Up until the mid-nineteenth century much of London’s milk was supplied by cows kept in cramped urban locations. This proved unhygienic and as a result of a cattle plague this practise diminished after 1865. Around about this time the milk started to be transported into London by rail on frequent express trains.
By the 1930s the volume of milk being transported had grown to a high enough volume that it was no longer deemed efficient to transport using traditional goods vehicles. A as a result United Dairies ordered a series of tank wagons, with six-wheeled tankers proving to be the most effective design although four-wheeled wagons were also used. United Dairies ended up operating over three hundred such tank wagons.