The new high-speed superpower | 290 comments (290 topical, editorial, 0 hidden)

Overspeed (4.00 / 2)

Setting aside that just mercantilism is viewed as criticism on my part and the question of what are the other forums like this one, I am very grateful for the link on the modifications applied on the CRH3 used on the WuGuang line (I read only of the windshield before). Sources in languages I speak are scarce on the CRH trains, so I gathered extra info from Chinese sources with Google translate (above all hasea.com) -- if you can link and/or translate further additions or corrections, I would be grateful.

However, the CRH3 changes you quoted upthrwad do not address the issue of "overspeed" on the entire range of CRH vehicles (including earlier CRH3), which applied from the 2007 timetable change resp. the 2008 opening of the Beijing-Tianjin line, that is, well before the modifications. On the other hand, that range of modifications, and operational data I found since, do indicate that engineers got more serious about making the vehicles suitable for the speeds permitted earlier, and the trains are operated more realistically.

On the issue of speed raises, let me first list the parts that are wear-and-tear-critical due to increased forces:

windshield,
pantograph,
axles,
bearings,
springs and their ports,
yaw dampers and their ports,
bogie frames,
cogwheels in the drive train,
sidewalls and isolation (tunnel entries).

Also critical due to increased power:

motors,
cooling,
brakes.

On one hand, the potential for tweaking of an existing design (as opposed to replacement with a full redesign) is different for these elements. On the other hand, the 'overclocking' of these elements without major modifications will lead to problems on different timescales, say motors can break down much earlier before axles show cracks.

As for the testing side, to approve a vehicle for a certain speed, standard practice is to conduct a number of tests on a given amount of kilometres at 110% of that desired top speed, and braking tests, and a number of parameters (f.e., the mean of filtered lateral accelerations above the second bogie pivot) must stay below given limit values. Once that's achieved, standard practice is to paint the approved speed on the vehicle.

Now, the CRH1 (A, B, E), CRH2 (A, B, E) and CRH5 have been ordered for and designed for 200 km/h, and apparently type-approval-tested for the same, as you see that speed painted on them (examples: CRH1-064E, CRH2-136E [on the right], a CRH5). Yet, all of them are operated at up to 250 km/h since 2007.

The CRH2C (first batch), also called CRH2-300, nameplate speed 300 km/h, is operated up to 350 km/h since 2008, though it wasn't tested up to 385 km/h (CRH2-061C 22 April 2008 record: 370 km/h). What could be the consequences?

I interpreted the withdrawal of CRH2C from the Beijing-Tianjin line as an indication that there might be issues -- and now I found this Chinese forum, where a commenter says (if I can trust Google translate) that indeed maintenance and safety was the deciding factor.
Then again, after modifications of the motor, test unit CRH2-061C achieved 394.2 km/h on the ZhengXi line, and CRH2C first batch run full-throttle on the WuGuang line (but, if I read this trip report right via Google translate, there are some uneven running and internal noise issues).
Still, that the CRH2C first batch in original form wasn't really suited for 350 km/h regular service is supported by the development of the CRH2C second batch, above all with increased power, but also with stronger first bogie and reinforced structure to hold the windshield, originally scheduled for delivery in December. (The small delay might explain the use of the first batch on the WuGuang line as temporary measure.)

You asked what I read about attempts to improve aerodynamics with a modified nose shape. You see that nose shape in the diary, and what I read was this, where the poster says (again if I can trust Google-translate) that aerodynamic tests showed that it wasn't better than the original nose shape.

The CRH3 is a special case. The nameplate speed is 350 km/h for all vehicles (including the prototypes built in Germany, see f.e. CRH3-002A), which I guess had to do with the PR of the Beijing-Tianjin line opening.

