Data from St Louis-Southwestern diagram from p 55 of Joseph A Strapac, Cotton Belt Locomotives (Huntington, Calif: Shade Tree Books, 1977, reprinted in 1999 by Indiana University Press), supplemented by data from StL&SW 1 - 1932 Folio 725 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 551-553 in October 1886, 554-557 in November, 558-560 in December, 561 in January 1887, 562-563 in February, and 564-565 in March.
As Strapac notes, these Eight-wheelers fell on the small side of contemporary 4-4-0 designs. As traffic demands grew on the StL, A & T (as on all other railroads in the late 1890s), these little engines were outmatched by the trains now required. Retirements began at that time with a big reduction in 1911. By 1914, only 9 of both the A1 and B1 classes combined remained. Two went to Jonesboro, Lake City & Eastern.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | A1 |
| Locobase ID | 8200 |
| Railroad | St Louis, Arkansas & Texas (StLSW) |
| Country | USA |
| Whyte | 4-4-0 |
| Number in Class | 15 |
| Road Numbers | 100-114 |
| Gauge | Std |
| Number Built | 15 |
| Builder | Dickson |
| Year | 1886 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 8 / 2.44 |
| Engine Wheelbase (ft / m) | 22 / 6.71 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.36 |
| Overall Wheelbase (engine & tender) (ft / m) | 53.54 / 16.32 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 57,400 / 26,036 |
| Engine Weight (lbs / kg) | 91,000 / 41,277 |
| Tender Loaded Weight (lbs / kg) | 83,700 / 37,966 |
| Total Engine and Tender Weight (lbs / kg) | 174,700 / 79,243 |
| Tender Water Capacity (gals / ML) | 3200 / 12.12 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 10 / 9 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 48 / 24 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 63 / 1600 |
| Boiler Pressure (psi / kPa) | 115 / 790 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 16" x 24" / 406x610 |
| Tractive Effort (lbs / kg) | 9533 / 4324.10 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 6.02 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 165 - 2" / 51 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 12 / 3.66 |
| Firebox Area (sq ft / m2) | 107.50 / 9.99 |
| Grate Area (sq ft / m2) | 15.60 / 1.45 |
| Evaporative Heating Surface (sq ft / m2) | 1050 / 97.58 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1050 / 97.58 |
| Evaporative Heating Surface/Cylinder Volume | 187.84 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1794 |
| Same as above plus superheater percentage | 1794 |
| Same as above but substitute firebox area for grate area | 12,363 |
| Power L1 | 3429 |
| Power MT | 263.40 |