Baptised in North Queensferry United Free Church on 19 March 1911. His father was a crane driver constructing HM Naval Base, Rosyth and came from Resolis in Ross & Cromarty. At the 1911 census, the family lived at New Buildings, North Queensferry.
Duncan’s father served in the First World War in the Kings Own Scottish Borderers, before being transferred to the Royal Engineers, where his crane driving skills were appreciated
Duncan joined the Merchant Navy in 1928 as a cabin boy in the tanker British Engineer and went on to become a ship’s cook.
He joined the Royal Navy on 27 November 1939. His service number indicates that he apparently joined as a long service regular, cook/seaman specialist, but his service record is stamped “Until the end of the present emergency”.
He was rated as an Able Seaman from the outset and allocated to Rosyth at the Boom Defence Depot, HMS Cochrane 2.
On 5 February 1940 he was transferred to HMS Fortitude, the shore base at Ardrossan.
He returned to HMS Cochrane 2 on 15 March 1940 and the following day was assigned to HMS Rooke, which was the Boom Defence Depot at Rosyth.
In the course of 1940, he married Euphemia Smith Allan in Inverkeithing and they set up home in 70 Malcolm Street, Dunfermline. They had two sons, Ralph, who died in infancy and Allan.
Although still on the books of HMS Rooke, from 15 February 1941 Duncan was detached to serve in HMS Sonnet, a boom defence vessel, reverting to the depot on 13 May 1941.
On 15 June 1941 he was again detached, this time to HMS Star of the Realm, which was a requisitioned trawler, used for boom defence. The vessel deployed at one stage to the Faeroes, but it is unclear if this was during Duncan’s time aboard.
On 29 June 1941 he again returned to HMS Rooke and on 4 July was promoted Acting Petty Office there. Two weeks later, on the 19th he was transferred to HMS Leonian, which was a boom carrier vessel.
He seems to have been briefly in Reykjavik, Iceland.
The following year he was confirmed in rank as a Petty Officer, Cook from 4 July 1942 and on 10 August 1942 was notionally back in HMS Rooke at Rosyth, but actually sick at Mearnskirk until 8 September, when he resumed duty.
Next, on 2 December 1942, he was transferred to HMS Aggressive, the boom defence establishment at Newhaven, East Sussex, but seems to have actually served in HMS Forward, the name given to the tunnels housing the headquarters outside Newhaven.
From 9 April 1943 he returned to HMS Rooke at Rosyth, being assigned for actual duty in HMS Star of the Realm once more from 27 April.
Confusingly he spent part of this period on the ration lists of the boom defence vessel HMS Barfair.
Finally, with effect from 7 May he was assigned to HMS Bishopgate which was a specialised Boom Defence Gate Lifting Vessel and formed an important part of the defences of HM Naval Base, Rosyth against submarines.
Not long before his death he dived into the Forth to rescue a man overboard. He died, after 35 days in Port Edgar RN Hospital, of Miliary (or widely distributed) Tuberculosis.