Eight incredible facts you may not know about the Northern line

The Northern Line is the second busiest line on the London Underground network and it serves some of the most popular destinations in the capital. Perhaps that is why it is so difficult to get a seat on it.

Running between north London and south London, it is much used by commuters and tourists alike. In September 2021, the line was given an extension, from Kennington to Battersea, and two stations opened: Nine Elms and Battersea Power Station.

Famous stops on the line include Camden Town, Leicester Square and King's Cross St Pancras.

The line, which is black on the Tube map, is steeped in history and was the first of the Underground's lines to be constructed by boring deep below the surface and the first to be operated by electric traction.

The railway opened in November 1890 from Stockwell to a now-disused station at King William Street. This was inconveniently placed and unable to cope with passenger numbers so, in 1900, a new route to Moorgate via Bank was opened. By 1907 the line had been further extended at both ends to run between Clapham Common and Euston.

But there is much more that is of interest about the Northern line, so brush up on your general knowledge and have a read through eight facts you may not know about the line.

Northern Line facts

1. The longest escalator is at Angel tube station, at 61 metres, which rises 27.4 metres over its length.

2. The Northern line has the highest maximum number of trains required for scheduled peak period service: 91.

3. King's Cross St Pancras tube station is served by more Underground lines than any other station on the network.

4. The deepest platforms on the Underground network are at Hampstead, which are 58.5 metres beneath the ground.

5. The longest continuous Tube tunnel is on the Northern line and runs from East Finchley to Morden (via Bank), a total of 17.3 miles.

6. The famous warning of “Mind the Gap” originated on the Northern Line in 1968. Sound engineer Peter Lodge recorded the phrase himself as well as the closing doors warning after the actor hired to do the lines demanded royalties.

The northbound platform at Embankment station is the only place where you can hear his original recording. His widow requested that it be reinstituted so she could hear his voice again.

7. In 2024, the Northern line was named as the Tube line with the highest level of dust. The study was commissioned by Transport for London across eight lines to assess the level of pollution, including PM2.5 and PM10 soot particulates, in train driver cabs.

Not so incredible.

8. Sting and Paul McCartney are rumoured to have busked on the Underground in disguise.