develop proposals to reduce this journey time.

One reason for these poor rail links is that, historically, rail companies developed their own London-centred routes, whereas the Northern network is an amalgam of competing routes built by rival rail companies that each built its own city centre stations. This is particularly problematic in Manchester which, until 1988, had separate northern and southern networks.

The current Northern Hub programme improves this situation further. It includes extra through platforms at Piccadilly where there is severe peak overcrowding and the construction of the Ordsall Chord which will directly link Victoria and Piccadilly for the first time and also avoids the need for east-west trains to cross Piccadilly station’s throat.

Leeds also experiences overcrowding. However, overall, Northern peak crowding is lower than the South East. As many trains are formed of two or three coaches, there is generally scope to lengthen trains without the need for platform extensions.

A key feature of two new franchises let in 2016 is the procurement of new rolling stock. The Northern franchise is to acquire 281 new vehicles (31 three-car and 12 four-car EMUs and 25 two-car and 30 three-car DMUs). This, together with trains from other franchises, will see a 37 per cent peak capacity increase on Northern services.

220 new coaches have been ordered by Trans Pennine Express (TPE) (12 five-car EMUs, 19 five-car bi-modes and 13 five-car locomotive push-pull sets). By 2020, TPE’s fleet size will have increased by 88 per cent, with 73 per cent being new stock, to give an 80 per cent increase in peak capacity.

In general, the current Northern Hub and Northern electrification programmes will provide the infrastructure needed to accommodate these trains. However, further infrastructure interventions will be required in the long term as the Northern network’s mix of freight, stopping and express services on two-track railways will become an increasing constraint, with peak rail demand forecast to grow by 115 per cent by 2043. It is envisaged that this will include a link, connecting the two branches of the HS2 network, between Manchester and Leeds.

Waterloo suburban services

Each day, main line rail carries 600,000 commuters in London. 110,000 use routes to Waterloo, which are amongst the UK’s most heavily trafficked. Since 2011, peak period demand into Waterloo has increased by 15.1 per cent, compared with the London’s average of ‘only’ 11.5.

To enhance capacity on suburban routes to places such as Dorking (22 miles) and Guildford (30 miles), Network Rail and South West Trains have a five-year programme to increase train lengths to ten coaches. This requires platform and signalling alterations for ten-car operation as well as bringing Waterloo’s former Eurostar platforms back into use.

Currently these services use a pair of coupled four-car units. These trains will be lengthened, either by adding two-car units or by converting the base four-car units to five-cars.

Older trains are to have new traction motors and control equipment fitted to give all trains on the route the same performance characteristics. In addition, 30 five-car Siemens-built trains are being procured. These Class 707 units (Rail Engineer September 2016) have full-width interior gangways and other features to increase capacity.

In total, these train and infrastructure projects will provide an additional 24,000 extra peak- time seats on shorter distance services by 2018, demonstrating the benefits of integrated planning by Network Rail and South West Trains, supported by Department for Transport.

Waterloo, Winchester and beyond

The demand for longer distance peak travel has increased to the extent that commuters stand for an hour or more on journeys such as the 67-mile journey from Winchester to Waterloo, despite almost all trains being the maximum possible length of 230/240 metres. Network Rail’s Wessex Route study estimates a 40 per cent increase in demand by 2043, for which the Fast line would have to carry 37tph, compared with the current 24.

The study concluded that it was unlikely that rolling stock options could reduce this train path requirement. Many stakeholders rejected 2+3 seating on long distance trains and considered this offered little extra capacity. Network Rail’s passenger rolling stock route utilisation study considered double decker trains and concluded that, with UK gauge and platform constraints, a 23-metre double-deck vehicle might offer 24 per cent more seats but would increase station dwell times and require costly gauge-clearance civil engineering work.

These lines could carry an additional two paths, but at increased risk to service punctuality and reliability. A further two paths could be provided if the current diesel service to Salisbury had the same performance as electric trains.

A new grade-separated junction and an additional platform at Woking would create some extra paths, as would a flyover at Basingstoke. This would also offer extra freight paths from Southampton, a reminder that the issue is not only passenger capacity.

However, the study concludes that the 37tph requirement will require two of three radical solutions. These are a fifth track between Surbiton and Clapham Junction at a cost of £1.2 billion with huge disruption, Crossrail 2 and ETCS level 3 to enable trains to run more closely.

Crossrail 2 would deliver significant extra capacity by providing a core route between Liverpool Street’s Lea Valley line and Wimbledon to reduce train services into Waterloo. Such cross-city limited-stop services were introduced in Paris in the 1970s and eliminated the significant capacity constraint of city-centre terminal stations. Forty years later, Crossrail will provide London its first such route.

Future technology

The industry’s capability development plan to promote the required innovations is described in the following article. This includes those that will increase capacity, of which perhaps the most important is running trains closer together using moving block signalling offered by ETCS level 3.

The Wessex study shows how this offers a significant capacity increase without the need for massive infrastructure projects. However, whilst moving block is widely used on metros throughout the world, its implementation on a complex mixed-traffic network remains an elusive holy grail.

Although the baseline specification for ETCS level 3 was written 20 years ago, its only European application is a low-traffic rural line in Sweden.

One reason for this is that before a route’s lineside signals can be eliminated, every train cab using the route must have the required equipment for any benefit to be realised. Who bears this substantial cost and how they benefit is a potential barrier that needs to be addressed.

In contrast, there has been rapid development of autonomous road vehicles which do not have to address complex interoperability and rail infrastructure system-compatibility issues. This includes freight vehicle platooning at 70mph, two metres apart, which has been successfully trialled. Such technologies present the rail industry with new competition. However, they also present an opportunity as they could be adapted for rail use and provide an impetus to accelerate the development of rail innovations.

The rail industry has an active innovation programme to develop the technologies required by the Rail Technical Strategy, some of which will provide additional capacity. Examples of technologies under development are SUSTRAIL, which could increase freight train speeds, and REPOINT, a radical new point design offering higher reliability and speed of operation, have much to offer. Both are described in issue 131 (September 2015).

Beyond catch-up

Commuters who pay considerable sums for their season tickets can be excused for blaming train operators for their crowded trains. Their frustration is often echoed by the mainstream media, which rarely considers the real reason why trains are overcrowded.

This is because the increase in demand was not predicted and no provision made to satisfy it. The industry is now playing catch-up with 5,600 new coaches on order and many infrastructure projects under way.

With Network Rail’s long-term planning process predicting a continuing increase in demand, the challenge is to act in time to prevent future overcrowding. It takes a few years to procure rolling stock and rather longer to deliver major infrastructure projects. The development of capacity-enhancing new technologies is a long-term business.

The IMechE report doesn’t just support HS2 and other projects to enhance rail capacity. It strongly promotes the creation of devolved regional transport authorities, such as TfN, to plan and fund their own projects. It also stresses the urgent requirement to bring innovations into operational use, particularly moving block signalling. This includes the need for increased funding for rail research to make up for the industry’s exclusion from EU-funded research projects.

The report does the industry a valuable service by informing policy makers and helping to maintain the current political impetus to ensure a long-term commitment for investment in new rail capacity.

Thanks to report lead authors Rebeka Sellick, Philippa Oldham and Chris Kinchin-Smith, and contributor Malcolm Dobell, for their help with this article. (The full report is available on the IMechE website).

Written by David Shirres