They were the most powerful goods locomotive on the VR, aside from the single H class, H220, which was confined to the North East line, until the advent of diesel-electric traction, and operated over the key Bendigo, Wodonga, and Gippsland mainlines.

This improved on some key shortcomings of the C class which were regarded as poor steaming and featured a very long 9 ft 7 in (2,921 mm) manually stoked firebox that was difficult to fire and prone to clinkering.

[3] The booster allowed an additional 9,000 lbf (40 kN) tractive effort at starting and low speeds to increase the hauling power of the locomotive, particularly on heavy grades.

[12] As with the C class, it was also occasionally pressed into mainline passenger service on key intercity routes, particularly during Christmas and Easter peak times.

[4] The X class, in common with all broad gauge VR steam locomotives built from 1907 onwards, underwent design modifications to the smokebox draughting and blastpipe dimensions referred to as 'Modified Front End', as well as other improvements such as the fitting of smoke deflectors, Automatic Staff Exchange apparatus and cross-compound air compressors.

With the grate automatically stoked via a tender-mounted conveyor screw and blower motor, it was now possible to harness the full steam-raising potential of the locomotive's boiler without the stamina of the fireman being a limiting factor.

Comparative performance tests with black coal-fired X30 revealed that X32 was able to generate a drawbar horsepower output of 1,440 hp (1,074 kW) at 30 miles per hour (48 km/h), exceeding by 5 to 10% that which could be produced by X30 with good quality Maitland or Lithgow coals.

[18] As early as July 1951 the Victorian Minister for Transport announced that the remaining 28 X class locomotives were to be converted to PBC operation.

[20] This, coupled with the demonstrated efficiency and economical operation of B class mainline diesel-electric locomotives introduced in 1952, made the high cost of installing storage and transport facilities for PBC uneconomic.

[25] By the end of the year X29 was already largely cut up, and VR employees sympathetic to preservation efforts had moved X36 to the back of the scrapping row to buy it time as negotiations continued over its future.

However, the locomotive was saved when the office of the VR Chief Mechanical Engineer intervened at the eleventh hour and deferred the scrapping.

The Railway Museum opened to the public on 10 November 1962 and X36, withdrawn after 741,609 miles (1,193,504 km) of service,[14] is today preserved alongside dozens of other former VR locomotives and rolling stock.