The son of the noted railway writer Cecil J. Allen, who was one of the formative figures in the early years of Ian Allan Ltd as a publishing company, GFA as he was known to colleagues first joined the business as a 26-year-old in 1948 as a writer for Trains Illustrated. He took over the editorship of the magazine in 1950 and, over the next decade, saw the publication become one of the most influential in the business and overseeing its transition to Modern Railways in 1962. He continued with that role along with an increasing involvement with the management of the company for a number of years. After leaving Ian Allan Ltd he became the editor of Jane's World Railways and a prolific freelance author of railway books. He died in 1995.