Data from Soo Miscellaneous Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 26564-26573 in July 1902 and 37598-37602 in May 1905.
Brooks delivered these Atlantics from two orders in three batches - ten in June and December 1902, the last five in May 1905. Like most Atlantics, these engines no longer had a role to play once passenger trains had grown too heavy. They were never superheated and all were out of service by 1940.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | K-20 |
| Locobase ID | 8742 |
| Railroad | Wisconsin Central (Soo) |
| Country | USA |
| Whyte | 4-4-2 |
| Number in Class | 15 |
| Road Numbers | 257-271/2900-2914 |
| Gauge | Std |
| Number Built | 15 |
| Builder | Alco-Brooks |
| Year | 1902 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 7.25 / 2.21 |
| Engine Wheelbase (ft / m) | 28 / 8.53 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.26 |
| Overall Wheelbase (engine & tender) (ft / m) | 55.65 / 16.96 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 88,100 / 39,962 |
| Engine Weight (lbs / kg) | 160,400 / 72,756 |
| Tender Loaded Weight (lbs / kg) | 113,400 / 51,437 |
| Total Engine and Tender Weight (lbs / kg) | 273,800 / 124,193 |
| Tender Water Capacity (gals / ML) | 5000 / 18.94 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 12 / 11 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 73 / 36.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 79 / 2007 |
| Boiler Pressure (psi / kPa) | 200 / 1380 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 20" x 26" / 508x660 |
| Tractive Effort (lbs / kg) | 22,380 / 10151.41 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.94 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 306 - 2" / 51 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 15.48 / 4.72 |
| Firebox Area (sq ft / m2) | 180 / 16.73 |
| Grate Area (sq ft / m2) | 48.32 / 4.49 |
| Evaporative Heating Surface (sq ft / m2) | 2634 / 244.80 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 2634 / 244.80 |
| Evaporative Heating Surface/Cylinder Volume | 278.73 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 9664 |
| Same as above plus superheater percentage | 9664 |
| Same as above but substitute firebox area for grate area | 36,000 |
| Power L1 | 9848 |
| Power MT | 492.87 |