Caldecott Tunnel & Devil's Slide Tunnel Shutdowns

[jeffe]

Both the Caldecott Tunnel on CA-24 and the Tom Lantos (Devil's Slide) Tunnel on CA-1 are scheduled to be shutdown either late tonight (Oct 8) or early tomorrow morning due to the PG&E Power Safety Shutoff impacting most of Northern California.

The shutdown of the Caldecott Tunnel will have a major impact; there's really no good alternate routes available.

Info from Caltrans:
https://twitter.com/CaltransD4/status/1181738374610092032

[Max Rockatansky]

Open Old Pedro Mountain Road and the Kennedy Tunnel back to traffic. 

[Plutonic Panda]

Is this normal? I have not ever heard of this and I'd be raising hell if I were a homeowner living here. They are paying money for a service and it's being willingly shut off. If the lines are that much of a threat above ground then they should be underground where necessary.

[Max Rockatansky]

Is this normal? I have not ever heard of this and I'd be raising hell if I were a homeowner living here. They are paying money for a service and it's being willingly shut off. If the lines are that much of a threat above ground then they should be underground where necessary.

None of it is normal but it's been known for about a year after Paradise that things like this would happen.  The problem the lighting and ventilation systems just aren't going to (granted I'm not certain what generator capacities they have) without power.  In the case of older Caldecott bores those are pretty nerve wracking to drive through when the lights go out. 

[rickmastfan67]

Caldecott, Devil's Slide Tunnels to remain open during PG&E power shutoffs

[Duke87]

Is this normal? I have not ever heard of this and I'd be raising hell if I were a homeowner living here. They are paying money for a service and it's being willingly shut off. If the lines are that much of a threat above ground then they should be underground where necessary.

PG&E has started doing work with this general goal in mind - not moving lines underground, but trimming vegetation away from them and adding insulation to wires that are currently uninsulated.

Problem is PG&E owns a lot of wires and it's going to be quite a few years before they're able to get this work done.


In the meantime, PG&E is currently in chapter 11 bankruptcy because they're on the hook for tens of billions of dollars in damage caused by wildfires over the past few years that their equipment was determined to have started. So they have a serious problem and they're taking extreme measures to prevent adding to their already crippling pile of liabilities.


It should be noted as well that it's not just the tunnels that are impacted - as many as 800,000 PG&E customers are potentially going to have no power for several days.


That said, I do find it interesting that these tunnels lack any source of backup power.
EDIT: Okay so CalTrans has figured out how to have a few generators carted in and hooked up so they can keep the tunnels open. That's good, though it's still interesting that there is no such solution permanently installed.

[Beltway]

the PG&E Power Safety Shutoff impacting most of Northern California.

I never heard of something like this.  Is California now a third world country?  Is this the real reason or is it because of underbuilt generating capacity?

What is a Public Safety Power Shutoff?

For public safety, it may be necessary for us to turn off electricity when gusty winds and dry conditions, combined with a heightened fire risk, are forecasted. This is called a "Public Safety Power Shutoff"  or "PSPS."

While customers in high fire-threat areas are more likely to be affected, any of PG&E's more than 5 million electric customers could have their power shut off. This is because the energy system relies on power lines working together to provide electricity across cities, counties and regions.

https://www.pge.com/en_US/safety/emergency-preparedness/natural-disaster/wildfires/public-safety-power-shutoff-faq.page

[Max Rockatansky]

the PG&E Power Safety Shutoff impacting most of Northern California.

I never heard of something like this.  Is California now a third world country?  Is this the real reason or is it because of underbuilt generating capacity?

What is a Public Safety Power Shutoff?

For public safety, it may be necessary for us to turn off electricity when gusty winds and dry conditions, combined with a heightened fire risk, are forecasted. This is called a "Public Safety Power Shutoff"  or "PSPS."

While customers in high fire-threat areas are more likely to be affected, any of PG&E's more than 5 million electric customers could have their power shut off. This is because the energy system relies on power lines working together to provide electricity across cities, counties and regions.

https://www.pge.com/en_US/safety/emergency-preparedness/natural-disaster/wildfires/public-safety-power-shutoff-faq.page

The problem is much of the power grid in California is hydroelectric based and located in really dry wooded mountain areas.  Right now the Santa Ana Winds are hitting which is what is prompting these closures.  PG&E has found liable in a lot of these recent larger fires due to poor infrastructure maintenance.  That said even some of the other utility companies are having the same issue on a smaller scale.  If I recall correctly Southern California Edison which owns the Big Creek Project might have outages affecting about 100,000 people. 

