Tasmanian Government Railways X class Tags: Locomotive.The X class was a class of diesel locomotives built by English Electric for the Tasmanian Government Railways between 1950 and 1952. They were the first class of diesel locomotive to enter mainline service on a Government-owned railway in Australia. thumbnail active years start year 1950-01-01T00:00:00+02:00 builder English Electric cylinder count 6 number built 32 top speed (kmh) 88.0 Learn more... Loading...