Now, one might imagine that the Velaro design should be suitable for 350 km/h, given that the Spanish version is for that speed. However, Velaro CN is wider and thus heavier and with a larger wind resistance, but has the same maximum power. Still, one CRH3 reached 394.3 km/h in a test run, so maybe it made the full 350+10% tests? However, you'll find reports sourced to Siemens engineers on the German Wikipedia indicating an official top speed of 300 km/h in August 2008 (and operation to 340). Speed profiles I saw trawling hasea.com (can't find it again, but this thread has trip
report photos in line with that) showed 330 km/h max. in regular Beijing-Tianjin operation.

Of the modifications mentioned in your link, I would be most interested in a precise translation on those affecting power output. The 6% improvement in drag (apparently achieved mostly by changing protruding parts) means only a 2% improvement in speed at the same power (due to air resistance running at the second power of speed, and power being speed times force), that is, f.e. same power needed for 336.5 km/h instead of 330 km/h. However, the CH3 maximum of 8800 kW remained unchanged, so they must have improved continuous output, mybe with better cooling?

On the other hand, I tried to find WuGuang line speed profiles at hasea.com. Didn't find any, but I found photo-documented trip reports, which showed that 350 km/h is reached but not maintained continuously, and a thread where they say that timeplans were laid out for 330 km/h max. That sounds like a more realistic and equipment-friendly operation.

Finally, there are the new versions code-named CRH2-350 and CRH3-350. I was hard on these too, because 380 km/h max is planned, even though sources (f.e. Chinese Wikipedia) say that tests are planned only up to 400 km/h, not 418 km/h. On the other hand, if their planned operation is similar, that is 380 km/h is reached only in spurts, the wear & tear and other effects would be less.

One finds a detailed list of the planned modifications and research for the CRH2-350 and CRH3-350 here. It's pretty wide-ranging (including the modification of the CRH2 cross-shape), so there is a serious effort, which is reassuring. One critical component I will note though is the pantograph [which is based on a standard German design both on the CRH2 and CRH3, the Japanese pantograph was not imported]: this is the main source of noise at those speeds, and also of wear, but the list only seems to mention optimisation of the existing design, rather than a replacement with a single-arm pantograph with active-regulated pressure on the catenary. It might be noise-relevant that they don't plan to change the CRH3 nose shape.

:: :: :: :: ::

Two more comments

Could you or marco translate what's in this thread? It seems to talk about a speed restriction to 250 km/h on the ZhengXi line, but the Google translate is rather unclear, so I didn't mention it in the diary.
There is a curious mistake repeated across several government news releases, including your link: the addition of 100 km to the length of the WuGuang line. (I had to check several sources to ascertain myself that the lower figure should be in the diary, f.e.

this hasea forum post.)

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Thu Feb 25th, 2010 at 06:04:58 AM EST
[ Parent ]

Re: Overspeed (none / 0)

Unfortunately the photos from hasea.com don't work as direct links.

by Gag Halfrunt on Thu Feb 25th, 2010 at 06:23:07 AM EST
[ Parent ]

Re: Overspeed (none / 1)

Damn. I think I linked only these four pictures:

CRH1-064E, CRH2-136E: thread link, cutouts of photos with indicated top speed:

CRH5-059A: thread link, shrunk cutout of photo of indicated speed:

CRH3-002A: thread link, shrunk photo of indicated speed:

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Thu Feb 25th, 2010 at 08:37:14 AM EST
[ Parent ]

Re: Overspeed (none / 1)

thanks for your reply. I find your interpretation of most of your sources very problematic. Let me go through them one by one:

1) "you'll find reports sourced to Siemens engineers on the German Wikipedia indicating an official top speed of 300 km/h in August 2008 (and operation to 340)"

I think no one is disputing that the export prototype is designated by the German engineers to have maximum operational speed lower than 350km/h. The question was rather whether Chinese engineers simply took these trains, and put a different label on them, and let them, de jure, run at a higher speed for which they are not designed.

