Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
No, not that kind of baked.

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.



Lighter Trains

Why do trains have to be so big and heavy?
  [vote for,

Of course, we have the Victorians to blame for the fact that the platforms are 4 feet high, and the doors need to be a similar distance up (if we want people to actually get on or off.) But why do trains need to be so heavy? I propose that trains are made of thin plastic, similar to a big shampoo bottle, with seats etc made of similar stuff. Just think of the energy that would be saved. The addition of a squeaker in one end would make for an excellent way of alerting the authorities to collisions, minor mishaps, overcrowding etc
Gran Tade, Jan 17 2002


       Hmm. I can just imagine what it would be like when First Great Western drive one of these train into a fully laden freight train again.
mcscotland, Jan 17 2002

       It's a good idea to keep the cars light, but the engine should be as heavy as possible if pulling anything hefty. There needs to be a lot of weight on the drive axles in order to keep the static friction force high.   

       Highspeed train engines are made signifigantly lighter than freight trains. This is to decrease fuel consumption and to allow for cheaper track (more weight = $$$). However, this has put the engines at the mercy of the rail conditions. If the rail is covered in leaves, the engine isn't nearly heavy enough to provide any workable friction force, the wheels lock, and the train skids.   

       This is an *extremely* bad thing to happen with trains. So bad, in fact, that car wheel brakes are purposefully underpowered so the wheels don't lock.
rapid transit, Jul 02 2003

       Trains need to be made of heavy gauge steel and bullet resistant glass to prevent debris that fly up from going through the walls or the windows. Believe me trains can throw debris hard enough to peirce right through somebody's skull. They also need to be made with heavy gauge steel so the train can pull alot of loads, if the train was made with too lite of steel, cars would literally break apart while trying to pull it's cargo or passangers at high acceleration. One more reason train need to be heavy is so it won't be destroyed if it hits a car, sometime jurks run the crossing gates or a person's car stalls on the tracks and the train can't stop in time. This is why they have to be so heavy.
jeffman, Jul 24 2003

       Party poopers. [+] for the squeaker idea. Maybe a separate invention?
hoopdy, Jul 24 2003

       It would never be allowed in the US because of the Federal Railroad Administration (FRA) and its hardline prohibition against commingling light and heavy rail on the same track. It's the reason why, for instance, tracks that are little-used (but not COMPLETELY abandoned) can't be used for light rail public transportation part-time.   

       "OK..." you say, "why not let the city transit agency have exclusive use of them between 6am and midnight, and let the freight line have exclusive use of them between midnight and 6am? Wouldn't that take care of the safety issue?"   

       Of course it would... but safety is just a pretense and excuse. The REAL driving force behind the rule was the fear of Rail unions that operators would slowly stretch the definition of "trolley" and increase the route lengths until lower-paid transit workers displaced the higher-paid rail workers. So, under the guise of safety, they successfully lobbied the FRA to take its long-held hardline position against ANY potential for commingling of light rail traffic with heavy rail traffic.   

       It's a major reason why high-speed passenger rail in Florida is going to cost BILLION$ of dollars to build. By FRA-dictated law, the trains have to be capable of surviving a head-on collision at 180mph with a mile-long freight train carrying limestone or cement blocks. The fact that mile-long, slow-moving freight trains won't even be ALLOWED on the high-speed tracks, and even if someone TRIED the electronic signalling and monitoring system would detect it immediately and stop or divert the passenger train is IRRELEVANT to the F.R.A.   

       I might be wrong, but I think the *only* exemption ever granted was to some New York City suburb in New Jersey... and to get it, they had to do something outrageously silly, like have workers PHYSICALLY REMOVE sections of track at the switchover time to humor the FRA and prove that a freight train can't "accidentally" encroach. I don't remember where I read it, but apparently the FRA wouldn't even settle for a mechanical barrier or system to automatically move the track. Nothing less than manual, outright removal of a section of track would satisfy them.   

       In the bizarre, strange world of government, "common sense" is a taboo concept.
miamicanes, Dec 20 2003

       A bridge in the Soviet Union was only able to carry one ton. A team of railway engineers was assembled and given eight months to build a train that would cross the bridge safely.   

       When the commissar came to inspect the results, the chief engineer was trembling and said: I'm sorry comrade, we were only able to go down to 1800 kilos. The team was promptly sent to Siberia and never heard of again.   

       A second team of railway engineers was given 9 months but was only able to make a train weighing just under 1680 kilos. They too were sent to Siberia as well as a third team which improved the result by only 45 kilos.   

       Finally, for a lack of railway engineers, a team of aeronautic engineers was assembled. At the end of the first month their terrified chief engineer reported that they had concluded it was impossible. They had done all the calculations, and even built several prototype models, but we're not able to make it heavier than 800 kilos.
pashute, Apr 13 2014


back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle