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

Class M-64 (Locobase 257)

Data from D&RGW 12-1937 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection. See also tables in 1930 Locomotive Cyclopedia, and DeGolyer, Volume 81, pp. 465-503+; and "D&RGW Class M-64 Standard Gauge Steam Locomotives" on the Rio Grande Info website at [], last accessed 25 June 2021. (Thanks to Chris Hohl for pointing out the differences between Baldwin's weight estimates and the D&RGW's actual figures.) 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 Nicholson thermic syphons in both the firebox and combustion chamber contributing to the firebox heating surface, boiler had Elesco K-50-C feedwater heater, piston valves measure 14" (356 mm) in diameter.

In their specs, Baldwin estimated the weights to be 252,000 lb (114,305 kg) on the drivers, 408,500 lb (185,293 kg) for total engine weight. Estimated loaded tender weight was only a little off at 269,500 lb (122,243 kg).

Known on the D&RGW as Westerns. Rio Grande Info cited Robert Schaefer's "D&RGW 4-8-4 Westerns" in "The Prospector", Volume 2 Number 2 for the very interesting origin story of this class. Originally the D&RGW was attracted to Alco's variation on the Delaware, Lackawanna & Western's 4-8-4, in part because Alco had developed a single-piece cylinder and frame casting.

Alco had booked so many orders that they subcontracted this 10-engine build to Baldwin.

Apparently miffed that Alco had fobbed them off on Baldwin, they objected. To mollify the railway, Alco bought the engines from Baldwin and entered into a five-year leasing. The builder promised to take the engines back if the D&RGW wasn't happy with them. The next four went to work in Colorado under the same terms.

It worked out, because "Clearly the railroad grew to like them," wrote Schaefer, "as they kept them through the end of steam." And the railway didn't turn down other Baldwin locomotives for some of its most striking designs.

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.

All went to the scrappers between June 1950 and June 1956.

Class M-68 (Locobase 258)

Data from D&RGW 1-1954 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "4-8-4 Cousins", Trains (December 1943, p. 29. (Thanks to Chris Hohl for his 22 February 2013 inquiry about the valve gear that led to the entry's update and for his 9 February 2018 emails supplying the Trains item..) Works numbers were 62130-62134 in 1937.

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.