Berlin Mills / Concord & Montreal 2-4-2 "Columbian" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 25 (Locobase 12065)

Data from Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 18, p.150,. Works number was 13186 in January 1893.

This tank had the dimensions of a typical light 4-4-0 of the time, but with the auxiliary trucks distributed to allow easier bi-directional running. When the B&M took over the C&M in 1895, it assigned new road numbers and at some later date, removed both auxiliary trucks. 57 was sold in March 1912 to Grovet Paper Company.


Class 6 (Locobase 12909)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 28, p. 206,. See also the Steamtown National Historical Site's Special History Study on the Berlin Mills Railway 2-4-2T Locomotive No. 7, as archived at [], last accessed 18 October 2013. (Thanks to Chris Hohl for his 27 July 2021 email supplying the coal capacity and correcting the tube length.) Works number was 27370 in February 1906.

Berlin Mills was a New Hampshire-based timber company. Curves to be negotiated ran as tight as 48.9 deg, which the specification helpfully translates as a 119 ft radius.

This double-ender resembled several other four-axle engines of this type, some of which would later join the 6 at Berlin Mills. Its saddle tank was to "arranged to be removed without interfering with throttle."


Class 7 (Locobase 5307)

Data from [], last accessed 21 July 2011. Vulcan works number for the 7 was 1679 in January 1911.

Unusual saddle-tanker with small drivers. 3 was bought in 1917 and 8 came in May 1920.

Principal Dimensions by Steve Llanso of Middle Run Media

Class2567
Locobase ID12065 12909 5307
RailroadConcord & Montreal (B&M)Berlin MillsBerlin Mills
CountryUSAUSAUSA
Whyte2-4-2T2-4-2ST2-4-2ST
Number in Class113
Road Numbers25/ 725/5767, 3, 8
GaugeStdStdStd
Number Built113
BuilderBurnham, Williams & CoBurnham, Williams & CoVulcan Foundry
Year189319061911
Valve GearStephensonStephensonWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)7 / 2.137 / 2.137 / 2.13
Engine Wheelbase (ft / m)22.67 / 6.9122.42 / 6.8322.58 / 6.88
Ratio of driving wheelbase to overall engine wheelbase 0.31 0.31 0.31
Overall Wheelbase (engine & tender) (ft / m)22.67 / 6.9122.42 / 6.83
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)65,000 / 29,48480,000 / 36,28785,000 / 38,555
Engine Weight (lbs / kg)95,000 / 43,091113,000 / 51,256115,000 / 52,163
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)95,000113,000115,000
Tender Water Capacity (gals / ML)1500 / 5.681800 / 6.821500 / 5.68
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 1.75 / 22 / 2
Minimum weight of rail (calculated) (lb/yd / kg/m)54 / 2767 / 33.5071 / 35.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)44 / 111844 / 111844 / 1118
Boiler Pressure (psi / kPa)170 / 11.70175 / 12.10140 / 13.10
High Pressure Cylinders (dia x stroke) (in / mm)16" x 24" / 406x61016" x 22" / 406x55917" x 24" / 432x610
Tractive Effort (lbs / kg)20,177 / 9152.1419,040 / 8636.4118,759 / 8508.95
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.22 4.20 4.53
Heating Ability
Tubes (number - dia) (in / mm)175 - 2" / 51180 - 2" / 51186 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)10.83 / 3.3010.58 / 3.3012.33 / 3.76
Firebox Area (sq ft / m2)77.70 / 7.22112 / 10.41
Grate Area (sq ft / m2)14.40 / 1.3414.30 / 1.3322.50 / 2.09
Evaporative Heating Surface (sq ft / m2)1062 / 98.701102 / 102.38
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1062 / 98.701102 / 102.38
Evaporative Heating Surface/Cylinder Volume189.98215.23
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation244825033150
Same as above plus superheater percentage244825033150
Same as above but substitute firebox area for grate area13,20919,600
Power L132354166
Power MT219.44229.61

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