The health and safety aspect is mind-numbingly overbearing. And for good reason. It is an underground workspace that is surrounded by the general public. When e

The health and safety aspect is mind-numbingly overbearing. And for good reason. It is an underground workspace that is surrounded by the general public. When escalators are replaced the entire work area gets boxed in. There must be significant controls in terms of dust, gas (like welding equipment), noise etc. Fire is a significant risk and the underground has history that makes them anxious about fire and escalators (see Kings Cross Fire). Most of the work probably has to take place after hours, and subject to other maintenance taking place. On the underground, you can't just put a new escalator in a docker container and spin it up. The Underground is a significantly complex environment.