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More than 154 years after it first opened, engineer Rob Bell has been given exclusive access to the London Underground network that weaves beneath our capital.

Stunning animation shows London Underground's 'beating heart' pulsing with passengers London Underground Stunning animation shows London Underground's 'beating heart' pulsing with passengers


At 10pm BST tonight (Monday April 10) on Channel 5, the second episode in Bell's series, Inside the Tube: Going Underground explores the construction of the Central Line. At 46 miles, the Central line is the longest line on the network, connecting Ealing Broadway to Epping. Transporting 260 million passengers a year, the Central Line is also the busiest train line in Britain, under or overground.



"The Central Line is the blood red artery that travels through the heart of London," said Channel 5.

The Central Line began 120 years ago as a privately-owned transport link. It was largely a financial gamble by Sir Ernest Cassel, one of the richest men of the day. Building a straight Tube line beneath London’s shops, mansions, and St Paul’s Cathedral risked massive payouts in compensation so Cassel built the Tube to follow London’s winding medieval roads instead. This route may have saved Cassell money, but it's one of the main reasons why the line is so unreliable today; these bends mean the tracks wear out 10 times faster than any other line.

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The Central Line was also the site of the Tube's most tragic event, known as the Bethnal Green Tube Station Disaster. On March 3, 1943, 173 people died in a crush as panic spread through the crowds of people trying to enter the station's bomb shelter in the East End of London. No bomb struck the site, though, making it the deadliest civilian incident of WWII and the biggest loss of life on the London Underground network. In tonight's episode, Bell meets a group of survivors who were children at the time. He later joins the maintenance workers who descend on the Central Line overnight to mend its bendy tracks and meets the Station Manager at Bank (a station where the line bends to avoid the vaults of the Bank of England.)


Tonight's episode is the second in the four-part series exploring the history of London's iconic, network. Last week, Bell discovered the remains of the first station on the Northern Line, King William Street, just before it is to be permanently sealed. He walked down on the tracks with the maintenance team at Camden Junction, who work across the network each night to keep the Tube working, and opened the sealed tunnels of an abandoned extension of the line in north London.

Gallery: behind the scenes at London Underground Gallery Gallery: behind the scenes at London Underground + 9

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Today, the Northern Line runs for 36 miles through London, carrying 700,000 passengers every day, between north and south London, across the Thames. To build it, its Victorian engineers, led by James Greathead, pioneered a machine that allowed deep tunnels to be built faster and more safely than ever before. The new Tube line also paved the way for electric trains, lifts and escalators.

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Although the Northern Line was the Tube's first 'deep' line (192ft at its deepest point at Hampstead), the London Underground opened in 1863 when the sub-surface Metropolitan Railway, between Paddington and Farringdon, began serving six intermediate stations. Since then, the Underground network has expanded to 270 stations and 11 lines.

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The Metropolitan line is known as sub-surface because, unlike the deep tube lines that followed, it was built using the 'cut and cover' method. This is used for shallow tunnels where a trench is excavated and an overhead support system is put in.

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The Northern line opened much later, in 1937, and was the amalgamation of the City and South London Railway, and the Charing Cross, Euston and Hampstead Railway. Scheduled plans to extend it beyond its current length, to Mill Hill, Brockley Hill, Elstree and Bushey Heath – known as the Northern Heights plan – were delayed due to World War 2 before being finally shelved in 1954.

In tonight's episode, Bell meets the station manager at Balham to learn how the Tube network was used during the Blitz, speaks to Dr Margaret McCollum, the widow of the famous 'mind the gap' train announcer Oswald Laurence, and goes behind-the-scenes of more recent tunnelling work extending the Northern Line to Battersea Power Station.

In next week's episode, Bell discovers more about the history of the Metropolitan Line and its hand-built brick tunnels built 150 years ago and takes a ride on one of the original steam trains that ran across the network.