D&RGW K-27 Mikado #463 switching in Chama on the Cumbres & Toltec Scenic Railroad.
At the beginning of the twentieth century, the most powerful narrow gauge locomotives of the Denver & Rio Grande were Consolidation type engines, relatively modest in size, acquired during the 1880s, and the need for more powerful engines to pull the heaviest trains soon became apparent, especially on the demanding 4% grade of Marshall Pass. In 1903, the Rio Grande ordered 15 Mikado from Baldwin Locomotive Works, numbered from 450 to 464, initially known as class 125, and later designated class K-27 in the new 1924 engine classification scheme. When they were put into service, these very modern engines for the time (they were the first Mikado locomotives on the railroad) were considered as "monsters" because of their size and weight, when compared to the older and smaller narrow gauge engines then in use, and could haul twice the load of the railroad's most powerful Consolidation up Marshall Pass grades. The K-27 were rapidly nicknamed Mudhens because of their outline and the way they waddle on the uneven tracks of the Rio Grande.
K-27 #463 in front of the water tank in Antonito while in operation on the Cumbres & Toltec Scenic Railroad.
As all other classes of Rio Grande narrow gauge Mikado, the K-27 are outside frame locomotives, meaning that the drivers are located within the frame and that only the counterweights and the rods are outside of the frame. They were built as 4-cylinder Vauclain compound engines (two 13" x 22" high-pressure cylinders and two 22" x 22" low-pressure cylinders) and were originally equipped with slope-back tenders. The K-27 would undergo a number of heavy modifications during their long career. First, they were all converted to simple engines between 1907 and 1916 because the compound system was suffering from reliability issues and had rapidly been proven too costly to maintain, despite the coal and water savings it offered. In 1918, their tenders were rebuilt with full size water tanks to increase capacity. Between 1924 and 1929, the K-27 underwent a series of improvements. Number 450, 451, 457 and 460 kept their original Stephenson valve gear, but all the other locomotives in the class received a Walschaert valve gear and were also equipped with superheating (except #462). Upon rebuilt as simple engines, they could develop a maximum tractive effort of 27,000 lbs, hence the K-27 denomination.
In their early days, the K-27 were restricted to Salida - Sargent, the only section of the Marshall Pass line where the track was heavy enough to use them. Then, their territory widened as the Rio Grande system modernized and its lines were relaid with heavier rails. In 1913, 65-pound rails were laid between Chama and Cumbres, allowing to use the K-27 as helper engines on the 4% grade of the west side of Cumbres Pass, but they would not be able to run the entire line between Alamosa and Durango before 1920, once the modernization of the line had been completed. From this date, the K-27 were used throughout the Rio Grande narrow gauge system, with the exception of a few branch lines where weight restrictions were in place, such as the Black Canyon line, the branch lines around Gunnison or the Ridgway - Ouray line. In the fourties, they were mostly active around Montrose toward Cimarron and Ridgway, and from Durango to Silverton and Farmington. Starting in the twenties, several K-27 have also been intermitently used on the Rio Grande Southern, which would then buy #455 in 1939 and #461 in 1950 (both were scrapped in 1953). The arrival of new, more powerful classes of Mikado on the railroad and several line closures on the Denver & Rio Grande Western narrow gauge system limited the activity of the K-27, and the locomotives of the class still having their original Stephenson valve gear and not equipped with superheating were the first to be scrapped, starting in 1939 (number 450, 451, 457 and 460). In 1941, #458 and 459 were sold to a railroad company in Mexico (Nacionales de Mexico). The remaining K-27 were retired during the fifties with #462 being scrapped in 1950, #456 in 1952, #454 in 1953 and #452 as well as #453 in 1954.
Two K-27 have been preserved today. #463 is currently on the Cumbres & Toltec Scenic Railroad. It had been sold in 1955 to the actor Gene Autrey for use in film shooting in California, and was later donated to the city of Antonito in 1972. Since 1989, #463 is on loan to the Cumbres & Toltec Scenic Railroad where it was refurbished and put back in service in 1994. #463 has been active on this tourist railroad until 2002 and is now awaiting an overhaul. The other K-27 preserved, #464, is operational on the Huckleberry Railroad, a county park located in Flint, Michigan. After finishing its career on the D&RGW between 1955 and 1957 as the Durango switcher, where it was then stored serviceable, #464 was retired in 1962 et eventually sold in 1973 to Knott's Berry Farm, an amusement park in California where it was rebuilt. But #464 was found to be too large for the tight curves of its track, and in 1981 was resold to Genesee County in Michigan for use on the Huckleberry Railroad where another refurbishment of the locomotive was completed in 1989. Following several years of inactivity, #464 was completely overhauled in 2005 and is now back in service.