The P-44 pulled the east bound "Atlantic Coast Limited" and the west bound "Pacific Coast Limited" until 1922, when they were replaced by 4-8-2s. The P-44s were then used on secondary mainline trains until 1945, when they replaced the 4-6-0s on the passenger trains of the Craig, Montrose, and Alamosa branches. The six pacifics were scrapped between 1949 and 1953.
Originally delivered to the Denver-Grand Junction, these were the Rio Grande's only Pacifics. The class's operating environment included high altitudes, 4% ruling grades, rail elevation of 6 deg, and curve radii as tight as 16 deg. In the Baldwin specs is a stricture limiting adhesion weight to 162,000 lb (73,482 kg), which which the builder successfully complied.
They were also among the few classes of 4-6-2s that had square cylinder dimensions. It seems clear that the D&RG was very interested in steam supply; it specified 16" (406 mm) piston valves, an unusually large diameter for a Pacific. Exhaust steam injectors of two types preheated the water. On the right side was a No. 11 size Simplex 12-tube lifting type and a no 11 Nathan non-lifting type was fitted on the left. These are probably the "Cylinders and operating mechanism" mentioned in the specs "for heating the steam to not less than 200 degrees superheat."
The sextet went through an update later on; see Locobase 1430.
Originally delivered to the Denver-Grand Junction as class F-3 and numbered 1001-1006, these were the Rio Grande's only Pacifics; see Locobase 16211 for the original specifications.
A later upgrade included the addition of 84 sq ft of Nicholson thermic syphons and a rise in boiler pressure to 200 psi (13.8 bar). Sellers E2 exhaust steam injectors replaced the original Nathan installation and tender capacity increased to 17 tons.
The class served the D&RGW until 1949.
|Specifications by Steve Llanso of Sweat House Media|
|Railroad||Denver & Rio Grande (D&RGW)||Denver & Rio Grande (D&RGW)|
|Number in Class||6||6|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||12.50 / 3.81||12.50 / 3.81|
|Engine Wheelbase (ft / m)||33.67 / 10.26||33.67 / 10.26|
|Ratio of driving wheelbase to overall engine wheebase||0.37||0.37|
|Overall Wheelbase (engine & tender) (ft / m)||65.04 / 19.82||65.48 / 19.96|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)||54,800 / 24,857|
|Weight on Drivers (lbs / kg)||162,000 / 73,482||160,440 / 72,774|
|Engine Weight (lbs / kg)||262,000 / 118,841||261,080 / 118,424|
|Tender Loaded Weight (lbs / kg)||175,800 / 79,742||183,500 / 83,234|
|Total Engine and Tender Weight (lbs / kg)||437,800 / 198,583||444,580 / 201,658|
|Tender Water Capacity (gals / ML)||9000 / 34.09||9000 / 34.09|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||14 / 12.70||17 / 15.50|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||90 / 45||89 / 44.50|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||67 / 1702||67 / 1702|
|Boiler Pressure (psi / kPa)||185 / 12.80||200 / 13.80|
|High Pressure Cylinders (dia x stroke) (in / mm)||26" x 26" / 660x660||26" x 26" / 660x660|
|Tractive Effort (lbs / kg)||41,251 / 18711.16||44,596 / 20228.43|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||3.93||3.60|
|Firebox Area (sq ft / m2)||234 / 21.74||317 / 29.45|
|Grate Area (sq ft / m2)||63 / 5.85||63 / 5.85|
|Evaporative Heating Surface (sq ft / m2)||3497 / 324.88||3654 / 339.46|
|Superheating Surface (sq ft / m2)||778 / 72.28||778 / 72.28|
|Combined Heating Surface (sq ft / m2)||4275 / 397.16||4432 / 411.74|
|Evaporative Heating Surface/Cylinder Volume||218.88||228.70|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||11,655||12,600|
|Same as above plus superheater percentage||13,753||14,868|
|Same as above but substitute firebox area for grate area||51,082||74,812|