Trasandino Chileno 2-6-2 Locomotives in Chile

Class Details by Steve Llanso of Sweat House Media

Class 4 (Locobase 20295)

Data from P C Dewhurst, "Locomotive Practice of the Chilian Transandine [sic]", Locomotive Magazine, Volume 20 (15 June 1914), pp. 161-169 (data on p. 169).

Locobase 20294 describes both the origins and character of the Trasandino (Chilean Transandean to its English owners) and the two all-adhesion tank locomotives that arrived in 1889. As that entry notes, this short connector on the Valparaiso-Buenos Aires main line laid several segments of rack when grades were too steep to allow the usually sufficient steel-steel adhesion of wheel and rail to grip.

After purchasing a single Shay from Lima Locomotive Works (works number 925), the railway turned to the well-known German builder for these two "rack and adhesion" locomotives. All the dimensions grew considerably, but the Belpaire firebox and boiler were apparently too small; see Locobase 20296 for an enlarged stablemate.

The specs show the cylinders used to turn the drivers on the less-steep sections. The rack drive, said Dewhurst, "is slung between the first and second coupled axles, and has two sets of rack pinions".A separate set of cylinders located under the smokebox were of identical diameter but a 450 mm (17.75 in) stroke drove the pinions.

Reversing the motion when descending these rack sections meant the cylinders acted as "dynamic" brakes (decades before diesels adopted them). Clean air came into the cylinders via a bypass below the blast pipe and repression valves allowed the compressed air to escape. One can imagine the heat this procedure generated and Borsig supplied an injector to squirt cooling water into the valve chests.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID20295
RailroadTrasandino Chileno
Number in Class2
Road Numbers4-5
Number Built2
Valve GearJoy
Locomotive Length and Weight
Driver Wheelbase (ft / m) 9.84 / 3
Engine Wheelbase (ft / m)21.98 / 6.70
Ratio of driving wheelbase to overall engine wheelbase 0.45
Overall Wheelbase (engine & tender) (ft / m)21.98 / 6.70
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)76,170 / 34,550
Engine Weight (lbs / kg)107,519 / 48,770
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)107,519 / 48,770
Tender Water Capacity (gals / ML)541 / 2.05
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 1.10 / 1
Minimum weight of rail (calculated) (lb/yd / kg/m)
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)35.40 / 900
Boiler Pressure (psi / kPa)217.60 / 15
High Pressure Cylinders (dia x stroke) (in / mm)15.35" x 19.69" / 390x500
Tractive Effort (lbs / kg)24,240 / 10995.09
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.14
Heating Ability
Tubes (number - dia) (in / mm)204 - 1.811" / 46
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 9.84 / 3
Firebox Area (sq ft / m2)75.89 / 7.05
Grate Area (sq ft / m2)19.05 / 1.77
Evaporative Heating Surface (sq ft / m2)1020 / 94.75
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1020 / 94.75
Evaporative Heating Surface/Cylinder Volume241.86
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation4145
Same as above plus superheater percentage4145
Same as above but substitute firebox area for grate area16,514
Power L14260
Power MT

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