The Thames Tideway Tunnel is a 25km tunnel being constructed under London at a cost of more than £4billion.
We join the workforce who are designing and building the biggest sewer since Victorian times. What skills do you need? What does working in construction mean to them?
See different formats of the Show
View the stories in the show again
Day in the Life - Jessica
Day in the Life - Gabriel
How do you build a town?
Port of Blyth
Down the sewer
Explore our shows
National Careers Week