Simpler, Lower Cost AC Electrification
Helping industry make innovations cheaper and practicable
For many years, AC electrification of the rail network has been desirable but too expensive to achieve. New work by RSSB shows both why the cost was so high and how costs could potentially be reduced by £70m over the next 10 years.
Outsiders might wonder why AC electrification of the rail network has been so slow, especially in recent years when mobile phones and digital technology have made the need for electricity as the base power supply almost ubiquitous.
In the UK we’re well used to seeing many technologies and systems move from climate-unfriendly fossil fuels, like coal or diesel, to electricity. Rail made the move from coal as a fuel many years ago, so the slow pace of rail network electrification seems puzzling to outsiders. This puzzle is increased when one considers the many benefits to operating trains on an electrified network, such as improved air quality, reduced noise, and faster journey times. In addition, as we move towards a net-zero state, electrification must be part of the solution, because it can come from renewable resources.
As might be expected, the reason is cost. AC electrification has been desirable but very expensive. Prohibitively so. This is because electrification of the network requires the installation of overhead line equipment (OLE) above the tracks and pantographs on locomotives and trains. Any tunnels or bridges that trains go through have to be high enough and wide enough for these additional structures to be installed, and installed safely. And there’s the snag.
Our railway is based on infrastructure designed by the Victorians. Many bridges and tunnels are, compared to other countries, low and narrow. Previously, this only added to costs of changing the OLE and the trains on which pantographs are mounted, and made electrification non-viable. A review of the relevant standards has simplified them, and made them less restrictive, while still maintaining safety. This will make the approval and acceptance process for introducing new or modified trains and locomotives simpler, quicker, and less expensive.
At many sites across the network this will mean that cost-effective OLE can be installed without the need to make expensive structural alterations to existing infrastructure. The resulting cost savings can extend the electrified line across more of the network. This can take us even further towards the country’s net-zero target and maintain rail’s position as the most environmentally friendly means of ground transportation.
So that’s one side of this very important story. But there’s another one that should encourage chief execs and technology officers: the ability of rail to make new technologies work in practice.
Technological lock-in can mean that an apparently no-brainer innovation is actually a frustrating case of ‘if you want to go there, you really can’t start from here’. The classic example of this is the ‘qwerty’ keyboard, designed in the 19thcentury to meet two requirements, neither of them ergonomics for typists. The technological system using qwerty included businesses offering training courses or typing manuals for (then largely male) typists, typists themselves, and typewriter manufacturers and sellers. None had sufficient short-term incentive to invest further in a new keyboard layout, there was no independent body to research, advice or compel ergonomic improvements, and so qwerty stuck despite better alternatives being available. It is only with the adoption of further, unexpected technological innovations, such as personal computing and detachable keyboards, that alternatives to qwerty have resurfaced.
In the case of AC electrification of the rail network, we’re also confronted with the design and construction consequences of an innovative 19th century system, trying to make that work optimally in the 21st century and beyond. Work to ensure the ‘new’ technologies required for AC electrification are efficient, safe and affordable has therefore been highly complex and demanding. Standards for AC electrification of the rail network were first introduced in 2014, slightly revised in 2019, but majorly revised in 2023. It has required many experts from different organisations to collaborate, being rigorous but not obstructive in their collaboration, despite coming from different organisations with different financial requirements.
This shows an industry able to learn how to make new technologies work, safely and efficiently, as well as the high value of ‘convening power’ in enabling the truly collaborative discussions required. In addition to the specific guidance now available to reduce AC electrification costs by £70m over the next 10 years, this puts rail in a good place for the further innovations to come.
