For the Melbourne - Adelaide service, two Joint Stock mail sorting vans were built.
EES 1 was built in 1907 and EES 2 built and entered service in 1908.
Also in 1908, the Joint Stock van _O__ 17 was altered to EES 3.
In the 1910 recoding, the vans were relettered to DS, retaining the same numbers.
In 1922/1923 the class was modified and relettered to other classes.
In 1922, DS 3 was placed in Way & Works service as _WW_ 4.
During March 1923, DS 1 and DS 2 had the mailing sorting equipment removed. They became _D__ 3 and 4 respectively.