He studied at the Sydney Technical College and was awarded a diploma in science.
Hannam was selected as part of the Australasian Antarctic Expedition. He helped to set up the wireless equipment on the Macquarie Islands. He is credited with being the first person to establish wireless contact with Australia from Antarctica.
He set up the wireless equipment at the main base and remained at Cape Denison as wireless operator for two summers and one winter.
On his departure in February 1913, Sidney Jeffryes took over his post as wireless operator. Hannam enlisted for service in World War I on 1 June 1915.
He served as an engineer in the Australian Motor Transport Corps and was discharged from service in 1919. After his war service, Hannam established an electrical business.
He died in 1965 in Terrigal.
He was a founding member of the Wireless Institute of Australia.