Data from Baldwin Locomotive Works, DeGolyer, Volume 30, p. 249; and Walter Camp, "Recent Baldwin Locomotives for Foreign Shipment", Railway and Engineering Review, Volume XLVII [47], No 39 (28 September 1907), p. 846 Works numbers were 31123-31124, 31142-31143 in June 1907. (Note: Several roster compilations show the 91-92s as 2-6-0 tender engines. But the original Baldwin specs and the 1907 R&ER report show all four as the 0-6-0 tanks in this entry.)
Engine weight as delivered reflects a note in the Baldwin specs to "make engine weigh as much as possible to secure better adhesion, but do not exceed adhesion.limits" In the specs, the limiit was 30 long tons (67,200 lb/30,481 kg). One reason for the request most likely was the 2% grades these engines would face.
Locobase infers from a "Hereafter" note in the specs that the Rio Tinto didn't find earlier engines (including possibly the 1901 0-8-0s from Baldwin) entirely to their liking Letters from the company and received in April and May 1907 the singled out issues from those earlier engines to be applied to these. In particular, a notation recommended : "Note copy of letter dated 5/18/06 from L H Fray [Lawford H Fry served as deputy to Baldwin president Samuel Vauclain] about complaints on previous engines, extract herewith.".
One such complaint may be represented in the admonition: "Particular attention to be given to equalizing beam pins, making them of best material thoroughly case hardened of ample bearing surface with suitable provision for oiling."
Coal capacity came to 44 cu ft (8.7 cu m).
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 89 |
| Locobase ID | 21176 |
| Railroad | Rio Tinto |
| Country | Spain |
| Whyte | 0-6-0T |
| Number in Class | 4 |
| Road Numbers | 89-92 |
| Gauge | 3'6" |
| Number Built | 4 |
| Builder | Burnham, Williams & Co |
| Year | 1907 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 10 / 3.05 |
| Engine Wheelbase (ft / m) | 10 / 3.05 |
| Ratio of driving wheelbase to overall engine wheelbase | 1 |
| Overall Wheelbase (engine & tender) (ft / m) | 10 / 3.05 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 67,700 / 30,708 |
| Engine Weight (lbs / kg) | 67,700 / 30,708 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 600 / 2.27 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 38 / 19 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 36 / 914 |
| Boiler Pressure (psi / kPa) | 150 / 1030 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 15" x 22" / 381x559 |
| Tractive Effort (lbs / kg) | 17,531 / 7951.94 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.86 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 146 - 1.75" / 44 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 9.17 / 2.80 |
| Firebox Area (sq ft / m2) | 59.30 / 5.51 |
| Grate Area (sq ft / m2) | 11.30 / 1.05 |
| Evaporative Heating Surface (sq ft / m2) | 666 / 61.87 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 666 / 61.87 |
| Evaporative Heating Surface/Cylinder Volume | 148.01 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1695 |
| Same as above plus superheater percentage | 1695 |
| Same as above but substitute firebox area for grate area | 8895 |
| Power L1 | 1925 |
| Power MT | 188.06 |