The chinese sources say that that is not what the chinese engineers did. They, according to these sources, modified the prototype to produce trains that are in fact capable of running at 350km/h in commercial operation.

2) "Speed profiles I saw trawling hasea.com (can't find it again, but this thread has trip report photos in line with that) showed 330 km/h max. in regular Beijing-Tianjin operation."

This pertains to the Beijing-Tianjin line, which I have also read/heard about. I do get the impression that the chinese were making claims ahead of time. But see below.

3) "I found photo-documented trip reports, which showed that 350 km/h is reached but not maintained continuously,"

I don't know how a handful of photos can "show" that a particular speed is not maintained continuously. For that you need a video.

4) " a thread where they say that timeplans were laid out for 330 km/h max. That sounds like a more realistic and equipment-friendly operation."

If you have read/translated the whole thread you quoted, you'd know that what the poster said was much more than this. He/she spoke of models of the "second-phase", which, according to him/her, have just come out. And according to him/her, models of the "second-phase" are capable of running at 350km/h, whereas models of the "first-phase" (to which both CRH2c and CRH3c apparently belong) were only capable of running at 330km/h.

The poster's main question was: given that these new models just came out, are they going to mix the models from these two different phases, and let both run on the Wuguang line, even though the new models are capable of the higher speed of 350km?

So the whole post does not question the 350km/h commercial speed, rather, it confirms it.

5) "You asked what I read about attempts to improve aerodynamics with a modified nose shape. You see that nose shape in the diary, and what I read was this, where the poster says (again if I can trust Google-translate) that aerodynamic tests showed that it wasn't better than the original nose shape."

Again, the poster seems to say something completely different. First, the whole thread about CRH2 series, not about CRH3 series. The article I quoted, where the aerodynamic improvement was mentioned, is exclusively about CRH3 series.

Second, the poster appears (I say this because I am not able to view the pictures he attaches to his post) to put some pictures of an improved nose of CRH2, and then he writes (about this I am certain) that "an modified nose before this version was abandoned, because tests showed that it was not better than the japanese original aerodynamically" (roughly). So what was not successful, according to the poster, was the modification before the one he was showing with a picture. In other words, there were at least two modifications, the earlier one was said to be not better than the japanese original. Nothing was said about the later modification.

So all in all, we should distinguish two issues:

A) did the chinese take trains designed for a lower commercial speed and made them, by fiat as it were, run at a higher commercial speed?

B) do the chinese in fact have trains that are capable of running at 350km/h commercially?

I think there is no evidence whatsoever the answer to A) is yes, and that is what mystifies me about your original blog (and many others similar to yours). All the chinese sources - both the government ones as well as the one's you are relying on from chinese fans - indicate otherwise.

With regard to B) I think it indeed seems likely that the chinese were making claims ahead of themselves: they only managed to create models capable of running at 330km/h when they claimed back in 2008 that they have trains running at 350km/h commercially.

But there seems to be - among the chinese fans whom you linked - a reference to a new set of models (those of the "second-phase") that have just come out, and that are indeed capable of the 350km/h speed they announced almost two years ago.

Thanks by the way for the this reference:

"One finds a detailed list of the planned modifications and research for the CRH2-350 and CRH3-350 here. "

very informative.

by Ariel74 on Thu Feb 25th, 2010 at 02:51:28 PM EST
[ Parent ]

Late replies (none / 0)

1) ... I think no one is disputing that the export prototype is designated by the German engineers to have maximum operational speed lower than 350km/h.

330 km/h is lower than 350 km/h... But the trains were designed for 300 km/h (see page 2 of Siemens brochure; they even show the traction effort curves).

They, according to these sources, modified the prototype to produce trains that are in fact capable of running at 350km/h in commercial operation.