[Beltway]

The problem is much of the power grid in California is hydroelectric based and located in really dry wooded mountain areas.  Right now the Santa Ana Winds are hitting which is what is prompting these closures.  PG&E has found liable in a lot of these recent larger fires due to poor infrastructure maintenance.  That said even some of the other utility companies are having the same issue on a smaller scale.  If I recall correctly Southern California Edison which owns the Big Creek Project might have outages affecting about 100,000 people. 

There have been a number of national news articles criticizing the forestal management practices in the state, saying that it greatly exacerbates the flammability of many of these areas, which leads to wildfires starting and then raging out of control.

So now an area of about 500 thousand population may be without power for 48 to 72 hours, including businesses and possibly the lighting of critical infrastructure including highway tunnels.

What about BART?  That requires electricity and lots of it.

[gonealookin]

That said, I do find it interesting that these tunnels lack any source of backup power.
EDIT: Okay so CalTrans has figured out how to have a few generators carted in and hooked up so they can keep the tunnels open. That's good, though it's still interesting that there is no such solution permanently installed.

Here's what they're giving as the explanation for that:
https://www.eastbaytimes.com/2019/10/08/caldecott-tom-lantos-tunnels-to-close-amid-power-outage/

Ney said crews had to work through the night to install the generators and that the state transit agency was already in the process of ordering permanent ones for the future.

"We've always known we would need backup generators,"  he said.

The tunnel has previously been immune from power outages because it draws power from both ends, from two different counties on different parts of the electricity grid, Ney said. He added that this was the first time Caltrans faced the possibility of losing power from both ends.
...
According to Tavares, the generators are temporary and smaller than a permanent backup generator, which is what is needed. Tavares said that in June 2019 he ordered a contract to get funding from the states's Office of Emergency Services to get a permanent backup generator. The generator, which costs about $6 million to build and install, is expected to be ready by spring 2020.

The exhaust fans in the Caldecott need electricity to move vehicle exhaust out of the tunnel. Tavares said the generators on site were not strong enough to power all the systems in the tunnel.

He also said he "could not imagine"  that the power would be shutoff to both substations of the Caldecott and that was "extremely surprised"  when he discovered last spring that there was no infrastructure to support a shutdown like this.

[Max Rockatansky]

The problem is much of the power grid in California is hydroelectric based and located in really dry wooded mountain areas.  Right now the Santa Ana Winds are hitting which is what is prompting these closures.  PG&E has found liable in a lot of these recent larger fires due to poor infrastructure maintenance.  That said even some of the other utility companies are having the same issue on a smaller scale.  If I recall correctly Southern California Edison which owns the Big Creek Project might have outages affecting about 100,000 people. 

There have been a number of national news articles criticizing the forestal management practices in the state, saying that it greatly exacerbates the flammability of many of these areas, which leads to wildfires starting and then raging out of control.

So now an area of about 500 thousand population may be without power for 48 to 72 hours, including businesses and possibly the lighting of critical infrastructure including highway tunnels.

What about BART?  That requires electricity and lots of it.

Apparently Bay Area Rapid Transit is unaffected.  That system might be tied to power grids owned by the City of San Francisco. 

[Beltway]

Close to 2 million people --
https://www.youtube.com/watch?v=Q6RDhj-NHAg

[Techknow]

Yes, the number of affected people would be in the millions because a PG&E customer is actually a household unit. Still a large number of households are affected, even though the public power shutoff does not affect many urban areas in the Peninsula, South Bay, and East Bay portions of the Bay Area, among other places.

[jeffe]

What about BART?  That requires electricity and lots of it.

Apparently Bay Area Rapid Transit is unaffected.  That system might be tied to power grids owned by the City of San Francisco.

BART gets it track power directly from the transmission grid at multiple connection points.  The power shutdown is only impacting distribution lines and not the transmission grid.  These connection points are linked by BART's own 34.5 KV network, so BART can operate even with a loss of some of the connection points.

