Denver & Rio Grande / Denver & Rio Grande Western 2-8-2 "Mikado" Type Locomotives


The Denver & Rio Grande Railroad merged with the Rio Grande Western Railroad in 1908 and through a series of corporate maneuvers finally became the Denver Rio Grande Western in 1921.

In 1903 the Rio Grande purchased fifteen narrow gauge "Mikado" type locomotives from the Baldwin Locomotive Company. These locomotives had outside frames and were delivered as Vauclain compound but were converted to simple engines between 1907 and 1909. They were designated as Class K-27 and the group was numbered 450 through 464. The simple two cylinder locomotives had 40" diameter drivers, 17" x 22" cylinders, a 200 psi boiler pressure and they exerted 27,022 pounds of tractive effort. The firebox was 113 square feet and the evaporative heating surface was 2149. The K-27s did not track well and derailed from time to time on the poorly maintained tracks. This earned them the nickname of "Mud Hens".

Twenty years after buying the "Mud Hens" the Rio Grande bought ten narrow gauge 2-8-2s from the American Locomotive Company. This group was designated as Class K-28 and was given road numbers 470 through 479. These locomotives had 44" diameter drivers, 18" x 22" cylinders, a 200 psi boiler pressure and they exerted 27,540 pounds of tractive effort. The firebox was 102 square feet, the evaporative heating surface was 1600 square feet and with the superheater the combined heating surface was 1,996 square feet. This group was well liked and the locomotives of the group were called "Sports Models". Seven, of this class were drafted into service during World War II and were put to work on the White Pass & Yukon Railroad in Alaska.

Just two years later, in 1925, ten more narrow gauge "Mikados" were added to the Rio Grande roster. This group came from Baldwin, designated as Class K-36 and assigned road numbers 480 though 489. These locomotives had 44" diameter drivers, 20" x 24" cylinders, a 195 psi boiler pressure and they exerted 36,164 pounds of tractive effort. The firebox was 145 square feet, the evaporative heating surface was 2,118 and with the superheater the combined heating surface was 2,693 square feet. This group of locomotives was never given a nickname.

Needing more motive power in the late 1920s the D&RGW's Burnham Shops in Denver began a program of building a new class of 2-8-2s. Ten were built by converting standard gauge 2-8-0s between 1928 and 1930. This group was designated as Class K-37 and was assigned road numbers 490 through 499. These locomotives had 44" diameter drivers, 20" x 24" cylinders, a 200 psi boiler pressure and they exerted 37,091 pounds of tractive effort. The firebox was 249 square feet, the evaporative heating surface was 2,102 square feet and with the superheater the combined heating surface was 2,597 square feet.

The D&RG had added a third rail to its tracks and ran both standard and narrow gauge motive power and rolling stock. Its Denver to Ogden main line was converted to standard gauge. The railroad needed standard gauge locomotives for its Denver to Pueblo freight service and it ordered fourteen for delivery in 1913 from Baldwin. These locomotives were designated as Class K-59 and were given road numbers 1200 through 1213. They had 63" diameter drivers, 27" x 30" cylinders, a 200 psi boiler pressure and they exerted 59,014 pounds of tractive effort. The firebox was 335 square feet, the evaporative heating surface was 3,700 square feet and with the superheater the combined heating surface was 4,495 square feet.

There was one more group of standard gauge "Mikados" used on the D&RGW. These locomotives were bought second hand from the Denver & Salt Lake in 1947. There were eight that were built by Lima in 1915, which were assigned road numbers 1220 through 1227, and two ALCO built locomotives that were built in 1916. The later pair received road numbers 1228 and 1229. These locomotives had 55" diameter drivers, 26" x 30" cylinders, a 200 psi boiler pressure and they exerted 62,700 pounds of tractive effort.

There are 22 surviving D&RGW 2-8-2s.

