I attended church at the LDS church in the town of Shasta Lake this morning. The Shasta Lake Ward is one of the friendliest congregations I have met with on this vacation! They gave me a very warm welcome. A good number of the members introduced themselves to me and told me they were glad I was there.
One of the women introduced herself as Paivi, which I recognized as a Finnish name. She's said she is not Finnish, but her father did missionary work in Finland, just like I did many years ago. He served a decade or two before me, and in different cities, but it was fun talking with him.
We met for the tour at the base of the second tower, near the top of the spillway. The plaque on the wall outside the tower entrance reminds us for whom the dam was built. 😀
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Below are closeups of one of the General Electric generators and its coil. Water spins a turbine, which is connected by a shaft to the generator coil. When the turbine spins, so does the coil, and the spinning coil produces electricity.
The far end of the diversion tunnel has been blocked, and the tunnel is currently used as a storage room.
Today was the monthly testimony meeting. Everyone who spoke was open with their experiences, down to earth, and I enjoyed listening to them. If I'm ever in the area again on a Sunday, I wouldn't hesitate to visit this ward again.
-- Shasta Dam --
After church, I drove to Shasta Dam and took the dam tour. Since I skipped visiting Hoover Dam near the beginning of my vacation, this was a fitting thing to do near the end. I enjoyed talking with the visitor center staff after my tour, and as one of them pointed out, the Shasta Dam tour is free, whereas the Hoover Dam parking is $10 and the tours are $15 to $30.
Shasta Dam has 15 million tons of concrete, which they say will take around 100 years to cure. Since the dam was constructed between 1938 and 1945, the concrete will be curing for several more years! It is the second largest concrete dam in the country -- second only to the Grand Coulee Dam in Washington.
The Shasta Dam is on the Sacramento River. The water is used both for hydroelectric power and for downstream irrigation in the California's central valley.
Mount Shasta is visible from the dam. The dam has a capacity of 4.5 million acre feet of water. I was told the water level is at about 57% of capacity right now.
Looking over the top of the dam in the downstream direction, the spillway and the 5 penstock pipes that feed water to the the hydroelectric turbines can be seen in the photos below. In the second photo, the electrical wires from the dam to the power distribution area are visible above the water.
The guard and tour guide unlocked the door. We had to empty our pockets and go through a metal detector before entering the dam. We then took a one minute elevator ride down to the tunnel pictured below. The tunnel shows how thick the dam is -- at one end is the lake, and the other end is the downstream side of the dam.
We emerged from the tunnel and walked outside to look up at the spillway. The spillway holes for releasing water are 8 feet in diameter! A few of the valves leak, and could use some maintenance, but they don't leak drastically.
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Our tour guide stood in front of a diagram that describes the basic workings of the dam. If the dam needs to release water but doesn't need to produce hydroelectric power, valves are opened in the spillway, allowing water to release. If the dam gets too full and water is nearing the top, there are 3 gates at the top of the spillway that can be opened to release water and keep that dam from overfilling.
To produce hydroelectric power, water is released into penstock pipes instead of being released onto the spillway. There are 5 penstock pipes. One or more can be opened, depending on how much power needs to be generated. The pipes feed the water to the 5 turbines that turn power generating coils.
The target temperature for release water is somewhere around 50 degrees. The water needs to be cool for the salmon and other fish that live in the river. King salmon swim upstream on the Sacramento river to spawn.
Below is a photo of the 5 penstock pipes that feed the generators. To give an idea of their size, our tour guide told us each pipe is large enough that a bus could be driven through it.
Next we went into the power generation room. Only one of the five generators was turning and generating power when we were there. A state power authority sets the schedule for generating power, deciding how many generators to activate and at what times, for each dam in the California.
A large hoist on rollers, high in the room, has hooks for lifting and doing maintenance on the generators. The generators actually produce twice as much power as they originally produced when they were first installed, due to more efficient windings on the generator coils.
Frank Crowe, the man who was in charge of constructing Hoover Dam, was also in charge of constructing Shasta Dam. Many of the 4,700 construction workers working on Shasta Dam had previously worked on Hoover Dam. Rocks needed for the concrete were excavated from downstream on the Sacramento River, and carried to the worksite on the 10 mile conveyor belt pictured below.
During dam construction, the river water had to be temporarily diverted into a diversion tunnel while the base of the dam was prepared and the concrete poured. An existing train tunnel was used for the diversion tunnel. The train tracks were rerouted to go around what would become Lake Shasta, as they otherwise would have been under water after the dam was built.
The dam tour was very worthwhile. Afterwards, I watched a movie of the dam construction in the visitor center, and then talked with some of the staff.
-- Sundial Bridge --
The Sundial Bridge is a footbridge that spans the Sacramento river in Redding. It is a beautiful bridge that actually works as a sundial. The tower points north, and the shadow can actually be used to mark time during the Summer months.
No part of the bridge touches the water, and the walkway is transparent glass. This lets light pass through the bridge and causes minimal disturbance to the fish below. Chinook salmon, also known as King salmon, swim upstream on the river to spawn.
Tension on the cables from the tower to the walkway helps hold the bridge up, and eliminates the need for footings in the water.
Along one of the banks, a tile arc on the ground has round markers identifying the time of day the sundial's shadow will pass that point on the ground at Summer solstice. The markers are for times between 11 am - 3 pm. The photo below shows the point the shadow will cross at 1:15 pm on June 21 of each year. When visible and moving across the tile arc, the shadow moves about one foot per minute.
I'll be spending the night at the Redding Winco again tonight. Tomorrow I'll head home to Rocklin so I can vote on Tuesday. Otherwise, I would probably stay out for a few more days.
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