After becoming a chief test driver in 1908, he led the RR team in the Austrian Alpine Trial in 1913. During the First World War the company designed its first aero-engine, the Eagle, and Hives developed it successfully; by 1916 he was Head of the Experimental Department. In 1919 the Eagle powered the twin-engined Vickers Vimy bomber on the first direct flight across the Atlantic. Other notable engines were later developed under Hives’ lead. Of these the Buzzard was the most important, leading to the ‘R’ series, which powered the Supermarine S.6 seaplanes that won the Schneider Trophy in 1929 and 1931 for Rolls-Royce, and most importantly the famous Merlin engine. In 1936 he became the general works manager of the factory and a year later was elected to the board. He lived at 37, St. Chads Rd., Derby until around 1937, then at 'Hazeldene', Duffield. In 1937, thinking war would soon be inevitable, he prepared the firm for a massive production increase in Merlin engines by splitting facilities between engineering and production. As the Merlin powered Hurricanes and Spitfires, this was a decision of vital strategic significance when war did come. It was thanks to Hives that a total of a hundred and sixty thousand Merlins were produced by 1945. In 1941 Hives quickly decided ‘to go all out for the gas turbine’, ensuring the company’s leading role in developing jet engines for civil and military aviation. Vice Chief of Air Staff Sir Wilfrid Freeman, one of the masterminds behind the dramatic advances in British aircraft production before and during World War 2, paid tribute to Hives's dedication in a letter to his wife: Hives became managing director in 1946 and chairman of Rolls-Royce from 1950 till 1957. He was appointed to the Order of the Companions of Honour in the 1943 Birthday Honours and on 7 July 1950 he was raised to the peerage as Baron Hives, of Duffield in the County of Derby. He played a critical role in the UK Nuclear Submarine programme. When the highly irascible but utterly pivotal Admiral Rickover visited the UK in 1957 to inspect the British nuclear design team at Rolls Royce, Rickover was “at his obnoxious worst”. After one particularly difficult morning he was introduced to Lord Hives. His son, Pilot Officer Edward Ernest Hives, was killed in action flying with RAF Coastal Command in October 1940. He retired in 1957 and died in April 1965, aged 79. He was succeeded in the barony by his son John. His younger daughter, Philippa Hives, married Judge Alexander Morrison in 1978.
