The Rio Grande ran fascinating combinations of heavyweight and streamlined cars in their trains from 1948 to 1968. Most heavyweight cars were painted from the old Pullman Green into the "Grande Gold" color scheme in the early 50s. This colorful period began with "Westerns" hauling the heavyweight EXPOSITION FLYER with brand-new Budd CALIFORNIA ZEPHYR cars (especially Vista- Dome coaches) mixed in. This is one of the few instances where one could ride a regularly-scheduled dome car behind a steam loco.
By 1956, all of the D&RGW "Westerns" had been sent to the scrapper. The "Westerns" gave way to FTs, Alco PAs, F3s and eventually the F7s. Once the CZ consists were complete, Rio's heavyweights were eventually repainted and used in the ROYAL GORGE, YAMPA VALLEY MAIL and PROSPECTOR. For the ZEPHYR, the PAs were painted solid silver with orange noses. The FTs, F3s and PAs were originally delivered and run in a black body/gold stripe scheme till the early 50s then all were repainted "Grande Gold". The PROSPECTOR and ROYAL GORGE were well-known for their combo consists till their demise in the mid-60s. The Rio Grande also purchased streamlined coaches, diners, dome-observation cars and RPOs from the Chesapeake and Ohio in the early 50s.
|Class||Road Numbers||Year Built||Builder|
Firebox fitted with combustion chamber that supplied 78 sq ft (7.25 sq m) and 103 sq ft (9.6 sq m) of thermic syphons contributing to the firebox heating surface, boiler had Elesco K-50-C feedwater heater, piston valves measure 14" in diameter. Known on the D & RGW as Westerns.
See the Utah Rails website -- [external link] -- for a discussion of the D & RGW's green boilers. The M-64s weighed considerably less than the later express M-68s (Locobase 258), which made them more suitable for the Moffat Tunnel route.
More frankly passenger haulers than their fourteen predecessor M-64s, these five Westerns (not Northerns, by the Rio Grande's reckoning) were superpower locomotives in all respects. The had roller bearings on axles carrying larger Baldwin disc drivers. Laid out as a , the firebox heating surface included 139 sq ft (12.91 sq m) of combustion chamber and 122 sq ft (11.3 sq m) of thermic syphons (located in both the firebox and the combustion chamber). 14" (356 mm) piston valves supplied steam to the cylinders.
Their design later formed the basis of the Missouri Pacific N-73s procured in 1943 (Locobase 266).
They ran from Denver to Salt Lake City -- 745 miles (1,199 km) through the Royal Gorge and Tennessee Passes hitting 80 mph (129 kmh) in some spots -- until retirement in 1952-1954.
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Railroad||Denver & Rio Grande Western (D&RGW)||Denver & Rio Grande Western (D&RGW)|
|Number in Class||14||5|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||18.75 / 5.71||19.25 / 5.87|
|Engine Wheelbase (ft / m)||44.42 / 13.54||47 / 14.33|
|Ratio of driving wheelbase to overall engine wheebase||0.42||0.41|
|Overall Wheelbase (engine & tender) (ft / m)||89.75 / 27.36||95.29 / 29.04|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)||70,448 / 31,955|
|Weight on Drivers (lbs / kg)||252,000 / 114,305||279,172 / 126,630|
|Engine Weight (lbs / kg)||408,500 / 185,293||479,360 / 217,434|
|Tender Loaded Weight (lbs / kg)||269,500 / 122,243||394,000 / 178,716|
|Total Engine and Tender Weight (lbs / kg)||678,000 / 307,536||873,360 / 396,150|
|Tender Water Capacity (gals / ML)||14,000 / 53.03||20,000 / 75.76|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||20 / 18.20||26 / 23.60|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||105 / 52.50||116 / 58|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||70 / 1778||73 / 1854|
|Boiler Pressure (psi / kPa)||240 / 16.50||285 / 19.70|
|High Pressure Cylinders (dia x stroke) (in / mm)||27" x 30" / 686x762||26" x 30" / 660x762|
|Tractive Effort (lbs / kg)||63,735 / 28909.74||67,299 / 30526.35|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||3.95||4.15|
|Firebox Area (sq ft / m2)||446 / 41.45||555 / 51.56|
|Grate Area (sq ft / m2)||88 / 8.18||106 / 9.85|
|Evaporative Heating Surface (sq ft / m2)||4917 / 456.97||5506 / 511.52|
|Superheating Surface (sq ft / m2)||2229 / 207.16||2336 / 217.02|
|Combined Heating Surface (sq ft / m2)||7146 / 664.13||7842 / 728.54|
|Evaporative Heating Surface/Cylinder Volume||247.33||298.67|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||21,120||30,210|
|Same as above plus superheater percentage||27,667||39,273|
|Same as above but substitute firebox area for grate area||140,222||205,628|