No trains south of London during cold weather? Blame a pair of Herberts for choosing the wrong electrical system

Empty Southern lines into Clapham Junction, during a strike. Image: Getty.

As is often the case when the weather is below freezing, commuters around London are having a terrible time this week. The blizzard has hit services on all lines around the capital. Trains running towards the south and southeast have had the worst of it, with services cancelled on Monday before the full impact of the storm really hit.

It’s frustrating to compare the UK’s lack of readiness when extreme weather hits with services in Switzerland or Sweden, which cheerfully run in heavy snow conditions.

It’s also not really a fair comparison: you build a system to deal with the weather conditions you’re expecting, and a Swiss railway that couldn’t handle snow would be useless for half the year. Building southern England’s rail network to Swiss weatherproofing standards would add a lot of extra cost for only a couple of days’ benefit per year.

Some commuters have a much better reason to be grumpy, though. The 750V DC third rail system used on railways south of the Thames is particularly vulnerable to cold. Because of its thickness and relatively low voltage, the conductor rail tends to have ice form on top of it, whether from snow or just moisture in sub-zero conditions. Once there’s an ice layer on the rail, the train can no longer pick up electricity.

Which is a bit of a problem if you want it to go anywhere.

It didn’t have to be this way. In the early 1900s, the London, Brighton and South Coast Railway (LB&SCR) began its electrification programme. It used the latest German technology from AEG to provide a high voltage 6.6kV AC overhead electrical pick-up system – very similar to the 25kV system now used on high speed main lines in the UK and the rest of Europe.

Many of the 25kV systems in use today were converted from similar systems. The electric trains in Glasgow and the ones running out of Fenchurch Street and Liverpool Street in London were converted to 25kV from 6.25kV in the early 1980s, after the quality of electrical insulators improved to allow lower clearance.

High voltage overhead electrification is cold-resistant; it’s what the Swiss and the Swedes use for their systems. Snow tends to fall off the narrow overhead wires, they run hot enough to avoid icing, and the high voltages involved make it easier for the train to pick up power.

It’s also better in general: the higher voltage makes power distribution more efficient, with fewer expensive substations required. The pickup design allows overhead electrified trains to run at up to 400km/h, compared to just 160km/h for third rail trains. Since 1956, 25kV overhead electrification has been specified as the only system allowed for new mainline railway electrification in the UK.

A map of the LB&SCR network, at Victoria station. Click to expand. Image: Oxyman/Wikipedia.

By 1913, the LB&SCR’s high voltage overhead electric lines stretched from Victoria and London Bridge to much of outer south London, covering what is now the Southern Metro network. The company was preparing to electrify the main line to Brighton and the Sussex Coast – effectively the whole present-day Southern rail franchise.

But World War I disrupted equipment supplies and used up manpower, putting electrification on hold. Then came 1921’s ‘grouping’, in which all the commuter railways south of the Thames were combined into the Southern Railway.

Unfortunately for today’s commuters, the Southern Railway wasn’t interested in the overhead system. The merged company’s general manager was Herbert Walker, who had previously run the London & South Western Railway (L&SWR), which had just electrified its own suburban tracks using the low-voltage DC third rail system.

Walker and his chief electrical engineer, Herbert Jones (Herbert was a popular name in the Edwardian railway industry, apparently) picked up their experience of electric railways in the USA, where commuter lines used DC third rails. While the LB&SCR was electrifying its London lines with the German-derived high-voltage AC overhead system, the L&SWR did the same with low-voltage DC.

This had the advantage of being cheaper to install, avoiding the need to build supporting pylons and their foundations. It also allowed the L&SWR to run up a greater length of electrified track faster than its neighbour, despite being otherwise inferior. 

The new Southern Railway needed to electrify its whole network: steam trains couldn’t support the high-intensity commuter operation that it needed to become. And it needed to adopt a single system rather than have complicated switching or incompatible routes. So, although ex-LB&SCR managers lobbied to roll out their system across the network, the Herberts’ pet project unsurprisingly won out.

By 1929, the last AC train ran on the Southern Railway. The masts were unceremoniously torn down and replaced with third rail. Subsequent electrification south of the Thames was also carried out using third rail, continuing through the British Rail period as late as 1988, despite the ban on ‘new’ third rail electrification. 

And so, trains in the south still run slowly all year round, and not at all when it’s icy.

In the long run, there may be hope for commuters. Former Network Rail head of electrification Peter Dearman (now at engineering consultancy Bechtel) says that there is no long-term future for third rail for speed and efficiency reasons, and the Office of Rail Regulation believes it is unsafe for track workers. The current electrification programme includes a pilot scheme to convert the third rail between Basingstoke and Southampton to overhead AC.

But given the delays to the Great Western electrification and the government’s recent cancellation of multiple add-on electrification projects, it doesn’t seem likely that southern commuters will see the return of the LB&SCR’s AC masts any time soon. And the best plan for icy days will still be to work from home, well beyond the 100-year anniversary of the Herberts’ botched job.

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Why doesn’t London build an RER network, like Paris did?

A commuter walking by a map of the RER B line at the Chatelet-Les Halles station in Paris. Image: Getty.

