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jis

Posted 22 November 2011 - 01:38 PM

Are all JR control centers connected to the earthquake warning system for automatic shutdown or is it just the Shinkansen ones.

Of course if the thing is only 10km from the epicenter nothing can be done, but it seems to me that as the location gets further and further away from the epicenter there could be an incremental increase in survivability from derailments, no? Of course nothing is absolute panacea, but each factor counts a bit towards overall safety of the system. Whether it is over or underrated is a judgement regarding whether one believes it plays a significant role or not. Currently I have no basis for forming an overall opinion on that based on information available to me.

George Harris

Posted 22 November 2011 - 01:31 PM




The success of the Japanese lines in earthquakes due to one main factor: The nature of the Japanese concrete slab support under the rails allowed the derailed train in the one earthquake caused derailment to simply slide to a stop along the concrete. Some cars were tilted, but there was no overturning. Everybody literally walked off.

The value of earthquake detection systems is highly overrated. The warning time is measures in seconds, if that. Earthquake are not predicitble to any meaningful level of certainty with current technology.

True, but on a bullet train, seconds can mean a substantial difference in the speed you're going when the quake hits. You can't get to a complete stop, but I think cutting that speed back even by a small amount counts for something.

I absolutely agree... a derailment at 50 would be a lot less destructive than a derailment at 100... but I do know that only maybe 10 seconds could not be enough to come to a complete stop, but if yu could hook a detection system up to an emergency brake, it would make a very large difference, IMO

To get 10 seconds warning you'd have to be more that 90 kM from the epicenter. The S-Wave propagates at about 9 kM/Sec.

This is exactly my point. 10 seconds does not give you any meaningful reduction in speed. for the two earthquake derailments that we have had (oen in Japan and one in Taiwan) the speeds were well above 200 km/h in both.

For some information on derailment in Japan, go to www.jreast.co.jp/e/press/20080202/index.html

The magnitude of the earthquake was 6.8 and the train was 9.8 km from the epicenter.

The derailment stages given in the article. When reading it, understand that car No. 10 was the front car of the train and car No. 1 was the last car. When looking at the pictures, the car that is seen leaned in toward the center is the last car of the train. (Japanese railways run left-handed.) The front car and most of the rest of the train remained well centered on the track, even though off the rails.

(1) 11 axles derailed due to seismic motion.
At 17:56:06, the fourth axle of car No. 10 derailed first. Subsequently, 4 derailments occurred during large lateral movements in a 4 - 5 second interval. 11 out of 40 axles derailed.

(2) Additionally, 11 axles derailed when the track was broken by derailed wheels.
After the fourth derailment, the second, third, and fourth axles of the No. 4 car fell to the track. Continued running while pushing apart the left and right rails. The eight axles of the No. 1 and No. 2 cars then also derailed. A total of 11 axles out of 40 axles derailed.

(3) Breakage of the IJ part.
The last railcar (No. 1 car) angled into the central return channel because a glued insulated joint (IJ) broke.

(4) The train was guided by the rails even after derailment and the attitude of the train was maintained until it came to a stop.
Since the train traveled along the rails with the rails pinched between the wheels and the bogie parts, the attitude of the train was properly maintained until it came to a stop.

I know I have seen the exact speed of the train somewhere, but it was not in the article and I do not have time to hunt it up right now.

Another little factoid from another discussion on this earthquake:
In the perid of 1994 to 2003, there were 960 earthquakes of magntude 6.0 or larger. 220 of these were in Japan.
Based on this, who do you think we should talk to when discussing dealing with seismic issues?

leemell

Posted 21 November 2011 - 06:33 PM





Amazingly enough Japan's HSR infrastructure seems to have fared surprisingly well considering the circumstances. I only wish I could say the same for their infamous nuclear industry.

The Japanese HSR control system is hooked in with the amazingly good early detection system that the Japanese operate island wide. That is what has been responsible for zero casualties on the HSR from earthquakes. I have no idea if California has anything remotely resembling that to hook into.

