In 1900 all of the W.A.G.R.'s 4 wheeled cattle trucks were grouped together as class B. A batch of 10 wagons on the 1902 15'-0" steel underframe were also put into class B (despite being nothing like earlier wagons) as were their wooden framed successors.

However, a classification problem arose in 1903 when new horseboxes were constructed as all of the other two letter "A" codes were used by carriages and so there was no space in the list available for them. This was resolved by putting all of the later horseboxes into the "B" group rather than class A. The W.A.G.R.'s later horseboxes were the six BA class bogie horseboxes of 1903 and the eleven BB class large 4 wheel horseboxes built from 1907.

The agricultural bank managers vans were given class BC (1926, 185 and 186) in 1907 when the last pair were built. The original van was not given a class letter in 1900.

The new larger cattle trucks of 1919 were initially put into class B but were soon reclassified BD. These vehicles became the standard for the next 30 years or so. Class BS appeared during the late thirties as surplus horseboxes were rebuilt as cattle wagons. In the post-war renewal program a new 4-wheeled cattle truck was included as class BE. This was the final design introduced into service and most of the older B, BS and BD class wagons were withdrawn from service as a result.

In 1964, when the W.A.G.R. took over the M.R.W.A., it acquired their cattle trucks. The only ones renumbered for retention were the CB class which became part of class BD despite being steel framed vehicles.

Bogie cattle trucks can be found in Classes T, TA, and TAD.