Roster by Richard Duley

Class Qty. Road Numbers From Other RR Year Acquired Year Built Builder Notes
K-27 15 450-464 1903 Baldwin 1
K-28 10 470-479 1923 ALCO 2
K-36 10 480-489 1925 Baldwin 3
K-37 6 490-495 1928 D&RGW 4
K-37 4 496-499 1930 D&RGW 5
K-59 14 1200-1213 1913 Baldwin 6
K-63 8 1220-1227 D&SL 1947 1915 Lima 7
K-63 2 1228-1229 D&SL 1947 1916 ALCO 8
  1. Numbers 450-464 narrow gauge locomotives. Numbers 450,451,457 and 460 scrapped in 1939. Number 455 sold to the RGS in 1940 and then scrapped in 1952. Numbers 458 & 459 sold to the National Railways of Mexico in 1941 and became NdeM numbers 400 and 401. Numbers 400 and 401 rebuilt as standard gauge 2-8-2s in 1949. Number 400 scrapped in 1963 and number 401 scrapped in 1957. Number 461 Sold to the RGS in 1949 then scrapped in 1952. Number 462 scrapped in 1950. Number 456 scrapped in 1952. Number 454 scrapped in 1953. Numbers 452 & 453 scrapped in 1954. Number 463 was sold to Gene Autrey in 1955 to be used in film making. Then it was donated to the City of Antonito in 1972. Since 1989 number 463 is on loan to C&TS. Number 464 retired in 1962 and sold in 1973 to Knott's Berry Farm where it was rebuilt but was found to be too large for the tight curves on its track. In1987. Number 464 was sold to Genesee County for use on the Huckleberry Railroad.
  2. Numbers 470-479 narrow gauge locomotives. In 1942, the United States Army requisitioned seven D&RGW locomotives, numbers 470,471,472,474,475,477&479, and they were transferred to the White Pass & Yukon Railroad which the Army had taken over control of its operations in order to feed supplies for the construction of the Alaska Highway. The seven locomotives were worn out by the end of the war and were scrapped in 1946. Numbers 473, 476 & 478 were sold to the Durango & Silverton Narrow Gauge Railroad in 1981.
  3. Numbers 480-489 narrow gauge locomotives. Numbers 480 & 481 sold to the D&SNG in 1981. Numbers 482, 483, 484, 487, 488 & 489 sold to the C&TS in 1970. Number 485 scrapped in 1954. Number 486 was donated to the Royal Gorge Park near Canon City in 1967 and later was made operational on the D&SNG.
  4. Numbers 490-495 narrow gauge locomotives. Numbers 490-495 converted from a standard gauge 2-8-0 by the D&RGW. Number 490 scrapped in 1963. Numbers 492, 494 & 495 sold to the C&TS in 1970. Numbers 493 sold to the D&SNG in 1981. Number 491 preserved at Colorado Railroad Museum in Golden Colorado.
  5. Numbers 496-499 narrow gauge locomotives. Numbers 496-499 converted from a standard gauge 2-8-0 by the D&RGW. Number 496 scrapped in 1955. Numbers 497-499 sold to the D&SNG in 1981.
  6. Numbers 1200-1213 standard gauge locomotives. All scrapped by 1955.
  7. Numbers 1220-1227 standard gauge locomotives. Came from the D&SL in 1947. Ex D&SL numbers 400-407. All scrapped by 1955.
  8. Numbers 1228 and 1229 standard gauge locomotives. Came from the D&SL in 1947. Ex D&SL numbers 408 and 409. Both scrapped by 1955.

Class Details by Steve Llanso

Class K-27-125 (Locobase 3753)

Data from D&RGW 1 - 1952 Folio L Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. See also Chris Lane, "Mountain Models (Division of PSC) K-27", Model Railroading, July 2005, pp. 18-21, archived on the web at , last accessed 24 May 2008. Works numbers were 21677, 21685 in February 1903; 21728-21729, 21781, 21788, 21796, 21803, 21824, 21832, 21845, 21854, 21894 in March; and 21910 and 21936 in April.

According to Drury (1993), this class started out as Vauclain compounds (two 13" HP, two 22" LP cylinders). Perhaps the compound cylinder arrangement driving such small wheels and traveling on 40-lb rail was the cause, but the "Mudhens" were not initially popular because of their tendency to derail. As they left the rail and skittered across the ties, according to bystanders, they had a waddling gate like that of a hen, hence the nickname.

