Germans are complaining that their trains aren’t as punctual as they used to be, but I was still impressed with the system. I was particularly amazed at how quiet and smooth the trains were even at high speeds of over 100 mph. One reason, seems to be the rails don’t have the gaps that make the familiar clickety-clack sound of most railways. However, how do they keep the tracks from buckling as they heat up? How do they lay the tracks in the first place? I looked as carefully as I could and couldn’t even see any weld points.
My friend also told me that the window glass contributed to the smooth ride, giving the appearance to passengers that the train was moving more slowly than it actually was. How is that possible?
I’m just a dilletante train expert, so I could be wrong, and a real train expert (maybe even a real German train expert) will be along shortly to correct me, no doubt, but I believe I’ve heard that modern high-speed rail lines are laid down by enormous factory-type machines that fabricate seamless rails and affix them to concrete ties (sleepers) all at once.
As for the window glass thing, it sounds like complete B.S. to me.
It doesn’t get all that hot or cold in Germany. Occasionally tracks will warp in the dead of summer but the Bundesbahn is pretty quick about fixing them.
2003 was the hottest summer in Germany in a very long time. Apparently there was not a single failure due to expansion, only one due to the sinking ground water table. The tracks and the concrete sleepers a very similar coefficient of expansion and everything is secured tightly in a bed of gravel.
I don’t speak German, so that link isn’t helping me. Is there an English and/or Vietnamese version anywhere?
That the tracks and sleepers have a similar coefficient of expansion sounds good, but I’m still confused. Are the tracks not metal? When I was there last week, it was about 7C. The week before, it had been -5C and last summer got up to 42C. That’s a pretty big range. A metal track would expand significantly, and it would need to expand to somewhere regardless of what the sleepers were doing. Maybe they use some kind of composite material that doesn’t expand as much as iron?
Nice cites there on welded rail. I thought I’d address the dangling questions from the OP. One point is implied but not stated explicitly in those cites, and that is that the normal state of affairs (except for the hottest days) is for the rail to in tension. The SDNR is putting in a passing siding down below where I live. I got to see them part the rails in order to put in the new switch. An abrasive wheel had just about finished its cut when the rail went WHAM and a inch-and-a-half gap opened up. It was pretty impressive.
I can’t think of any mainline I’ve seen in the last ten years that wasn’t welded rail. The RRs get a couple of really nice benefits from their outlay for new rail. There is less abuse to rolling stock and wheels, for one. But the other is the flip side: There is less abuse to the rail and roadbed from passing trains. The company can always get a bad order car into a shop to true its tires up, but it is a gigantic bitch to get out there on-site and repair track with the attendant interruption in service. They tend to picky about that sort of thing.
For big mainline stuff they take manufactured, heat-treated rail out on special trains. The rail is in 1000’ lengths carried on flat cars without end bulkheads. It’s then dragged of the end of the train at the point where it will be laid.
For the passing siding near my house they manufactured the lengths (about 800’) on-site. There was an automated welding rig turning out new welds every 5 minutes, or so. The weld was then dressed by a mechanic with an abrasive wheel. They were doing very nice work. I looked at some of the welds and as soon as they’re rusty you won’t be able to find them.
Not sure about the window glass, but I know the double-decker trains I ride around here give a strong illusion of lower speed from your viewpoint being an extra ten feet of the ground.
Come over to Viet Nam! You probably don’t remember the thrill of awakening from an overnight ride with grit in your mouth either. Things are progressing though. Most of the trains do have window glass now.
As far as the German window glass, the only theory I have is that the windows somehow contrive to focus your attention on the background rather than foreground objects. (Riding on the second level would also do that.) I’d be inclined to dismiss the whole idea too, but I rode on one train that seemed to be going quite slow, then I looked up at the signboard and saw we were going 150 km/h. Smoothness is one factor, but even so …
