The Denison smock was a coverall jacket issued to Special Operations Executive (SOE) agents, the Parachute Regiment, the Glider Pilot Regiment, Air Landing Regiments, air observation post squadrons, Commando units, and other Commonwealth airborne units, to wear over their Battle Dress uniform during the Second World War, remaining in service with the British Army until the early 1970s when it was replaced by a version in the Disruptive Pattern Material (DPM) smock.
The smock replaced an expedient first issue khaki-drill paratroop jump-jacket that had been directly copied in 1940 from the German parachutist's Knochensack ("bone sack").
[1] This first "smock" was designed to be stepped into and pulled up over the body like a set of overalls which had had the legs removed from mid-thigh.
The Denison was a popular garment among officers who could acquire them—Company Sergeant Major CC Martin, DCM, MM of The Queen's Own Rifles of Canada mentioned in his memoir Battle Diary that senior officers and sergeant majors of his battalion wore the Denison universally.
A "beaver tail" fastened beneath the crotch from the back to the front of the smock – which kept it from riding up during a parachute descent.
In the early smocks the colours were meant to be impermanent and wash out, leaving the garment looking like a typical French artisan or labourer's chemise, and thus, hopefully, aiding the wearer's Escape and Evasion chances.
As the newly formed Airborne Forces expanded, so the need for smocks grew, meaning that they were by now screen printed for easier production.
This sleeveless smock had a long external zip (often removed and used to make the half-zip Denisons full zip), a monkey tail that press studded to the outside front of the oversmock and two elasticated open pockets on the lower front which were to hold grenades for use whilst in the air or immediately upon landing.
By the time of the D-Day airdrops, some officers had had their jackets modified with a full-length zip by their personal tailors, since this was not available on the issue item.
This Parachutist's Oversmock also featured a tail flap and its sole intention was to prevent the paratroopers equipment from snagging while emplaned or during a jump.
It remained standard combat dress for the Royal Marines and the Parachute Regiment until the mid-1970s (see below), and changed little from the wartime issue.
A full-length brass zip had become standard with no cloth flap to cover it and the knitted cuffs deleted on the 2nd Pattern smock were reintroduced.
The '59 Pattern retained the full length zip and knitted wool cuffs, but the flannel lining of the collar was changed from khaki to light green.
The pattern became less random, more defined, with broad, vertical brush-strokes, and greater contrast between the base light khaki and the overprinted tones.
"Although a status symbol in the British Army, the Denison," wrote ex-SAS officer, Barry Gregory, "was windproof but not waterproof and stank after use like a coal-miner's sweat shirt.
The new DPM replacement was not constructed of the Denison's heavyweight twill, but was instead made from the same cotton material as the '68-Pattern combat jacket.
However, it was cut like the Denison smock, with smaller Newey press-stud (snap) fastened (but now bellowed) pockets, a full-length zip without buttons down the front, the traditional olive green knitted wool cuffs, and a 'crotch flap' on the outside of the back.
The Denison smock was also utilized by most of the soldiers in the French army's 8e Bataillon de Parachutistes de Choc (8e BPC) in Indochina, including while the unit was at Dien Bien Phu; the majority of the smocks worn were in their original configuration, but modifications (particularly to the front and neck openings) were often made by local tailors or unit riggers.