Against a background of increased urbanisation and longer commuting distances, railway operators around the world are witnessing unprecedented levels of demand in both passenger and freight transport.
London is a typical example. With the city’s population forecast to grow from 8.4 million to around 10 million over the next 15 years, the city’s infrastructure and services will be under tremendous pressure to keep pace with demand.
In Great Britain, more than 4.5 million rail journeys are now made every day on the railway – that’s 1.65 billion passenger journeys a year, double what it was 20 years ago.. As a result, large parts of the rail network are struggling to cope, many services are regularly overcrowded and station platforms are heavily congested at peak times.
With these trends forecast to continue, the industry as a whole faces the challenge of how to match this growing demand with increases in capability and technology, providing much-needed extra capacity while continuing to deliver safe, comfortable, fast and efficient journeys.
Clearly, one option is to build new lines. But this is expensive, takes a long time to deliver and causes significant disruption over a prolonged period. So the key challenge is to get more capacity out of the existing network, with the development of the digital railway and the provision of modern signalling and communication systems integral to success.
For many years, Siemens has delivered automatic train protection (ATP), automatic train operation (ATO) and control systems to some of the world’s most complex metro systems. This technology is now increasingly being applied to main line railways, where the ability both to accurately position trains and develop a greater understanding of performance provides operators with significantly more control.
For example, communications-based train control (CBTC) systems use up-to-date information sent by every train to allow other trains to safely move around the network in an optimal way. Instead of having conventional fixed blocks, based on trackside train detection, CBTC systems use flexible moving blocks to maintain safe distances between trains. This kind of architecture provides significantly more capacity within the railway, with more trains able to operate on the network as a result.
In 2012, Siemens fully commissioned its CBTC system on London Underground’s Victoria Line, enabling 34 trains per hour (tph) to operate during peak hours. Already the busiest line on the London Underground network (carrying over 183 million passengers each year), Siemens is now working with the operator to increase capacity to 36 tph.
Path to the Digital Railway
The company’s work with Network Rail for Thameslink is a prime example of the development, integration and delivery of complex systems on a mainline railway, with the project representing the starting point of the journey to a fully digital railway. Due for completion in 2018, the government-sponsored Thameslink programme will transform north-south rail travel through London with passengers set to benefit from more connections, more reliable journeys, better stations and new trains. Train frequency will increase from 16 to 24 tph in each direction through the core area, from Blackfriars to St Pancras, in peak times.
As part of the overall programme, Siemens is helping to deliver the High Capacity Infrastructure project, which will provide the European Train Control System (ETCS) and enhanced signalling control systems needed to support ATO and timetable management.
The Siemens system is ‘vertically integrated’, meaning that the company is providing the trains, train control and signalling systems that will allow safety, reliability and capacity to be increased. ETCS will be at the core of this, increasing capacity and energy efficiency through more effective train control.
The introduction of ETCS and ATO follows a progressive programme of integration and system testing. The first stage of this was completed in the System Integration laboratory, the programme’s hardware test environment which was engineered and built by Siemens in collaboration with Network Rail. With successful results here, further extensive trials were undertaken at the ETCS National Integration Facility, where the new Siemens Class 700 train was also recently introduced. Finally, before its introduction into revenue service, a series of tests will be undertaken with the system in the Thameslink core.
Thameslink will be the first operational application of full ATO over ETCS in Europe and represents Siemens’ first operational application of ETCS in the UK. Its introduction means that every train runs at the optimised speed and braking profile, performs accurate stopping, and maintains a strict adherence to station dwell times. The continuous automatic train protection (ATP) system, provided as part of the ETCS, means that it will do all of this with an increased level of safety protection.
When deployed across the Thameslink core and London Bridge areas, the enhanced control system and ETCS protection will enable the train-borne ATO unit to achieve the necessary driving performance at closer intervals and greater throughput – both of which are required to achieve the 24 tph timetable.
In addition to its work on Thameslink, Siemens is also developing intelligent control centres for main line application with, for example, systems able to optimise the use of infrastructure by scheduling freight trains between passenger trains. Recognising their different speed and braking characteristics, this allows the tracks to be more fully utilised. These control centres can also minimise the impact caused by any disruption, with a core team able to take a broad view of the railway as a whole to bring all elements quickly back into alignment.
Modern railways are a complex combination of systems working together. Many of these can operate automatically to set routes, regulate trains and make decisions about passenger flow, but performance and costs of the whole system are only truly optimised when they are fully integrated. This involves clear and detailed system engineering to ensure information is available to all systems that need it, including the operators who need support to make decisions quickly and efficiently.
Having signalling and control systems in the same room as telecommunications, public address and passenger information is not necessarily new, but the additional integration of systems such as closed-circuit television, lifts, escalators, ventilation, power distribution and traction control systems is. Bringing all such functions to a small number of multi-headed workstations will also allow operational savings to be made through more efficient use of staff and more rapid and effective response to unplanned events.
The introduction of new technology must also be considered in the context of the environment in which they function; the world isn’t simply a model of clean, clear variables with defined interactions. Trains move people around and people interact with one another, so human factors have to be considered. Commuters and tourists are very different customers, all of whom behave differently whether it’s sunny, cold or raining.
Having a signalling system and high- performance trains capable of achieving a high-capacity service won’t help if a passenger’s umbrella gets stuck in the doors, or if escalators and stairways get congested and people can’t move quickly off the platform. And the more saturated the network gets, the greater this issue becomes.
So, understanding how people behave, and then predicting and responding to those behaviours, is an area where mobile technology and data-farming can start to be used. Engineers can then be better informed in the design of systems to respond to such factors. Along with its supply chain partners, industry stakeholders and academia, Siemens is investing in finding and developing innovative approaches to respond to this challenge.
Written by Mark Ferrer, new technology director at Siemens Rail Automation.