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Old February 4th, 2013, 10:37 PM   #1341
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I have to say, I am quite pleased by the flat nose on CRH6. It would look good for regional and intercity services, I think.

By the way, is it known if any of the technology bought from Bombardier, Siemens and Alstom is used in CRH6, or can CSR/CNR freely offer this product on the world wide market? It might be interesting to see the manufacturer entering European rolling stock procurements with CRH6.
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Old February 4th, 2013, 11:48 PM   #1342
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The CRH380A was initially designed to be CRH400A with a 400km/h service speed, but that was deemed crazy and reduced to 380km/h. So technically they should test it 440km/h, but I get what you are saying, which I think was why it was initially tested at 416km/h when the train was introduced on the Shanghai-Hangzhou line. Now we know it can safely travel at 486km/h without any modifications.
I would rather say that the train has travelled at 486km/h without derailing. We do not know what technical problems emerged during the trial. (i.e.' excessive wear of catenary, of pantograph, of engines, wheel behaviour, rail - wheel interactions, etc).

It has has been known for sometime that it is possibile to travel at speed above 400km/h. Indeed the French did push their TGV at 515 km/h as far as 1991, and thri conventiona trains were pushed up 355 km/h as far back as 1955.(if I remeber correctly).

The problem is that, at the moment, with the available technology, is extremely uneconomical to travel at MaxSpeed in excess 320 km/h. The Chinese have soon discovered this factor , as soon as they pushed the top commercial speed at 350 km/h.

The rail/wheel adherence limit is estimated to be around 630 -700 km/h , and above this speed the train tends to derail The catenary limits are estimated to be around 620 km/h....

I suspect that in the near future the Chinese Governement will authorise commercial top speed in the range of 320-330 km/h. This appears to be a reasonable compromise between wear and tear of the roling stock and of the infrastructure and cost/revenue.

However, the Chinese have built their HSLs with extremely long sections in which the trains can constantly run at 300+ km/h. Therefore the average commercial speed is extremely impressive, even if they run HSTs at only 300 km/h.

I suspect that the maglev is better suited for 500+ km/h ( or 1000+ km/h?) top speed, and China has the size and the volume of passengers (and now the technolgy..) for the maglev trains.

Who knows: in 20 years there China could well have a Shanghai-Beijing maglev service......
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Old February 4th, 2013, 11:50 PM   #1343
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Whaaat?
Sorry I was a little carried away by your exciting RCT posting
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Old February 5th, 2013, 01:05 AM   #1344
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I think that the critical speed is where the boogies start to have too much hunting oscillation and other vibrations, for them to be deemed safe.
Yes.
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Old February 5th, 2013, 10:21 PM   #1345
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CRH3A


hello! I wonder how can small but photos of these trains? Behind this photo is a mockup of a metro train in Rio de Janeiro, Brazil.
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Old February 6th, 2013, 12:30 AM   #1346
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I would rather say that the train has travelled at 486km/h without derailing. We do not know what technical problems emerged during the trial. (i.e.' excessive wear of catenary, of pantograph, of engines, wheel behaviour, rail - wheel interactions, etc).

It has has been known for sometime that it is possibile to travel at speed above 400km/h. Indeed the French did push their TGV at 515 km/h as far as 1991, and thri conventiona trains were pushed up 355 km/h as far back as 1955.(if I remeber correctly).

The problem is that, at the moment, with the available technology, is extremely uneconomical to travel at MaxSpeed in excess 320 km/h. The Chinese have soon discovered this factor , as soon as they pushed the top commercial speed at 350 km/h.

The rail/wheel adherence limit is estimated to be around 630 -700 km/h , and above this speed the train tends to derail The catenary limits are estimated to be around 620 km/h....

I suspect that in the near future the Chinese Governement will authorise commercial top speed in the range of 320-330 km/h. This appears to be a reasonable compromise between wear and tear of the roling stock and of the infrastructure and cost/revenue.

