Peter Bermingham, 70, began his career 50 years ago in 1964 when he worked on the construction of the Victoria line from Green Park to Oxford Circus.
Since then the Cryodon born tunneller has worked on more than 20 projects in and around London including the Jubilee Line Extension, the Olympic Park and the King’s Cross redevelopment.
Bermingham worked for almost five years on the Channel Tunnel, during which time he was awarded the British Empire Medal for services to tunnelling.
He has also worked in Hong Kong, Australia, Fiji, Singapore and Copenhagen.
Bermingham is about to complete a record tenth tunnel underneath the River Thames as part of Crossrail.
He said: “When I started out tunnelling back in 1964, I never thought that I’d still be doing it 50 years later.
“It’s the camaraderie and the spirit among the lads that’s kept me in the industry for so long and I’ll miss it when I retire.
“Going under the Thames for the tenth time as part of Crossrail felt pretty special, in particular on a project that is going to have such a big impact on London.
“I’ve seen enormous changes. Back when I started out, we dug tunnels by hand using pneumatic spades and shovels, normally with a cloth cap or a handkerchief on our heads.
“Now we’re using ten million pound machines to build the tunnels beneath the streets of the city.”
Bermingham’s sons Dan and Robert are also tunnellers on Crossrail.
Dan said: “My dad’s a bit of a legend in the tunnelling industry. After half a century working underground, he’s certainly earned a good break. We’ll all miss having him around at work.”
The Mayor of London, Boris Johnson, said: “Throughout the vast changes and improvements to tunnelling equipment and underground conditions over the last 50 years, the one constant has been Peter’s hardworking spirit and endeavour.
“This record-breaking Londoner has earned his richly deserved rest and I take my hat off to him for his role in the modernisation and transformation of our fine city.”
Andrew Wolstenholme, Crossrail Chief Executive, said: “Peter should be rightly proud of the 50 years service that he has given to the tunnelling industry and to London.
“The wealth of experience that he has brought to Crossrail has been unparalleled and we all wish him the very best for his retirement.”