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Authors: Andrew Martin

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The Central London Railway had wanted to turn their line into another circle, not an ‘inner circle' – that had already been done – but an ‘inner
most
circle', and their scheme was rejected in favour of Morgan's more comprehensive plan. But Yerkes torpedoed
that
on discovering a rift between Morgan and his partners in London United Tramways over how the proposed line would be managed. He exploited the rift in order to buy a controlling interest in London United Tramways, so the Morgan scheme collapsed, and Yerkes's own plan to link the Great Northern & Strand with the Piccadilly & Brompton was authorised. From America, Pierpont Morgan sent a telegram to his son, who'd been overseeing the deal: ‘Deeply sympathetic with you in your bother over Tubes. Would seem to be the
greatest rascality and conspiracy I ever heard of.' And he had heard of a few.

Incidentally, the Morgan Tube (on which it had been intended to run trains throughout the night) would have been a
network
. The Metropolitan and District were really networks as well, and this was a consequence of building Tubes by means of a competitive free-for-all. Each company wanted to expand its territory at the expense of the others. The Northern Line that Yerkes was incubating would also become a network, and one far too complicated for its own good.

The digging of the ‘Hampstead Tube' and the ‘Piccadilly Tube' would start in 1902. In 1903 the digging of the Baker Street & Waterloo was resumed. Yerkes would not live to see any section of any of these lines opened, but he would see electrification brought to the cut-and-cover lines, and he would build ‘The Chelsea Monster'.

TRACTION CURRENT EXPLAINED

Easy to write that heading, less easy if – like me – you can't wire a plug, to deliver the goods.

We begin with a sinister vignette …

A train steams into Aldgate station at four o'clock one afternoon. A lady sits in a first-class compartment, facing the window, ‘evidently oblivious of the fact that on this line Aldgate is the terminal station'. She is dead, and it will transpire that she has been murdered. The scenario is from a short story of 1901 by Baroness Orczy,
The Mysterious Death on the Underground Railway
. It features a sage-like character called The Old Man in the Corner (he is always to be found in the corner of an ABC coffee house), who reflects, ‘In these days of tubes and motor traction of all kinds, the old-fashioned “best, cheapest and quickest route to the West End” is often deserted, and the good old
Metropolitan Railway carriages cannot at any time be said to be overcrowded.'

Not being electrified, the cut-and-cover lines were coming to seem a picturesque curiosity, and a trigger for nostalgic affection in their older users. In
The Soul of London: A Survey of a Modern City
(1905) Ford Madox Ford wrote:

I have known a man, dying a long way from London, sigh queerly for a sight of the gush of smoke that, on a platform of the Underground, one may see, escaping in great woolly clots up a circular opening, by a grimy, rusted iron shield, into the dim upper light. He wanted to see it again as others have wished to see once more the Bay of Naples, the olive groves of Catania.

In 1901 the Metropolitan had seemed ready to proceed with electrification by means of overhead wires, but on his arrival at the District, Yerkes favoured a system whereby the power would be provided by two electrified rails – a method tried and tested on the elevated railways of Boston. Board of Trade arbitration favoured this scheme, and what went for the District would have to go for the Met, given the entanglement of the two on the Inner Circle; and in September 1905 the first electric service ran around the Circle. The Tube lines would also eventually adopt this system.

How did it work?

You will have noticed that the Underground tracks seem annoyingly cluttered. There are the two running rails and another two loitering about near by: the power rails, one of which is outside the tracks, the other one in between them. Four rails in all. On the main-line railways running into the southern termini of London things are neater, and there are three rails: the two running rails and one power rail to the side. That system is
called third-rail electrification; London Underground has four-rail electrification.

With the third-rail system, the train collects 750 volts from the outer rail. The Underground operates at a lower voltage: 630 volts, and this voltage is split. The outer of the two power rails is at +420 volts; the inner rail is at −210 volts. This splitting is to create a shorter distance to earth (which is zero volts). The main reason for this splitting is to minimise a phenomenon few non-electricians have ever heard of, namely current leakage. If this occurs on the main-line electrified railways, it doesn't really matter. But current leakage in a Tube tunnel can cause electrolysis to occur in steel retaining walls, which in turn causes them to rust; it could also damage the foundations of nearby buildings.

The inner, or negative, rail is also known as the ‘current return' rail, because electrical current needs a circuit – a return path to earth, in other words. On the Underground, the non-electrician might be advised to imagine earth as being located in the sub-station from which the power was originally derived, and to where it is – so to speak – sent back by the negative or current return rail. On the main lines the voltage is returned to earth via the carriage bogies (that is, the under-frames and wheels) and the running rails. Any power rail needs to be well insulated from earth, to minimise current leakage, and so the
two
power rails on the Underground sit on curiously genteel and antique-looking porcelain pots.

In addition to this power circuit for traction current, was another electrical system which would provide for an early form of automatic signalling or train protection. A small voltage is fed to the running tracks, and this sets the relevant signal to green. When a train runs onto the track, thus connecting the two rails, a short circuit is created, the current drops out and the signal is switched to red. The system operates in conjunction with a lever on the tracks. If a train should pass a red light, the lever, which
is called a tripcock, comes into play. The tripcock releases the air from the train's air-braking system, thus causing the brakes to come on and stopping the train. Annoyingly for people like me who've only just got to grips with this mechanism, it is now being replaced by a more fluid, computerised system of signalling called ‘moving block'. By this, the relative positions of trains on tracks is controlled by computer, and instead of a tripcock, a computer will apply the brakes of any train running too close to another one. The installation of moving-block signalling is the main work of the Tube Upgrade currently ongoing. It will allow a greater frequency of trains, and so ‘increase capacity'. Moving block will ultimately be used in conjunction with automatically driven trains such as those run – at the time of writing – on the Victoria, Central and Jubilee Lines only. Yes, the trains on those lines do have fully trained drivers sitting in the cabs, but they're not doing much apart from closing the doors, which is why they tend to be sitting with their feet up and picking their noses as they enter the stations.