The DRG later upgraded with 50-60 lb rail and converted the class to 2-cylinder simple engines in 1907-1911. Curiously, during the conversion, the railroad elected to install slide valves operated by Stephenson link motion in place of the Walschaert-actuated piston valves that had fed the two cylinders on each side. While 10 were retrofitted with 11" piston valves when superheated in the 1920s (see Locobase 9465), 462, alone among the saturated survivors, eventually received piston valves as well.

459 later went on to serve the Nacional de Mexico as their 401.

Class K-27-125-superheated (Locobase 9465)

Data from D&RGW 1 - 1952 Folio L Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

When the little Mikes shown in Locobase 3753 received superheaters, the boilers underwent the usual exchange of tubes in favor of flues -- 119 of the former were removed to make room for 22 of the latter. Even though the tractive effort rating remained unchanged, the steam distributed by relatively capacious 11" diameter piston valves was drier and consequently gave more push per pulse. The first few conversions (454, 456, 458, 461) retained the inside-frame valve chest location (so that from the front the cylinders "tilt" in toward the boiler from either side). The later conversions favored the outside-valve chest location that lined up the valve with the Walschaert valve gear.

On an Internet forum, a post from El Coke (Ed Coker), titled Runnning [sic] the last K-27s and time-stamped December 12, 2005 07:39PM gave a thorough "review" of how at least one of the class felt to run:

"This was a very enjoyable engine to run. The engine was comfortable to operate, with controls placed where an engineman did not neeed to reach far to operate. It had a very reponsive throttle and tracked very well, though not quite as good as 473 and 476. It had a short wheelbase and a big overhang in the back-like the 480s, and would nose around in curves but with none of the violence the 480s would display. It also, like the 470s, could go relatively fast and feel safe. It had no backhead insulation so the cab was hot. The lifting injectors always worked fine. The negative-and it was a big one-was the engine steamed poorly. It served the engineeer and fireman well to clean the fire themselves- and as thoroughly as possible, especially in front. Earl and I agreed that if the perfect notch in the cutoff and the perfect notch in the throttle were found it would run up Cumbres without running out of steam. "

Another correspondent -- Re: Runnning the last K-27s, Posted by: earl (IP Logged), Date: December 15, 2005 08:40AM -- added his comments about why the K-27 steamed poorly: "The problem with K27's is the firebox is very shallow with little room up front between the grates and the arch. You had to be a good shot with the scoop. Too high and you'd hit the arch and the coal would fall in the middle. Too low and the coal would land short of the front. Either way, you end up with a pile about 2 feet from the front - a pile that would extend from the grates all the way to the arch - with nothing burning against the flue sheet. The shallow box didn't allow much room for air to combine with the gases, which effected its ability to steam and keep the smoke down."

"Earl" continues with fascinating detail about what it took to fire a flawed design: "It took lots of little scoops of coal to keep 463 against the peg. Her hard draft would burn the coal right off the scoop. You had to keep after her, and be on your feet most of the time (right next that unlagged backhead). She had real big injectors (10's) which were oversized for her. They wouldn't cut back far enough to run all the time and you had to trade water and steam - fire the gun off when you had 199.95 lbs, then fire until you dropped to 192 or so, kill the gun, get your steam back, start the gun, etc. You were a real busy fireman. Even at its best by the time you got to below Coxo the fire was getting deep, and her steaming ability was beginning to fade (along with the fireman). If a stop at Cresco was made, it gave the fireman a chance to shake the fire down a bit, which amde life on the upper part of the hill much easier. After a few days on 463, firing 489 was like laying off."

Retirements began in the late 1930s. 458-459 enjoyed an unusual post-DRG career beginning January 1942 when they were sold to the Nacional de Mexico as their class KR-7 #400-401, converted to standard-gauge running in 1949 (July and June, respectively) and renumbered 2250-2251 in classes KR-7 and KR-8. Considering that meant lengthening the axles by more than a foot and a half, this was a pretty drastic step to take on 40-year-old locomotives.

