Allen was born in Cardiff, the son of William Henry Allen, and was educated at Christ College, Finchley. He received a private technical education and was apprenticed for four years at his father's firm. He worked as a draughtsman with John Elder and Co. in Glasgow, and then with the Naval Construction and Armaments Co. at Barrow in Furness. In 1890, he visited the United States, and returned as assistant manager at W. H. Allen and Co. When the company's works were transferred to Bedford in 1894, he became a partner and later managing director.Institution of Mechanical Engineers - Engineering Heritage
