Manila Railroad 4-8-2 Locomotives in Philippines


Class Details by Steve Llanso of Sweat House Media

Class 171 (Locobase 9693)

Data from "New Mountain Type and Santa Fe Type Locomotives for the Manila Railroad", Railway and Locomotive Engineering, Vol XXXV, No. 3 (March 1922), pp. 55-56. Works numbers were 62729-62738 in March 1921.

This class of Mountains was built to exactly the same specs as the class 201 Santa Fes shown in Locobase 9694. Only the driver diameter and weight distribution were different. The design featured a healthy amount of superheat, 11"-diameter (279 mm) piston valves. Although they had among the largest cylinders of any non-articulated Cape gauge engines, these designs had relatively small boilers and grates.

According to the 1922 article: "In designing the locomotives the constructing engineers arranged to have as many as possible of the detail parts of the two types of locomotives the same in order to facilitate maintenance and reduce the number of extra parts which would have to be carried by a road situated at so remote a distance from the point of

manufacture. That the designers succeeded to a high degree is evidenced from the fact that the interchangeable parts include the boiler complete with attachments, cylinders complete, except in height, valve motion parts with exception of eccentric cranks; trailing truck; cab; tenders ; cocks and valves ; fittings and brake cylinders. The following parts are also interchangeable except for the modifications required because of the use of lateral motion driving boxes on the forward axle of the 2-10-2 type locomotive; rods, crank pins, driving axles and driving boxes, driving box saddles, shoes and wedges, equalizing arrangement details and spring hangers."

Principal Dimensions by Steve Llanso of Middle Run Media
Class171
Locobase ID9693
RailroadManila Railroad
CountryPhilippines
Whyte4-8-2
Number in Class10
Road Numbers171-180
Gauge3'6"
Number Built10
BuilderAlco-Brooks
Year1921
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.75 / 4.80
Engine Wheelbase (ft / m)34.58 / 10.54
Ratio of driving wheelbase to overall engine wheelbase 0.46
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)119,000 / 53,978
Engine Weight (lbs / kg)183,000 / 83,008
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)5000 / 18.94
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)6 / 6
Minimum weight of rail (calculated) (lb/yd / kg/m)50 / 25
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)60 / 1524
Boiler Pressure (psi / kPa)180 / 1240
High Pressure Cylinders (dia x stroke) (in / mm)20" x 28" / 508x711 (3)
Tractive Effort (lbs / kg)42,840 / 19431.92
Factor of Adhesion (Weight on Drivers/Tractive Effort) 2.78
Heating Ability
Tubes (number - dia) (in / mm)130 - 2" / 51
Flues (number - dia) (in / mm)22 - 5.375" / 137
Flue/Tube length (ft / m)18.50 / 5.64
Firebox Area (sq ft / m2)176 / 16.36
Grate Area (sq ft / m2)35.20 / 3.27
Evaporative Heating Surface (sq ft / m2)1999 / 185.78
Superheating Surface (sq ft / m2)493 / 45.82
Combined Heating Surface (sq ft / m2)2492 / 231.60
Evaporative Heating Surface/Cylinder Volume130.90
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation6336
Same as above plus superheater percentage7603
Same as above but substitute firebox area for grate area38,016
Power L18623
Power MT639.01

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