The Branches: Rocky Flats Branch

One of the elements I like about how this plan came together was the ability to include many of the branches in the area. One relatively minor branch runs from Rocky siding, north along Highway 93 towards Boulder. The branch also serves an aggregates plant, and at one time there was a lumber dealer and a sand and gravel dealer as well.

The Rocky Local climbs the ridge above Rocky Siding in this 2005 photo by Tyler Eaton.

The branch climbs out of rocky on a 4% grade to get out of the upper part of Barbara Gulch before crossing Highway 93 and Highway 72 as it swings north. I've modeled it as shown below.

Rocky Flats Branch leaving Rocky in the Layout.

My rendition has to have the branch follow the main line back towards Barbara Gulch before it will cross Highway 93 and disappear from view into a helix. The helix allows the line to drop down below the layout at Rocky on a lower deck at 27.5" off the floor. This gives it about 12" of clearance to the bottom of the benchwork supporting Rocky siding. I envision that the branch would be operated from a rolling chair or stool, which means that the track level is a little below that of an office desk. The initial grade of 4% out of Rocky is also modeled, so the branch climbs before descending the helix.

The Lower Deck portion of the Rocky Branch.

After descending the helix to the lower deck, the branch emerges from the helix through a cut and crosses Highway 72 before swinging over the South Boulder Diversion Canal and approaching what on the D&RGW timetable is called AEC Spur. This spur served the old Atomic Energy Commission Rocky Flats Nuclear Site, which produced Plutonium Triggers for the US nuclear weapons arsenal. In my era, the site is still served, with cleanup and the removal of nuclear materials being the primary traffic off the spur.

Further up the branch, I included a spur for the lumber dealer and a sand and gravel dealer. I also freelanced the addition of a Bentonite Plant after reading about modeling such a facility and remembering that Bentonite is also common in the area. There never was such a facility, but the idea caught my interest, was plausible and so I added it in to the branch. I also added a spur to the National Wind Test Center, located just past the end of the branch. This center tests wind power generation equipment. My era is a little early for it, but I decided to include it and this allows me to have some wind turbine traffic delivering equipment to be tested at the site.

Its July 30, 1996, firmly in my era and a pair of DRGW GP30s are on the Rocky Local switching the Aggregates plant at the northern end of the branch. Mike Danneman Photo.

After looking at the pictures of the aggregates plant, I decided instead to model it as a cement and aggregates plant. The aggregates come from a quarry on the west side of Highway 93, while the plant is on the east side of the highway with the railroad. At the end of the branch, there is a tight runaround track, so planning is important to switch the plant. Fortunately, there is only one train on the branch at a time.

The plant would be an interesting model to build. While it is about 30" deep, the tracks all stay to the front, so the depth should not hinder operations. It would however be a sizable scratch building project. One other interesting item to note, there is an old plant switcher sitting at the plant in view of Highway 93 on its own panel track. So I could have another really interesting model.

Its 1997 and a pair of GP30s are still on the Rocky Local working the aggregates plant. Photo by MRL390 (aka Tom Danneman).

The branch is not that long, but includes six industries. The track layout is very close to prototypical, with limited runarounds available, so planning of movements is key. Furthermore, the 4% grade into the branch and the helix out of the branch will tax the pair of 4-axle units typically assigned, meaning that to the local may have to leave some cars at Rocky, work part of the branch at return to swap out the remaining cars to complete the job. It will require a bit of coordination between the engineer and the dispatcher to keep the local from plugging Rocky while the local does its work. Add to that the local serving the industries between North Yard and Rocky on the mainline and there is a sizeable amount of potential work. Enough that I can have industries served during different operating sessions. Throw in a special train of nuclear materials from Rocky Flats, or a special windmill train to the NWTC, and this could be very interesting to operate. I'm really excited about modeling this branch. It should be a fun and realistic operation away from the hustle and bustle of the Mainline through the Rockies.

Cameron Turner