Not every steam locomotive’s most dramatic moment happens on the railroad it was built for. For Durango and Silverton No. 473, the defining chapter of its story is a wartime appeal that kept it out of Alaska and, quite possibly, out of the scrapyard. More than a century after it rolled out of ALCO’s Schenectady works, it’s still hauling passengers through the San Juan Mountains.
No. 473 was one of ten K-28 class 2-8-2 “Mikado” locomotives built in 1923 by the American Locomotive Company’s Schenectady works for the Denver and Rio Grande Western Railroad. The K-28s earned the nickname “Sport Models” for their fast, light-footed design, a build well suited to express passenger work rather than heavy, slow freight hauling. No. 473 and its nine siblings hauled premier narrow gauge trains across the D&RGW’s network spanning Colorado and New Mexico.
At 3 foot narrow gauge, with 44 inch drivers, 200 psi boiler pressure, and 27,540 pounds of tractive effort, the K-28 class was built to move people quickly and reliably over challenging mountain terrain. That combination of speed and capability is exactly what made these engines valuable enough that, when war came, the U.S. military took notice.
Ten locomotives is a small class by mainline railroad standards, which makes every individual engine’s fate within that group easier to trace than it would be for, say, a class of several hundred. All ten K-28s were built in the same year, at the same ALCO works, to the same specification, for the same railroad. That uniformity is part of what makes the wartime split, three retained versus seven requisitioned, such a stark dividing line in the class’s history. It wasn’t a gradual attrition through decades of ordinary retirement. It was a single wartime decision that permanently separated the class into two very different outcomes.
During World War II, the U.S. Army requisitioned seven of the ten K-28s for service in Alaska. That left the Rio Grande with only three of its original ten Sport Models, and the railroad successfully appealed to retain those three, including No. 473, to keep operating in Colorado.
That appeal turned out to matter enormously for No. 473’s survival. The seven requisitioned sister engines suffered badly in Alaskan conditions and were later scrapped. No. 473 never left Colorado, and that single decision, a railroad’s successful wartime appeal to hold onto its own equipment, is the reason this particular Sport Model still exists at all.
Following the 1981 division of the D&RGW’s narrow gauge assets, No. 473 was formally transferred to the newly independent Durango and Silverton Narrow Gauge Railroad and restored to full operating condition that same year. In May 2021, it was converted from coal to oil firing, a change made specifically to reduce wildfire risk along its mountain route.
The numbers behind the K-28 class explain why these engines earned the “Sport Model” reputation in the first place. No. 473 currently weighs approximately 156,000 pounds, with 113,500 pounds of that riding on the drivers as adhesive weight, the portion of a locomotive’s mass that actually generates traction. Its 44 inch drivers are notably tall for a narrow gauge engine, a design choice that favored higher speeds over raw pulling power, exactly the tradeoff you’d want for premier passenger trains rather than heavy freight drags. At 200 psi boiler pressure and 27,540 pounds of tractive effort, No. 473 was never meant to out-muscle the heavier K-36 class Mikados built two years later for the same railroad. It was built to move people quickly and comfortably across the D&RGW’s mountain network, and more than a century later, hauling excursion passengers through the San Juan Mountains, it’s still doing essentially that same job.
No. 473 is based in Durango, Colorado, owned and operated by the Durango and Silverton Narrow Gauge Railroad. It remains one of the workhorses of the D&SNG’s steam fleet, hauling scenic excursion trains through the San Juan Mountains between Durango and Silverton, a route widely regarded as one of the most continuously operated narrow gauge tourist railroads in the United States. The oil-firing conversion means passengers today are riding behind a locomotive purpose-adapted for the very real wildfire risk of its mountain environment.
You can see the full spec sheet for Durango & Silverton No. 473 here, including its complete build and service history.
What strikes me most about No. 473’s history is how much of its survival comes down to a single administrative decision made under wartime pressure. Ten sister engines, one design, one class. Seven went to Alaska and were lost to harsh conditions and eventual scrapping. Three stayed in Colorado because the Rio Grande made the case that it needed them. That’s not a story about engineering superiority or lucky preservation, it’s a story about a railroad successfully arguing for its own equipment during a national emergency, and that argument is the entire reason we can still see a K-28 Sport Model running today. Had that appeal failed, or had it come a few months later, No. 473 could just as easily have ended up in Alaska alongside its seven sisters, and none of the K-28 class might exist in operating condition now.
No. 473 also represents something important about how narrow gauge tourist railroads keep real, working railroad history alive rather than static. This isn’t a locomotive sitting on display. It’s still doing essentially the job it was built for in 1923: hauling passenger trains over demanding mountain grades. The Durango and Silverton route between Durango and Silverton is one of the most continuously operated narrow gauge lines in the country, and No. 473 has been part of that continuity since the line’s founding transfer in 1981. Add in the 2021 oil conversion, a modern safety adaptation layered onto a century-old machine, and you get a genuine picture of how heritage railroading actually operates: old iron, continuously updated just enough to keep running safely into the future.
What is a K-28 “Sport Model” locomotive?
The K-28 class was a group of ten 2-8-2 Mikado narrow gauge locomotives built in 1923 by ALCO for the Denver and Rio Grande Western Railroad. They were nicknamed “Sport Models” for their fast, light-footed design suited to express passenger work.
What happened to No. 473’s sister engines during World War II?
The U.S. Army requisitioned seven of the ten K-28s for service in Alaska. Those seven suffered badly in Alaskan conditions and were later scrapped. The Rio Grande successfully appealed to retain the remaining three, including No. 473, in Colorado.
Where does No. 473 operate today?
No. 473 is owned by the Durango and Silverton Narrow Gauge Railroad and hauls scenic excursion trains between Durango and Silverton, Colorado, through the San Juan Mountains.
Why was No. 473 converted from coal to oil firing?
In May 2021, the locomotive was converted from coal to oil firing specifically to reduce wildfire risk along its route through the San Juan Mountains.
How much tractive effort does No. 473 produce?
No. 473 produces 27,540 pounds of tractive effort at 200 psi boiler pressure, running on 44 inch drivers, figures that reflect its design for fast passenger service rather than heavy freight hauling.