Crescent Siding

After a long climb of nearly 3 scale miles, we have reached the siding of Crescent, Colorado. Having visited Crescent, it truly has the feeling of being in the mountains. However, it is accessible via car, so it becomes a favorite railfanning location.

DRGW5319 and DRGW5376 lead a freight west through a meet a Crescent Siding in  May1977. Photo by Tim.

At Crescent, the rolling terrain that began to emerge after Tunnel 17 opens into a wide valley in South Boulder Canyon. In fact, below Crescent lies Gross Point Reservoir. Crescent Siding is only 5550 feet long, and is the shortest siding in the Tunnel District. However, it is halfway between Plain and Cliff sidings and provides an important point for shorter trains to pass and for crew access or helper engines to make it back down the mountain without interfering with traffic.

DRGW 5389 approaching the east end of Crescent Siding, May 5, 1988. Photo by Tom Byrnas.

DRGW3106 approaching the east end of Crescent, October 4, 1984. Photo by John Rus.

DRGW5344 leads a train downgrade through Crescent siding on October 3, 1982 on the way to Denver. Photo by Timothy Tonge.

Crescent siding rests on a sweeping curve on the western end. While short, its location makes it a commonly used siding for meets, particularly with shorter manifest freights or passenger trains.

Track Plan for Crescent, Colorado.

The plan for Crescent Siding is to allow the layout to cross the doorway on a nod under, and connect to a shelf along a half wall across the garage to a narrow shelf on the far wall that will lead the main line back over towards the Big 10 curve region, but at a higher elevation. Crescent is planned as a flat siding at an elevation of 38" above the reference elevation at Prospect Junction. While Crescent has a sweeping curve on the west end in the prototype, I have had to make the curve on the east end in the plan, so as to follow the flow of the benchwork. Like the prototype, this is the shortest siding along the Tunnel District at about 98", making it about 2" shorter than Clay siding.

I suppose it may be possible to swing the siding a little further around on the east end, and introduce at least a bit of curvature on the west end. I may need to consider that line change at some point and see if it is feasible. However, I can live with this configuration as is. Crescent serves its purpose to provide a dramatic pause in the climb, a place for trains to meet, and a point to transition from the Middle Region of the Tunnel District, to the Upper Region of the Tunnel District.

12 Days, 12 Posts to Go.

Cameron Turner

Tunnels 17 and 18

The last two tunnels of the Middle Region of the Tunnel District are Tunnels 17 and 18. Tunnel 17 is the longest tunnel on the district, save the Moffat Tunnel at the summit. At 1730 feet in length, Tunnel 17 bores through a major ridge descending from Scar Top Mountain. To the West of this ridge lies Johnson Gulch, which drains a number of natural springs in the area. Due to the springs, water is often heard at the west portal of Tunnel 17.

Approach to Tunnel 17. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

East Portal of Tunnel 17. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

To the east of Tunnel 17 was a spur named Quartz. The spur was removed by 1949, but up to that point, it was a source for some mineral shipments from the area. Should I decide to employ a little modelers license, I could include this spur at this location. At a minimum, I will need to allow for space for an abandoned spur in the area.

Tunnel 18 by contrast is a short tunnel with a length of 238 feet. It penetrates a shallow ridge coming off the northern side of Scar Top Mountain, and very easily could have been daylighted, but never has been. Tunnel 18 represents the western end of the Middle Region of the Tunnel District.

SP124 heads west out of Tunnel 18. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

The space for the modeled representation of this area is physically located above the Cargill area just past North Yard. That part of the layout is at an elevation of 2.5" above the reference elevation while the mainline at west end of Tunnel 18 reaches 38" above the reference elevation. The elevation climb is an amazing accomplishment.

Track Plan for Tunnels 17-18 in relation to Tunnels 7, 8 and 10.

Tunnel 17 helps achieve its length (83.2") by using the same trick of penetrating the the backdrop (previously used in Tunnels 8 and 10). However, in this case, the track of Tunnel 17 will be hidden in the mountainside above the track between Tunnels 8 and 10. At that point the elevation difference is about 5.5", so it should be easy to hide into the hillside. Tunnel 17 as modeled is a little shorter than Tunnel 10, but I may be able to address that discrepancy by moving the east portal of Tunnel 10 a few inches.

Beyond Tunnel 17, the hillsides become a bit more open and rolling as we approach Crescent Siding. Tunnel 18 is represented with a 16.5" long tunnel through the rolling ridge. Before leaving the garage, the main swings around to cross the doorway. With a mainline elevation of 38", I expect to be able to achieve a nod under crossing of the doorway with a lower edge of the benchwork at about 36" above the reference height. Since the reference elevation is likely to be around 30"-32", this places the nod under at about 66"-68", which should be fairly comfortable for many users.

13 Days, 13 Posts to Go.

Cameron Turner

Into the South Draw and Tunnel 16

Tunnel 15 leads the main line into the South Draw, a valley between Eldorado Mountain, Crescent Mountain and Scar Top Mountain. In the South Draw, the main line makes a 180 degree horseshoe curve as part of the climb, including a penetration through Tunnel 16.

