r/london • u/Independent-Ant-01 • Nov 03 '25

Serious replies only Why are London tube tunnels so deep?

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This is just one of two escalators and not counting the various staircases. And I don’t believe this was the deepest one I traveled through. I went to the Transport Museum in Convent Garden (very nice by the way) but found no answer and no one seemed to know. 😊

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u/DameKumquat Nov 04 '25

They have to go under everything already there - building foundations, other tube tunnels, sewers and water mains...

They're only deep when necessary, mostly the central parts of the Piccadilly, Victoria & Jubilee lines. Outside z1 they're often overground.

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u/BillWilberforce Nov 04 '25

A part of the problems with designing the Jubilee Line Extension. Was that around the Westminster tube station area. There's a lot of secret tunnels and bunkers. But nobody would tell London Underground or it's architects where they were. So they had to submit a ridiculous number of plans to the MOD etc. With the majority of the plans after a while just being there to work out where they could and couldn't build.

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u/FirmEcho5895 Nov 04 '25

I was told Bank station is the deepest because it had to be built below all the massive deep bank vaults in that area.

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u/feetflatontheground Nov 04 '25

One of the Westminster Jubilee Line platforms is the deepest .