Data from Charles Rous-Martens, "British Locomotives for Abroad", Page's Magazine, Volume III, No 2 (August 1903), p. 117; and "Anglo-Chilian [sic] Nitrate & Railway Type 4-8-4", Locomotives Constructed by Kitson & Co. Limited (Leeds, UK: n.d). Works numbers were 4108-4109 in 1902.
One of the first rigid-wheelbase locomotives with eight axles (four adhesion, four truck), this locomotive clearly aimed at spreading the weight over a lot of bearing points.Their rigid wheelbase measured 6 feet 8 inches (2.03 m) and they were rated to pull a gross load of 85 long tuns up a 4% grade.
Data from "Heavy Tank Locomotives, Nitrate Rys", Locomotive Magazine, Volume XXX [30], Whole No. 383 (15 July 1924), p.199. Works numbers were 1941-1946 in 1924.
This powerful design was meant for 1 in 25 (4%) grades and relatively tight curves of 280 ft radius. Its "over-square" cylinders received its superheated steam through 11" (279 mm) piston valves. As 4-8-4 tank locomotives went, this engine fell in the middle as far as weight was concerned. Its drivers, almost the smallest possible, certainly served requirements in the Andes.
| Principal Dimensions by Steve Llanso of Middle Run Media | ||
|---|---|---|
| Class | 18 | Class 97 |
| Locobase ID | 13597 | 20844 |
| Railroad | Anglo-Chilean Nitrate (Tocopilla al Toco Ry) | Anglo-Chilean Nitrate (Tocopilla al Toco Ry) |
| Country | Chile | Chile |
| Whyte | 4-8-4T | 4-8-4T |
| Number in Class | 2 | 6 |
| Road Numbers | 18-19 | 97-102/101-106 |
| Gauge | 3'6" | Std |
| Number Built | 2 | 6 |
| Builder | Kitson & Co | Yorkshire Engine |
| Year | 1902 | 1924 |
| Valve Gear | Stephenson | Walschaert |
| Locomotive Length and Weight | ||
| Driver Wheelbase (ft / m) | 8 / 2.44 | 12 / 3.66 |
| Engine Wheelbase (ft / m) | 28 / 8.53 | |
| Ratio of driving wheelbase to overall engine wheelbase | 0.29 | |
| Overall Wheelbase (engine & tender) (ft / m) | 28 / 8.53 | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | ||
| Weight on Drivers (lbs / kg) | 73,920 / 33,530 | |
| Engine Weight (lbs / kg) | 115,360 / 52,326 | 250,880 / 113,797 |
| Tender Loaded Weight (lbs / kg) | ||
| Total Engine and Tender Weight (lbs / kg) | ||
| Tender Water Capacity (gals / ML) | 2485 / 6.82 | 4080 / 15.45 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 2.20 / 2.50 | 1200 / 1090.90 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 31 / 15.50 | |
| Geometry Relating to Tractive Effort | ||
| Driver Diameter (in / mm) | 38.50 / 978 | 42 / 1067 |
| Boiler Pressure (psi / kPa) | 160 / 1100 | 180 / 1240 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 17" x 21" / 432x533 | 22" x 20" / 559x508 |
| Tractive Effort (lbs / kg) | 21,439 / 9724.58 | 35,263 / 15995.05 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.45 | |
| Heating Ability | ||
| Tubes (number - dia) (in / mm) | 154 - 2" / 51 | |
| Flues (number - dia) (in / mm) | 22 - 5.375" / 137 | |
| Flue/Tube length (ft / m) | 15.96 / 4.86 | |
| Firebox Area (sq ft / m2) | 93.15 / 8.65 | 164 / 15.24 |
| Grate Area (sq ft / m2) | 16 / 1.49 | 39.75 / 3.69 |
| Evaporative Heating Surface (sq ft / m2) | 970 / 90.12 | 1945 / 180.70 |
| Superheating Surface (sq ft / m2) | 362 / 33.63 | |
| Combined Heating Surface (sq ft / m2) | 970 / 90.12 | 2307 / 214.33 |
| Evaporative Heating Surface/Cylinder Volume | 175.82 | 221.04 |
| Computations Relating to Power Output (More Information) | ||
| Robert LeMassena's Power Computation | 2560 | 7155 |
| Same as above plus superheater percentage | 2560 | 8300 |
| Same as above but substitute firebox area for grate area | 14,904 | 34,243 |
| Power L1 | 2672 | 8624 |
| Power MT | 318.76 | |