Anglo-Chilean Nitrate Beyer-Garratt Locomotives in Chile

Class 8 (Locobase 3623)

Data from Lionel Wiener, Articulated Locomotives (1930, reprinted by Kalmbach, 1970). See also "Articulated Tank Locomotive, Nitrate Railways", Locomotive Magazine, Volume XVIII [18] (14 September 1912), p. 185. For a history of the ACN&R's FCTT, see Robert Stirling, "The Tocapilla Railway" (Paper 3198), Minutes of proceedings of the Institution of Civil Engineers, Volume 142 (3 April 1900) pp. 89-102 with discussion of Economical Railway Construction (pp. 103-119).

So important to the world economy were the nitrate deposits in Chile and Bolivia that several railroads scaled the mountains lining the Chilean coast to haul the chemicals out. Many of them used Kitson-Meyer locomotives, most on narrow-gauge lines. The present set, however, rode on the standard-gauge railway that started out from Iquique and Pisagua, nearly at sea level, and rose to Montevideo (3,809 ft) and Nevel (3,612 ft), respectively, over lines with 4.47% grades and curve radii of 300 ft.

Stirling pointed to another operational demand. The FCTT had no fresh water sources anywhere along its route, even from the brackish Rio Loa. So the ACN&R built two desalination plants at the Loa river, the other in the port of Tocopilla. They used vacuum distillation and were able to make 90t per day of fresh water each. A watering station at km16 (alt 660m) was supplied from Tocopilla, requiring 62 bar (900 psi) at the pump. Water from the Loa plant was pumped to a 180t reservoir tank at the summit and two smaller intermediate tanks.[4]

These Yorkies used the Fairlie layout of back-to-back boilers joined by a single firebox. They handled 202 tons up a 19 1/4 mile hill at 8.5 mph (13.7 km/h) without needing to replenish either fuel or water.

Wiener notes that they had 27-element feedwater heaters fitted in the rear water tanks. These heaters received exhaust steam from the rear cylinders, which passed through the 40"-diameter elements.

Class unknown (Locobase 20525)

Data from "Articulated and Duplex Locomotives", Railway Engineer, Volume 32, No 3 (March 1911), p. 76.

This Belgian-built locomotive naturally had Egide Walschaert's valve gear and Alfred Belpaire's firebox. It is not an articulated locomotive, but a twin tank. That is, the two locomotives are coupled back to back, but they don't share any major components like frames or fireboxes. A single engineer could operate both locomotives with a special linkage. No word in the article concerns stoking duties, but given the high operating altitude, Locobase suspects that two firemen would have been required.

Each locomotive's heating surface areas were 102.85 sq m (1,107 sq ft) evaporative, 9.5 sq m (102.26 sq ft) firebox, 21.8 sq m (235 sq ft) superheater, and 2.3 sq m (24.76 sq ft) grate area. Locobase doubled all four values to arrive at the figures in the specs.

But so far Locobase is unable to supply additional information. It is likely, however, that the twins were separated not long after the engine's introduction.