The enlargement must have proved satisfactory, for the NdeM didn't retire 459/401/2251 until 1957 and only condemned 458/400/2250 in 1962.

Class K-28-148 (Locobase 5042)

Data from D&RGW 12 - 1937 Folio 10 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. See also Chris Lane, "Mountain Models (Division of PSC) K-28", Model Railroading, April 2006, pp. 17-20, archived on the web at , last accessed 24 May 2008 and an extended discussion at , last accessed 28 October 2011.

These were first Mikes procured by the Denver & Rio Grande Western's narrow-gauge line since the "Mudhens" of 1903 (see Locobase 3753, 9465). Drury (1993) notes that they were nicknamed the "Sports Models" (probably from the taller drivers allowing more speed) and adds that tractive effort was little different from the earlier class. Lane notes the distinguishing features of these Mikes, including a large counterweight just on the 3rd driver (to balance the main rod big end) and a cross-compound air pump on the left-hand smokebox door.

They replaced Ten-Wheelers pulling passenger trains on the Alamosa-Durango and Salida-Gunnison services. These runs included the last named-narrow gauge passenger train, the San Juan. Lane says the success of the design, which ran smoothly and powerfully, led to other orders including a set of four for the Oahu Land & Railway Company.

When World War II began, seven of the 10 in the class were appropriated by the US Army and sent to the Yukon & White Pass Railroad; 470-472, 474-475, 477, and 479 were renumbered in sequence 250--256. They didn't return to the D&RGW, but were scrapped in 1945 in Seattle (6) and 472 in Ogden, Utah .

The other three ran in the Rockies for as long as the DRG&W maintained its narrow-gauge division, being retired only in the late 1950s. All three later went to the Durango & Silverton to operated on those rails, a service that soon transformed into a thriving tourixt-line attraction.

Class K-36-189 (Locobase 13)

Data from D&RGW 12 - 1937 Folio 10 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection see also , last accessed 28 October 2011 and DeGolyer, Volume 76, pp. 283+. Works numbers were 58541, 58558-58559 in July 1925; 58584-58590 in August. (For some reason, the first engine was assigned road number 482. The others were numbered in order of their works numbers.)

The last new narrow-gauge locomotives bought by the D&RGW. Drury (1993) notes that these had outside frames (drivers between the frames, counterweights and crankpins visible outside the frames). Piston valve diameter was 11" (279 mm).

A general statement in Baldwin's specifications sheets indicate the close fit between design and anticipated operating environment: "Engines to operate at elevation of 11,000 ft [3,353 m]. Maximum emergency speed for stability, on 26 degree curves, 25 miles per hour [40 km/h]. Operating speed on 26 degree curves, 15 mph [24 km/h]. Track gauge on 26 degree curve, 36 1/2" [927 mm]. Track elevation on 26 degree curve, 3 3/4" [95 mm]."

Another interesting spec is the one addressing steam flow, in which the designers state that "throttle, dry pipe and steam pipe area based on approximate steam flow of 6,000 ft per minute under maximum power, and not over 7,000 ft per minute through superheater." Locobase doesn't remember seeing this particular ratio described in any other Baldwin spec, although clearly such considerations preoccupied builders and operators during the whole of the steam age., last accessed 24 May 2008 -- A website detailing the DRG & W's narrow-gauge operation -- notes: "They had one third more pulling power than the K-28s [Locobase 5042] and were used on the steepest grades."

The author adds: "Most of the people who ran the narrow gauge engines consider the K36s to be the best narrow gauge engines on the D&RGW. " They were not without their flaws, however, the most frequently mentioned being poor riding qualities.

Class K-37 (Locobase 9466)

Data from D&RGW 1 - 1952 Folio L Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. See also George Woodman Hilton, American Narrow-Gauge Railroads (Stanford, Calif: Stanford University Press, 1990, 155 and , last accessed 8 July 2014.

