Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
Electrification and quai height are appearing as a double standard.

Your comment on gauge makes it sound like kinematic and dynamic aren't synonyms. I had to check. :)

In your other comment where you mention German vs French polishing, I assume that German polishing is much more infrequent since:

  1. DB runs HSTs at higher axle loads and lower speeds.
  2. DB runs freight extensively.
  3. Siemens decided not to use Jacobs bogies for the ICE3 so they "could be removed more easily" which is preposterous unless they have much higher wear rates

Unless they simply couldn't build an EMU with Jacobs bogies at the time.
by richardk (richard kulisz gmail) on Sun Jan 28th, 2007 at 11:46:35 AM EST
[ Parent ]
I brought up polishing practices as a track/vehicle-connectedness issue, e.g.: running polishing trains daily is a higher infrastructure cost, but results in less wheel wear and better ride comfort, while the intent of running freight trains not only results in higher construction costs (smaller maximum grade -> more tunnels/bridges) but more track wear and worse running comfort.

Regarding your points on polishing, I see multiple issues mixing here.

High axle loads, lower speeds and freight are a characteristic of the ICE-1, ICE-2 trains and the older lines. The ICE-3 and the Cologne-Frankfurt line don't differ from the TGV system in these respects (where the ditching of mixed traffic was definitely the abandonment of a bad idea).

Regarding bogies, it is true that the somewhat higher axle density (ICE-3: 32, most TGVs: 26 for the same 200 m length) and more uneven distribution of that mean higher track stress and wear, but it is not so significant compared to the above problems.

The "could be removed more easily" you read of could mean multiple things.

Either it was a reference not to the ICE-3 but the earlier generations, and not only to bogie maintenance but car maintenance (say one car is vandalised, it is removed while the rest of the train can get back into service) and operational rearrangement. The latter differs from the fixed-composition TGV concept and parallels the Shinkansen concept: the ICE-1 can run with 10 to 14 middle cars, the ICE-2 can even be arranged into an ICE-1-like "long train" by dropping driving trailers.

If it was a reference to the ICE-3 and removal of bogies, then the main issue is that the ICE-3 has distributed traction. Both Siemens (DB series 425) and ex-ADtranz-Bombardier (DB series 423) has motorised Jacobs bogies. The problem is that currently, there is no high-speed-suited motorised Jacobs bogie in service anywhere in the world - not in France, not in Japan (where all Shinkansens have distributed traction, including the prototypes for 360 km/h trains). So far there is only the two test bogies in the two cars of Alstom's mothballed partial AGV prototype "Elisa", though the technology shall be revived this year, in the "Pégase" prototype and in the new attempt to break the world speed record with TGV POS 4403.

I also note that Jacobs vs. standard bogies aren't relevant to the question of interoperability standards, they were relevant in the failed pursuit of an all-European high-speed train (one unifying French, German, Italian and Spanish technology) that would have cut costs by economies of scale.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Wed Jan 31st, 2007 at 07:13:17 AM EST
[ Parent ]
I forgot the link for the new speed record attempt: en français, in English.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Wed Jan 31st, 2007 at 07:36:24 AM EST
[ Parent ]
In other words, my second supposition was correct and they couldn't build an EMU with Jacobs bogies. You know, it's mildly irritating how you ignore what I've said in favour of reprising the topic from scratch. Which is only made tolerable because you really know the subject and that expertise is greatly appreciated. Especially with reference to the significance of various effects.

I did not consider vandalism before. I wonder if it's a serious problem. I'm guessing it isn't since the much lower cost of the TGV compared to the earlier ICEs would have allowed the SNCF to stock up on extra trainsets. Swapping cars isn't a problem when you can afford to roll an entire trainset to the shop.

by richardk (richard kulisz gmail) on Fri Feb 2nd, 2007 at 09:15:40 PM EST
[ Parent ]
Your comment on gauge makes it sound like kinematic and dynamic aren't synonyms. I had to check.

Er, yes, I meant static. But here is a fuller classification of gauge types (though I'm not sure I got the English terminology right in each case), generally from narrowest to widest:

Construction gauge/vehicle limit profile/loading gauge at standstill:
this is the actual limit for the cross section of a specific railway vehicle.
'Static' loading gauge:
a railway vehicle must fit into this even considering the worst combinations of curves and the lateral play of moving parts (wheel in rail, axle in axlebox, suspensions). Until recently, the construction gauge was caluclated from this.
Kinematic (dynamic) gauge/reference profile:
similar to the previous, but dynamic effects like tilt in curves and uneven track are also considered. It's also called reference profile because both construction gauges (for vehicles) and structure gauges (for track) can be derived from it.
Structure limit gauge:
derived from the reference profile by considering the tolerances of track-laying.
Inner structure gauge:
the standard of a railway company for the space within which nothing fixed can protrude.
Outer structure gauge:
the standard of a railway company for what extra spaces to keep clear (for aerodynamics, for track workers, for waiting passengers etc.) in various situations: tunnels, bridges, overpasses, stations, side-by-side tracks etc.
the entire room demanded by a railway line, including ballest bed and catenary

BTW, for A swedish kind of death, here is a drawing from my work (clickable thumbnail):

Free Image Hosting by FreeImageHosting.net

It displays the rough outline of a Swedish IC car to be measured (no precise data was available then), the Hungarian and Swedish (Scandinavian "A") static loading gauges, and the narrowest (old standard, non-electrified line) and widest ('new' East Bloc standard, electrified line) structural gauges of potential test tracks in Hungary. It can be seen that corner height could be expected to be a problem on old lines, would it not be the case that the car apparently doesn't utilise the Scandinavian loading gauge in full.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Wed Jan 31st, 2007 at 07:15:36 AM EST
[ Parent ]


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