This trio of Pacifics blended characteristics of the two USRA Pacific designs shown in Locobases 172 and 173. From the lighter of the two came the grate and firebox, wheelbase, cylinder volume, and the weight range, while the heavier USRA design contributed the tube and flue count. Different from both government designs, however, was the two additional feet of tube length, which substantially enhanced the superheater ratio.
by RRHS Membership Chairman, " Rutland Railroad Historical Society 80?s and 90?s on the Rutland", Rutland Railroad Historical Society blog archived at http://www.rutlandrr.org/2013/04/25/80s-and-90s-on-the-rutland/, last accessed 23 September 2014. (Thanks to Chris Hohl for his September 2014 email pointing out the absence of this class.) Works numbers were 68052-68054 in October 1929.
Locobase 14568 describes the three modern Pacifics that were derived from the USRA's Light Pacific design. This trio followed four years later with boilers reflecting the growing interest in the Type E superheater, which led to more superheater area, but more maintenance as well.
Taller drivers increased running speed and conferred a graceful profile on the design. Any loss in tractive effort was offset by a 15-psi (1.03 bar) increase in boiler pressure, while the 12" (305 mm) piston valves were big enough for the Rut. Other "special equipment" were the cast-steel locomotive bed, front end American multiple throttle, type BK stoker, Alco reverse goal, Nathan 24-point mechanical lubricator, Cleveland low water alarm, right-hand-side exhaust steam injector.
The RRHS chairman noted the trio's service area and reputation: "These steamers were used throughout the Rutland system and frequently powered the Mount Royal and Green Mountain Flyer trains, as well as time-sensitive milk trains. They were considered a favorite of engine crews." They served the Rutland until 1951-1953.
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Railroad||Rutland (Rutland)||Rutland (Rutland)|
|Number in Class||3||3|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||13 / 3.96||13.67 / 4.17|
|Engine Wheelbase (ft / m)||35.83 / 10.92||35.92 / 10.95|
|Ratio of driving wheelbase to overall engine wheebase||0.36||0.38|
|Overall Wheelbase (engine & tender) (ft / m)||71.04 / 21.65||721.20 / 21.65|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)|
|Weight on Drivers (lbs / kg)||170,500 / 77,338||175,500 / 79,606|
|Engine Weight (lbs / kg)||278,000 / 126,099||292,500 / 132,676|
|Tender Loaded Weight (lbs / kg)||196,800 / 89,267||202,300 / 91,762|
|Total Engine and Tender Weight (lbs / kg)||474,800 / 215,366||494,800 / 224,438|
|Tender Water Capacity (gals / ML)||11,000 / 41.67||11,000 / 41.67|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||14 / 12.70||14 / 12.70|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||95 / 47.50||98 / 49|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||69 / 1753||73 / 1854|
|Boiler Pressure (psi / kPa)||200 / 13.80||215 / 14.80|
|High Pressure Cylinders (dia x stroke) (in / mm)||25" x 28" / 635x711||25" x 28" / 635x711|
|Tractive Effort (lbs / kg)||43,116 / 19557.11||43,810 / 19871.91|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||3.95||4.01|
|Firebox Area (sq ft / m2)||242 / 22.48||234 / 21.74|
|Grate Area (sq ft / m2)||66.70 / 6.20||66.70 / 6.20|
|Evaporative Heating Surface (sq ft / m2)||4108 / 381.64||3994 / 371.05|
|Superheating Surface (sq ft / m2)||1060 / 98.48||1808 / 167.97|
|Combined Heating Surface (sq ft / m2)||5168 / 480.12||5802 / 539.02|
|Evaporative Heating Surface/Cylinder Volume||258.24||251.07|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||13,340||14,341|
|Same as above plus superheater percentage||16,141||18,786|
|Same as above but substitute firebox area for grate area||58,564||65,906|