National Railways of Patagonia 2-8-2 Locomotives in Argentina

Class Clase 75B (Locobase 5879)

Data provided by [] (confirmed 11 July 2004) and latrochita.org.ar/TrochiIngles/locmotoras.htm (8 Feb 2004). See also DeGolyer, Vol 72, pp. 179+, Railways of the Far South website and its coverage of the 1922 locomotives (expecially [], which presents Enrique S Perez's 1925 report on the railway and [], both last accessed 1 December 2014.) Works numbers were 55429-55453 in May 1922.

Both Henschel (Locobase 5880)and Baldwin were awarded contracts for narrow-gauge Mikes to operate on the Patagonian network. Baldwin's production of the entire batch was completed within the 40 days required for the first one under the contract. Total contract price was 101,000 English pounds. The entire class arrived in Bueno Aires aboard the INDIAN PRINCE, where six were transhipped to San Antonio and the others unloaded at Puerto Madryn.

The Baldwins proved most suitable for the 35-lb (17.5 kg/metre) rail and operated for years over the network's 150 miles (242 km). To allow for flexibility around the tight curves, the center two drivers on each side were unflanged and had a wider tread. In addition, the other axles had oversized bushings to allow for lateral play. In addition, Baldwin used an outside frame.The lines included Puerto Madryin to Trelew (later extended to Alto de las Plumas and Rawson), Esquel to Ingeniero Jacobacci, Lorenzo Vintter to Conesa, and Comodoro Rivadavia to Rada Tilly. The LV to Conesa line included the Ingenio San Lorenzo sugar refinery.

A few were superheated later in their careers; see Locobase 4943.

Class Clase 75B - superheated (Locobase 4943)

Data provided by members.madasafish.com/~mcoombs/6bthe1922locos.html and latrochita.org.ar/TrochiIngles/locmotoras.htm (8 Feb 2004).

Locobase 5880 describes the twenty-five locomotives that were delivered in 1922 with saturated boilers.

NB: Tube length is an estimate based on the calculation of tube surface area by subtracting reported firebox heating surface from reported total evaporative heating surface

Class unknown (Locobase 5880)

Data provided by Railways of the Far South website and its coverage of the 1922 locomotives (expecially [], which presents Enrique S Perez's 1925 report on the railway and []), both last accessed 1 December 2014, and latrochita.org.ar/TrochiIngles/locmotoras.htm (8 Feb 2004). Henschel works numbers 19402-19451.

Locobase 4943 gives the details of La Trochita's program for locomotive purchases in 1922. This entry gives the data for the Henschel saturated-steam batch. Compared to the two Baldwins, the Henschels had a larger grate with more firebox heating surface. In addition, the Henschel had a larger boiler than that of the saturated-steam Baldwins (Locobase 5879) and its backbone was an inside frame. The latrochita.org.ar site says the cylinder diameter was "300 to 315 mm", from which Locobase takes the higher value. Also, the adhesion weight is that of the Baldwin design because the total engine weight is so close.

NB: Tube length is an estimate based on the calculation of tube surface area by subtracting reported firebox heating surface from reported total evaporative heating surface