Boston & Maine class B-15
Between 1903 and 1907, ALCO built 140 Moguls for the Boston & Maine. These were numbered between 1360 and 1499 and the first variant was designated B-15. All of these were built at Manchester between 1903 and 1907. A batch built at Schenectady in 1909 and two more batches built at Manchester in 1910 and 1911 were 2,200 pounds heavier and were designated B-15a.
78 of these locomotives were superheated and upgraded in other aspects starting in 1918. Due to the different weight of the two variants, the B-15 were called B-15b and the B-15a were called B-15c after the rebuild. In 1926, the B&M sold some of the non-rebuilt locomotives to smaller operators and the others were retired between 1930 and 1936. The last of the superheated locomotives was retired in 1955.
Technical data
General
| Property | B-15, B-15a | rebuilt B-15b, B-15c |
|---|---|---|
| Built | 1903-1907 | ab 1918 |
| Manufacturers | ALCO | Boston & Maine |
| Wheel arrangement | 2-6-0 (Mogul) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | B-15, B-15a | rebuilt B-15b, B-15c |
|---|---|---|
| Wheelbase | 6.93 m | |
| Total wheelbase | 15.60 m | |
| Service mass | 65.8 t | 68 t |
| Adhesion mass | 55.7 t | 58.1 t |
| Total mass | 97.9 t | 100.2 t |
| Rigid wheelbase | 4.57 m | |
| Axle load | 18.6 t | 20.8 t |
| Water capacity | 18,927 l | |
| Fuel capacity | 9.1 t (coal) | |
Boiler
| Property | B-15, B-15a | rebuilt B-15b, B-15c |
|---|---|---|
| Grate area | 2.806 m² | 2.815 m² |
| Firebox surface | 14.809 m² | 14.679 m² |
| Tube heating surface | 161.057 m² | 119.659 m² |
| Evaporative heating surface | 175.866 m² | 134.338 m² |
| Total heating surface | 175.9 m² | 162.4 m² |
| Superheater surface | 28.057 m² |
Power plant
| Property | B-15, B-15a | rebuilt B-15b, B-15c |
|---|---|---|
| Driver diameter | 1,600 mm | |
| Boiler pressure | 13.8 bar | |
| Expansion type | simple expansion | |
| Cylinders | two, 483 x 660 mm | |
Power
| Property | B-15, B-15a | rebuilt B-15b, B-15c |
|---|---|---|
| Power source | steam | |
| Estimated power | 708 kW (963 PS) | 858 kW (1,167 PS) |
| Starting effort | 112.7 kN | |
Calculated values
| Property | B-15, B-15a | rebuilt B-15b, B-15c |
|---|---|---|
| Factor of adhesion | 1 : 4.85 | 1 : 5.06 |
| Optimal speed | 39 km/h | 47 km/h |
| Power-to-weight ratio | 10.8 kW/t | 12.6 kW/t |
| Heating Surface Equivalent | 249.9 m² | 263.8 m² |
| Cylinder volume/HSE | 1 : 966.75 | 1 : 915.69 |
| Adhesive weight/Total | 1 : 1.18 | 1 : 1.17 |
| Tractive force/Heating surface | 1 : 13.38 | 1 : 14.49 |
| Grate area/Heating surface | 1 : 62.67 | 1 : 57.69 |
| Firebox/Tube surface | 1 : 10.88 | 1 : 8.15 |
| Total/Superheater | 1 : 4.79 |
