He left school at the age of 17, working briefly in a shoe factory before moving to the postal sorting office.
He initially had a short-term, seasonal, contract, but he led a movement against redundancies among these workers, and was successful in retaining his job.
[1] In 1939, Duhamel was enlisted into the French Army, joining the meteorological service, based initially in France, but then in Algeria.
In this role, he signed a declaration of friendship with East Germany, leading to his suspension from the postal service in 1951.
[1] Duhamel was made a knight of the Legion of Honour in 1981, and the same year, was finally reinstated at the postal service, becoming a deputy departmental director.