In 1926, the Cordoba Central Railway in Argentina received 15 4-6-4T tank locomotives from the North British Locomotive Company. They had been designed by the railway's chief mechanical engineer Lightly Simpson and were used for mixed traffic. Being meter-gauge and having driving wheels of 4 ft 6 in and a great length, they looked very sleek. With a rigid wheelbase of only ten feet at a total wheelbase of 33 ft 7 in, they most likely had good running characteristics in tight curves. In 1939, the whole railway became part of the Argentine State Railway. In 1942 and 1943, they were rebuilt to 4-6-2 tender locomotives in the railway's Alta Cordoba shops to increase their supplies. 