Danny, it was an indeed a Mk IX in those photos.
Here's what I've been able to unearth about those times:
During the war, the Heneger and Constable brewery donated free beer to the troops. After D-Day, supplying the invasion troops in Normandy with vital supplies was already a challenge. Obviously, there was no room in the logistics chain for such luxuries as beer or other types of refreshments. Some men, often called sourcers, were able to get wine or other niceties from the land or rather from the locals.
RAF Spitfire Mk IX pilots came up with an even better idea.....
It was discovered that the Mk IX’s under wing bomb pylons could be modified to carry beer kegs. According to pictures that can be found, various sizes of kegs were used. Whether the kegs could be jettisoned in case of emergency is unknown. If the Spitfire flew high enough, the cold air at altitude would even refresh the beer, making it ready for consumption upon arrival.
A variation of this was a long range fuel tank modified to carry beer instead of fuel. The modification even received the official designation Mod. XXX. Propaganda services were quick to pick up on this, which probably explains the official designation.
As a result, Spitfires equipped with Mod. XXX keg-carrying pylons were often sent back to England for maintenance or liaison duties. They would then return to Normandy with full beer kegs fitted under the wings.
Typically, the Ministry of Revenue and Excise stepped in, notifying the brewery that they were in violation of the law by exporting beer without paying the relevant taxes. It seems that Mod. XXX was terminated then, but various squadrons found different ways to refurbish their stocks. Most often, this was done with the unofficial approval of higher echelons!
Roughly 40 years later, Luftwaffe F-4 aircrew evolved a similar method for resupplying their Tornado mates at Cottesmore with German beer and schnapps. This involved an F-4 with a highly modified 4000 lb centreline tank....
