He ultimately became chairman, managing director and partner of shipping companies (Glen Line, Alfred Holt & Co), deputy director of sea transport in the UK Ministry of War Transport during the Second World War and was knighted for organising shipping during the Suez crisis in 1956.
McDavid was educated at the Liverpool Institute and started working for Alfred Holt & Company in 1915, where two of his maternal uncles were also employed.
[1] In the First World War, McDavid enlisted when he was 18 in 1916 and was initially in the UK in the Army Reserve and then Liverpool Scottish Battalion.
In 1936 he was transferred to London to join the management of the recently acquired Glen Line with 10 ships that provided similar services but from ports in eastern England.
He developed improved methods for loading and unloading military shipping and had a leading role in planning landings in north Africa, Sicily, Italy and Normandy.
He was a part-time non-executive director of Glen Line until late 1965 as well as a board member of the Ocean Steamship Co. Ltd and a partner in Alfred Holt & Co.
[1] In 1947 he was made an officer of the Order of Orange Nassau by the Netherlands[6] and received the American Medal of Freedom with silver palm.