The early American journal of railroading proclaimed that the two engines being built at the Lowell shops, "....where the union of the best Yankee and foreign mechanical skill produces the highest perfection in machinery." (The second engine was to be named David Crockett in yet another example of the fame once owned by the Tennessee frontiersman.) Once the railroad was finished, said the ARJAII, and the two received "...the 'go ahead', it will be in earnest."
According to Wikipedia's extensive entry on the Boston & Lowell, the early roadbed was so rigid that the two locomotives that opened service on the line in 1835 took a terrible pounding from the lack of "give" and needed extensive repairs almost every night.
See David R Meyer, Networked Machinists: high-technology industries in Antebellum America (Baltimore: Johns Hopkins University Press, 2006), p. 115, in which he discusses the Locks and Canals Shops' role as an incubator of talent.
The St Clair was designed by the Essex's superintendent Caleb W Marvel. Locobase suspects that the Huron (later #21 of the O & LC) was a sister engine.
The O & LC would eventually merge with the Rutland.
NB: Boiler pressure and tube length both represent estimates.
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Railroad||Boston & Lowell||Boston & Lowell|
|Number in Class||1||1|
|Builder||Lowell Machine Shop||Essex Company|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)|
|Engine Wheelbase (ft / m)|
|Ratio of driving wheelbase to overall engine wheebase|
|Overall Wheelbase (engine & tender) (ft / m)|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)|
|Weight on Drivers (lbs / kg)||14,500 / 6577|
|Engine Weight (lbs / kg)||23,000 / 10,433||48,740 / 22,108|
|Tender Loaded Weight (lbs / kg)|
|Total Engine and Tender Weight (lbs / kg)|
|Tender Water Capacity (gals / ML)|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||24 / 12|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||60 / 1524||72 / 1829|
|Boiler Pressure (psi / kPa)||90 / 6.20||100 / 6.90|
|High Pressure Cylinders (dia x stroke) (in / mm)||11" x 16" / 279x406||15" x 20" / 381x508|
|Tractive Effort (lbs / kg)||2468 / 1119.47||5313 / 2409.94|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||5.88|
|Firebox Area (sq ft / m2)||61.31 / 5.70|
|Grate Area (sq ft / m2)||6.40 / 0.59||10.75 / 1|
|Evaporative Heating Surface (sq ft / m2)||300 / 27.87||692 / 64.29|
|Superheating Surface (sq ft / m2)|
|Combined Heating Surface (sq ft / m2)||300 / 27.87||692 / 64.29|
|Evaporative Heating Surface/Cylinder Volume||170.47||169.17|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||576||1075|
|Same as above plus superheater percentage||576||1075|
|Same as above but substitute firebox area for grate area||6131|