However, the Chinese have built their HSLs with extremely long sections in which the trains can constantly run at 300+ km/h. Therefore the average commercial speed is extremely impressive, even if they run HSTs at only 300 km/h.

I suspect that the maglev is better suited for 500+ km/h ( or 1000+ km/h?) top speed, and China has the size and the volume of passengers (and now the technolgy..) for the maglev trains.

Who knows: in 20 years there China could well have a Shanghai-Beijing maglev service......

Very interesting. So it just happens that the law of physics causes significantly more wear and tear as trains go above 320km/h? I'm not sure what can be changed. It seems that the Chinese have increased speeds by brute force but are now running into obstacles that results from going that fast.

Kinda blows my hopes for seeing trains run at 350-380km/h and that super cool looking CRH500 running at 500km/h. Are there an changes that could be made to make those speeds economical? Different metal for catenary wires or different material for wheels?
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Old February 6th, 2013, 12:50 AM   #1347
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You could try reducing wear and tear by having the trains run in a vacuum, but I expect that to be quite a costly operation. If speeds as high as 500 kph are needed, it might be more interesting to opt for maglev instead.
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Old February 6th, 2013, 01:20 AM   #1348
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Very interesting. So it just happens that the law of physics causes significantly more wear and tear as trains go above 320km/h? I'm not sure what can be changed. It seems that the Chinese have increased speeds by brute force but are now running into obstacles that results from going that fast.

Kinda blows my hopes for seeing trains run at 350-380km/h and that super cool looking CRH500 running at 500km/h. Are there an changes that could be made to make those speeds economical? Different metal for catenary wires or different material for wheels?
FM,

Yes.

Above 300 km/h the air resitance becomes the prevalent factor.

For instance, a TGV Duplex consumes 40% more energy when travelling at 360 km/h compared to what it consumes when it is travelling at 300 km/h.

Also this causes premature wear and tear to the engines wheels, infrastructure etc.

To exceed quickly the 500 km/h the TGV modified was made of 2 locos + 3 carriages, the latter with 1-2 bogie/s motorised. The prototype which broke the world record reaching 574,8 km/h developed about 19800 Kw for a train weighing about 230 tons.

The experimental CIT500 has similar feature.

Futhermore in order to travel in excess of 500 km/h the French strenghtened the catenary.

(The pantogragrah exterting pressure on the catenary tends to create wawes/oscillations of catenary which, in turn, can cause the detachment of the panto from the catenary and the formation of arches).

The theoretical limit for the French type of streghtened HSL type of catenary is 620 km/h.

For the German type of catenary the theoretical limit is about 590 km/h..

Another problem is caused by the friction exerted on the contact between pantograph and cantenary.

Finally, above 550 km/h the train tends to "take off" and detach itself from the rail....

To make it possibile to travel more economically at speed abore 300-320 km/h you t make the train lighter and more powerful , with a smaller frontal section (i.e: Talgo Avril 380 , which is still on the drawing boards); and, hopefully it wil be possibile to attain 380 km/h commercial speed, but these services will be limited only to some lines.

One will have to build a train carryng 1 pax for every 500kg of weight of the train and being capable of travelling at 380 km/h consuming only 20 ~30% more than a conventional HS train travelling at 300 km/h.

But..... that's it.


On the other hands the maglev is a train with half of engine acting as tracks and lifting mechanism.

The maglev has no contact therefore no friction with the rails, it has no friction between pantograph and catenary becuase it doesn't need pantograph and catenary, and it does not have wheels and bogies......

It is ligher than the conventional train and offer more and better performance/energy comsumption ratio than conventional train or plain.

The only limitation it has is the air-resistance exerted at subsonic/supersonic speed.

This can be overcome putting the maglev in a tunnel or in a tube, in which a partial vacuum has been created.


In order to obtain quickly a sustantial experience on the HS train sector the Chinese, very wisely bought Japanese, French and German technology and soon they will be able to export on a global scale the tecnology acquired.

Furthermore, in my opionion, China is very weel suited to develop a network of subsonic and supersonic maglevs systems.

