Jon Davis of [] says that these were the very first Mallets built by Baldwin. See also DeGolyer, Volume 27, p. 137. Works numbers were 24827-24829 in November 1904 and 24947 in January 1905.
Tom Farin's [] has the builder's card for this class and all the data comes from that source. He says three were delivered. The photograph shows a Radley & Hunter cabbage stack, outside radial valve and Belpaire screw-type regulator.
The class operated on the ARR for several decades.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 35 |
| Locobase ID | 4761 |
| Railroad | American (Porto Rico) |
| Country | USA-Puerto Rico |
| Whyte | 0-6-6-0 |
| Number in Class | 4 |
| Road Numbers | 35-38 |
| Gauge | metre |
| Number Built | 4 |
| Builder | Burnham, Williams & Co |
| Year | 1904 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 27.34 / 8.33 |
| Engine Wheelbase (ft / m) | 20.33 / 6.20 |
| Ratio of driving wheelbase to overall engine wheelbase | 1.34 |
| Overall Wheelbase (engine & tender) (ft / m) | 42.67 / 13.01 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 106,650 / 48,376 |
| Engine Weight (lbs / kg) | 106,650 / 48,376 |
| Tender Loaded Weight (lbs / kg) | 49,350 / 22,385 |
| Total Engine and Tender Weight (lbs / kg) | 156,000 / 70,761 |
| Tender Water Capacity (gals / ML) | 2200 / 8.33 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 4.50 / 4 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 30 / 15 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 37 / 940 |
| Boiler Pressure (psi / kPa) | 200 / 1380 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 12.5" x 20" / 318x508 |
| Low Pressure Cylinders (dia x stroke) (in / mm) | 19" x 20" / 483x508 |
| Tractive Effort (lbs / kg) | 20,042 / 9090.91 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 5.32 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 155 - 2" / 51 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 15.50 / 4.72 |
| Firebox Area (sq ft / m2) | 106 / 9.85 |
| Grate Area (sq ft / m2) | 18 / 1.67 |
| Evaporative Heating Surface (sq ft / m2) | 1357 / 126.12 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1357 / 126.12 |
| Evaporative Heating Surface/Cylinder Volume | 478.35 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 3600 |
| Same as above plus superheater percentage | 3600 |
| Same as above but substitute firebox area for grate area | 21,200 |
| Power L1 | 3546 |
| Power MT | 439.81 |