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.
|Specifications by Steve Llanso of Sweat House Media|
|Railroad||Rutland (Rutland)||Rutland (Rutland)|
|Number in Class||3||3|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.36||0.38|
|Overall Wheelbase (engine & tender)||71.04'||721.20'|
|Axle Loading (Maximum Weight per Axle)|
|Weight on Drivers||170500 lbs||175500 lbs|
|Engine Weight||278000 lbs||292500 lbs|
|Tender Light Weight||196800 lbs||202300 lbs|
|Total Engine and Tender Weight||474800 lbs||494800 lbs|
|Tender Water Capacity||11000 gals||11000 gals|
|Tender Fuel Capacity (oil/coal)||14 tons||14 tons|
|Minimum weight of rail (calculated)||95 lb/yard||98 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||200 psi||215 psi|
|Cylinders (dia x stroke)||25" x 28"||25" x 28"|
|Tractive Effort||43116 lbs||43810 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||3.95||4.01|
|Firebox Area||242 sq. ft||234 sq. ft|
|Grate Area||66.70 sq. ft||66.70 sq. ft|
|Evaporative Heating Surface||4108 sq. ft||3994 sq. ft|
|Superheating Surface||1060 sq. ft||1808 sq. ft|
|Combined Heating Surface||5168 sq. ft||5802 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||258.24||251.07|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||13340||14341|
|Same as above plus superheater percentage||16141||18786|
|Same as above but substitute firebox area for grate area||58564||65906|