Posted on 02/12/2017 4:26:47 PM PST by janetjanet998
Edited on 02/12/2017 9:33:58 PM PST by Admin Moderator. [history]
The Oroville Dam is the highest in the nation.
OH NO!
Take care of yourself. We all greatly appreciate the work you have done on this thread, and hope it will also find its way into the formal analysis of this mess.
Prayers up.
Get well.
You need to take care. Educated FReepers are in short supply sometimes.
Take care of yourself first.
Your input is appreciated.
Bets wishes and good luck with the ticker.
Mrs alfa6 has had some issues with arrhythmia in the past so I have a bit of understanding .
Best Regards
alfa6 ;>}
Something interesting. This image is no longer found in the image gallery. Not sure why. I put notes on this "saved" image - i.e of points of note. Perhaps DWR felt that the slop of hardened repair mortar looked unprofessional and removed it from the gallery (btw- another "lake view" reservoir image inserted in replacing this one).
Not sure what to make of the odd tilt of the rock bolt. Checking zooms of other rock bolts (they all look perfect & straight vertical) and accounting for camera angle, this rock bolt shows a "tilt". Perhaps the drilling angle was specified from what was observed with the ground penetrating radar.
Deleted DWR image from gallery. Tilted rock bolt. Mortar slop, chipped repair mortar (assumed from recent spillway flow).
For "tilt" reference - compare vertical angle of corner of plate to edges of nut.
Intel Corp, back in 1979 & early 80's had the absolute finest drafting tables. Electric motor height control, tilt control, glass back lit surface (for layout drafting tape design on mylar D size sheets), swing arms with precision angle degree rotation compass pivots for clear acrylic delineated square angle ruler ... weighed a ton.
My engineering lab cubicle was across from a drafter who loved smoking -pipes & cigars (cigarettes too). That was back when smoking was ok in the workplace.
We used the guy to help in an airflow analysis of a new high-tech "switcher" power supply module. He'd suck on a cigar 'till the cherry was about to drop, then blow into a tube. The eddy turbulence in the airflow identified "dead" spots that the mini fan cfs induced (used clear acrylic enclosure pieces in place of the metal enclosure to view the electronics).
Hi Meyer, here is your answer to the 6th turbine. There is an interesting backstory to this. DWR has been stating that flow has been at maximum through the powerhouse, yet they did not mention that this conflicts with one of the turbines being out of service. The press has noted this discrepancy. The issue becomes "accuracy" in specifics in DWR statements to the press/public, especially in the high state of interest in this spillway crisis.
= = Article clip:
"Oroville >> During the Oroville Dam spillway crisis, the state Department of Water Resources has frequently said the Hyatt Powerplant was releasing flows at maximum capacity, but technically, thats impossible."
"Inside the hydroelectric plant are six turbines, machines that produce power by water flowing through a wheel or motor. And one of those turbines has been out of commission since August 2015."
"When asked by this newspaper about DWRs claim the plant is operating at full capacity, Lauren Bisnett, a department spokeswoman, said the turbine will be reinstalled by December."
= = end clip
= = Article clip: (emphasis mine)
"Requests to DWR to interview an employee who could speak about powerplant operation specifics were not granted Wednesday or Thursday this week. Questions continue to be filtered through a public information officer and responded to via email by a PIO."
= = end clip
Lake Oroville turbine, out of order since 2015, inoperable for rest of year
Zoom with angle reference lines illustrating the tilt to this particular rock bolt. Investigations of other rock bolts in images show they are accurately vertical to the concrete surface.
IMO: I'm beginning to suspect they ran into unstable rock as this side of the spillway has shown known "seams" of rock that have easily caved away from the damaged end view of the upper spillway (before covered with mesh/shotcrete). They may have had to re-angle the drill to get a better anchor emplacement in rock.
Aligned angle point lines reveal a tilt angle to this particular emplaced rock bolt - angle is 3 degrees arc left from vertical. Suspect drilling ran into poor rock & re-drilled at a new angle.
I wonder if the bolt was installed slightly off angle. They might have been hurrying to get the last few in, and they were operating the drilling rig on a fairly steep slope towards the bottom of the spillway.
Something to watch for certain.
Thanks for the info regarding the 6th turbine. I had read that the turbine was removed for rebuild/overhaul/maintenance but didn’t have a lot of details as to the extent of the work.
It sounds like a complete rebuild, which would explain why it was taken off site. Routine maintenance would have been done on site, either by employees or contractors that specialize in specific aspects of the maintenance.
I’m curious now, and will look into it further - they did some upgrade work at several of TVA’s hydro plants over the last several years, which in many cases ended up with a slight increase in efficiency (more MW for the same water flow) due to a revised turbine blade design. I wonder if that’s what they’re doing at the “Mighty Hyatt”...
I guess you more-or-less answered my post before I sent it. :)
View of more emplaced rock bolts with Excavators in the distance.
This one was emplaced in the middle of the drilling repair process.
The extra mortar on the spillway may have been from excessive pressurized mortar "back ejection" from a second attempt at an angled re-drill. If there are any "drill experts" out there, chime in... this may be part of why the image was pulled from the gallery (i.e. revealed a bit more to the situation).
Someone left their boot prints in the mortar. You’d think that walking on a paste type of material with the angled slope would be unwise. OSHA?
A little more information on the Hyatt Powerplant refurbishment operation.....
The article is from 2009, but describes some of the ongoing work that was done in the 2000-2010 decade to refurbish some of the generator units at the Hyatt plant. I doubt that it relates to today’s situation - that is, I’m certain that they haven’t had unit 6 out for that many years. Although, budgets being what they are in government, they may not have started the unit 6 work until recently. (as a side note, the Chickamauga Dam lock replacement project in Chattanooga has been sitting in an idle, half-competed condition since George W. Bush left office).
Here, also for your viewing pleasure, is a slideshow presentation on the work done on units 2 and 4, with an implied project to continue on to unit 6. This is dated 2006...
http://www.slideserve.com/foster/project-status-update-hyatt-modernization-program
And one more link on the power plant, this one from the California DWR, with some nice pictures. There seem to be some discrepancy on the megawatt/MVA capacity of the 6 units depending on what source you read. I don’t know why.
This may have been linked to earlier in the thread.
https://mavensnotebook.com/wp-content/uploads/2017/02/Hyatt-Powerplant-Oroville-Dam.pdf
SHhhhhh......
Don’t tell OSHA! They’ll be demanding to see everyone’s work boots!
State and federal officials make Oroville Dam report secret
Citing potential security risks, state and federal officials have blocked the publics ability to review the latest report from an independent panel of experts brought in to guide state officials repairs at the crippled Oroville Dam.
The move to block the report comes eight days after The Sacramento Bee reported on a earlier memo drafted by the four engineering consultants that pointed out troubling design flaws at Oroville Dams main spillway that might have led to the crater to form in its center on Feb. 7. Problems with the adjacent emergency spillway triggered two-day evacuations of nearly 200,000 people Feb. 12.
Read more here: http://www.sacbee.com/news/state/california/water-and-drought/article141963119.html#storylink=cpy
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