Satellite View of the South Draw Area.

Tunnel 16 is 698 feel long, and serves as a portion of the 180 degree curve. Upon exiting Tunnel 16, the main continues out of the South Draw, through the site of Old Tunnel 17. Old Tunnel 17 never was a tunnel. It started as a tunnel, but the rock proved to be too unstable and the tunnel collapsed during construction. The attempted tunnel was eventually removed, and the remains became a wide spot in the roadbed and a cut into the hillside of Scar Top Mountain. From there, the line continues around the ridge and back into South Boulder Canyon.

Looking across the South Draw towards the site of Old Tunnel 17. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

Approach to the East Portal of Tunnel 16. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

Track Plan for the South Draw and Tunnel 16.

The layout plan for the South Draw and Tunnel 16 is a compromise of the prototype region versus the benchwork. While I was able to include part of the 180 degree curve, I had to reverse the curve in Tunnel 16. The result is less of a 180 degree horseshoe curve, and more of a dip into the South Draw gap and then an extended run up the draw. Tunnel 16 is represented with a 39.9" tunnel, and Old Tunnel 17 is also represented. Interestingly, its location falls near the track to Tunnel 10. At this point, the main line is about 35-3/8" (above the zero elevation) at Old Tunnel 17 and at 32" within Tunnel 10. Like the prototype, the main curves sharply around the end of the ridge coming off Scar Top Mountain and heads towards Tunnel 17.

14 Days, 14 Posts to Go.

Cameron Turner

Tunnels 11, 12, 13, 14 and 15

Beyond Tunnel 10, the Moffat continues its climb up South Boulder Creek Canyon by cutting through numerous ridge lines that run down into the canyon. The first of these tunnels is Tunnel 11, a 230 foot tunnel piecing a rocky ridge on the northwestern side of Eldorado Mountain.

DRGW5389 heads east out of Tunnel 11 in 1992. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

Amtrak Number 5, the Westbound California Zephyr exits the other side of the ridge through Tunnel 11 in 1995. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

After a few hundred feet, the mainline encounters another ridge of Eldorado Mountain, and penetrates it with the curving 429 foot Tunnel 12. While the eastern slope is very steep and rocky  like Tunnel 11, the western side of the ridge is much more rounded.

Just West of Tunnel 12, and Eastbound coal train is about to enter Tunnel 12. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

Tunnel 13 penetrates yet another ridge off the western side of Eldorado Mounatin. Tunnel 13 lies to the west of a long curved fill and to the east is another curved fill leading to Tunnel 14. The combination of curves and grade pose a significant test to trains climbing through the Tunnel District. Crews report that trains that successfully make it through to Tunnel 14 are usually successful for the rest of the climb.

DRGW5369 heads west out of Tunnel 14's western portal. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

Tunnel 14, like Tunnel 13 has two faces. The eastern face is steep, and rocky, while the western side is rounded, covered with grass and trees. Tunnel 15 penetrates the last ridge running from Eldorado Mountain, and brings the main line into the South Draw. The bore of Tunnel 15 is 427 feet long. To the west of Tunnel 15, there was a deep drop into the depths of the South Draw drainage. This trestle location was filled in using materials from Tunnel 9, and the original Tunnel 17, leaving a long fill.

Western portal of Tunnel 15 with DRGW3015 emerging with a westbound into the South Draw.

The plan for this stretch of tunnels wraps around the first peninsula of the layout over Arvada and C&S Junction. Because of the Belina drop hiding the end of the peninsula on the lower level, the end of the peninsula on the second deck appears all on its own, with no lower deck to fight for attention.

Track Plan for Tunnels 11-15.

Again, the tunnels are proportional in length and spacing. Tunnel 11 is 16.5" long, Tunnel 12 is 36.5" long, Tunnel 13 is 20.6" long, Tunnel 14 is 27.4" long and Tunnel 15 is 22.5" long. From the west portal of Tunnel 10, to the East portal of Tunnel 16, the main line is just over 20' long, and climbs from 32.5" to 35" (above the zero reference point). Most of the climb lies between Tunnel 12 and Tunnel 14, where the grade reaches 1.5%, while navigating the 18" radius curve between Tunnels 13 and 14. This curve mimics the tight curve on the fill found tot he west of Tunnel 13 in the prototype and should test trains just like this stretch of track does in the prototype. However, there is still some grade between these points.

One modification to be made to this plan is to replace the tangent track between Tunnel 12 and 13 with a curved track as in the prototype. While I am not sure I can achieve the reverse curve seen in the prototype and still work around the end of the peninsula, I am sure I can add curvature here to mimic the prototype.

