The need to increase our railway capacity

Over the last 20 years our rail network has seen a 116% increase in passenger usage and a 34% rise in use for freight. Network Rail’s own market analysis expects passenger travel to double again over the next 30 years, so how do we ensure that this mode of transport offers a service that is fit for purpose? Philippa Oldham, head of transport and manufacturing at the Institution of Mechanical Engineers reports.

The UK has one of the safest railways in the world, but it operates on some of the oldest infrastructure which has lacked investment and which, consequently, constrains capacity. To be able to offer a viable alternative to our road network for our businesses and passengers we need to invest in our rail infrastructure. It is essential that our existing network becomes more efficient, resolving known bottlenecks and addressing how we can accelerate the pulling through of proven innovation into the system as a whole.

The World Economic Forum’s Global Competitiveness Report ranks the UK’s infrastructure at 24th so the Government needs to continue to invest in our railways to ensure that we move up the rankings. The 2016 National Needs Assessment stated that in 2014-5 the UK Government financed £49 billion in infrastructure development from a combination of public and private sources. While this investment is welcome, it is nearly 40% short of the Organisation for Economic Co-operation and Development (OECD) recommended target of £80 billion per year by 2020-21.

Why invest so much money to improve railways? The World Economic Forum estimates that every dollar spent on capital projects generates an economic return of between 5% and 25% (PWC and Oxford Economics 2014). National and devolved governments have built rail capacity growth into their overall economic development plans. The Department for Transport expects one of our case studies, High Speed 2, to return more than £2 for every £1 invested even with pessimistic cost, demand and growth scenarios, boosting annual productivity by £8-15 billion.

More capacity

Capacity is often measured in trains-per-hour (tph) – how many trains can operate on each section of a route. The greatest tph capacity is achieved with an identical fleet of trains that all accelerate and brake at the same fast rate, with matching and minimal start-stop patterns.

However, in Britain, most routes have differing types of trains (freight and passenger), of varying lengths, stopping patterns, speeds and braking abilities. In addition, current fixed block signalling, which requires the train behind to be able to stop before the last known position of the train in front, inhibits capacity growth.

Alternative and more holistic measures than tph for capacity are people-per-hour (pph) and Journey Time Capability (JTC). JTC develops pph to include speed, reliability and comfort criteria, whether seated or standing. Pph and JTC provide policymakers with greater scope in their decision-making by allowing more radical options to be considered for enhanced capacity on the railway network, although neither take account of freight trains on mixed traffic routes.

Fundamentally, the Institution of Mechanical Engineers believes that society should expect interconnected sustainable transport and to achieve this we need to start looking at our railway network as a system looking at what other sectors are developing to ensure that they don’t get left behind. The Government should capitalise on the potential that our rail network acting as a system could offer the country in terms of delivering a key element of the sustainable and universally accessible concept of ‘Mobility as a Service’ (MaaS).

The four C’s

Now is the opportunity to optimise the delivery of transport capacity for customers, minimising carbon and cost. Conceptually simple but technically challenging and world-leading delivery of moving block signalling across Britain’s railways for example would improve on all the four C’s (Carbon, Capacity, Cost and Customer) of the Rail Technical Strategy. Moving block would unlock more capacity by creating more paths to run trains, enabling more efficient use of the railway. It would reduce journey times to further enhance customer benefits – and deliver more sustainably than other transport modes.

To increase overall transport capacity and optimise the value of the railway sector to the UK in the coming decades, the Institution of Mechanical Engineers recommends that the railway sector concentrates on capacity, in particular to:


  • Fast-track step changes to unlock network capacity – pioneering world-leading development and implementation of and beyond moving block signalling in order to ensure sufficient funding and impetus

  • Urgently bring capacity-enhancing innovations into operational use

  • Initiate the next raft of new solutions to create further capacity. As Brexit means leaving EU-funded shared R&D projects like Capacity 4 Rail, the DfT and other government agencies should ramp up British R&D investment

  • Speed-up the roll-out of known solutions to relieve capacity bottlenecks. Government investment and commitment must continue with the enhancement of capacity through existing best practice, including the construction of new railway infrastructure capacity (new high speed lines, electrification, local connectivity) and other well-proven techniques
Unexpected demand

We should embrace and celebrate the unparalleled renaissance of rail transport in the UK. There has been an unexpected level of growth in freight and passenger demand throughout national rail, light rail and metro networks over the last 20 years.

The national networks are struggling to meet this continued growth demand, becoming congested and capacity-constrained. Therefore, the significant ongoing and proposed investment in railway infrastructure, rolling stock and control systems is paramount. The interconnected nature of railways means, for example, that dedicated high-speed passenger routes, joined up freight corridors and ‘local’ improvements will release capacity for other freight and passenger traffic, with impacts penetrating far across the network.

Simplification of the mix of trains on any route enhances its capacity. Therefore, identifying and drawing out the highest speed, least frequently stopping services (e.g. through alternative intercity provision with HS2), or the slower running, most frequently stopping services (eg. by regional/city authorities applying ’metro’ principles) increases the capacity of the existing railway to deliver other train services.

Forecasts indicate that transport demand will continue to increase over the coming decades. The UK needs a transport network that is integrated and incorporates all modes seamlessly. As engineers, we are committed to sustainability and we understand the strengths of rail. We want to capitalise on the energy, economic and safety benefits of rail over road to deliver longer distance and inter-urban passenger and freight flows, as well as passenger movement both within and into cities.

Institution of Mechanical Engineers www.imeche.org

 

 

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