A large waste water pumping station dating from 1875 and originally home to four James Watt & Co beam engines. Now (1991 anyway) has W H Allen 6 cylinder diesel engines and remains in use. The magnificent chimney ventilates the sewers.
This is in the basement looking down (a long way) onto the top of two centrifugal pumps. The drive shafts from the diesel engines are in the bottom left and bottom right corners. The discharge is via the large grey pipes in the centre of this view. I think it would be harder to get a shot like this in 2021.