4 ms·
The oldest deep London Underground lines have iron tunnel segments, which might make this method particularly difficult. https://www.ltmuseum.co.uk/collections
by Symbiote 2y ago
The oldest deep London Underground lines have iron tunnel segments, which might make this method particularly difficult.
https://www.ltmuseum.co.uk/collections/collections-online/infrastructure/item/1999-4235-part-0 https://www.ltmuseum.co.uk/collections/collections-online/in...