Very likely, in about 2-4 decades, China will have an extensive network made of:

1-
a network of convetional trains travelling at 160-220 km/h
2-
a network of Very high speed trains travelling between 250 a 320/330 /350(?) km/h
3-
and eventually a smaller network of malgev trains travelling at top speeds between 500 ~ 1000 km/h.
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Old February 6th, 2013, 01:28 AM   #1349
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Quote:
Originally Posted by FM 2258 View Post
Very interesting. So it just happens that the law of physics causes significantly more wear and tear as trains go above 320km/h? I'm not sure what can be changed. It seems that the Chinese have increased speeds by brute force but are now running into obstacles that results from going that fast.

Kinda blows my hopes for seeing trains run at 350-380km/h and that super cool looking CRH500 running at 500km/h. Are there an changes that could be made to make those speeds economical? Different metal for catenary wires or different material for wheels?
FM,

Sorry: double post

Last edited by joseph1951; February 6th, 2013 at 01:35 AM. Reason: double post
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Old February 6th, 2013, 05:42 AM   #1350
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Quote:
Originally Posted by joseph1951 View Post
FM,

...

To make it possibile to travel more economically at speed abore 300-320 km/h you t make the train lighter and more powerful , with a smaller frontal section (i.e: Talgo Avril 380 , which is still on the drawing boards); and, hopefully it wil be possibile to attain 380 km/h commercial speed, but these services will be limited only to some lines.

China already has three designs capable of running at 380km/h operational speed: 380A, 380B and 380D. CRH500 should have even more potential.

The trains are running at ~310km/h now due to political reasons, mostly. At least this is what I think

I wrote here, after the Wenzhou accident, speed will increase eventually back to 350km/h in 2 years. I have ~5 more months left

The infrastructure is already suitable for higher speeds even above 350km/h. 380A did 486km/h without any modifications on the track or on the train.

I am really excited about CRH500. We'll see.
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Old February 6th, 2013, 02:25 PM   #1351
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China already has three designs capable of running at 380km/h operational speed: 380A, 380B and 380D. CRH500 should have even more potential.

The trains are running at ~310km/h now due to political reasons, mostly. At least this is what I think

I wrote here, after the Wenzhou accident, speed will increase eventually back to 350km/h in 2 years. I have ~5 more months left

The infrastructure is already suitable for higher speeds even above 350km/h. 380A did 486km/h without any modifications on the track or on the train.

I am really excited about CRH500. We'll see.
Well, it's not a question of ability to run at those speeds, it's a question of being able to run at those speeds economically, which no-one's really been able to do yet.

They're not really running at 310, only for short sections to make up speed, and most HSR infrstructure that has 300km/h trains on it can handle travelling at more than 400.

(What's the maximum design speed for normal operations on the TGV which set the world record?)
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Old February 6th, 2013, 07:02 PM   #1352
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Well, it's not a question of ability to run at those speeds, it's a question of being able to run at those speeds economically, which no-one's really been able to do yet.
That's what I am saying, I think it is economically doable.

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They're not really running at 310, only for short sections to make up speed, and most HSR infrstructure that has 300km/h trains on it can handle travelling at more than 400.
If you are talking about Chinese network, yes. If you are talking about other countries, not really.

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(What's the maximum design speed for normal operations on the TGV which set the world record?)
There is not any operational speed parameter for that train. It is purpose build.
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Old February 6th, 2013, 09:30 PM   #1353
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1-
Well, it's not a question of ability to run at those speeds, it's a question of being able to run at those speeds economically, which no-one's really been able to do yet.

They're not really running at 310, only for short sections to make up speed, and most HSR infrstructure that has 300km/h trains on it can handle travelling at more than 400.
2-
(What's the maximum design speed for normal operations on the TGV which set the world record?)
1-
That's right.

2-
320km/h on the new section Paris Gare de l'Est Strasbourg. 270-300 km/h in the other lines.

The new HSL section Tours - Bordeaux will be built for 350 km/h but, initially, the top commercial speed will be limited to 320 km/h.

