Ernest Frederic Crosbie Trench CBE, TD was a British civil engineer.
Ernest was born on 6 August 1869 to George Frederic Trench and Frances Charlotte Talbot Crosbie.
He was educated at Monkton Combe School and at Lausanne before studying for a Master of Arts degree from Trinity College, Dublin.
Anne of York, Duchess of Exeter, sister to Edward IV and Richard III was an ancestor of Ernest's mother. He worked primarily as a railway engineer and in 1923 he was appointed as the chief engineer of the London, Midland and Scottish Railway, retiring on 1 April 1930. He became involved in the Institution of Civil Engineers as an associate member in 1897, progressing to a full membership in 1904, he was first elected to the council in 1915 and would serve on it for the next seventeen years.
He was elected vice president of the institution in 1924 and served as its president from 1927-1928. In 1920 he was appointed a Commander of the Order of the British Empire for "services rendered in connexion with 1914-18 war" and in 1931 received the Territorial Decoration for service as a volunteer Colonel in the Engineer and Railway Staff Corps. He died in Marlborough, Wiltshire on 15 September 1960.