This class represents a rare instance in which a standard-gauge locomotive design was converted to narrow-gauge operation. Obviously trying to put as much power over a single set of wheels as was possible on three-foot gauge as cheaply as possible, the railroad took its class of Baldwin-built C-41s (see Locobase 1461), added a trailing axle under the firebox and squeezed the wheels 1 1/2 feet closer together in a new frame. The C-41s made over in this program were originally numbered 1008, 1014, 1020-1021, 1026, 1004, 1023, 1003, 1009, and 1025.

The resulting Mikado was slightly smaller than the built-for-3-ft K-36 (see Locobase 13), but put down a 3,600-lb (1,633 kg) higher axle loading. Hilton comments that the K-37s "...were particularly identified with the Monarch branch, which combined difficult curves and heavy mineral traffic." And noting a structural feature, adds, "The engines were a demonstration of the attractions of the outside frame, allowing a large boiler of standard-gauge dimensions on 3' track." (Hilton also observes that so large a boiler on the narrow-gauge was a moderately scaled vessel on the 4' 8 1/2" alignment.

493-494 and 497 were modified with steam heating equipment to serve the Shavano passenger trains between Salida and Gunnison.

The specifications reflect a later update in which a few boiler tubes were removed as part of a firebox overhaul that resulted in the installation of 46 sq ft (4.25 sq m) of thermic syphons to contribute to the firebox heating surface area.

All but two were preserved after the narrow-gauge era ended; 496 was scrapped in 1955 and 490 was scrapped in 1963-1964 .497 operated on the Durango & Silverton until it was traded to the C&TS for K-36 #482. Its tube life expired in 2003, but is "stored serviceable." 491's restoration to service at the Colorado Railroad Museum (Golden, CO) was due to complete in 2014. In addition, several members were on display at several Colorado locations: 493 at the Freight House Museum, Silverton; 494-495 at the Cumbre &Toltec Scenic yard in Antonito; 498 at the Durango & Silverton in Durango, and the 499 at Royal Gorge Park at Canon City, CO.

Class K-59 (Locobase 1464)

Data from 1937 & 1952 D & RGW locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection. Works numbers were 38772-38781 and 38870-38873 in November 1912.

As delivered, this class had relatively capacious 16" (406 mm) diameter piston valves. In its final form, the firebox heating surface included 38 sq ft of arch tubes to which had been added 60 sq ft of syphons. At least one locomotive (1202) was fitted with circulators instead, which added 40 sq ft to original firebox area. 1202's boiler tubes and flues also measured 6" longer.

According to Drury (1993), these engines were spirited enough to pull passenger trains over the Moffatt Tunnel route in the 1930s-1940s. Most were dismantled in the 1950s. Engine numbers reflect D&RGW renumbering in 1924.