Beyond Tunnel 15, the tracks enter a bowl called the South Draw, where the train curves around and through Tunnel 16 as it continues up the canyon and through 3 more tunnels before finally reaching the siding of Crescent and the first real break in the climb since Plain siding. At this point, Plain siding is nearly 2 scale miles behind and 8.5" below the current main line elevation. Crescent is almost another scale mile ahead with another 3" to climb. Now that is a helper grade between two sidings that will feel like traveling somewhere.

15 Days, 15 Posts to Go.

Cameron Turner

Tunnel 10 – Wait what about Tunnel 9???

The next tunnel after Tunnel 8 is Tunnel 10 as we continue up the Middle Region of the Tunnel District. The observant might be wondering what happened to Tunnel 9. There was a Tunnel 9, briefly. The tunnel was about 120 feet long, through a spur off Eldorado Mountain, but was unstable from the beginning. A tight radius shoo-fly was built around the tunnel, and remained until 1938 when the tunnel and unstable spur were removed for the present alignment. I plan to model the remaining wide spot of the shoo-fly, but no tunnel.

The original tunnel 9 cut through the ridge in the picture above. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

So, the next tunnel on the line is Tunnel 10. Tunnel 10 is a large tunnel at 1572' in length. In 1943, the tunnel caught fire and had to be sealed to extinguish the fire. The tunnel is linear, but I modeled it with a long curve to turn the corner of the benchwork. The two tunnel portals are about 600 scale feet apart, but the train travels over 7 feet between portals. Some trains will completely disappear into the tunnel, although not for long. Again, I use the track piecing through the backdrop but remaining below the scenery on the far side of the layout to achieve this distance.

Tunnel 10 cuts through a major ridge line reaching into South Boulder Canyon. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

The long spacing between the portals affords me the opportunity for a large area of nothing but scenery. While this may seem like a disadvantage, I am looking at it as a significant opportunity to gain the illusion of distance. Tunnel 10 pierces the first of several ridge lines as the main line climbs up the canyon. even scaled down, this ridge line will further emphasize the magnitude of the scenery in the area.

Tunnel 10 LDE Plan.

Tunnel 10 ends up with a modeled length of 86.9". The grade, which paused at the start of Tunnel 8, resumes with the visible track emerging from Tunnel 8. This helps prevent the mainline from climbing too much as it works its way back around the room and gaining too much elevation for the upper deck. By the time the track emerges from the west portal of Tunnel 10, it has climbed to 32.5" above the reference point (Prospect Junction) and 1.5" in its climb through the Middle Region of the Tunnel District.

16 Days, 16 Posts to Go.

Cameron Turner

Tunnel 8

Tunnel 8 is the end of the Flatirons Region of the Tunnel District and the start of the Middle Region of the Tunnel District. As such, Tunnel 8 is a critical point of demarcation between the two regions in the Tunnel District.

The prototype Tunnel 8 penetrates beneath the peak of Eldorado Mountain to swing from a generally northerly direction to head west up South Boulder Canyon.

Satellite View of the Tunnel 8 Area.

The track swings to the right as it goes into Tunnel 8, and continues to the right as it plunges through the tunnel. This gives ample opportunity to use the hidden track to reorient the track to follow the benchwork.

The view of the east portal of Tunnel 8 at the west end of the Flatirons Region of the Tunnel District. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

Further, since Tunnel 8 marks a change in scenery, it makes sense to physically separate the Flatirons Region scenes from those in the Middle Region. Tunnel 8 is the longest tunnel yet at 753 feet. This led to the track plan below.

Track Plan for Tunnel 8.

In the plan, Tunnel 8 begins with a curve to the right just as in the prototype. However, this turn pushes the track through the backdrop dividing the two sides of the benchwork. In turn, this leads to a reverse curve that extends the length of the tunnel so as to bring the tunnel back to the viewable side of the benchwork. This trick should work as the trackwork in Tunnel 8 will be below the scenery level on the opposite side of the benchwork. With some care, I should be able to make sure that the track is accessible. The overall tunnel length is a little long, at 69.1", but the portal to portal distance is about 59" which is closer to the prototype tunnel length of 44". However, given the location of the support post, and the desire to separate the scenes, the tunnel length works to minimize the impact of the support post on the west portal of Tunnel 8 scene.

The west portal of Tunnel 8 in the Middle Region of the Tunnel District. Photo from Rio Grande Secret Places, Volume 1 by R.C. Farewell.

The exit from the west portal of Tunnel 8 has very little curvature to it. The plan requires a little more curvature than the prototype, but not so much as to be unacceptable. While Tunnel 8 is a long tunnel at almost 6 feet in length, many of the trains I expect to run on the layout will be in the range of 7 to 15 feet, and thus trains should be visible despite the length of the tunnel. By the time the main line reaches Tunnel 8, the track elevation has reached 31 inches above the reference elevation. The deck separation at this point is ranges from about 16 inches at the low spots in the scenery, to approximately 24 inches at track level of greater. Furthermore, the flatirons occupy their own distinct area on the layout with a clear scenic demarcation to the middle region. I believe that this plan continues to work well.

18 Days to go. 18 Posts to go!

Cameron Turner