Obituary: Professor J. F. C. Conn

John Farquhar Christie Conn, engineer and teacher: born Aberdeen 5 July 1903; scientific staff, Ship Division National Physical Laboratory 1929-44; Chief Naval Architect, British Shipbuilding Research Association 1945-57; John Elder Professor of Naval Architecture, Glasgow University 1957-73; married 1935 Doris Yeatman (one son, one daughter); died Glasgow 27 March 1993.

J. F. C. CONN, the former John Elder Professor of Naval Architecture at Glasgow University and formerly Chief Naval Architect to the British Ship Research Association, made significant contributions to many aspects of ship design - particularly resistance and propulsion and structural design.

John Conn was a native of Aberdeen and embarked on his professional career as an apprentice in Alexander Hall's shipyard. In 1925 he went to study Naval Architecture at Glasgow University. After graduating he worked for a short time in shipyard design offices on the Clyde and the north-east coast of England before joining the the Ship Division at the National Physical Laboratory.

Conn soon gained a reputation for his work on the hydrodynamics of ships and published a number of papers in this field. During the Second World War he collaborated with Barnes Wallis on model tests which led to the development of the bouncing bomb used in the breaching of the Mohne dam. During this period he was also largely concerned with the design of seaplane hulls. In 1946 he was awarded the Doctor of Science degree for his work on propeller vibration.

On the formation of the Shipbuilding Research Association he was appointed its Chief Naval Architect. He developed a research programme covering all technical aspects of ship design, and had a particular interest in the correlation of hydrodynamic tests on models with the performance of full-scale ships which culminated in the 'Lucy Ashton' tests on the Gare Loch in 1953. In order to separate the interaction between a ship's resistance and its underwater propulsion system, Conn arranged for the Lucy Ashton, a former ferry, to be propelled by four aircraft jet engines and thus replicate the conditions during resistance testing in a test tank. The results clarified the problem of extrapolating from model tests to full-scale ships and gave the industry greater confidence in required engine-power predictions.

One of Conn's first acts on appointment to the Chair at Glasgow University was to raise money to build a ship model testing tank which could provide a good research facility as well as giving students a greater insight into the hydrodynamic problems of the ships. With the assistance of his many friends in the Clyde shipyards and oil companies the tank was completed in 1961 and has fulfilled his objective in attracting research workers, including many from overseas.

In the same year he helped to organise the first International Ships Structures Congress which was held at the university and which has continued to expand and flourish. He was a UK delegate to the International Towing Tank Conference for many years.

In an era when the increasing volume of research output has tended to force specialisation in many branches of engineering, Conn ranked as one of the few people who maintained a commanding knowledge of all aspects of his profession. His ability to quote references on previous research was the envy of his colleagues.

He was a Vice-President of the Royal Institution of Naval Architects, and the Institution of Engineers and Shipbuilders in Scotland awarded him its Gold Medal on two occasions. His wide knowledge and experience was called upon as an assessor in several Courts of Enquiry into the loss of ships at sea.

Despite his wide research interests John Conn always took a keen interest in the progress and careers of his students who appreciated the care and attention he gave to his lectures. Throughout his career he remained a modest man who gained the respect and friendship of all who knew him.