Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 25, p. 103. (Thanks to Matt Olmsted for his 3 December 2023 email correcting the wheel arrangement.) Works numbers were 21114 in October 1902, 21893 in March 1903, and 24734 in September 1904. The first two cost $8,000 each. Baldwin shaved $250 off the next order.
See Locobase 11782 for an account of the Tweetsie's history. This trio came onto the road to supply some additional power to this slim-rail line. The buyer was not entirely satisfied with their new engines, according to a note in the specs:
"Please note frames have broken thro[sic] last bolt hole in main.frame at top rail splice. For Hereafter make frame at this point same depth as thro top of pedestal and ....back thro splice."
In the mid-teens, all three engines were used to support construction of the 14-mile (22.5 km) extension from Montezuma by the Linville River (another Applachian railroad bought by the Tweetsie in 1913 and known as the Arbuckle Coffee Line). Boone, NC, 8 miles (12.9 km,) further off would see its first passenger service in May 1919.
4 and 5 were scrapped in November 1936 and 6 in July 1937.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 4 |
| Locobase ID | 12637 |
| Railroad | East Tennessee & Western North Carolina |
| Country | USA |
| Whyte | 2-8-0 |
| Number in Class | 3 |
| Road Numbers | 4-6 |
| Gauge | 3' |
| Number Built | 3 |
| Builder | Burnham, Williams & Co |
| Year | 1903 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 10.83 / 3.30 |
| Engine Wheelbase (ft / m) | 18.17 / 5.54 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.60 |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 63,000 / 28,576 |
| Engine Weight (lbs / kg) | 73,000 / 33,112 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 2000 / 7.58 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 26 / 13 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 37 / 940 |
| Boiler Pressure (psi / kPa) | 160 / 1100 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 15" x 20" / 381x508 |
| Tractive Effort (lbs / kg) | 16,541 / 7502.88 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.81 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 154 - 2" / 51 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 11.65 / 3.55 |
| Firebox Area (sq ft / m2) | 87.50 / 8.13 |
| Grate Area (sq ft / m2) | 14 / 1.30 |
| Evaporative Heating Surface (sq ft / m2) | 1012 / 94.05 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1012 / 94.05 |
| Evaporative Heating Surface/Cylinder Volume | 247.43 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2240 |
| Same as above plus superheater percentage | 2240 |
| Same as above but substitute firebox area for grate area | 14,000 |
| Power L1 | 3497 |
| Power MT | 489.50 |