The BAR "Mountains" had 22.5 x 30 cylinders, 63" drivers, a 240 psi boiler pressure which resulted in a tractive effort of 50,000 pounds. The weight on the drivers was 214,500 lbs and the total weight for each locomotive was 318,500 lbs. With a full load of 12,000 gallons of water and 18 tons of coal the combined weight of the locomotive and tender was 551,500 pounds.
The BAR also purchased five used "Mountains" from the NYO&W in 1946 and scrapped them by 1949. The ten from ALCO were retired by 1953. There are no survivors.
Class | Road Numbers | Year Built | Builder |
---|---|---|---|
M | 100-103 | 1929 | ALCO |
M | 104-106 | 1930 | ALCO |
M | 107-108 | 1935 | ALCO |
M | 109 | 1945 | ALCO |
Data from tables in 1930 Locomotive Cyclopedia and BAR 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for supplying the valve gear ID and for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error .Thanks also to Larry Walton for his 8 January 2021 email noting several corrections in the works numbers and build dates.) Works numbers were 68218-68221 in 1928 and 68525-68526, 68705-68706 in 1930. A ninth engine built to the same design was delivered as works number 73055 in February 1945.
Firebox had thermic syphons. Feed water heater was an Elesco A. Relatively small Mountain types with small drivers for low-speed freight hauling. Originally listed weight on the drivers came to 204,000 lb (92,533 kg). Of the ten in the class, nine had the same boiler and firebox. See Locobase 16524 for the 106, which used larger diameter tubes and flues.
Somehow the BAR managed to apply seven different classifications to them.
Data from tables in 1930 Locomotive Cyclopedia and BAR 1 - 1938 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection. (Thanks to Chris Hohl for supplying the valve gear ID and for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error; and to Leo Drake for his 26 February 2024 email pointing out a truncated comment.) Works number was 68527 in 1930.
Nine of the B&A's 4-8-2 freight class M used the same boiler. But in 1930, one more was delivered with larger-diameter small tubes (2 1/4" instead of 2") and flues (5 1/2" instead of 5 3/8"), leading to a 40-tube reduction in small tubes.
Locobase hasn't uncovered any explanation for why this engine, the last of the 1929 batch, was so modified.
Regardless of its differences, the 106 worked with the other eight until 1953, when it was scrapped.
Principal Dimensions by Steve Llanso of Middle Run Media | ||
---|---|---|
Class | M | M-H |
Locobase ID | 192 | 16524 |
Railroad | Bangor & Aroostook | Bangor & Aroostook |
Country | USA | USA |
Whyte | 4-8-2 | 4-8-2 |
Number in Class | 8 | 1 |
Road Numbers | 100-105, 107-108 | 106 |
Gauge | Std | Std |
Number Built | 8 | 1 |
Builder | Alco-Schenectady | Alco-Schenectady |
Year | 1929 | 1930 |
Valve Gear | Baker | Baker |
Locomotive Length and Weight | ||
Driver Wheelbase (ft / m) | 16.50 / 5.03 | 16.50 / 5.03 |
Engine Wheelbase (ft / m) | 38.08 / 11.61 | 38.08 / 11.61 |
Ratio of driving wheelbase to overall engine wheelbase | 0.43 | 0.43 |
Overall Wheelbase (engine & tender) (ft / m) | 73.67 / 22.45 | 76.71 / 23.38 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | ||
Weight on Drivers (lbs / kg) | 213,360 / 96,779 | 212,000 / 96,162 |
Engine Weight (lbs / kg) | 317,490 / 144,011 | 315,300 / 143,018 |
Tender Loaded Weight (lbs / kg) | 232,000 / 105,234 | 232,000 / 105,234 |
Total Engine and Tender Weight (lbs / kg) | 549,490 / 249,245 | 547,300 / 248,252 |
Tender Water Capacity (gals / ML) | 10,000 / 37.88 | 12,500 / 47.35 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 15 / 13.60 | 18 / 16.40 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 89 / 44.50 | 88 / 44 |
Geometry Relating to Tractive Effort | ||
Driver Diameter (in / mm) | 63 / 1600 | 63 / 1600 |
Boiler Pressure (psi / kPa) | 240 / 1650 | 240 / 1650 |
High Pressure Cylinders (dia x stroke) (in / mm) | 22.5" x 30" / 572x762 | 22.5" x 30" / 572x762 |
Tractive Effort (lbs / kg) | 49,179 / 22307.25 | 49,179 / 22307.25 |
Booster (lbs) | 11,300 | 11,300 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.34 | 4.31 |
Heating Ability | ||
Tubes (number - dia) (in / mm) | 208 - 2" / 51 | 168 - 2.25" / 57 |
Flues (number - dia) (in / mm) | 38 - 5.375" / 137 | 38 - 5.5" / 140 |
Flue/Tube length (ft / m) | 20 / 6.10 | 20 / 6.10 |
Firebox Area (sq ft / m2) | 351 / 32.61 | 351 / 32.61 |
Grate Area (sq ft / m2) | 65.60 / 6.09 | 65.60 / 6.09 |
Evaporative Heating Surface (sq ft / m2) | 3583 / 332.87 | 3424 / 318.10 |
Superheating Surface (sq ft / m2) | 932 / 86.58 | 932 / 86.58 |
Combined Heating Surface (sq ft / m2) | 4515 / 419.45 | 4356 / 404.68 |
Evaporative Heating Surface/Cylinder Volume | 259.45 | 247.94 |
Computations Relating to Power Output (More Information) | ||
Robert LeMassena's Power Computation | 15,744 | 15,744 |
Same as above plus superheater percentage | 19,050 | 19,050 |
Same as above but substitute firebox area for grate area | 101,930 | 101,930 |
Power L1 | 25,047 | 24,757 |
Power MT | 1035.23 | 1029.81 |