Baltimore & Ohio class B “Thatcher Perkins”
In 1862 and 1863, the Baltimore & Ohio built eleven ten-wheelers for the increased demand in the Civil War which they designated class B. The first one, numbered 117, had 64 1/2 inch drivers and a combustion chamber that soon had to be removed due to leakage issues. It also had flangeless front drivers. Although they belonged to the same class, the rest had drivers with a diameter of 60 or 58 inches.
The second locomotive was preserved and stored in 1892. For the “Fair of the Iron Horse” in 1927, it was rebuilt, renumbered to 117 and was given the name “Thatcher Perkins”. When the Mount Clare roundhouse in Baltimore collapsed due to excessive snow in 2003, the 117 was one of the locomotives which were heavily damaged. In the meantime, it was cosmetically restored.
Technical data
General
- Built
- 1863
- Manufacturers
- Baltimore
- Wheel arrangement
- 4-6-0 (Ten-wheeler)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Wheelbase
- 6.49 m
- Service mass
- 41.1 t
- Adhesion mass
- 31 t
- Total mass
- 69.7 t
- Rigid wheelbase
- 3.38 m
- Axle load
- 10.3 t
- Water capacity
- 11,356 l
- Fuel capacity
- 3.6 t (coal)
Boiler
- Grate area
- 1.801 m²
- Firebox surface
- 10.557 m²
- Tube heating surface
- 93.495 m²
- Evaporative heating surface
- 104.052 m²
- Total heating surface
- 104.1 m²
Power plant
- Driver diameter
- 1,473 mm
- Boiler pressure
- 5.2 bar
- Expansion type
- simple expansion
- Cylinders
- two, 483 x 660 mm
Power
- Power source
- steam
- Estimated power
- 186 kW (253 PS)
- Starting effort
- 45.9 kN
Calculated values
- Factor of adhesion
- 1 : 6.62
- Optimal speed
- 24 km/h
- Power-to-weight ratio
- 4.5 kW/t
- Heating Surface Equivalent
- 156.8 m²
- Cylinder volume/HSE
- 1 : 1,540.47
- Adhesive weight/Total
- 1 : 1.33
- Tractive force/Heating surface
- 1 : 9.21
- Grate area/Heating surface
- 1 : 57.77
- Firebox/Tube surface
- 1 : 8.86
