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demolishing buildings. Originally scheduled to be completed in 21 months, the construction of
the underground line took three years. It was built just below street level
using a technique known
as ‘cut and cover’. A trench about ten metres wide and six metres deep was dug, and the sides
temporarily held up with timber beams. Brick walls were then constructed, and finally a brick
arch was added to create a tunnel. A two-metre-deep layer of soil was
laid on top of the tunnel
and the road above rebuilt.
The Metropolitan line, which opened on 10 January 1863, was the world’s first underground
railway. On its first day, almost 40,000 passengers were carried between Paddington and
Farringdon, the journey taking about 18 minutes. By the end of the Metropolitan’s
first year of
operation, 9.5 million journeys had been made.
Even as the Metropolitan began operation, the first extensions to the line were being authorised;
these were built over the next five years, reaching Moorgate in the east of London and
Hammersmith in the west. The original plan was to pull the
trains with steam locomotives, using
firebricks in the boilers to provide steam, but these engines were never introduced. Instead, the
line used specially designed locomotives that were fitted with water tanks in which steam could
be condensed. However, smoke and fumes remained a problem, even though ventilation shafts
were added to the tunnels.
Despite the extension
of the underground railway, by the 1880s, congestion on London’s streets
had become worse. The problem was partly that the existing underground lines formed a circuit
around the centre of London and extended to the suburbs, but did not cross the capital’s centre.
The ‘cut and cover’ method of construction was not an option in this part of the capital. The only
alternative was to tunnel deep underground.
Although the technology to create these tunnels existed, steam locomotives could not be used in
such a confined space. It wasn’t until the development
of a reliable electric motor, and a means of
transferring power from the generator to a moving train, that the world’s first deep-level electric
railway, the City & South London, became possible. The line opened in 1890,
and ran from the
City to Stockwell, south of the River Thames. The trains were made up of three carriages and
driven by electric engines. The carriages were narrow and had tiny windows just below the roof
because it was thought that passengers would not want to look out at the tunnel walls. The line
was not without its problems, mainly caused by an unreliable power supply. Although the City &
South London Railway was
a great technical achievement, it did not make a profit. Then, in 1900,
the Central London Railway, known as the ‘Tuppenny Tube’, began operation using new electric
locomotives. It was very popular and soon afterwards new railways and extensions were added to
the growing tube network. By 1907, the heart of today’s Underground system was in place.
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