Highgate (ZHG)

Highgate mainline station was opened in 1867 by the Great Northern Railway, in the 1930s London Transport was expanding the Northern Line branch through to High Barnet as part of the Northern Heights project and aimed to take over the-then LNER operated lined and connect them to the growing tube network. A new tube station was built below the existing mainline station with a new subterranean ticket office for both stations [1].
Information
Type: Transport for London
(Northern Line)
Station code: ZHG
Opened: 1941
Platforms: 2

World War 2 interfered with London Transport's plans though work on the new station was sufficiently advanced for Highgate tube station to open in 1941 (trains ran though to East Finchley from 1939 but the station could not be opened until escalators had been completed). Passengers could use Highgate before the official opening however, as an air raid shelter though had to board trains at Archway to get to the Highgate platforms.

Post-war the Northern Heights project was largely abandoned and the main line station was closed in 1954. The tube station remained though grandeose plans by Charles Holden for an elaborate new building for both stations were greatly cut back.

One interesting aspect of the tube station is that they were designed for 9-car trains though since opening shorter trains have been used [2]. Unlike most stations therefore which are an exercise in squeezing a train in there is some leeway at Highgate.
95ts 51622 arrives on a service for High Barnet

End of the platform

Look down the platform, the original tiling still in place

Station name on tiles

A train has arrived

[1] Siddy Holloway, Highgate wilderness walkabout (London Transport Museum, 2017) p. 10
[2] Jason Cross, London Underground Guide 2017 (Train Crazy, 2017) p. 132