The stations themselves are powered by the local distribution grid.  BART has a mix of permanent and portable generator to keep the stations running.

I never heard of something like this.  Is California now a third world country?  Is this the real reason or is it because of underbuilt generating capacity?

PG&E has been underinvesting in its infrastructure since the early 1990s. The Energy Policy Act of 1992 started deregulation with the unbundling of generation and transmission. In preparation for this, PG&E laid off lineworkers and reduced maintenance spending.  In 1996 the electricity market was further deregulated in California and PG&E started acting less like a traditional utility and more like a for profit company focused on quarterly results.  Between 2000 and 2015 PG&E shifted $100 million from safety and maintenance to profit for stockholders and bonuses for executives.  [Source]

We're now seeing the results of almost 30 years of deferred maintenance.  Last year's fire that killed 85 people and caused $16.5 billion in damage was caused by the failure of a 99 year old transmission tower with a design life of 75 years.  Other towers on the same line had collapsed in previous years due to storms, but no fires were started due to the rain.  PG&E had allocated money to replace this line, but the money was diverted to profits and the improvement were never made.

[Beltway]

BART gets it track power directly from the transmission grid at multiple connection points.  The power shutdown is only impacting distribution lines and not the transmission grid.  These connection points are linked by BART's own 34.5 KV network, so BART can operate even with a loss of some of the connection points.
The stations themselves are powered by the local distribution grid.  BART has a mix of permanent and portable generator to keep the stations running.

That would take a lot of diesel fuel to keep backup generators running and generating that much electricity.

From their website --
BART is one of the largest consumers of electric power in Northern California, using about 400,000 megawatt hours of electricity annually.  This is about as much as the City of Alameda uses each year.
...

Over 1 gigawatt hours per day.  Do they really have enough generators stationed around the system, with enough fuel onsite, to provide the needed full operating power, as in normal-length trains on normal headways?

We're now seeing the results of almost 30 years of deferred maintenance.  Last year's fire that killed 85 people and caused $16.5 billion in damage was caused by the failure of a 99 year old transmission tower with a design life of 75 years.  Other towers on the same line had collapsed in previous years due to storms, but no fires were started due to the rain.  PG&E had allocated money to replace this line, but the money was diverted to profits and the improvement were never made.

They are not the only ones.  Dominion Energy here in Virginia doesn't deal with wildfires, but it is an ongoing frustration with lack of right-of-way maintenance and tree-trimming, so while power outages were very rare 30 years ago, now all it takes is a bad thunderstorm and tens of thousands (or more sometimes) customers lose power for several days in a metro of a million population, and crews have to go out and fix the breakages.  With a tropical storm the outage percentage and time to restore is much worse.

They are doing "strategic undergounding" projects in some neighborhoods that have had lots of "mature tree growth" (as in trees that now are 70 to 100 feet tall), but this is maybe 1% of the customers at best.

[deathtopumpkins]

BART gets it track power directly from the transmission grid at multiple connection points.  The power shutdown is only impacting distribution lines and not the transmission grid.  These connection points are linked by BART's own 34.5 KV network, so BART can operate even with a loss of some of the connection points.
The stations themselves are powered by the local distribution grid.  BART has a mix of permanent and portable generator to keep the stations running.

That would take a lot of diesel fuel to keep backup generators running and generating that much electricity.

From their website --
BART is one of the largest consumers of electric power in Northern California, using about 400,000 megawatt hours of electricity annually.  This is about as much as the City of Alameda uses each year.
...

Over 1 gigawatt hours per day.  Do they really have enough generators stationed around the system, with enough fuel onsite, to provide the needed full operating power, as in normal-length trains on normal headways?

Read the post you're quoting again. The generators only power stations. I think we can safely assume the majority of that 400,000 MWh is for traction power, which is NOT affected.

[Beltway]

Over 1 gigawatt hours per day.  Do they really have enough generators stationed around the system, with enough fuel onsite, to provide the needed full operating power, as in normal-length trains on normal headways?

Read the post you're quoting again. The generators only power stations. I think we can safely assume the majority of that 400,000 MWh is for traction power, which is NOT affected.

