General Mining Association-Sydney Mines Railway 2-4-0 "Porter" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class J D Hill (Locobase 16572)

Data from DeGolyer, Volume 19, p. 159. See also David Samson, "Industrial Colonization: The Colonial Context of the General Mining Association, Nova Scotia, 1825-1842" at [], last accessed 22 January 2022; and "Old Sidney Collieries No. 25" thread on the phpBB Home Machinist forum at [], last accessed 22 January 2022. Works numbers were 14105 in September 1894 and in June 1900.

GMA bought the first of this pair of saddle tanks to operate on its Sydney Mines Railway. Operating conditions (absent snow and cold, of course) presented modest demands. Two short curves lay on the level, bending at 430 ft radii. One long curve of 3,960 ft radius measured 2,500 ft long (762 m) and climbed at a gradient of 1%.

Six years later, the GMA had merged with Nova Scotia Coal and Steel, which took delivery of the second. No 8 carried the name E E Bigge. (NSS&C had begun expanding its presence on the peninsula north and west of Sydney, NS.) At some point, both locomotives acquired four-wheel tender, losing the prominent saddle tank in the process.

phpBB poster Jim Leggett noted that the 25 has "reversed links". Where most Williams-Howe (aka "Stephenson") setups placed the eccentrics on the axle taking the drive from the main rod (connecting rod in Anglo countries), the 25's eccentrics cycled around the front axle and the link arms extended to the rear. (Locobase supposes this arrangement provided clearances the more standard setup wouldn't.)

Each locomotive went on to serve other railways. NSS&C sent the 7 to the Sydney Mines Railway in 1920, where it took #24. Not long after, the 24 acquired the livery of the Maritime Coal Railway & Power Co and wore #7. MCR&P sold the 7 to Victoria Coal, which kept the road number. VC 7 was scrapped in 1934.

The 8 went to Dominian Coal, where it took #25 as a tender engine. Old Sydney Collieries bought the 25 in 1924. Decades later in October 1962, the Canadian Railway Museum acquired the 25 and placed it on a length of trestle in front of the CRM in St-Constant/Delson, Quebec

Principal Dimensions by Steve Llanso of Sweat House Media

ClassJ D Hill
Locobase ID16572
RailroadGeneral Mining Association-Sydney Mines Railway
Number in Class2
Road Numbers7-8
Number Built2
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 7.08 / 2.16
Engine Wheelbase (ft / m)15.25 / 4.65
Ratio of driving wheelbase to overall engine wheelbase 0.46
Overall Wheelbase (engine & tender) (ft / m)15.25 / 4.65
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)66,000 / 29,937
Engine Weight (lbs / kg)77,000 / 34,927
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)77,000
Tender Water Capacity (gals / ML)1000 / 3.79
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)52 / 1321
Boiler Pressure (psi / kPa)150 / 10.30
High Pressure Cylinders (dia x stroke) (in / mm)16" x 24" / 406x610
Tractive Effort (lbs / kg)15,065 / 6833.38
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.38
Heating Ability
Tubes (number - dia) (in / mm)157 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)9 / 2.74
Firebox Area (sq ft / m2)83 / 7.71
Grate Area (sq ft / m2)16 / 1.49
Evaporative Heating Surface (sq ft / m2)815 / 75.72
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)815 / 75.72
Evaporative Heating Surface/Cylinder Volume145.80
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2400
Same as above plus superheater percentage2400
Same as above but substitute firebox area for grate area12,450
Power L12860
Power MT

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