For the transportation of bulk flour, seven cement wagons of the _X__ class were modified. Two were modified in 1961 and five in 1962.
When modified, the wagon class was altered to FX. Photographs of the vehicles under test show them painted silver. The wagons X 1 - 7 were reclassed to FX 1 - 7, wagons keeping their old numbers.
Of interest, these seven wagons were originally built in the late 1940's as _CK_ wagons for pulverised brown coal transport for locomotive trials.
As the last letter 'X' was no longer suitable in 1962 on account of the bogie exchange markings, the wagons were recoded to FJ in 1963 with the old numbers retained.
With FJ 1 - 7 in service, some more wagons were modifed for the traffic. Two wagons done in 1964, one wagon on 1965 and two more in 1967. This made twelve FJ wagons, numbers 1 - 12. These later wagons were converted from _J__ cement wagons ( late X coding ).
FJ 8 ex J 45, FJ 9 ex J 47, converted 1964. FJ 10 ex J 46 converted 1965. FJ 11 ex J 41 and FJ 12 ex J 42 converted 1967.
In 1971/1972, ten FJ wagons were converted back to cement 'J' wagons, in the process receiving their old numbers. These conversions may have been due to the introduction of bogie bulk flour transports coded _FX_.
The last two FJ wagons in service were numbers 8 and 9. They were out of service by the 1990's and were noted in storage 1992.
In the late 1970's, several flour containers were introduced to service. It seemed these containers would remove the FJ's from service, but they did not appear to be successful.