Narrow-Gauge Railroads of the Rocky Mountains

[OlDoinyo]

The 1880s saw a boom in railroad construction in the Rocky Mountains, fueled principally by mining discoveries. The new mining towns needed transportation to connect them with each other and with the outside world, and rails were the preferred way of acomplishing this. But laying rails in mountainous terrain also posed unique challenges. The primitive engineering and construction technologies of the day did not permit the kind of massive cuts, tall trestles, and multi-kilometer tunnels that are possible today; to a greater extent, one had to work with the terrain rather than merely blasting through or under it. The result was many long, tortuous routes with sharp curves, too sharp for standard-gauge (1435mm) track to be easily used. Thus, a new 914mm gauge, commonly referred to as "narrow gauge," was introduced and became the go-to solution for what ultimately became thousands of kilometers of miniature railway criscrossing the Rockies.

 

Very little of this remains today. Most of the lines were either demolished or straightened and upgraded to standard gauge long ago (and many have been subsequently demolished after the upgrade.) Only three active, intact narrow-gauge fragments remain: one is the 7.5-km Georgetown Loop Railroad just west of Denver, which will not be discussed here. The second two had their genesis in the plan of one William Jackson Palmer, a railroad tycoon who built a narrow-gauge branch line of his Denver & Rio Grande Railroad west from Denver to reach the lucrative gold and silver mines around Silverton, Colorado. Originally about 800 kilometers in length, the line ran from Denver south to Walsenburg and thence over La Veta Pass to Alamosa; from there it bore south to Antonito and over Cumbres Pass to Chama, New Mexico before turning west through Pagosa Springs and Durango and finally up the Animas River canyon to Silverton. In the 1890s, the trip took several days, and miniature sleeper trains plied the route. Over the years, the section between Denver and Antonito was gradually upgraded to standard gauge, and a part of this is now preserved as the Rio Grande Southern Scenic Railroad (of which no more will be said.) The section between Chama and Durango was abandoned in 1968 and subsequently demolished, although traces of the old right-of-way may yet be seen on Google Earth of one knows where to look.

 

The 72 kilometers at the end of the line between Durango and Silverton were never abandoned; the D&RGW Railroad continued to operate what was increasingly a historic attraction up until 1981, when it was sold off to independent operators who continue to run it to this day. The 103-kilometer stretch between Antonito and Chama was abandoned briefly in 1968 but was bought by a consortium of the state governments of Colorado and New Mexico who have renovated it and operated it since then as the Cumbres & Toltec Scenic Ralroad. Both attractions are well worth a visit if you happen out that way, as our family recently did. As I had appropriate gear along, I managed to take advantage of the high-country sun to record a few UV images.

 

All images were acquired with the Sony A900 and display intent is BGR. Lens apertures were f/16. Unless otherwise indicated, the lens is the Steinheil Cassar-S 50mm with the Baader U2 filter.

 

The first image shows Greene Street in downtown Silverton (elevation 2,837m:)

 

 

There are several interesting things about this colorful scene; to me, one of the most salient is how similarly to normal the colors of American flags seem to be rendered. This is certainly not the case in any IR imagery I have seen, and I did not expect it--I had anticipated that the red stripes would render as pure black, and that the blue would render as orange or brown. Not so. Many of the parked vehicles show orange wheels, the result of UV-absorbing varnish that is often seen on metal wheels.

 

The next image shows the train parked downtown, ready to head back down the canyon.

 

"The 482 at Silverton:"

 

 

The number plates on the locomotive show orange, indicating that they have been repainted with titanium dioxide paint. A similar effect is seen on the sides of the tender. The entire train appears coal-black, which I find a somewhat otherworldly effect.

 

Osier, Colorado (elevation 2,932m) is the lunch stop used by the Cumbres & Toltec, and a good place to get out and take pictures of the trains, which meet from both directions here in the middle of the day. The scenery of the upper Pinos valley is seen here:

 

 

I have taken pictures of locomotive number 487 before, but not in the UV. Here are my efforts:

 

(Tamron 21mm; UG11/S8612 filter:)

 

 

The chromaticity of the Tamron is more limited than that of other lenses, but one can see that the C&TS has not used the TiO₂ paint on their number plates! The building that shows dark orange in the background is the lunch hall, which is in reality pale yellow.

 

I also shot the scene with the Steinheil for comparison. Color is better, but the perspective is less striking. When I shot the scene 11 years ago I used a Tamron 14/2.8 (sadly, this last optic can in no way, shape, or form be used for UV imaging.) The headlight lens looks more distinctly yellow with the Steinheil, due no doubt to its wider bandpass; the sky is also more distinctly colored.

 

 

I also photographed the locomotive of the opposite-direction train after it stopped (Tamron 21mm; UG11/S8612 filter:)

 

 

Note that this locomotive has a standard cowcatcher rather than the prow-blade sported by the 487. This is one of the snowiest parts of Colorado, and in the old days, when the line operated year-round, the ability to plow snow was very important. It is much less so now that operations are mainly confined to summer and early autumn.

 

Some track work was also occurring near the station, including clearing of built-up earth from the right-of-way with a backhoe. The decals on said backhoe reflect only the longest UV wavelengths:

 

"Supervising Track Work, Osier:"

 

 

The windows on the backhoe are heavily UV-absorbing and show dark orange. The scene shows a surprising amount of color, even considering the fact that I did some modest color boosting on many of these images. There may even be a hint of actual skin tone on exposed flesh--curious, that.

[Andrea B.]

Clark, I have read this with great interest!! A really interesting and informative article.

 

I have family in Durango, Colorado and have seen the Silverton-Durango train at its station in Durango but have not yet ridden it to Silverton and back.

[Andy Perrin]

Lovely photos! I like the Steinheil's renderings best.

 

I am confused why titanium dioxide paint would render as orange, given TiO2 is strongly UV absorbing and used as the active ingredient (along with ZnO2) in sunscreen.

[OlDoinyo]

Lovely photos! I like the Steinheil's renderings best.

 

I am confused why titanium dioxide paint would render as orange, given TiO2 is strongly UV absorbing and used as the active ingredient (along with ZnO2) in sunscreen.

 

TiO₂ reflects strongly in the 380-400nm range, although it absorbs most shorter wavelengths. The "blue" channel (and to a lesser extent, the "green" channel) of the sensor can pick up this reflectance, which is then rendered orange in the standard image workup.

 

I agree that the Steinheil is a better UV lens--it transmits below 330nm and is one of the best out there short of a specialized quartz lens. But it lacks the field of view of the Tamron, which spans a full 92 degrees corner-to-corner, even if it cannot see much below 360 nm (at least my example--I understand that Mr Rørslett has a souped-up version which may be more capable.) The ability to shoot wide-angle images is sometimes important.

[JCDowdy]

I am confused why titanium dioxide paint would render as orange, given TiO2 is strongly UV absorbing....

 

Andy, the false colors rendered by this BGR processing initially had me confused also.

 

Here is OlDoinyo's description:

"Display intent BGR" is shorthand for: the "blue" channel is Displayed as red, the "green" channel is Displayed as green, and the "red" channel is Displayed as blue.

[OlDoinyo]

Postscript: The 489 at Osier, 4 years later

 

Taken with the A900 and the Tamron 17 with a U360/S8612 filter stack. Display intent BGR.

 

 

The color rendition is not dissimilar from that of the earlier image with the Tamron 21. This despite the sunny conditions when the later image was acquired versus overcast during the previous visit.

[colinbm]

Fantastic

This would look great in 3D Anaglyph