Denver & Rio Grande Western 4-8-4 "Northern" Locomotives of the USA

For its passenger service, the Denver & Rio Grande Western Railroad purchased 4- 8-4s in two orders, from the Baldwin Locomotive Works. In 1929, 14 Class M-64 locomotives and in 1938, another five, this time Class M-68. The D&RGW liked the name "Western" instead of "Northern" for these locomotives.

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.

Roster by Richard Duley

ClassRoad NumbersYear BuiltBuilder

Class Details by Steve Llanso of Sweat House Media

Class M-64 (Locobase 257)

Data from tables in 1930 Locomotive Cyclopedia. DeGolyer, Vol 81, pp. 465-503+. Works numbers were 60712-60721 in February 1929 and 60920-60923 in July.

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 -- -- 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.

Class M-68 (Locobase 258)

Data from D&RGW 1-1954 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. (Thanks to Chris Hohl for his 22 February 2013 inquiry about the valve gear that led to the entry's update.) Works numbers were 62130-62134 in 1937.

More frankly passenger haulers than their 14 predecessor M-64s, these five Westerns (not Northerns, by the Rio Grande's reckoning) had roller bearings on axles carrying larger Baldwin disc drivers. Laid out as a superpower locomotive in all respects, 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.

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.

Specifications by Steve Llanso of Sweat House Media
Locobase ID257 258
RailroadDenver & Rio Grande Western (D&RGW)Denver & Rio Grande Western (D&RGW)
Number in Class145
Road Numbers1700-17131800-1804
Number Built145
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase18.75'19.25'
Engine Wheelbase44.42'47'
Ratio of driving wheelbase to overall engine wheebase 0.42 0.41
Overall Wheelbase (engine & tender)89.75'95.29'
Axle Loading (Maximum Weight per Axle)70448 lbs
Weight on Drivers252000 lbs279172 lbs
Engine Weight408500 lbs479360 lbs
Tender Light Weight269500 lbs394000 lbs
Total Engine and Tender Weight678000 lbs873360 lbs
Tender Water Capacity14000 gals20000 gals
Tender Fuel Capacity (oil/coal)20 tons26 tons
Minimum weight of rail (calculated)105 lb/yard116 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter70"73"
Boiler Pressure240 psi285 psi
Cylinders (dia x stroke)27" x 30"26" x 30"
Tractive Effort63735 lbs67299 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.95 4.15
Heating Ability
Firebox Area446 sq. ft555 sq. ft
Grate Area88 sq. ft106 sq. ft
Evaporative Heating Surface4917 sq. ft5506 sq. ft
Superheating Surface2229 sq. ft2336 sq. ft
Combined Heating Surface7146 sq. ft7842 sq. ft
Evaporative Heating Surface/Cylinder Volume247.33298.67
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2112030210
Same as above plus superheater percentage2766739273
Same as above but substitute firebox area for grate area140222205628
Power L13832055121
Power MT1340.971741.16



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