The success of the Japanese lines in earthquakes due to one main factor: The nature of the Japanese concrete slab support under the rails allowed the derailed train in the one earthquake caused derailment to simply slide to a stop along the concrete. Some cars were tilted, but there was no overturning. Everybody literally walked off.

The value of earthquake detection systems is highly overrated. The warning time is measures in seconds, if that. Earthquake are not predicitble to any meaningful level of certainty with current technology.


True, but on a bullet train, seconds can mean a substantial difference in the speed you're going when the quake hits. You can't get to a complete stop, but I think cutting that speed back even by a small amount counts for something.


I absolutely agree... a derailment at 50 would be a lot less destructive than a derailment at 100... but I do know that only maybe 10 seconds could not be enough to come to a complete stop, but if yu could hook a detection system up to an emergency brake, it would make a very large difference, IMO


To get 10 seconds warning you'd have to be more that 90 kM from the epicenter. The S-Wave propagates at about 9 kM/Sec.

johnny.menhennet

Posted 21 November 2011 - 05:49 PM




Amazingly enough Japan's HSR infrastructure seems to have fared surprisingly well considering the circumstances. I only wish I could say the same for their infamous nuclear industry.

The Japanese HSR control system is hooked in with the amazingly good early detection system that the Japanese operate island wide. That is what has been responsible for zero casualties on the HSR from earthquakes. I have no idea if California has anything remotely resembling that to hook into.

The success of the Japanese lines in earthquakes due to one main factor: The nature of the Japanese concrete slab support under the rails allowed the derailed train in the one earthquake caused derailment to simply slide to a stop along the concrete. Some cars were tilted, but there was no overturning. Everybody literally walked off.

The value of earthquake detection systems is highly overrated. The warning time is measures in seconds, if that. Earthquake are not predicitble to any meaningful level of certainty with current technology.


True, but on a bullet train, seconds can mean a substantial difference in the speed you're going when the quake hits. You can't get to a complete stop, but I think cutting that speed back even by a small amount counts for something.


I absolutely agree... a derailment at 50 would be a lot less destructive than a derailment at 100... but I do know that only maybe 10 seconds could not be enough to come to a complete stop, but if yu could hook a detection system up to an emergency brake, it would make a very large difference, IMO

Anderson

Posted 21 November 2011 - 04:10 PM



Amazingly enough Japan's HSR infrastructure seems to have fared surprisingly well considering the circumstances. I only wish I could say the same for their infamous nuclear industry.

The Japanese HSR control system is hooked in with the amazingly good early detection system that the Japanese operate island wide. That is what has been responsible for zero casualties on the HSR from earthquakes. I have no idea if California has anything remotely resembling that to hook into.

The success of the Japanese lines in earthquakes due to one main factor: The nature of the Japanese concrete slab support under the rails allowed the derailed train in the one earthquake caused derailment to simply slide to a stop along the concrete. Some cars were tilted, but there was no overturning. Everybody literally walked off.

The value of earthquake detection systems is highly overrated. The warning time is measures in seconds, if that. Earthquake are not predicitble to any meaningful level of certainty with current technology.


True, but on a bullet train, seconds can mean a substantial difference in the speed you're going when the quake hits. You can't get to a complete stop, but I think cutting that speed back even by a small amount counts for something.

George Harris

Posted 20 November 2011 - 06:30 PM


Amazingly enough Japan's HSR infrastructure seems to have fared surprisingly well considering the circumstances. I only wish I could say the same for their infamous nuclear industry.

The Japanese HSR control system is hooked in with the amazingly good early detection system that the Japanese operate island wide. That is what has been responsible for zero casualties on the HSR from earthquakes. I have no idea if California has anything remotely resembling that to hook into.

The success of the Japanese lines in earthquakes due to one main factor: The nature of the Japanese concrete slab support under the rails allowed the derailed train in the one earthquake caused derailment to simply slide to a stop along the concrete. Some cars were tilted, but there was no overturning. Everybody literally walked off.

