the 1987 King's Cross fire was also escalator related: https://en.wikipedia.org/wiki/King%27s_Cross_fire

Smoking on the escalators, wooden steps, and build-up of trash in the inaccessible area underneath them all contributed.

If you want a really interesting read, which is great at showing how a methodical enquiry is carried out is here: https://www.theisrm.org/documents/Fennel%20(1988)%20Investig...

It might look long but is still really interesting to read, the simple questions that needed to be answered, the interviews and the conclusion.

> This sudden transition in intensity, and the spout of fire, was due to the previously unknown trench effect, discovered by the computer simulation of the fire, and confirmed in two scale model tests.

https://en.wikipedia.org/wiki/Trench_effect

I just missed that fire as I left early that day to get back home for a DnD game.

My normal commute would have taken me right into the center of the fire.

The Wilshire Vermont metro station in Los Angeles has the longest escalator west of the mississippi river. It's so long that its much faster actually to take the elevator from that platform, if you can out run people from the train to the single elevator that is. The escalator system at Universal Studios Hollywood is also pretty impressive.

The longest single-span Escalators on the London Underground, are at Angel Station.

https://www.youtube.com/watch?v=fFqQOlYE4EE

"the longest escalators on the Underground network, and the fourth-longest escalators in Western Europe"

https://en.wikipedia.org/wiki/Angel_tube_station

Angel is much deeper than Kensington, so the Kensington ones won't be that long.

IIRC, they're not particularly long. The deep level tunnels are something like 20m below the subsurface tunnels, I'd guess 30m in total from the ticket hall?