The Turning Point – Part 4: Coal Creek Canyon

Continuing up the hill from Clay where we left off in the previous post of the series, the railroad first curves into the mouth of Coal Creek Canyon (now heading west) which it uses to execute another 180 degree turn to once again head east out of the mouth of Coal Creek Canyon, before encountering Tunnel #1 and swinging back to the north to reach the site of Plainview. As part of the continuing climb to separate the two decks of the railroad, two significant scenes are worth modeling before we reach Tunnel #1.

BNSF Dash 9-44CWs 1006, 4944 & 4014 climb towards Blue Mountain Drive Crossing in Coal Creek Canyon. Photo by Andrew Naylor.

Blue Mountain Drive is the first stop along this climb and is a common photo spot. Especially if you can shoot from the north side of the tracks which allows you to catch the train as it climbs up the canyon. However, the light is better from the south, but this means you have to wait for the train to cross to move on to the next set of shots, which usually means heading to Plainview. Of course, if you are catching an eastbound, you can continue into the development and climb up on the ridge above the Big 10 Curves to get some long range shots of the train descending through Clay, the Big 10 and Rocky below you. Nonetheless, Blue Mountain is a railfan spot that you almost must have. Just a simple crossing.

Further up the canyon, the intensity increases as the line makes its loop around the rapidly narrowing canyon. The loop crosses over Colorado Highway 72 on a deck girder bridge, and a Colorado Department of Transportation Sanding Facility (for loading salting and sanding trucks in the winter) is located within the loop. The grade continues in this region at a steady 2% and the canyon echos with the engines straining to climb the grade.

From high above Coal Creek Canyon, you can see the entire loop and the east portal of Tunnel #1. Photographer unidentified.

This is an ideal scene for a walk-in effect, and so it makes a lot of sense to try to locate it at the far end of the aisle from the Big 10 Curves. With this in mind, the resulting plan for these features is shown below.

Track plan for the region including Blue Mountain Drive and the 180 degree curve at the upper end of Coal Creek Canyon.

A few notable comments on this part of the plan. As discussed last time, the second deck bench initially provides about 6" of clearance from the track at Rocky to the lower edge of the upper deck bench work. Not a lot, but at least in the mock up, it appears workable. The track continues to climb, gaining another 3/4" in elevation by the time it reaches the area proposed for the Blue Mountain grade crossing, reaching an elevation of +19.5" inches at the bridge over Colorado Highway 72 in the upper reaches of Coal Creek Canyon. At this point in the scene it is important to remember that the roadway will be closer to an elevation of +18" as it goes under the tracks, and the bottom of the bench work will be closer to +16". Below, the track is at about +8", but this is where US Highway 93 crosses over the mainline, which will be at about +10". US Highway 93 then has a grade crossing with the Rocky Flats branch (also +10"). This means that even in this area, my clearance is about 6".

The plan does allow for a broad 26" radius curve through the 180 degree return loop, which should look very much like the effect of the loop in the photo above. By the time the line is heading east out of the mouth of Coal Creek Canyon, the main line has climbed to an elevation of +20.5", while the main line below (located in Barbara Gulch) is at approximately +7.5". We have climbed 13"over a run of about 68', or more than 2 scale miles. Because of the flat grade in Rocky, that works out to be an average grade of 1.5%. In the Big 10 Curves, I reached a maximum grade of 2.5% (slightly over the 2% grade of the real thing) but allow that grade to drop to 2% in Coal Creek Canyon. I could play with these grades a little more to try to adjust deck heights, but this looks like it will work, although I will likely try to tweak things a little more before the design is complete.

Cameron Turner