A couple of yers ago Mr Pepys, CEO of SNCF stated pubblicly in London that the problem is NOT building trains capable of 400 km/h in commercial revenue, but the problem is to run these trains economically at 400 km/h.

Mr Pepys wants a 360-400 km/h per hour VHS train capable of carryng more passengers than the TGV Duplex with a pax/weight ratio of 1 pax/400 kg of train, and capable of running at 360-400 km/h with an energy consumption of a TGV Duplex running only at 300 km/h.

So far, in Europe, only the Talgo Avril 380 series G4 seems, second generation, is capable of achieving some of these goals. But this trains is still on the drawing board.

http://es.wikipedia.org/wiki/Talgo_AVRIL


Also these Very High Speed trains should be very gently on the infrastructure.


At present these technical specifications are not been achieved. However, if the cost of running trains at 360 - 400 + km/h is not important, nobody will prevent the Chinese from running trains on commercial services at 360 - 400+ km/h.

Personally I suspect that in the future (2020?), in Europe, but only on a limited amount of HS lines, there will be some trains running at 350 -380 km/h.


China is very different from Europe and 350-380+ km/h runnings will be more jusitified, but non necessarily in the next couple of years.

Last edited by joseph1951; February 6th, 2013 at 09:45 PM.
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Old February 7th, 2013, 12:08 AM   #1354
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Economies of scale is what gives China some advantage for running trains at higher speeds. Maintenance should be considerably cheaper not to mention ability to fill large trains running at frequent intervals simply because China has larger urban centers than anything in Europe.
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Old February 7th, 2013, 04:51 AM   #1355
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Economies of scale is what gives China some advantage for running trains at higher speeds. Maintenance should be considerably cheaper not to mention ability to fill large trains running at frequent intervals simply because China has larger urban centers than anything in Europe.
India also has, but you don't see the Indian high speed network developing at the same pace, do you? So I believe you should add to the equation the fact that more engineers are produced by Chinese universities in a year than in all the rest of the world put together, the general level of industrialization, and other such considerations.
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Old February 7th, 2013, 06:34 AM   #1356
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How many engineers and how many people a country has is irrelevant to how fast components wear down and need replacing. A large number of engineers means one can tackle technological challenges faster (like catching up 40+ years of technology in five years), but it does not grant China a "cheat code" for having to replace wheels, rails, and wires without cost.

Unless China can find a new kind of technology that reduces the rate of wear on components at high speeds, 300km/h (max 320 km/h) seems to be the limit of economic feasibility.

That being said, with ChunYun coming up, CRH should slash prices and increase services on HSR to help with transportation bottlenecks. I've calculated (roughly) that an optimal HSR system can serve nearly one million people a day--CRH should do everything they can.
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Old February 7th, 2013, 06:39 AM   #1357
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1-
Economies of scale is what gives China some advantage for running trains at higher speeds
. Maintenance should be considerably cheaper not to mention ability to fill large trains running at frequent intervals simply because China has larger urban centers than anything in Europe.
Economy of scale can be optimised in mass-producing an enormous amount of high speed trains of constant acceptale quality (which today is not always the case).

Economy of scale will have a minimum impact of increasing the ,let's say from 300 to 360 km/h.

There is an increase of costs and of wear and tear of the infrastructure and rolling stocks in running a train at 360 / 400 km/h rather than 300 /320 km/h, and this has very little to do with the economy of scale but it has a great deal to do with the law of physics, the type, the design, the limit and the state of the art of the means of transportation chosen.

The HSTs is a mature technology and it is quickly reaching the limits of its envelope. It is a technology that China has only very recently bought from other Countries such as Japan, France , Germany where this technology was first developed.

First it will take some time to instruct the chinese workforce to produce HST of acceptable constant quality. Secondly: some improvement of technolgy will occur, but it will not be as impressive as the improvements seen in the last 20-30 years.

