Once again, I'm remined that out West you don't have to worry about any trees blocking your view.
 |
| Street View, Sep 2015 |
 |
| US Bureau of Reclamation Boysen Dam is a zoned earthfill structure having a structural height of 220 feet. An overflow, weir-type spillway controlled by radial gates is located on the right abutment and surcharges immediately upstream and left of the power plant. Design discharge through the spillway is 25,000 cubic feet per second at elevation 4725.00 The Boysen Reservoir has a total controlled storage capacity of 802,000 acre-feet at water surface elevation 4725.00. The outlet works is on the right abutment of the dam. Discharge is through a 66-inch-diameter steel pipe located above the power penstock and a 57-inch-diameter steel pipe joined to the 10-foot-diameter power penstock serving Unit 1 in the powerhouse. The power plant has an installed capacity of 15,000 kilowatts developed by two units operating under an average head of 99 feet. Each unit is served by a 10-foot-diameter steel penstock joined to a common 15-foot-diameter steel penstock immediately upstream from the power plant. The 15-foot-diameter penstock leading from the intake structure to the units was located to utilize the bore of an existing railroad tunnel made available through relocation of the CB&Q railroad. Other features of the construction activity were the relocation of 13.5 miles of the railroad track, which required a tunnel 1.25 miles long, seven bridges, two sidings, and other construction features. Folded and faulted shales and sandstones lying over pre-Cambrian diorites, with up to 70 feet of alluvium in the riverbed. |
 |
| Kim Birchfield, Apr 2020 |
The power plant has two 7.5mw units with Francis turbines and a plant factor of 30%. [USBR-hydro, Details tab]
 |
| Steven Pehrson, Oct 2019 |
 |
| wyohistory Boysen Dam about 1951, shortly after its construction. American Heritage Center. "The power plant at the dam produces more than 37.8 million kilowatt-hours of electricity annually." |
This post motivated my research of this dam.
 |
| Third photo posted by John Weeks Have you ever seen those click-bait ads on the Internet that have things like the 10 most dangerous bridges or 50 best bike trails in the USA? Well, I saw one that had the 10 most dangerous railroad lines. I know better than to click on them, but I couldn't help myself. The most dangerous railroad line in the US was listed as the line from Casper, Wyoming, heading up to Montana. It runs through a spectacular canyon in the Wind River Indian Reservation. The rock at the top of the canyon keeps breaking off and falling on the tracks, sometimes hitting trains. I was interested in this rail line, so I looked it up on Google Maps. The click bait ad didn't give a specific location, but I found it pretty quickly. But, in checking out the map, I found something far more fascinating...the rail line continues up the canyon and disappears where Boyson Dam is located. If you follow the reservoir another mile and a quarter, the rail line emerges from the edge of the water. I was very curious what was going on. Turns out the rail line was built and in operation for decades, then the government wanted to put in a dam and create a large reservoir. There was no way to relocate the railroad track because the canyon was hundreds of feet deep. So, they built a waterproof cover over the tracks, then built the dam. The tracks essentially run along the bottom of the lake until the tunnel re-emerges over a mile from the dam. It is a remarkable civil engineering feat. It also looks odd to see a hole in the face of the dam where the tracks appear to simply disappear into the dam. I just happened to randomly stumble over this place today. When I was in the canyon, I had to wait about 20 minutes for a road construction project. I took this photo looking across the river towards the railroad tracks. You can see a huge slide that came down and wiped out the railroad tracks in the recent past. The tracks are fixed now. Since there is a little grass in the slide area, I suspect it happened 2 or 3 years ago. |
John's comment about the CB&Q route not being moved was wrong because they did build 13.5 miles of new track that included a 1.25 mile tunnel. The red line on this satellite image shows the location of the new tunnel. But the comment about building a waterproof cover might be true because the new route passes through a side lobe that might have the track under water.
 |
| Satellite plus Paint |
I first noticed the new route possibly going under water on this topo map.
 |
| 1978 Boysen Quadrangle @ 1:24,000 |
The oldest topo map available is 1951, so I could not find the original CB&Q route and its original tunnel that the dam reused to hold the powerhouse penstock and the outlet pipes.
The tunnel was 7,131' (1.35 mile) long. "Boysen Dam is a rock and earthfill structure 220 feet high, 1,143 feet long, and containing 1,527,000 ubic yards (cy) of material. The outlet works consist of a 66-inch diameter outlet pipe and a 57-inch diameter penstock bypass pipe. Each are controlled by a 48-inch hollow-jet valve. The capacity of the outlet works is 1,300 cubic feet per second (cfs). The spillway is concrete lined chute on the right abutment controlled by two 30-by 25 foot radial gates. The maximum capacity of the spillway is 25,000 cfs. Boysen Reservoir has a maximum capacity of 1,493,000 acre-feet (af) with a normal operating capacity of almost 820,000 af. The reservoir covers more that 30,750 acres at maximum capacity. Boysen Powerplant houses two 7,500 kW generating units. Each generator is driven by a 10,500 horsepower (hp) Francis-type turbine. The total rated capacity of the facility is 15,000 kW. Water is supplied to the turbines by a 15 -foot diameter steel penstock which splits in to two 10 ½ -foot penstocks immediately upstream from the turbines." [usbr-pdf]
Update: A reader has provided the following analysis concerning CB&Q's original route.
Some scars are still visible on recent satellite photos, providing evidence of the rail line that was west of the present line. Traveling westward/northward, the new line appears to diverge from the old line on a "causeway" (?) at www.google.com/maps/@43.2813033,-108.1351019,220m/data=!3m1!1e3 and continues another 2.2 miles before dipping its toes twice into the Boysen reservoir and finally disappearing under the surface at www.google.com/maps/@43.3196665,-108.161255,220m/data=!3m1!1e3 . North of the dam on the east riverbank is an access road to the powerhouse at the foot of the dam. That road appears to be using the original CB&Q r-o-w northward until it turns east under today's BNSF bridge over Wind River. From this point the CB&Q continued north over the river and into a short tunnel. - (Truss?) bridge at 43.42488, -108.17919 (see a poor quality 1948 aerial photo at historicaerials.com), soon to be replaced by the new bridge which hadn't been constructed yet for the aerial photo; - South portal at www.google.com/maps/@43.4252258,-108.1795703,60m/data=!3m1!1e3, visible on Google Street View at www.google.com/maps/@43.4227479,-108.1770819,3a,16.3y,323.2h,82.73t/data=!3m6!1e1!3m4!1s18dUFuHyEqDnMvannNzS7A!2e0!7i13312!8i6656 ; - North portal at www.google.com/maps/@43.4259177,-108.1799235,55m/data=!3m1!1e3 . After crossing onto the west bank, another road uses a dry creek to duck under the BNSF and continues north; this appears to be the old r-o-w again. The old line is rejoined by the new line at www.google.com/maps/@43.441234,-108.1749146,55m/data=!3m1!1e3 . See also 1. www.nprha.org/NP%20Track%20Segments%20of%20BNSF/BNSF%20Track%20Segments%20Version%2010.pdf (pg 18): "1950-MP 307.39-MP 319.54 relocated by CB&Q due to Boysen Dam Project." 2. fragis.fra.dot.gov/GISFRASafety/ search for "Bonneville Rd, Shoshoni, WY, 82649, USA" and zoom out to see mileposts of present line.
No comments:
Post a Comment