To provide a MotoRail service on the "Overland" between Melbourne and Adelaide, an ALX_ wagon was fitted with test 'aligned' bogies.
ALX 46 was used for the trials and was recoded to ALF 46. The trials lasted about a fortnight during 1978.
Two wagons were used in the Motorail service on the 'Overland' train between Melbourne and Adelaide.
ALF 46 was subsequently recoded to ALP 46. ALX 58 was fitted with high speed bogies as well and recoded ALP 58.
In the 1979 recoding the ALP class was altered to VMPY.