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

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 3-foot gauge as cheaply as possible, the railroad took its class of C-41s, added a trailing axle under the firebox and squeezed the wheels 1 1/2 feet closer together in a new frame.

The resulting Mikado was slightly smaller than the built-for-3-ft K-36 (see Locobase 13), but an 3,600-lb 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.

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 of thermic syphons to contribute to the firebox heating surface area.

D&RGW 492 at Cumbres, Colorado 20-08-1965

D&RGW 492 at Cumbres, Colorado 20-08-1965


D&RGW K-37 #492, Chama, NM, August 20, 1965, photo by Chuck Zeiler

D&RGW K-37 #492, Chama, NM, August 20, 1965, photo by Chuck Zeiler

From Wikipedia, the free encyclopedia

Denver & Rio Grande Western K-37
D&RGW #491 at Colorado Railroad Museum
Power type Steam
Dimensions are as rebuilt unless noted
Builder Baldwin Locomotive Works
Build date 1902
Rebuilder D&RGW Burnham Shops
Rebuild date 1928–1930
Configuration Original: 2-8-0
Rebuilt: 2-8-2
UIC classification 1′D1′ h2
Gauge Original: 4 ft 8 12 in (1,435 mm)
Rebuilt: 3 ft (914 mm)
Leading wheel
Rebuilt:28 in (711 mm)
Driver diameter Original:55 in (1,397 mm)
Rebuilt:44 in (1,118 mm)
Trailing wheel
Rebuilt: 28 in (711 mm)
Wheelbase 29 ft (8.8 m)
Length 41.1 ft (12.5 m)
Width 10.4 ft (3.2 m)
Height Engine:13.3 ft (4.1 m)
Tender: 13.5 ft (4.1 m)
Locomotive weight 183,920 pounds (83,420 kg)
Boiler pressure 195 psi (1.34 MPa)
Cylinders 2
Cylinder size 21 in × 30 in (533 mm × 762 mm)
Valve gear Walschaerts
Tractive effort 37,100 lbf (165 kN)
Locomotive brake Air
Train brakes Air
Class D&RG: 190
D&RGW: C-41
after rebuild K-37
Number in class Original class 190: 30
Rebuilt class K-37: 10
Locale Colorado and New Mexico
Disposition Eight preserved; two (#490, 496) scrapped

Denver & Rio Grande Western K-37s are 2-8-2, Mikado type, narrow gauge steam locomotives. They were originally built by Baldwin as part of an order for thirty standard gauge 2-8-0, Consolidation type, locomotives, class 190, in 1902. They were renumbered into class C-41 during the railroad’s reorganization in 1924 and were converted to three foot gauge in 1928-30 at the railroad’s Burnham Shops with many new parts including new frames and smaller drivers. They were then renumbered into class K-37.

The locos worked out of Salida, Colorado to Gunnison, Colorado and up the Crested Butte Branch as well as the Monarch Branch. The locos also worked out of Alamosa, Colorado to Antonito over Cumbres Pass to Chama and on to Durango and the Farmington Branch. Like the K-36s the locos were not permitted West of Gunnison or on the Silverton branch. However, the Silverton branch has since been upgraded to take K-36s.

Of the eight preserved K-37s, only #497 has been operational, both on the Durango and Silverton Narrow Gauge Railroad and on the Cumbres and Toltec Scenic Railroad but it is now awaiting a major overhaul.

Although the K-37s are actually about 2% lighter than the K-36s, they have proven to be much harder on track. Although the D&S originally owned four of the K-37s, they found that the longer engines were too hard on their track, so they traded #497 to the C&TS for K-36 #482 and #499 to Royal Gorge Park in Canon City for #486.


Class K-37
Class 190
Class C-41
490 1114 1014 20695 1928 n/a Retired 1962
Dismantled 1963-64
491 1126 1026 20829 1928 Colorado Railroad Museum,Golden Retired 1970
492 1121 1021 20749 1928 C&TS To C&TS 1970
493 1105 1005 20550 1928 D&SNG Retired 1970
To D&SNG 3/1981
At Freight House Museum, Silverton
494 1120 1020 20748 1928 C&TS Retired 1962
To C&TS 1970
495 1104 1004 20522 1928 C&TS Retired 1962
To C&TS 1970
496 1123 1023 20751 1930 n/a Dismantled 1/31/1955
497 1103 1003 20521 1930 C&TS To D&SNG 3/1981
Traded to C&TS for #482, 1991
498 1109 1009 20640 1930 D&SNG To D&SNG 3/1981
499 1125 1025 20753 1930 Royal Gorge Park
Canon City
Retired 1970
To D&SNG 3/1981
Traded to Royal Gorge Park for #486, 1999

Comments are closed