The value of earthquake detection systems is highly overrated. The warning time is measures in seconds, if that. Earthquake are not predicitble to any meaningful level of certainty with current technology.

jis

Posted 20 November 2011 - 05:12 PM

Amazingly enough Japan's HSR infrastructure seems to have fared surprisingly well considering the circumstances. I only wish I could say the same for their infamous nuclear industry.

The Japanese HSR control system is hooked in with the amazingly good early detection system that the Japanese operate island wide. That is what has been responsible for zero casualties on the HSR from earthquakes. I have no idea if California has anything remotely resembling that to hook into.

Devil's Advocate

Posted 20 November 2011 - 04:08 PM

Could some of the enormous cost estimates for CA's HSR have come from issues related to designing and building a system that can survive major earthquakes? This seems like a rather obvious engineering issue and money consideration, but for some reason I don't recall hearing anyone mention it in all the posts and threads I've read about it. Amazingly enough Japan's HSR infrastructure seems to have fared surprisingly well considering the circumstances. I only wish I could say the same for their infamous nuclear industry.

leemell

Posted 20 November 2011 - 03:53 PM


George,
I've looked through the plan. I've actually got a serious question: Would it be plausible, absent future funding, for CA to use $5 billion of the $12 billion they have available ($3 billion federal, $9 billion in bonds) on the initial valley segment and then to use at least some of the rest to get some sort of passenger link from LA to Bakersfield? As things stand, with the new alignment in the valley and something going to LA, I'd think you could at least manage a substantially time-improved run (the initial segment is about 130 miles long), and I'm hard-pressed to see a conventional line eating up $7 billion since you could cut down on at least a portion of the gratuitous tunneling that HSR is likely to require.

Yes, I know this wouldn't be the project of everyone's dreams, but it would both be better than nothing and it would enable direct downtown-to-downtown service if you could manage a link with Caltrain (and you'd at least have direct service between the Bay Area and LA even without that).



Yes, leemell, you have to start somewhere. No matter where the line starts someone, or even lots of someones will think it is the wrong place. You have to take a balance between the ridership demand and the ability to get something done. It was not by accident that in general the rural sections of the interstates were built before the urban sections. In fact, under the current situation where the flood of reports and ease with which every little pressure group, legitamte or otherwise, can stop things, most of the interstate system and probably almost all of the urban portions would not have been built at all. If you have a better idea of where to start, don't keep it a secret, but be sure to bring a large checkbook, because in many ways this section is the "low hanging fruit" in both implementation time and cost.


That is exactly the point I was trying to make in very short simple sentences for the OP.

afigg

Posted 20 November 2011 - 12:17 PM

Of course, there's always the question of how much could be accomplished with some track work and so forth, but I do definitely see your point. I suspect the question does come down to a combination of what route you use, how much you're willing to spend to straighten the track out, and so forth.

By the way, two other questions:
1) How much is the link from San Jose to the Valley Line expected to cost, and is there existing RoW that a redirected San Joaquin could use to get to San Francisco?
2) Is there a way that a train could get from Bakersfield to LAX quicker than Antelope Valley would seem to allow?

I agree with Mr. Harris that the cost of building a slower but decent average speed diesel power line from Bakersfield to Palmdale and to LA may be a significant percentage of the cost of building a true HSR line. The route from Bakersfield to LA, whichever actual route is chosen, will have to go through some of the most challenging terrain, geography, and elevation changes of any prospective HSR or passenger train corridor in the US. Given the cost and the years it will take either way and the political challenges of building a new passenger corridor from Bakersfield to LA, might as well get it right the first time.

There may be cost compromises such as running the HSR trains at slower speeds through the tunnels to allow for smaller tunnel sizes or use steeper grades for shorter routes. The faster the speed the larger the tunnel diameter has to be to prevent pressure shockwaves from injuring the passengers. These sort of details and design issues are discussed in the many, many engineering and study documents on the CHSRA website. Here are the CHSRA Bakersfield to Palmdale studies, presentations, alternative route analysis, etc. Click on the Project Section, Library, Studies links on the right side for days and days of reading material if you are interested.

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