Rio Grande owned a total of 73 SD40T-2 locomotives, nick-named “tunnel motors” for their unique radiator arrangement which drew intake air from deck-level grilles at the rear of the unit. This was designed to more efficiently cool the engines when inside tunnels by drawing air from lower down. Arguments occur over how effective the technique was, but what is not argued is the fact that these units were highly successful in a demanding role.
Tunnel Motor No. 5373 was part of an order received in August 1975 that included units 5367 through 5373. These were the last order to come with the 81-inch “short” nose. Other features included the ratchet-style hand brake on the nose (fireman’s side). As delivered, they had Mars lights mounted in the low nose, although many of these were replaced later in life by Pyle gyralights. After the merger with Southern Pacific, many of these were removed.
No. 5373 may have lasted into the Union Pacific era without significant modifications. My photo from November 1994 above shows it in as-delivered form. Its current configuration shows low-mounted ditch lights, which was not SP practice.
UP retired the unit on August 29, 2001. Subsequently it was acquired by Balfour Beatty, painted blue and renumbered 203. It was then picked up by Iowa Pacific Holdings and sent to its San Luis & Rio Grande short line (along with two other Balfour Beatty alumni). It arrived in Alamosa in September 2009.
I photographed the unit in Alamosa on December 28, 2009. At the time it was parked near the fueling facilities in the downtown yard, which made it impossible to photograph the sunny side except from the front.
I find the photos interesting for several reasons. First, this is a great contemporary look at a unique and historic model of locomotive. Then, it’s a chance to add another page to its history, which goes back some 35 years now. For aficionados of short line railroading, the unit is a beefy addition to a line that has heretofore only operated 4-axle power. And for historians of the D&RGW, here we find an old Rio Grande unit still at work, although in different paint.