Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
As a general note, I wonder what is your reasoning behind choosing maximum design speed (or line speed) rather than maximum operating speed in the 'effectiveness ratio' comparisons? If it is to be a proxy for the elaborateness (and thus price) of construction, I see that as problematic for three reasons:
  1. A lot of the relations you researched contain significant sections with lower line speeds. For example, on the Madrid-Sevilla line, 300 km/h applies only a third of the way from Madrid, then it's 250 km/h to Córdoba, and just 200 km/h to Sevilla.
  2. Some of the older lines (almost all in Japan, the first in France and the first two in Germany) saw their line speeds raised compared to the original design value without significant new construction.
  3. Design speed is usually taken to mean the speed permitted by the geometry (distance of tracks, curve radius, tunnel diameter) and the strength of superstructures. However, when actual operating speed is lower, that isn't necessarily because of a bureaucratic decision or technical problems, but the simpler scale of some components (which also brings costs savings): e.g. catenary with lower tension, less stable track, both of these maintained with wider tolerances; and there are the commissioning tests, too.

Some specific notes on line speeds:
  • France: I never heard of a line speed raise on the LGV Atlantique from 300 to 320 km/h, what's your source? As for the LGV Méditerranée, 320 km/h is the maximum operating speed (on a short section near Avignon, as test for TGV Est operation), design speed is 350 km/h. As for LGV Nord, design speed is 350 km/h too, but maximum operating speed is 300 km/h.
  • Spain: the LAV Córdoba-Málaga has a design speed of 350 km/h, too.
  • Italy: I think most of the new lines (maybe excepting Bologna-Florence) have a 350 km/h design speed, too. And FS ordered new high-speed trains with a maximum speed of 360 km/h (which doesn't mean that they will actually be operated that fast, of course; but IMHO it does mean that they considered requesting a line speed increase above the original design speed).
  • Germany, Mannheim-Karlsruhe: the 22 minute runs use the NBS (SFS) Mannheim-Stuttgart for half the distance, thus maximum line speed is 280 km/h. (Incidentally, this section was one limited to 250 km/h upon opening.)
  • Germany, Hamm-Bielefeld: it's worth to note that this is a mostly straight and level, four-tracked section, which was used for high-speed tests before the first high-speed lines were finished (record: 317 km/h with the InterCity Experimental).
  • Germany, Augsburg-München: 230 km/h is the design speed for after the upgrade and four-tracking, which was just finished (I travelled over it a week later BTW), but train schedules will change in December only.
  • Great Britain: 140 mph (225 km/h) is the design speed of the IC225 trains, but actual top speed and line speed on the ECML remained limited to 125 mph (201 km/h) due to a lack of signalling upgrade. (Hence London-York has an even more impressive travel/max speed ratio.)
  • Japan: Tokyo-Morioka line speed was raised from 275 to 300 km/h this March with the introduction of (and only for) the new E5 Shinkansens, and will be raised along with E5 operating speeds to 320 km/h later. This line started out at 210 km/h. Note that it now reaches well beyond Morioka: to Aomori.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Sun Jul 17th, 2011 at 10:29:52 AM EST
[ Parent ]
(1): I used the maximum speed of the whole relation to see how balanced or effective those investments were. I didn't even know about 250 to Cordoba or 200 to Sevilla. Being a neophyte I wonder whether it makes sense to build 300-250-200 instead of building 250 uniformly for example. Did they do it for capacity reasons? Was it easier? The point was to get beyond the max speed fetish.

(2) + (3): "Design speed" is a bit confusing here. I took whatever was the maximum e.g. the 380 on Beijing-Shanghai, or whatever is currently allowed on the older HS lines - didn't know they had been upgraded/up-permitted. I should change that to "maximum speed currently allowed by authorities". Though, aside from economic reasons (e.g. less curvy = less maintenance), why build for 350-380 in the first place? If they up-permit it later then maybe using maximum design speed is not so wrong.

I will correct those numbers later.

Schengen is toast!

by epochepoque on Sun Jul 17th, 2011 at 11:52:52 AM EST
[ Parent ]
For Madrid-Sevilla, the explanation for 250 km/h is that that section crossed mountains. I don't know why they saved on the Córdoba-Sevilla section, maybe because it is a fertile valley with relatively high population density -> more NIMBY problems if they don't build it alongside an existing traffic corridor (they built the 200 km/h alignment along the old Iberian gauge line).

aside from economic reasons (e.g. less curvy = less maintenance)

Well, less curvy is also = more superstructures, and less maintenance only if operated at the same speed.

why build for 350-380 in the first place? If they up-permit it later then maybe using maximum design speed is not so wrong.

The speed raises in the past as well as the design speeds higher than initial line speeds had a variety of reasons, not all of which can be extrapolated.

  • First there is the maturing of a brand-new technology: say, going from 130 to 210 km/h was a great leap for Japan, but what they built was actually suited for even more by just increasing the mechanical tension of the catenary. Speed raises are obviously not so simple anymore.
  • Over the past few decades, there was a parallel improvement of track maintenance (the ability to keep tighter tolerances) and the running quality of vehicles (less strain on the tracks from random movements, lower propensity to derail), which allowed the elevation of speed limits in curves for example. There will surely be further optimisation, but these are no more the main obstacles (more later).
  • The last speed raises on Tokyo-Osaka and Tokyo-Aomori are related to the introduction of tilting high-speed trains. Tilting trains come around the problem of side accelerations felt by passengers, at the price of higher lateral track forces. But you rather don't do that on high-speed lines with ballasted track.
  • Sometimes line speeds are related to signalling. On France's first high-speed line, the less curved sections were uprated to 300 km/h after the signalling upgrade (of course with catenary improvement too). In Spain, the 300 km/h limit in operation is related to the lack of trust in the ETCS L2 signalling system, while all the rest of the infrastructure was in theory ready for 350 km/h.
  • As for China's 350 km/h Beijing-Tianjin and 380 km/h Beijing-Shanghai lines, as I wrote in my diaries, I think those are more a case of 'overclocking' than over-engineering (signalling inclusive).  
  • IMHO the  European lines with 350 km/h design speed have a somewhat similar issue, too. Here the thinking is that trains, rails, trackbed, catenary and signalling is replaced in a few decades, while lines will be there for a century or more, thus those replacements will allow the application of optimised technology without extra cost. However, I have growing doubts that this would go without a total track replacement (in particular for FS's 360 km/h plans). The Italian, French and Spanish lines with 350 km/h design speed have ballasted track, which for high-speed applications is inferior to slab track in several respects, in particular flying ballast due to vortices under the train. (This was an issue for the ICE3 in its original form on Belgian lines at much lower speeds.) I'm doubtful that further advances in underframe aerodynamics and tamping technology will suppress this problem enough, especially in snow.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Sun Jul 17th, 2011 at 02:30:05 PM EST
[ Parent ]
Tokyo-Osaka is ballasted.
by Alon (alon_levy1@yahoo.com) on Mon Jul 18th, 2011 at 04:43:03 AM EST
[ Parent ]
I second-guessed my memory on Madrid-Sevilla, and checked the current network statement, which shows maximum operating speeds on Map 6, page 206. Indeed the top speeds on the slower sections are different: 270 km/h from Ciuad Real to Córdoba, and 250 km/h from Córdoba to Sevilla. Ferropedia shows a more detailed (and generally lower) permissible speed profile, but I'm not sure it is up to date.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Mon Jul 18th, 2011 at 01:52:04 PM EST
[ Parent ]


Occasional Series