Boston, Revere Beach, & Lynn 2-4-4 Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 8 (Locobase 424)

Data from Bruce (1952). See also Francis B. C. Bradlee, "Boston, Revere Beach & Lynn Railroad" at [], and"BRP[sic]&LRR 2-4-4T" at Iron Horse 1:29's Mason Bogies site (both last accessed 26 August 2012). (Thanks to Chris Hohl for his 19 February 2024 email identifying the valve gear.) Works numbers were 1741-1742 in 1900, 25872 in 1902, unk in 1905, 39054 in 1906; 42268, 42741-42743 in 1907; 50830-50831 in 1913; and 54590-54592 in 1914. The first eleven came from Manchester, NH's Manchester Locomotive Works, which was absorbed by American Locomotive Company in 1901. Built as needed, the series consisted of 8, 13 (1900), 14-17 (1902, 1903, 1905, 1906) , 18-21 (1907), 22-23 in 1913, and 24-26 from Schenectady in 1914.

Low-drivered narrow-gauge (36") commuter tank locomotives, the 1914 batch were the last three engines to be built for this 8.8 mile (14.2 km) line that brought commuters down from the near North Shore to Boston. The basic dimensions were little changed from the series of Mason Bogies that had constituted the line's motive power. In fact, says Iron Horse 1:29: "The Boston, Revere Beach & Lynn RR, believed in their Mason Bogie 2-4-4Ts. They bought a number from Mason between 1882 and 1887. They then obtained blueprints and patterns and continued to have the same engine built by three other manufacturers, the last in 1914."

At the time of the final delivery, "ELS" wrote to the Brotherhood of Locomotive Firemen and Enginemen's Magazine asking about the brick arch he encountered while firing the locomotives. [Locobase can't say for certain that it was the class in this entry.] He wondered if having the arch laid level or at an angle made any difference, especially with regard to temperature stress:

"The one I fire is on the level. I claim the back end is too low, that every time you open the door the air goes straight through the door into the flues, where with those on the slant, the back end is higher and the air would naturally strike it first before the flues, saving them a lot of contraction and expansion." (BFLE Magazine, Vol 56, May 1914, p. 594.)

The BLFE Magazine replied that it certainly did matter and that he was right in suspecting that the back end should be higher than the top of the firedoor opening. A correctly arranged brick arch would be "so set that the air would strike against the under side of the arch, more nearly perfect combustion would be obtained, and little, if any, damage could be done to the flues even though the firebox door were allowed to remain open."

After the highly successful line was electrified in 1928, all of the steam locomotives were retired and most were scrapped in 1929

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID424
RailroadBoston, Revere Beach, & Lynn
Number in Class15
Road Numbers8, 13-26
Number Built15
BuilderManchester, Alco-Schenectady
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 5.50 / 1.68
Engine Wheelbase (ft / m)11.54 / 3.52
Ratio of driving wheelbase to overall engine wheelbase 0.48
Overall Wheelbase (engine & tender) (ft / m)29.92 / 9.12
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)47,000 / 21,319
Engine Weight (lbs / kg)56,000 / 25,401
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)56,000
Tender Water Capacity (gals / ML)1200 / 4.55
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)39 / 19.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)49.50 / 1257
Boiler Pressure (psi / kPa)150 / 10.30
High Pressure Cylinders (dia x stroke) (in / mm)14" x 18" / 356x457
Tractive Effort (lbs / kg)9087 / 4121.80
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.17
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 9.83 / 3
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2)15.90 / 1.48
Evaporative Heating Surface (sq ft / m2)676 / 62.83
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)676 / 62.83
Evaporative Heating Surface/Cylinder Volume210.59
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2385
Same as above plus superheater percentage2385
Same as above but substitute firebox area for grate area
Power L1
Power MT

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