You are speaking about your source on modifications done by the end of 2009 for the WuGuang line. The approval for 350 km/h is valid from August 2008, and actual operation was above the 300 km/h design speed from the start too. In addition, I went into the details on why the modifications listed don't appear to be sufficient for a raise of permanent top speeds from even 330 to 350 km/h -- so, with your choice of words, the operation in the 330-350 km/h band discussed further below can be seen as CR still making claims a bit ahead of time, with even the latest version, which appears to be suited for permanent running at 335-340 km/h.

2) ... I do get the impression that the chinese were making claims ahead of time.

An approval for 350 km/h, even painted on the side of the CRH3, is not mere "making claims". Also, the Wikipedia comment says 340 km/h for August, so 330 km/h is already a reduction.

3) ... I don't know how a handful of photos can "show" that a particular speed is not maintained continuously.

Have you even looked at the links? The photographed displays also show the time. One of them shows speed kept around 330 km/h for a few minutes before the push for 350 km/h, and then writes in text that speed fluctuated in the 330-350 km/h band thereafter. Another guy wrote in his travel report that he missed the opportunity to photograph hitting 350 km/h because he was just then in the toilet.

4) ... He/she spoke of models of the "second-phase", which, according to him/her, have just come out.

Read my comment again, I did write about the CRH2C second batch... The first were planned for delivery in December, but the first finally came out at the end of January (see CRH2-091C further down in this comment). The line was operated from December -- with the CRH2C first batch.

So the whole post does not question the 350km/h commercial speed

No one questions the 350 km/h commercial speed... the question is whether it is held continuously. (As an example of similar operation, the predecessors of the Siemens Velaro, the German ICE3, had timeplans laid out for 300 km/h max, but being trains approved for 330 km/h, they were allowed to reach that speed when late.) And if only 330 km/h is held continuously, then that is a more equipment-friendly operation, and means to me that the Chinese railways aren't really reckless -- which was your original point!

5) ... the whole thread about CRH2 series, not about CRH3 series

Um, my claim on the less successful nose shape modification which you challenged pertained to the CRH2 series, not the CRH3 series.

So what was not successful, according to the poster, was the modification before the one he was showing with a picture.

Thanks, that sounds better. [If you or marco are still reading this, could you please give me a complete translation of that comment?] At any rate, not even this nose shape was used for the CRH2C 2nd batch (but the classic head with some very modest external modifications, see for example here, reproduced below for you), so if this nose shape proves successful, it will be CRH2-350 stuff.

I think there is no evidence whatsoever the answer to A) is yes... With regard to B) I think it indeed seems likely that the chinese were making claims ahead of themselves

Well... whichever way you say it, if the CRH3 were good for 330 km/h only, then the approval for 350 km/h was by fiat. And, as I indicated, some problems with operation even at 330 km/h may show itself only in a few years: I would watch out for cracks in axles and bogie frames in particular.

Now, this is just the CRH3. The CRH2C first batch seem to have been unfit for even 330 km/h in 2008. And then there are also the 200 km/h vehicles oversped to 250 km/h. Of these,

the Bombardier Regina (CRH1A, CRH1B) has a similar cross-section as the originals, but are a slower-speed design;
the CRH5 are, like the CRH3, a wider and heavier version of a faster (250 km/h) design (one that had a number of variants with axle problems!);
the slower CRH2 variants are structurally fit for the higher speeds (the E2-1000 run at 275 km/h after all), and from the little I know, the CRH1E (Bombardier Zefiro-250) too, for these, problems might arise in engines and the drive train only.

So looking at all types, the answer to A) is a definite yes.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Sat Mar 6th, 2010 at 01:36:37 PM EST
[ Parent ]

Re: Late replies (none / 0)

Well, I can't say the same about all your nitpicking as you said of mine :-)

Ad 1) Fine. But I was simply distinguishing two things: the designated speed of Velaro prototypes being lower than the speed at which Chinese CRH3 ran (whatever that speed is) vs. the question how they did it, by fiat or by optimization done on the prototypes.

It's completely irrelevant whether the speed-discrepancy is 300 vs. 330 or 300 vs. 350 or 330 vs. 350 or what have you.

