The VWAA wagons were recoded from _QB_ in the 1979 recoding.
These well wagons were originally built for specail loading and the transportation of steam engine boilers. As locomotives increaded in size during the early 1900's, existing wagons were unable to cope with the larger boilers.
In the mid 1970's the vehicles were modified with container anchor brackets. The author has a photo of one of these vehicles loaded with a 20' ISO container. VWAA numbers were 1 to 12.