112 mile long rapid rail transit system with service of the downtowns of S.F. and Oakland, with suburban lines to Millbrae, South Fremont, Pleasanton, Antioch and Richmond.

So this power outage isn't going to interfere with commercial grid power reaching every part of the system?

BART's own 34.5 KV network doesn't need to get power from the commercial grid?

[ClassicHasClass]

You mean the Public Utility Safety Power Shutoffs.

SCE's turn down south (about 13,000 customers down as of this writing), though the turmoil should be a lot less because SCE's physical plant is much better than PG&E's (it could hardly be worse, admittedly). For example, the circuit in my neighbourhood is all buried, so we're not on the shutoff consideration list. I don't know of any tunnels in So Cal presently affected.

[jeffe]

BART's own 34.5 KV network doesn't need to get power from the commercial grid?

BART has their own substations that convert the 230 or 115 KV transmission voltage to 34.5 KV. The transmission grid, which uses steel towers, is considered robust enough that it will not be impacted by the high winds.  PG&E has boasted about the extensive repairs to they made to the transmission network, which can also highlight how decrepit the system was, based on one's point of view.  The transmission grid will not be shutdown, so BART traction power will keep working.

The distribution grid, which operates at 21, 12, and 4 KV, uses wooden poles.  These are more vulnerable to damage from trees, bare conductors slapping together, and mechanical failure from lack of maintenance.   Certain circuits in the distribution grid that run through high fire risk areas are what is being shut down.  The stations themselves, or "house power" as BART calls it, are fed by these circuits and will need backup generators.  The station demand is small compared to the traction power demands and can fed by a generator the size of a fridge, or so.

That said, I do find it interesting that these tunnels lack any source of backup power.
EDIT: Okay so CalTrans has figured out how to have a few generators carted in and hooked up so they can keep the tunnels open. That's good, though it's still interesting that there is no such solution permanently installed.

Yeah, I was surprised by this too. The thinking was that the Caldecott tunnel is served by two separate substations in two separate counties so the risk of a dual failure was low. However, Caltrans did realize that this was still vulnerable and is in the process of purchasing its own custom-build 3-megawatt generator to provide power in future emergencies. The $6 million generator is expected to be delivered in Spring 2020.
[source]

[Beltway]

BART's own 34.5 KV network doesn't need to get power from the commercial grid?

BART has their own substations that convert the 230 or 115 KV transmission voltage to 34.5 KV. The transmission grid, which uses steel towers, is considered robust enough that it will not be impacted by the high winds.  PG&E has boasted about the extensive repairs to they made to the transmission network, which can also highlight how decrepit the system was, based on one's point of view.  The transmission grid will not be shutdown, so BART traction power will keep working.

The BART railroad is an extensive and widely dispersed network.  Does the main transmission grid have enough interface points to directly connect to -all- the BART substations?

[jeffe]

The BART railroad is an extensive and widely dispersed network.  Does the main transmission grid have enough interface points to directly connect to -all- the BART substations?

BART has two types of substations:

• Traction power, which converts the 34.5 KV into 1000 V DC
• Bulk power, which converts 115 KV from the transmission grid into 34.5 KV.  This is also where the power is metered for billing purposes.

There are over 60 traction power substations.  Transmitting power via the 3rd rail isn't very efficient; the original design was a steel I-beam with aluminum filled in on one side to improve conductivity.  The updated design is an aluminum I-beam with a stainless steel cap.  This newer design allows for the substations to be spaced further apart.

There are 12 bulk power substations.  Running 115 KV lines and installing 115 KV transformers at each of the more than 60 traction power substation would be cost prohibitive.  This is why the bulk substation are used to power the 34.5 KV cable, which then powers the traction substations.

All of the 12 bulk substations are connected together via the 34.5 KV cables with three exceptions:

• There is no cable through the Transbay tube
• The Contra Costa line has 3 bulk substations but is not connected to the rest of the system
• The Richmond has only 1 bulk substation and is not connected to the rest of the system

There's a map on page 4 here.  It seems like the Richmond line has a single point of failure.

[Beltway]

So every part of BART is connected to the bulk substations thru the 34.5 KV cables?

I can see where the transbay tube would not have the 34.5 KV cable, as I would surmise that traction power would be supplied at each end.