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 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 |
| References:[1][2] 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 1⁄2 in (1,435 mm) Rebuilt: 3 ft (914 mm) |
| Leading wheel diameter |
Original:unknown Rebuilt:28 in (711 mm) |
| Driver diameter | Original:55 in (1,397 mm) Rebuilt:44 in (1,118 mm) |
| Trailing wheel diameter |
Original:none 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 |
| Career | DRGW, D&SNG, C&TS |
| 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.
Roster
| Class K-37 Number |
Class 190 Number |
Class C-41 Number |
Builder’s Number |
Rebuilt in |
Current Owner |
Notes |
|---|---|---|---|---|---|---|
| 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 |