Mind the Gap: The history of London Underground

Sign for the Elizabeth Line
The Elizabeth Line was officially opened in May 2022 | Image: Shutterstock

“Would Inspector Sands please report to the operations room immediately?"

If you hear this on the London Underground network, you should know that it is code for a fire alarm, but not one that requires the station to be evacuated.

But in this context, we’re simply using the phrase to grab your attention. We’re going on a journey deep down into the Underground to check out what happened before the opening of the Elizabeth Line in 2022. There are many surprises lurking down there!

But first, let’s find out how the Underground established itself in the nineteenth century, way before the Underground network was powered by electricity and penetrated the very fabric of London.

1863 to 1899

The original method of tunnelling for the Underground network wasn’t any more complicated than digging a deep trench, laying the lines, allowing space for trains, and covering the lot up. This is how the Metropolitan Line was born. It opened in 1863 and ran underground steam trains between Paddington and Farringdon, stopping off at Edgware Road, Baker Street, Portland Road, Gower Street, and King’s Cross along the way.

Despite the noise and smog, it proved successful enough to warrant extending the line west to Hammersmith, branching off to Kensington, and heading across to Moorgate in the east the following year.

The District Line, operated by another company, opened to the south of the Metropolitan in 1868 and originally ran from South Kensington to Westminster. By 1884, both lines had joined to the east and west of central London, effectively creating the yet-to-be-named Circle Line, which was officially christened in 1949. Now both lines had stations as far as Harrow in the north, Putney Bridge in the south, and Windsor in the west. In the east, the infrastructure around Aldgate continued unabated.

In 1890, the same year the network became known as the ‘Tube’, the City and South London Railway (the original name of the Northern Line) opened between King William Street and ran south to Stockwell. This was the Tube’s first electric line and, thanks to engineer James Henry Greathead, was much deeper underground than its counterparts. The former cut and cover method was scrapped in favour of preventing leaks with compressed air, while a circular bore was used to excavate the tunnel, before being lined with cast iron rings. Today’s Northern Line is still the deepest tunnel on the Underground, with Hampstead being the deepest station at 58.5 metres (192 feet).

Just before the 20th century, in 1898, the Waterloo and City Line opened to connect the city and London Waterloo. These days Waterloo is the busiest station on the Tube network, serviced by 23 escalators. For the record, Angel has the longest escalator at 61 metres (200 feet).

1900 to 1999

By now the Tube network had 121 stations and was at a total length of 118 miles (190km). In 1906, a former section of the Bakerloo Line - the ‘Baker Street and Waterloo Railway’ - opened between Baker Street and Elephant & Castle. The Piccadilly Line made its debut as the ‘Great Northern and Piccadilly Brompton Railway’.

Meanwhile, in 1904 and 1907, the ‘Great Northern and City Railway’ and the ‘Charing Cross, Euston and Hampstead Railway’ lines were added to the future Northern Line.

The Underground network was expanding, and contracting, at a frenetic pace. The multiple companies building new lines and tweaking existing ones realised that working together would be in everyone’s interests and, by 1933, all of London’s public transport system was publicly owned.

The first station to open after the war was in 1968. Between September 1940 and May 1945, the Tube network had acted as an effective bomb shelter for millions of Londoners, just as it had between 1915 and 1918. The new Victoria Line ran between Walthamstow and Highbury & Islington. Just over a decade later the Jubilee Line opened between Stanmore and Charing Cross and the Hammersmith and City Line opened in 1990, effectively replacing a section of the former Metropolitan Line.

2000 to the future (and the past)

The Docklands Light Railway (DLR) and the London Overground (aka ‘the Ginger Line’) are not considered part of the London Underground Network, although they are part of the ‘Transport for London’ network. We're not just mentioning this as an excuse to note that only 45% of the actual London Underground network is actually below ground, but also to remind Tube fans that (as the Hammersmith and City Line is new in name only) the last true new Underground line was the Jubilee, named after the Queen’s Silver Jubilee in 1977.

The Elizabeth Line: Don't call it a tube line

Like the Jubilee Line, the Elizabeth Line, which opened in May 2022, was named in honour of Britain's longest-serving monarch, but unlike the Jubilee Line, it is not technically a tube. However it does form part of Transport for London's overall network, alongside the DLR and Overground.

In a press briefing, Cross Rail's Mark Wild explained: 'The thing to think about the Elizabeth line is that it's not a Tube line. It might be called 'a line', but it's actually a new mode of transport...There's been nothing like this in the UK; in the world, it is one of the most complex and biggest digital railways.'

London Underground today

From its modest beginnings as a single line with a clutch of stations to a network encompassing 272 tube stations stretching over 250 miles, the London Underground has always been in a state of flux, expanding exponentially and adjusting constantly, innovative while providing a surprisingly profound link to London’s past.