Now … How would you go about electrocuting yourself on the Underground lines?

In the terrible horror film
Creep
(2004), a harassed couple (they are being chased, naturally enough, by a flesh-eating zombie) prepare to flee along a Tube tunnel in the small hours of the morning. The woman, evidently unaware that the current is switched off every night after the service stops, asks how to avoid being electrocuted, and the harassed man, also evidently unaware of the fact just mentioned, replies uncertainly, ‘Er … Don't step on
that
rail or that … Look, don't step on
any
of the rails.' The scene is part of an honourable tradition among creative types of vagueness about Underground electricity.

In
The Man in the Brown Suit
(1926), by Agatha Christie, a man in a heavy overcoat falls onto the rails at Hyde Park Corner Tube station: ‘There was a vivid flash from the rails and a crackling
sound.' The man is then lifted off the ‘live rail'. A doctor who happens to be on hand– ‘a tall man with a brown beard' (brown-ness being something of a theme in the book) – examines the body and pronounces, ‘Dead as a doornail. Nothing to be done.' But what is ‘the live rail'? Both the power rails are live, as we've just seen. Yes, there is more voltage in the third rail, the outer one (which is why it's positioned on the far side of the tracks from the platforms in Tube stations), and if you touch that you will certainly die as long as you have some other part of you on one of the running rails, the other live rail or something else that connects to earth and enables the current to flow, such as damp track ballast. Keep in mind that the pigeon who is often seen to stand on the electrified rails with such insouciance has wings. He has landed on it from above. He has not
stepped
on it; his legs are not long enough to allow him to do that, thankfully for him. In electrical terminology he is ‘at elevated voltage', but he is not ‘carrying current'. By the same token, any reader who finds himself – as a result of whatever nightmarish scenario – standing with both feet on an electrified line should jump off it rather than step down.

In
Railways on the Screen
(1993) John Huntley points out that in a film of 1941 called
Manhunt
, which features a scene supposedly set on the Piccadilly Line, ‘the villain is electrocuted on the centre (earth return) rail of the system instead of the outer positive rail.' But is that so remarkable? If you were earthed, you would probably be killed by that rail as well, even with its weaker voltage. Most people who jump in front of trains will therefore be electrocuted twice over besides being cut up by the train. But I suppose they want to make sure.

We turn next to the question that has been mused over by every London male while waiting for a train: would you die if you urinated on an electrified rail? Yes probably, because while pure water does not conduct electricity, ionised water does, and that is the category into which urine comes, but you may be saved
by the fact that your stream will be broken into drops, and if the gaps between the drops are big enough you will be insulated. A friend who works for the Underground said the only death-by-urination that he knew of involved a Metropolitan Line driver, who late one night was being given a lift back to the depot by another driver. He leaned out of the cab to relieve himself, and his head struck a signal post.

Another matter ruminated upon by the platform daydreamer: why do you sometimes see sparks under a Tube train? This beautiful little display which as a boy confirmed for me the glamour and danger of London, occurs when there is a break in either of the conductor rails, which may happen as points come up, or the track curves. When a break occurs, the conductor rail slopes downwards away from the collecting shoe, and the sparks represent the electricity reaching poignantly and vainly for its connection, and ionising the air in the process. Why does the train keep moving? Because other rail-shoe connections remain in place along its length. Incidentally, try to avoid saying, ‘Oh, the train's making pretty blue sparks!' Say instead that it is ‘throwing an arc.'

BY THE WAY: THE CHELSEA MONSTER

In order to power his underground railways Charles Yerkes built a generating station in Lots Road, Fulham. It was opened in 1904 as the largest traction power station in Europe and one of the first to use steam turbines, which have been the only game in town for power stations ever since. The Chelsea Monster, as it became known, was built on a bend of the river that the romantic, but stroppy, artist James McNeill Whistler had often depicted in his ‘Nocturnes', and he is said to have remarked that the builders ‘ought to be drawn and quartered'. So here were two Americans appropriating a bank of the Thames: Yerkes for industry, Whistler for art.

Lots Road Power Station in Fulham or, as estate agents say, Chelsea. It opened in 1904, and powered the underground railways of the American plutocrat, Charles Yerkes. Today, the Underground is powered from the National Grid. Lots Road was de-commissioned in 2002, and only two of the four towers remain. The silent film Underground (1928), directed by Anthony Asquith, features a genuinely gripping chase sequence across its roof.

Yerkes provocatively offered to supply the Metropolitan from Lots Road. But the Met would build its own power station at Neasden (demolished in 1968), and its coal would be brought by rail, whereas Lots Road was supplied by barge. Today buddleia grows out of the Chelsea Monster, and only two of the four 275-foot chimneys survive, so that it looks like a lopsided version of Battersea Power Station, which would be built thirty years later on the opposite side of the river. Lots Road would close in 2002, by which time it ranked as a
small
power station – almost cute. It produced 50 megawatts of power on opening. Today, a medium-sized power station produces 600 megawatts, and a nuclear power station will produce 1,200.

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