Since the advent of the steam train in commercial services , around the 19th century, the commercial speed of trains has increased at an average rate of 1,5 ~2,5 km/h per year, with a break during the two world wars. However, in that last 20 years the speed has increased only of about 1km/h per year. (from 300 to 320)

China is huge country, and is also the world's most populous country, with a population of over 1.3 billion, and despite the recent progress in rail infrastructures it has a long way to go to modernise the entire rail system, especially the hystorical rail network carrying goods and passengers.

It is true to say that China has the longest high speed rail network in the world (around 10,000 ~12, 000 km) but, compared to the population, it is still wery litte.

For instance, Spain has 2,665 km of high speed rail, but Spain has only 46 million inhabitants and China has 10,000 ~12,000 km of HSLs and about 1,337,000,000 inhabitants.Therefore, in order to have the same ratio HSLs-km / inhabitant of Spain, China should build about 78,000 km of High speed lines.

Also similar problems are evident with the historical rail network, and the Chinese one is also in great need of improvement.

Altogether China has about 77,000 -85,000 km of rail netwok for 1,3 billion inhabitants while European countries such as France have 32,000 km of rail network for 60 million inhabitants.


So it is clear the China will quickly build a massive classic and modern rail netwok for conventional passenger train travelling at 160-250 km/h + a massive HSL rail network with VHS trains travelling at 300-350, and perhaps at 380 -400 km/h on some VHSL lines.

But this does not mean that travelling at over 300 km/h makes "economy of scale"..

Also the chinese rail network for goods trains is in urgent need of improvement, and I think that the Chinese government will invest a great deal in this rail sector.


In the near future there will be some further technological improvements of the wheel/ rail system in the region of 360-400 km/h. But no matter how you put it, it takes more energy to increase the speed of a given train from 300 to 400 km/h, even if you halve the weight and the size of the train

I strongly suspect that in order to travel at around 500+ km/h, in the next 30-40 years, China will have to build maglev lines.

These 500+ km/h maglev will comsumes only 50% of the energy of a subsonic plane, but 3,5 more energy than a Japanese Nozomi N700 train travelling at 270km/h..

Futhermore China is ideally suited to build supersonic maglev trains for extremely long distances. But, in order to reduce energy consumption, this supersonic maglevs will have to travel in tubes /tunnels in which a partial vacuum has been made...

The Chinese scientists seems to be very keen in developing this technology.
.

Last edited by joseph1951; February 7th, 2013 at 06:59 AM.
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Old February 7th, 2013, 06:54 AM   #1358
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Originally Posted by Silver Swordsman View Post
How many engineers and how many people a country has is irrelevant to how fast components wear down and need replacing. A large number of engineers means one can tackle technological challenges faster (like catching up 40+ years of technology in five years), but it does not grant China a "cheat code" for having to replace wheels, rails, and wires without cost.

Unless China can find a new kind of technology that reduces the rate of wear on components at high speeds, 300km/h (max 320 km/h) seems to be the limit of economic feasibility.

That being said, with ChunYun coming up, CRH should slash prices and increase services on HSR to help with transportation bottlenecks. I've calculated (roughly) that an optimal HSR system can serve nearly one million people a day--CRH should do everything they can.
I totally agree with you.
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Old February 7th, 2013, 11:35 AM   #1359
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India also has, but you don't see the Indian high speed network developing at the same pace, do you? So I believe you should add to the equation the fact that more engineers are produced by Chinese universities in a year than in all the rest of the world put together, the general level of industrialization, and other such considerations.
I had in mind only the running and maintenance but you're right about the engineers too.
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Old February 9th, 2013, 03:39 PM   #1360
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Unless China can find a new kind of technology that reduces the rate of wear on components at high speeds, 300km/h (max 320 km/h) seems to be the limit of economic feasibility.
.
The germans or dutch have developed a metal that resists the type of wear that leads to stress fractures, increasing longevity 3-fold and reducing the need re-grind the railhead. I don't remember much detail - it was an article in rail professional or something.

Basically, with current materials 320km/h seems an economic maximum, but the future will not have todays materials, so there is no such limit necessarily in the future.
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