Men of an RAF barrage balloon unit spend their free time planting vegetables.
Full title reads: "Sausage and Veg".
VS of RAF (Royal Air Force) men digging up vegetables and tending the plants on allotments they have made on the edge of their balloon base.
VS As the alarm sounds the men running from the allotment and manning and raising the barrage balloon.
N.B. The Sausage of the title is obviously the Barrage Balloon.