With the construction of a new line from Launceston to Bell Bay, Tasmanian Government Railways placed an order for four 1752 kW locomotives with English Electric. However, with the locomotive still under development, it was decided to purchase four 1380 kW locomotives that were an evolution of the Western Australian RA class locomotives with a low nose profile and vacuum brakes. At 96 tons, they were considerably heavier than the previous heaviest locomotives on the network, the Y class at 58 tons, requiring significant upgrades to infrastructure.[1][2]
In March 1978 the Z class were included in the transfer of the Tasmanian Government Railways to Australian National. In 1984-1985 all had their vacuum brakes replaced with air brakes.[3]
In June 1998 all were renumbered as the 2110 class.[4] All four locomotives were modified for driver-only operation between 1998 and 2001, by having their noses lowered further and the size of the front cab windows increased.
All remained in service with TasRail until stored in May 2014 with the entry into service of the new TR class, new drivers having ceased training on these locos 8 months prior.
In 2022, The Q Train acquired Z1&4 for revenue use on their restaurant rail services on the Bellarine Railway. Z1 was delivered in March and Z4 in May.[5] Z3 was also donated and delivered in May to Don River Railway. Z2 would be delivered to the Don River Railway the following year. On 23 January 2024, Z4 was outshopped in AN green and gold, and was later sighted on test runs. This is the first time any member of the class has operated since 2014. The driver-only operation modifications, however, have not been reversed.