It is also true, it seems to me, that there the more recent generation(s) of CRH3 have experienced far more extensive modifications and optimizations. (But see below, especially the article cited at the end my post).

Now as I was not privy to the engineering processes at the Chinese Railway Ministry, I can at best surmise what happened during those 8 and 1/2 weeks between these two announcements (good catch by the way). Mr. Zhang's boast (which I take it at face value, as true) was that various "parameters" of the test results for CRH3 of that (first) generation was better than their German Velaro counterparts, despite handicaps such like thicker air and wider train body. Presumably, these parameters would include things like noise, stability, air-tightness of cabins etc. It may simply be that, after the tests reviewed that the chinese CRH3s behave a lot better at 300km/h than Velaro counterparts at the same speed, they decided to have the CRH3s run at a higher speed, initially at 350km/h. But later on experience showed that 330km/h was a better choice.

The key argument here is that, unless the chinese decided to optimize what the Siemens offered them from the get go, they would not be achieving better "parameters" in tests under more adverse conditions than in Germany.

It is true that I don't know the extent of the optimization in the first generation CRH3. But the point was that they must have been doing that from the very beginning. Otherwise, their better test results under more adverse conditions would have been a pleasant cosmic accident. (For a second argument about CRH3, backed by another source, see the article cited below. The article appears to say that the chinese changed the shape of the pantograph on CRH3 to optimize its areodynamic properties).

Ad 2) Ok, they are doing more than "making claims", and the point being? (see the discussion above).

Ad 3) Well, I did check all your citations, including this one. All I saw was a handful of pictures. I thought your original claim was that the photos themselves show 350km/h is not maintained continuously, which is obviously absurd. Can you give the reference to the toilette episode again?

Ad 4) First of all, I was talking about continuously maintained operational speed, if that was not clear to you. The overall point of the post you cited was that models have come out that are capable of the 350km/h speed (yes, continuously maintained). It is true that the post also mentions the scheduling, saying that it is made for slower operational speed.

But the problem is that you are taking one element of the post to draw a conclusion (that the chinese CRH3s are not suitable or capable, as a matter of fact, of running at 350km/h) that is contradicted by the entire post, at least partially (for, though your conclusions might be true of the older generation CRH3, it is not for the newer ones).

My main point here is just to point out the misleading way in which you are using your sources.

Now about the main substantial point of disagreement between us - whether the chinese carried out modifications and optimizations on their first generation CRHs (since you seem to agree that the later generations have sustained substantial modifications) - there are more evidence than Mr. Zhang's boasting, which was perhaps only an indirect indication. Here is an article where you can read directly some details of the early modifications the chinese engaged in:

http://www.fyjs.cn/bbs/htm_data/159/1003/238886.html

For illustration, I will just quote one sentence: "2007年底，项目攻关取得突破， ;当月下线的首列时速350公里动车组，轴重变成15吨，问题迎&# 20995;而解。"

What that means is that by the end of 2007, way before CRH2s were running on Beijing-Tianjin HSR line, the chinese engineers had successfully changed the weight of the axle from the 14 tons of the Japanese prototype to 15 tons, in order to make the trains stable at the speed of 350km/h.

Now if that is not significant modification, and indeed of the first generation CRH2, I don't know what is.

