Engineer and inventor of the steam catapult. Born in Edinburgh, the son of artist John Campbell Mitchell (1862 - 1922), Mitchell was educated at Edinburgh Academy and the University of Edinburgh, where he read engineering. He began his career at MacTaggart Scott & Co of Loanhead, where he designed the first steam catapults to launch aeroplanes from aircraft carriers and also arresting gear to stop aircraft on landing. During World War II he was appointed to the Engineering Department of the Admiralty and was awarded an OBE for his services to marine engineering within the Royal Navy.
Thereafter he was appointed Technical Director of Brown Brothers, marine engineers in Edinburgh, and worked on new steam catapult designs for the British and US Navies. One of his catapults was installed on the Audacious-class carrier HMS Ark Royal in 1955.
In 1955, Mitchell became the first non-US citizen to be awarded the Newcomen Gold Medal by the Franklin Institute of Philadelphia and in 1958 he received the US Medal of Freedom in recognition of his services to the US Navy and they said of him "No on man has contributed more to the Carrier Navy".
He was elected a Fellow of the Royal Society of Edinburgh in 1962. He is remembered on his father's gravestone in the kirkyard of Gogar Parish Church.
