Sir John Audley Frederick Aspinall (25 August 1851 – 19 January 1937) was an English mechanical engineer who served as Locomotive Superintendent of the Great Southern and Western Railway (GS&WR) of Ireland and Lancashire and Yorkshire Railway (L&YR) of England. He introduced vacuum brakes to his locomotives in Ireland, a trend which was followed in Britain, and designed several locomotives. He was also president of the Institution of Mechanical Engineers and of the Institution of Civil Engineers.

Biography

Aspinall was born on 25 August 1851 in Liverpool to a Roman Catholic judge. He attended the Roman Catholic boarding school of Beaumont College, Berkshire before being apprenticed to engineers John Ramsbottom and Francis Webb of the London and North Western Railway in 1868. and introduced a form of vacuum braking to his locomotives which was soon adopted by several other lines, including the London and North Western and Great Northern Railways.

He became the Chief Mechanical Engineer of the Lancashire and Yorkshire Railway in 1886. Continuing the work of his predecessor, William Barton Wright, he modernised the locomotive stock and continued Barton Wright's philosophy of standardisation, bringing in several of his own design. He served as president of the Institution of Civil Engineers between November 1918 and November 1919. Aspinall also conducted the inquiry into the Sevenoaks railway accident. He was the first recipient of the Institution of Mechanical Engineers' James Watt International Medal, receiving it in 1937.

He died on 19 January 1937.

He wrote seven academic papers and was the holder of fourteen patents.