Berlin Mills / Concord & Montreal 2-4-2 "Columbian" Locomotives of 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 Vol 22, p. 228,. 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. Works number was 27370 in February 1906.

Berlin Mills was a New Hampshire-based timber company.

This double-ender resembled several other 4-axle engines of this type, some of which would later join the 6 at Berlin Mills.

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.

Specifications by Steve Llanso of Sweat House Media
Locobase ID12,065 12,909 5307
RailroadConcord & Montreal (B&M)Berlin MillsBerlin Mills
Number in Class113
Road Numbers25/ 725/5767, 3, 8
Number Built113
BuilderBurnham, Williams & CoBurnham, Williams & CoVulcan Foundry
Valve GearStephensonStephensonWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft)777
Engine Wheelbase (ft)22.6722.4222.58
Ratio of driving wheelbase to overall engine wheebase 0.31 0.31 0.31
Overall Wheelbase (engine & tender) (ft)22.6722.42
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)65,00080,00085,000
Engine Weight (lbs)95,000113,000115,000
Tender Loaded Weight (lbs)
Total Engine and Tender Weight (lbs)95,000113,000115,000
Tender Water Capacity (gals)150018001500
Tender Fuel Capacity (oil/coal) (gals/tons)2
Minimum weight of rail (calculated) (lb/yd)546771
Geometry Relating to Tractive Effort
Driver Diameter (in)444444
Boiler Pressure (psi)170175140
High Pressure Cylinders (dia x stroke) (in)16" x 24"16" x 22"17" x 24"
Tractive Effort (lbs)20,17719,04018,759
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.22 4.20 4.53
Heating Ability
Firebox Area (sq ft)77.70112
Grate Area (sq ft)14.4014.3022.50
Evaporative Heating Surface (sq ft)10621102
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)10621102
Evaporative Heating Surface/Cylinder Volume190.15215.25
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 L132384166
Power MT219.65229.61


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