When they were out on the line for possibly lengthy snow-fighting operations (it was the case for rotaries OM and OY operating on Cumbres Pass), the D&RGW steam rotary snowplows were accompanied (in addition to the many locomotives needed to pull the train) by specific auxiliary outfit cars, constituting rotary trains. These cars were of several types. Some were used to increase the length of time the rotary could be kept in action (a steam snowplow by itself had enough water and coal supplies to operate only three hours on its own).
At first the Rio Grande used old tenders from retired steam engines as auxiliary tenders to extend the time its snowplows could remain in continuous operation. Then in the mid fifties, the D&RGW bought two narrow frame oil tank cars from UTLX (Union Tank Car Company) to convert them to auxiliary water cars for rotaries OM and OY by removing their dome and adding tool boxes on their sides.
Behind the locomotives pushing the snowplow itself, the rotary train included a coal gondola (if needed), several outfit cars, usually old boxcars transformed into non-revenue cars, as well as passenger cars and baggage cars used as company cars. These outfit and passenger cars served several purposes, such as to carry spare parts and tools for the rotary and to house its crew and the track gang that came along with the snowplow: bunk cars, cook cars, etc. These outfit cars were usually assigned to a specific snowplow. A rotary train was kept in Chama (West of Cumbres Pass) with rotary OM, and another in Alamosa (East of Cumbres Pass) with rotary OY.
Narrow frame tank car #0472, used as auxiliary water car for steam rotary snowplow OY, active today on the Cumbres & Toltec Scenic Railroad.
Before using tank cars in the late fifties, the D&RGW rotary snowplows used old modified tenders similar to those, seen in Chama, as additional water supply.
Tank car #0471, seen in Chama, was used as auxiliary water tank for rotary OM. As tank car #0472, this car is a former UTLX tank car built in 1908 and bought later by the D&RGW.
Outfit car #04258 built in 1895-96 as a boxcar and modified at the beginning of the twentieth century to be used as a bunk car for the section men during rotary OY snow-fighting campaigns.
Cook car #053, used on OY rotary train, is a former mail & baggage car built in 1885 by the Denver & Rio Grande converted to a bunk car in 1929, and then to a cook car during the forties.
X54, awaiting restoration in Chama, is also a mail & baggage car, built in 1880 by Billmeyer & Small and converted in 1951 after the end of the San Juan, for use as a bunk car for rotary OY enginemen.