The NZR C class consisted of twenty-four steam locomotives built to perform shunting duties on New Zealand's national rail network. It is sometimes known as the big C class to differentiate it from the C class of 1873. History and construction In the late 1920s, trainloads were getting heavier as mainline locomotives became more powerful and increasingly capable of pulling larger loads, but the locomotives assembling and shunting these trains in railway yards were struggling to cope with the weight. Some of the older mainline locomotives that had been displaced by the newer locomotives were modified to perform shunting duties, but this was not an adequate solution. The decision was therefore taken by Chief Mechanical Engineer G. S. Lynde to design a new shunting locomotive and a committee was formed to plan the design features of the new locomotives. The chief designing engineer, R. J. Gard, initially wanted a 0-8-0 tender locomotive. While it was agreed the new locomotive would be a tender engine rather than a tank locomotive as possibly considered, it would also be designed to pull passenger trains as well as work as a heavy shunter. The existing WF class 2-6-4T tank locomotive was to be used as the basis of the new locomotive, which was to be built by NZR at their Hutt Workshops in Wellington and Hillside Workshops in Dunedin. The C class as built were fitted with superheated boilers with wide fireboxes and developed 30% greater tractive effort than the Canterbury J class 2-6-0s and with a light axle loading to give the same amount of running rights as the U class 4-6-0s. The cab was the same as that fitted to the AB class while there were notable elements of American design in the slope-backed tender and a multiple-valve front-end throttle, and also design elements from W. G. Bagnall, whom Gard had worked for prior to joining the NZR in 1926. Twenty-four locomotives were built at Hutt and Hillside, a total of 12 each, starting in October 1930 with C 845 and ending in November 1931 with C 868. Service The C class were placed into service initially in Auckland, Wellington, and Christchurch although some locomotives did spend short periods of time in Dunedin following overhaul at Hillside Workshops or as a short-term allocation following their completion. It was found that while the C class were extremely capable, the locomotives were insufficiently heavy