Much has been made by the Mayor’s office about the great age of the Underground system in order to justify the current heinous amounts of engineering work. Not that I disagree, mark you, I appreciate that the system is very, very old. Ironic, really, given that when it was built it was actually slightly ahead of its time.
Sometimes, you see, technology gets a bit ahead of itself. In the case of the Underground in the 1860s, the problem was that while they could dig a tunnel just fine, they couldn’t find a clean way to send a train through it. Steam engines, as you are no doubt aware, produce the Dickens of a lot of smoke and steam. A number of solutions were tried. Those pipes you see on the front of the engine above left, the ones running from the cylinders up, you see those? Those are condensers, which collect the waste steam and, yes, condense it for re-use. Every so often, the tunnels were fitted with large ventilation shafts – including one that was ingeniously disguised as a pair of fake houses. The Metropolitan, unusually for a Victorian railway, allowed its drivers and firemen to grow enormous ZZ Top-style beards in the hope that said shrubbery would act as a kind of air filter. They even tried brazening it out, claiming that the smoky air was actually really good for bronchial complaints (although at least one chemist sold “Metropolitan Mixture,” a cough medicine targeting regular Underground users).
One solution was proposed by John Fowler – remove the fire altogether. He suggested an engine with an “egg-ended boiler” – in reality a storage receptacle for steam produced by a stationary boiler. This engine was never built, but what was eventually produced was a strange locomotive known as “Fowler’s Ghost,” and I can give no better explanation of it than that offered by the Museum of Retrotech.
On the same site, I came across an interesting little snippet about a concept tested at the Metropolitan District Railway’s Lillie Bridge Depot (that’s the District Line to you) in 1875. The idea was a clockwork tram. I know, right? Now, I’d heard a vague rumour that such a thing was tried, but no more than that. Was this trial carried out in the hope of finding a smokeless alternative to steam on the Underground? Sadly, the indices of the various Underground histories I have list “clockwork tram” under “piss, taking the” and offer little further information.
There were various other possibilities, none of them all that great. Isambard Kingdom Brunel had been something of a champion of the atmospheric railway – as seen left, this was powered by a piston in a vaccuum pipe. I’ve not come across any evidence that this was ever suggested for the Tube, though see the Pneumatic Dispatch for a similar idea that actually was tried. Ironically, Brunel himself, when consulted early on about the proposed Metropolitan, suggested that there was no need to worry, as the smoke from a steam engine would surely not be a problem in the first place.
Another was cable haulage. This was employed on the Glasgow Subway and, less successfully, on the London and Blackwall Railway in its early days. When it came to constructing the City and South London Railway (now roughly the City Branch of the Northern Line) in the 1880s, this was the favoured choice. Unlike the earlier Metropolitan and Metropolitan District Railways, the C&SLR was constructed entirely below ground in very narrow tunnels rather than being built by the cut-and-cover method (this, incidentally, is also why the former lines today have much larger trains than the latter). You can make excuses about a few coughing passengers, but full asphyxiation was generally frowned upon even back then.
However, by 1886, train technology had caught up with the Underground and the cable concept was dropped in favour of more flexible and easier to maintain electric trains, hauled by dinky little locomotives like that one there. However, there was still a little work to do – one of the early problems the system had was that the power plant wasn’t able to generate enough electricity to get trains up the gradient at Stockwell, which was a bit embarrassing. Nevertheless, once these teething troubles were ironed out, it was clear that finally there was a clean solution to the Underground problem, and the other lines soon followed in the adoption of electric power.
You know what’s ironic in all of this? The Metropolitan was one of the only railways not to ban smoking in its carriages. Was this a wangle to avoid taking responsibility for bronchial irritation? It is a mystery.