Cranwell was born in Auckland, New Zealand, and moved to Ireland around 1969/70 with his Cork girlfriend, Una Cassidy, whom he later married. In 1973 Cranwell won the Leinster Open and received his first cap for the Ireland team. A profile of Cranwell for Squash Review noted that he ‘regards himself as an Irishman—or the next best thing!’ He went on to gain 43 caps in a row and was made captain of the national team in 1975. As a coaching administrator he was crucial to the growth in publicity for the game in the 1970s. In the 1978 final of the Golden Pages tournament, Cranwell shocked Mohammed Ali Somjee by becoming the first ‘home player’ (sic) to defeat the Pakistani professional in a final. As of the same year, the only titles to elude the New Zealander were the Irish Open and the Irish Close.