The "(T)" in his rank signifies that he is a Gunner (Torpedos). According to some very quick and incomplete searching, Mr. Haycraft's seniority as a "Gunner" dates from 1913 (according to a Navy List of 1918) and that he had served in
Teazer from June 1917.
His Royal Humane Society
Bronze Medal dates from 1914
Apparently he was promoted from Gunner (T) to Commissioned Gunner (T) in 1941
https://www.thegazette.co.uk/London/...5203/page/3677