All in all, I have not seen anything (sources or arguments) credible that you provided indicating that the answer to my question A) is anything but a resounding NO.

by Ariel74 on Mon Mar 15th, 2010 at 12:41:33 PM EST
[ Parent ]

Re: Late replies (none / 0)

A small correction of what I wrote:

"Now if that is not significant modification, and indeed of the first generation CRH2"

I meant of course the first generation CRH2 designated to maintain the speed 350km/h. The very first generation of CRH2 appeared even earlier, of course.

by Ariel74 on Mon Mar 15th, 2010 at 02:18:34 PM EST
[ Parent ]

Re: Overspeed (4.00 / 2)

Two more points:

1) about the wider body of the chinese CRH3: there is a video where the vice-head-engineer of the chinese railway ministry (???) Zhang Shuguang boasts on board the newly minted CRH3 on the Beijing-Tianjin line, in front of some Siemens engineers, that the chinese achieved "better parameters" despite the higher air density on the chinese line (than in Germany) and the wider car-body. The scene occurs around 1:41 in:

http://www.youtube.com/watch?v=mWwQsRWtveI

What this means is that clearly they were making modifications to optimize from the very beginning, otherwise one could reason simply the way you did, from the fatter train body (and the thicker air in china) to the implausibility of higher speed.

2) Your reference to the "Planned modifications and research" is a blog discussion in July 2009, about a book that was then already published (by the very Mr. Zhang Shuguang in the video mentioned above). So it is not clear if the modifications and research goals are still "planned", or are already (partially) realized.

by Ariel74 on Thu Feb 25th, 2010 at 03:23:21 PM EST
[ Parent ]

CRH3 modifications (none / 0)

Zhang Shuguang boasts on board the newly minted CRH3

I posted an English-dubbed version of the news clip with the boasting Zhang Shuguang in an earlier diary of mine, though without that particular boasting, here it is:

What this means is that clearly they were making modifications to optimize from the very beginning

Well, without basis in any details, that's a rather far-fetched assumption from what you yourself call boasting. You are assuming extensive modifications in the timespan of a few weeks by engineers without prior experience with these technologies and this speed region. Furthermore, that boasting was on a record run, which doesn't say anything about regular service - limiting top speed in actual service to 340, then 330 km/h is more instructive.

So it is not clear if the modifications and research goals are still "planned", or are already (partially) realized.

The CRH2-350 and CRH3-350 are code-names for the new batches ordered in March and September 2009, to be put in service 2011-12. So no, this is not about stuff already applied in the existing sets, but about on-going research.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Sat Mar 6th, 2010 at 12:53:25 PM EST
[ Parent ]

Re: CRH3 modifications (none / 0)

You are assuming extensive modifications in the timespan of a few weeks

8½ weeks if counted between the 26 April start of the Beijing-Tianjin test runs and the 24 June record run, 3 months if counted until the opening of the line.

BTW, even in March that year, the design top speed for even the Chinese-built trains was given as:

China-made bullet train to link Beijing, Tianjin in Aug - The Official Website of the Beijing 2008 Olympic Games

The first China-made bullet train designed to run at 300 kilometers per hour has completed a test run and will be in service between Beijing and Tianjin in early August, a railway official said on Sunday.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Sat Mar 6th, 2010 at 02:20:49 PM EST
[ Parent ]

Re: Overspeed (none / 0)

Sorry to be nitpicking, but I forgot another erroneously interpreted/relayed reference in your reply:

6) "Finally, there are the new versions code-named CRH2-350 and CRH3-350. I was hard on these too, because 380 km/h max is planned, even though sources (f.e. Chinese Wikipedia) say that tests are planned only up to 400 km/h, not 418 km/h."

The passage you are referring to in the Wiki article says:

"最高試驗速度400km/h以上"

which means: highest test-speed above 400km/h.

NOT : .... up to 400km/h

by Ariel74 on Fri Feb 26th, 2010 at 10:24:39 AM EST
[ Parent ]

Re: Overspeed (none / 0)

Good nitpicking, but the error was in my sentence, not my reading. IOW tests are planned only above 400 km/h, not 418 km/h.

BTW, I ask you or marco again: could you translate for me the 250 km/h reference (for the first CRH2C second batch on the ZhengXi line) in this thread?

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Sat Mar 6th, 2010 at 01:42:14 PM EST
[ Parent ]

The new high-speed superpower | 290 comments (290 topical, 0 editorial, 0 hidden)

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