Arica-La Paz No. 21 to 23

In 1913, the Esslingen machine works built three rack locomotives for the Arica-La Paz in their subsidiary at Sarrono, Italy. Their numbers were 21 to 23 and their names “José Manuel Balmaceda”, “Jermán Riesco” and “Domingo Santa María”. Basically they were built like Mallets, but the leading bogie only had two carrying axles and the rack drive. The rear group of five driving axles was mounted in the frames.

They were only used on the Chilean part of the line, starting at Central station at an altitude of 1,480 metres (4,855 feet) and running to Puquios at an altitude of 3,728 metres (12,230 feet). On this stretch, there was an incline of 43 km that had a gradient of up to six percent. Although it was found out that they did not wear out the tracks much faster than other locomotives, they were withdrawn in 1923.