Time for a rethink on third rail?

A British passenger train, painted red and white, with overhead wires which have been blown down by a stormLast Thursday a major (for this country) storm brought strong winds and rain, bringing down trees and power cables across coastal areas and central and eastern England and Scotland. Virtually all the major railway networks suffered serious disruption, the main exception being the southern region — not just the actual Southern network, serving Surrey and Sussex, which is beset by ongoing industrial disputes, but the south-eastern and south-western networks that serve Kent and the Hampshire/Dorset region respectively. This area wasn’t as badly hit by high winds as places further north, but even if it had, rail disruption would have been less, for the simple reason that they use ground-level electrics, not overhead power lines.

Third-rail electrics are found on some urban light rail systems (trams use overhead lines, for obvious reasons) such as the London Underground, and on suburban rail systems in Liverpool and south London and on main lines to the south of London; there are a few stretches in north London left that still use it also. The rest of the electrified network (which consists of the lines to Birmingham, Liverpool, Manchester, Glasgow, Edinburgh, Newcastle, Leeds, Norwich and Southend, but not Bristol, Oxford or Nottingham, or the cross-country rail network, which remains reliant on diesel power) uses overhead wires. I grew up in an area served by third rails and when I first encountered overhead wiring on the line to Norwich, while at boarding school in Ipswich, I was struck by how ugly and intrusive they were. Years later, when there were debates about the building of an “eruv”, an area bounded by poles and wires within which Jews can carry out certain activities on the Sabbath that they could not otherwise do, I remember people complaining that “people do not like to be boxed in like that”, yet they have no problem with much more noticeable wiring whenever they travel by train.

Third rails are confined, as a matter of policy, to the Southern Region and Merseyrail, because they are more likely to cause problems when it snows (the notorious “wrong sort of snow” which caused disruption in the 1980s). Yet because of the changing climate, snow has become a markedly less severe problem in recent years in southern England; we have not seen severe snowfall since 2011, while strong winds are an increasing problem and every year there are overhead electric wires brought down by them, resulting in trains having to be stopped until they are fixed; if ground-level electrics failed, diesel trains could still run, although train companies do not keep spare diesels around for that purpose. Even when we still had snow fairly regularly, it was still only one or two days during a whole winter, while we have started seeing several strong storms each winter in recent years.

The Great Western line, running from London to south Wales via Bristol, is in the process of being electrified using the overhead system. The process is already complete through west London, serving the Heathrow airport branch, but it is ongoing, although several major sections of the project have been deferred. This has resulted in bridges having to be closed so as to be raised so as to accommodate the overhead wires, in one case resulting in an important local road in Wiltshire being closed for months, resulting in an 8-mile detour. And when the wires are finally up (though even then, the lines to the south Devon coast will still use diesel, as electrifying places like Dawlish Warren is not feasible), locals will face the new problem of lines down every time we have strong winds, something that does not happen right now (trees on the line may already be a problem, however).

A large rail junction with several lines, all of them electrified with third rails, with a train wash with a train passing through it, and a passenger train with Stagecoach red, orange and white livery on the right.Very much of this additional disruption could have been avoided if a third-rail system had been chosen. The GW main line joins with the Southern region at Reading, and services already run (using diesel trains) from the south coast and London to Bristol and south Wales via Salisbury; a third-rail electrification of the line to Bristol would make electrifying these lines and running through services (such as in the event of the London-Reading line needing to be closed) a lot simpler. It is probably too late to switch the method of electrification used on the GWR, while the Midland Mainline is already wired as far north as Bedford, though those trains are dual-voltage as they run through London onto the Southern Region, but given the heritage status of the GWR (several of whose workings and stations are World Heritage Sites), it seems a mystery that they allowed it to go ahead.

There are two main weather-related hazards to electric railways: wind and snow. Given the ugliness of the wiring and the alteration it requires to bridges and tunnels, it does not make sense that the government refuses to consider third-rail electrics beyond the Southern Region and has even mooted using wires in parts of the Southern Region. The weather and safety implications are a trade-off, not a case of one being plainly superior, yet the government and rail industry treats overhead electrics as if they were plainly superior.

Credit for second image: Wikimedia Commons, licensed under the Creative Commons Attribution Share-Alike 2.0 Generic licence.

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