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.

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Cameron Turner