I’ve heard many people make many different complaints about the Parisian transport system. That it does a bad job of linking a rich, white city with its poorer, more diverse suburbs. That, even as subway systems go, it’s a hostile environment for women. That the whole thing smells distractingly of urine.

I’m familiar with all of these complaints – I’ve often smelt the urine. And I’m aware that, in many ways, London’s is the superior transport network.

And yet I can’t help be jealous of Paris – In large part, because of the RER.

Central Paris. The Metro lines are thinner, and in pastel shades; the RER lines are thicker, and in brighter colours. Image: RATP.

Paris, you see, has not one but two underground railway systems. The more famous one is the original Paris Metro, opened in 1900: that’s the one with those fancy green portals with the word “metropolitain” written above them in a vaguely kooky font.

The Metro, though, mostly serves Paris Intra-muros: the official city, inside the Boulevard Périphérique ring road, site of the city’s last set of walls. As a result, it’s of very little use in most of the city’s suburbs. Its stations are very close together, which places a limit on how fast its trains can cross town. It was also, by the mid 20th century, becoming annoyingly overcrowded.

So starting in the 1960s, the city transport authorities began planning a second underground railway network. The Réseau Express Régional – Regional Express Network – would link suburban lines on either side of Paris, through new heavy rail tunnels beneath the city. Its stations would be much further apart than those of the metro – roughly one every 3km, rather than every 600m – so its trains can run faster.

And fifty years and five lines later, it means that 224 stations in the suburbs of Paris are served by trains which, rather than terminating on the edge of the city, now continue directly through tunnels to its centre.

The RER network today. Image: RATP.

London is, belatedly, doing something similar. The Elizabeth Line, due to open in stages from later this year, will offer express-tube style services linking the suburban lines which run west from Paddington to those which run east from Liverpool Street. And Thameslink has offered cross-town services for 30 years now (albeit not at tube-level frequencies). That, too, is going to add more routes to its network over the next few years, meaning direct trains from the southern suburbs to north London and vice versa.

Yet the vast majority of suburban National Rail services in London still terminate at big mainline stations, most of which are on the edge of the centre. For many journeys, especially from the south of the city, you still need to change to the London Underground.

So, could London ape Paris – and make Thameslink and Crossrail the first element of its own RER network?

In a limited way, of course, it’s doing just that. The next big project after Crossrail is likely to be (original name, this) Crossrail 2. If that gets funding, it’ll be a new south-west to north-east route, connecting some of the suburban lines into Waterloo to those in the Lea Valley.

The proposed route of Crossrail 2. Click to expand.

But it’s not immediately obvious where you could go next – what Crossails 3, 4 or 5 should cover.

That’s because there’s an imbalance in the distribution of the remaining mainline rail services in London. Anyone who’s even remotely familiar with the geography of the city will know that there are far more tube lines to its north. But the corollary of that is that there are far more mainlines to the south.

To usefully absorb some of those, Crossrail 3 would probably need to run south to south in some way. There is actually an obvious way of doing this: build a new tunnel from roughly Battersea to roughly Bermondsey, and take over the Richmond lines in the west and North Kent lines in the east, as a sort of London equivalent of RER C:

Our suggestion for Crossrail 3. Image: Google Maps/CityMetric.

But that still leaves a whole load of lines in south and south east London with nowhere to send them beyond their current terminal stations.

In fact, there are reasons for thinking that the whole RER concept doesn’t really fit the British capital. It was designed, remember, for a city in which the Metro only served the centre (roughly equivalent of London’s zones 1 & 2).

But London Underground wasn’t like that. From very early in its history, it served outer London too: it was not just a way of getting people around the centre, but for getting them there from their suburban homes too.

This is turn is at least in part a function of the economic geography of the two cities. Rich Parisians have generally wanted to live in the centre, pushing poorer people out to the banlieues. In London, though, the suburbs were where the good life was to be found.

To that end, the original operators of some lines weren’t just railway companies, but housing developers, too. The Metropolitan Railway effectively built large chunks of north west London (“Metroland”), partly to guarantee the market for its trains, but partly too because, well, housing is profitable.

In other parts of town, existing main line railways were simply added to the new underground lines. The Central line swallowed routes originally built by the Great Western Railway and London & North Eastern Railway. The District line absorbed part of the London, Tilbury & Southend Railway.

At any rate: the Tube was playing the same role as the RER as early as the 1930s. London could still benefit from some RER-type services, so hopefully the Elizbaeth Line won’t be the last. But it doesn’t need an entire second metro network in the way 1960s Paris did.

There is another idea we could more profitably steal from Paris. Those suburban railways which aren’t connected to the RER are still run by the national rail operator, SNCF. But it uses the Transilien brand name, to mark them out as a part of the Parisian transport network, and – as with the RER – each route has its own letter and its own colour.

The Transilien & RER networks in Paris. Image: Maximilian Dörrbecker/Wikimedia Commons.

This would not have the transformative effect on London that building another half a dozen Crossrails would. But it would make the network much easier to navigate, and would be almost infinitely cheaper. Perhaps we should be starting there.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and on Facebook as JonnElledgeWrites

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