The first passenger carriages of the Victorian Railways (VR) were fixed-wheel, with a mixture of first- and second-class bodies on either four- or six-wheeled underframes. They were built to the British side-loading, swing-door, cross bench compartment (non-corridor) style; later a saloon style was used to a limited extent, featuring fewer doors per side and perimeter seating - which increased total capacity by allowing more standing passengers.
Initial designs had some common themes: A and B type carriages were for first- and second-class travellers; C indicated third-class initially, though later was re-allocated for flat wagons to transport horse-drawn carriages, and later still for hearse vans (the first three of which had been modified from E class mail vans); D was used for guards' vans, E for mail vans, and F for horse boxes. The first vehicles were built on four-wheeled underframes, with some later designs (mostly first-class) being built on six-wheel underframes. Some cars were built locally, while others were imported. Between 1860 and 1880 the Victorian Railways took-over a number of private railway operators, and their rollingstock was absorbed into the VR fleet, being renumbered to suit. This explains why records show some cars as being built in 1855, even though the Victorian Railways did not start operating until 1858.
At first, fleet numbers of each type of carriage were generally kept consecutive with no regard for differing capacities or axle loads. When a vehicle was scrapped, either a new one would be built with the same number, or another existing car would be renumbered to fill the gap.
Some later cars were built or re-coded with multiple letters, such as AB, AD, BD and ABD. Another category was introduced for older cars which allowed them to be used in restricted service; a superscript H added to the class to indicate Holiday traffic - BH. This H superscript was initially just a clerical note next to the code, although it later became an official part of the code. Initially only second-class carriages were marked as such.
When bogie carriages were added to the fleet, they initially were allocated vacant numbers in the appropriate class series, one of the first examples being 70 A. From 1886 the bogie cars were re-coded as AA, BB, or ABAB; it is thought that this was necessary due to mix-ups with carriage capacities. Twenty seven bogie carriages of the American end-loading saloon design had been built for the Victorian Railways between 1874 and 1887 (thereafter, so-called dog box bogie cars were built), along with at least one bogie double-saloon car inherited from the former private suburban railway company (those cars were re-classed about the same time). As bogie carriages displaced their fixed-wheel predecessors, the older cars were reassigned to other duties. In particular, with the majority of bogie carriages being first-class, first-class fixed-wheel vehicles were downgraded to second-class and re-coded as 'B'.
Cars still in service in the 1940s were converted to workmen's sleepers known as WS or W Class; three of the latter were placed on bogie underframes and became WW class.
First-Class Carriages A/X/XH
This group ranged from numbers 1 to 274, although over 100 numbers were recycled at least once. Most of the cars were similar to each other; typically four or five compartments with doors either side and long bench seats across the width of the carriage, allowing for a total of forty or fifty passengers per car; with a curved roof and a four- or six-wheeled underframe.
The cars were built from the 1850s to the 1880s, with a handful built after that and a large number obtained from other railways: 17 A and 18 A came from the Geelong Railway; 117 A to 156 A were ex-English cash 22 to 65, though a handful had already been scrapped; and 105 A as well as the majority of 163 A to 255 A were ex-South Suburban and Hobsons Bay stock.
In the 1910 en-masse renumbering of all passenger stock found the letters A, B and D replaced with X, Y and Z respectively. So the A cars mostly became X class; two, numbers 43 and 44 (ex 54 A and 61 A) were converted to XH on account of their condition, and restricted to occasional traffic only. The resulting post-1910 fleet numbered 1 to 42 X and 45 to 82 X. Cars 1 to 41 had been built as A Class but re-coded to B class previously. In 1913, when the Deniliquin & Moama Railway was taken over, one of their first-class cars was renumbered to 43 A to recycle that number.