The CL class is a class of diesel locomotives built by Clyde Engineering, Granville for the Commonwealth Railways in several batches between 1970 and 1972. The class was the last in the world to be built with the Electro-Motive Diesel bulldog nose but differed from previous builds in having a mansard roof. Construction In 1968, Commonwealth Railways placed an order for five 2237 kW locomotives with Clyde Engineering to operate services on the Trans-Australian Railway from Port Pirie to Kalgoorlie. They were mechanically similar to the Western Australian L class of 1967. The initial design was to have a Do-Do wheel arrangement and a USA style EMD FP45 cab. This was later changed to a streamlined carbody and conventional Co-Co wheel arrangement. History The first locomotive was completed in January 1970, with two further orders resulting in 17 locomotives being built with the last delivered in October 1972. Their operating sphere was extended through to Perth on Indian Pacific services and for a time in the 1970s they operated through to Lithgow, New South Wales. In July 1975, all were included in the transfer of Commonwealth Railways to Australian National. The CLs began to operate to Alice Springs and Adelaide when these were converted to standard gauge in 1980 and 1983. In 2004, they began to operate to Darwin following this line opening. Remanufacturing In August 1992, Australian National awarded Morrison Knudsen Australia a contract to remanufacture the CLs at its Whyalla factory. As part of the deal, Morrison Knudsen purchased the locomotives and leased them back to Australian National for 12 years. Seven were rebuilt as CLFs to operate freight services and ten as CLPs with head end power to operate the Indian Pacific, Ghan, and Overland passenger services. The rebuilding involved stripping back to the frame, with everything except for the nose section and monocoque frame removed. Changes included the EMD 645E3 engines being replaced with overhauled EMD 645E3C engines imported from Morrison Knudsen in the US, the original main alternators were rebuilt from AR10/A4-D14 to the AR10/A9-D14 type, refurbished D78 traction motors replaced the originals along with a new gear ratio, and new MK-LOC microprocessor controls were fitted. The cab was upgraded to modern standards, the brake setup was also changed from twin to single shoe per wheel, and a number of other small changes were made to assist maintenance. After rebuilding, the locomotives did not retain