Specifications by Steve Llanso
Class K-27-125 K-27-125-superheated K-28-148 K-36-189 K-37 K-59
Locobase ID 3753 9465 5042 13 9466 1464
Railroad Denver & Rio Grande (D&RGW) Denver & Rio Grande Western (D&RGW) Denver & Rio Grande Western (D&RGW) Denver & Rio Grande Western (D&RGW) Denver & Rio Grande Western (D&RGW) Denver & Rio Grande (D&RGW)
Whyte 2-8-2 2-8-2 2-8-2 2-8-2 2-8-2 2-8-2
Road Numbers 450-464 452-56, 458-9, 461, 463-4 470-479 480-489 490-499 1200-1213
Gauge 3' 3' 3' 3' 3' Std
Builder Burnham, Williams & Co DRGW Alco Baldwin DRGW Baldwin
Year 1903 1924 1923 1925 1928 1912
Valve Gear Stephenson Walschaert Walschaert Walschaert Walschaert Walschaert
Locomotive Length and Weight
Driver Wheelbase 11.42' 11.42' 12.25' 12.25' 12.25' 16.50'
Engine Wheelbase 24.50' 24.50' 28.83' 28.08' 29.08' 34.75'
Ratio of driving wheelbase to overall engine wheebase 0.47 0.47 0.42 0.44 0.42 0.47
Overall Wheelbase (engine & tender) 51.04' 51.04' 53.50' 58.65' 56.15' 66.62'
Axle Loading (Maximum Weight per Axle) 27475 lbs 27969 lbs 28448 lbs 36064 lbs 39700 lbs 54000 lbs
Weight on Drivers 105425 lbs 108300 lbs 113500 lbs 143850 lbs 148280 lbs 212000 lbs
Engine Weight 136650 lbs 140250 lbs 156000 lbs 187100 lbs 187250 lbs 276000 lbs
Tender Light Weight 83300 lbs 83300 lbs 98500 lbs 99500 lbs 120000 lbs 157700 lbs
Total Engine and Tender Weight 219950 lbs 223550 lbs 254500 lbs 286600 lbs 307250 lbs 433700 lbs
Tender Water Capacity 4100 gals 4100 gals 5000 gals 5000 gals 6000 gals 8600 gals
Tender Fuel Capacity (oil/coal) 8.5 tons 8.5 tons tons 9.5 tons 9 tons 14 tons
Minimum weight of rail (calculated) on which locomotive could run 44 lb/yard 45 lb/yard 47 lb/yard 60 lb/yard 62 lb/yard 88 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter 40" 40" 44" 44" 44" 63"
Boiler Pressure 200 psi 200 psi 200 psi 195 psi 200 psi 200 psi
Cylinders (dia x stroke) 17" x 22" 17" x 22" 18" x 22" 20" x 24" 20" x 24" 27" x 30"
Tractive Effort 27022 lbs 27022 lbs 27540 lbs 36164 lbs 37091 lbs 59014 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.90 4.01 4.12 3.98 4.00 3.59
Heating Ability
Firebox Area 113 sq. ft 113 sq. ft 102 sq. ft 145 sq. ft 249 sq. ft 335 sq. ft
Grate Area 30.17 sq. ft 30.17 sq. ft 30.10 sq. ft 40.20 sq. ft 46.60 sq. ft 63 sq. ft
Evaporative Heating Surface 2149 sq. ft 1526 sq. ft 1600 sq. ft 2118 sq. ft 2102 sq. ft 3700 sq. ft
Superheating Surface 407 sq. ft 396 sq. ft 575 sq. ft 495 sq. ft 795 sq. ft
Combined Heating Surface 2149 sq. ft 1933 sq. ft 1996 sq. ft 2693 sq. ft 2597 sq. ft 4495 sq. ft
Evaporative Heating Surface/Cylinder Volume 371.83 264.03 246.93 242.70 240.87 186.11
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation 6034 6034 6020 7839 9320 12600
Same as above plus superheater percentage 6034 7301 7224 9485 11091 14868
Same as above but substitute firebox area for grate area 22600 27346 24480 34213 59262 79060
Power L1 6261 13274 12843 13139 13113 13236
Power MT 523.71 1080.85 997.85 805.46 779.85 550.57



  • The Denver and Rio Grande Western Railroad, Rebel of the Rockies By Robert G. Athern, Published by Bison Books
  • Rio Grade to the Pacific by Robert A. LeMassena (Sundance Limited)
  • Big Power in the Rockies by Robert A. LeMassena in "Vintage Rails" September/October 1999 Issue page 64-70.
  • Rio Grande Modeling & Historical Society
  • A very good source for D&RGW photos are Mr. Richard Cox's "Vanishing Vistas" color postcards. For a catalog, write to:
    Richard E. Cox
    P.O. Box 1491
    Rocklin, CA 95677-1491
    Richard and his father, Mr. Lyman Cox acquired and printed a dozen-plus shots of Rio trains and power as described above. You will find hobby shops and railroadiana shows to be hit-and-miss with these cards.
  • Another good source for D&RGW photos is Tom Klinger's Railroad Photos. (phone: 303-424-6376) Tom sells 5x7 black-and-white sets and regularly prints sets which cover Rio Grande in Every Dimension.


Introduction and roster provided by Richard Duley . Class details and specifications provided by Steve Llanso of Sweat House Media.