I came across these photos of an early prototype 3.7" Vickers A.A. gun whilst researching 76th HAA Regt. These are Vickers' factory photos, probably originating from 1935. Whilst not good reproductions, I thought they might be of interest, particularly as it shows the gun and detachment (assumed to be factory employees in this case) from different angles. In the decade after World War I there was little significant development of anti-aircraft guns, this being restricted principally to the modification of some of the original 3” calibre guns brought into service during WW1, modification being principally to provide mobility through the fitting of trailer mountings. Guns at T.A. units in the inter war years, however, remained as static or semi mobile mountings of World War I vintage - it is interesting to read of accounts of T.A soldiers using these for drill, as late as 1938/9: "T.A. parades were on Tuesday evenings, with periodic obligatory week-end “camps” at H.Q. Evening parades, I recall, were from 19.00hrs to 21.00hrs, consisting of a variety of activities, including rifle drill, dismounted cavalry drill, lectures on guns and ammunition, and, treat of all treats, gun drill on a sadly worn World War I 3” A.A. gun. This had its amusing side, since it was supposed to be mobile, and there were hilarious sessions of taking the gun “out of action” on its wheels." It was not until the early 1930’s that the need to replace the 3” guns with a device more capable of dealing with higher and faster flying aircraft than those of WW1 vintage was recognised, together with the need for this to be mobile. A specification was developed and issued by the Director of Artillery, a new 3.7” QF (quick firing - meaning round and charge were combined) gun being prototyped from this by Vickers in 1934, and subsequently, after modification, going into initial manufacture in 1936. By 1937 the new 3.7” Vickers H.A.A. gun had completed the necessary trials and production been instructed, but the first deliveries did not commence until 1938, and then only in small quantities. By September 1938 just 480 guns had been delivered compared with a requirement for 1,260, a number that was to be subsequently increased. To meet the shortfall 450 existing First World War 3” guns were brought into service, approximately 200 of these having previously been modernised.