The Sky Route secured this high-adhesion locomotive to scale the steep slopes that led to the deep quarries. Cylinder specification called for their walls to be thick enough to allow boring out to 17" (432 mm).
After almost 20 years, the Boulder was sold to the Montpelier & Wells River in 1909 and renumbered 10. Fifteen years later, in March 1926, the Rock of Ages monument company bought the 10 and operated for another ten years before scrapping it.
Works number was 20931 in September 1902.
As mentioned in earlier entries (Locobases 11614 and 11700), the Sky Route served some pretty rugged terrain in central Vermont, at the heart of which was an immense granite quarry. 5% grades were stiff enough of a challenge and the engine gained boiler size, but and cylinder volume to cope, but the 20-deg curves (58-metre/190-ft radius) elicited the note to "...make swing of drawbar to suit". That is, if the drawbar behind the bunker didn't have enough play, it could bind and derail the engine.
In 1913, the Barre merged with the East Barre and Chelsea Railroad Company (originally established in 1892), the successor being dubbed the Barre and Chelsea and, after 1940, for the Rock of Ages line that connected Barre with the quarry.
Seven years after the Granite City went to work on the Barre (Locobase 12618), the granite railroad returned to Baldwin for its last purchases. All significant dimensions increased for more power (granite is pretty heavy ...). The Hercules followed the Monarch three years later.
A year later, the Hercules was renamed Frank H Smith as the Barre merged with the East Barre & Chelsea to become the Barre & Chelsea. Both were sold by the B & C to the Rock of Ages Quarry, the 5 in September 1948, 6 in October 1952.
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Number in Class||1||1||2|
|Builder||Burnham, Parry, Williams & Co||Burnham, Williams & Co||Baldwin|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||10 / 3.05||10 / 3.05||10.50 / 3.20|
|Engine Wheelbase (ft / m)||18.50 / 5.64||18.50 / 5.64||20.50 / 6.25|
|Ratio of driving wheelbase to overall engine wheebase||0.54||0.54||0.51|
|Overall Wheelbase (engine & tender) (ft / m)||18.50 / 5.64||18.50 / 5.64||20.50 / 6.25|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)|
|Weight on Drivers (lbs / kg)||88,000 / 39,916||96,000 / 43,545||120,000 / 54,431|
|Engine Weight (lbs / kg)||92,000 / 41,731||110,000 / 49,895||138,000 / 62,596|
|Tender Loaded Weight (lbs / kg)|
|Total Engine and Tender Weight (lbs / kg)||92,000||110,000||138,000|
|Tender Water Capacity (gals / ML)||1000 / 3.79||1600 / 6.06||2000 / 7.58|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||49 / 24.50||53 / 26.50||67 / 33.50|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||46 / 1168||50 / 1270||51 / 1295|
|Boiler Pressure (psi / kPa)||160 / 11||180 / 12.40||180 / 12.40|
|High Pressure Cylinders (dia x stroke) (in / mm)||16" x 24" / 406x610||17" x 24" / 432x610||19" x 24" / 483x610|
|Tractive Effort (lbs / kg)||18,165 / 8239.52||21,224 / 9627.06||25,992 / 11789.79|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.84||4.52||4.62|
|Firebox Area (sq ft / m2)||79.70 / 7.40||87.70 / 8.15||114 / 10.59|
|Grate Area (sq ft / m2)||9.40 / 0.87||14.40 / 1.34||18 / 1.67|
|Evaporative Heating Surface (sq ft / m2)||1094 / 101.64||1348 / 125.28||1564 / 145.35|
|Superheating Surface (sq ft / m2)|
|Combined Heating Surface (sq ft / m2)||1094 / 101.64||1348 / 125.28||1564 / 145.35|
|Evaporative Heating Surface/Cylinder Volume||195.88||213.80||198.58|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||1504||2592||3240|
|Same as above plus superheater percentage||1504||2592||3240|
|Same as above but substitute firebox area for grate area||12,752||15,786||20,520|