Velgam Posted January 8, 2008 at 06:44 AM Report Posted January 8, 2008 at 06:44 AM If the distance from my house to maglev was only 20+ meters, My family will get what kind of effect on health. :cry: Quote
adrianlondon Posted January 8, 2008 at 11:22 AM Report Posted January 8, 2008 at 11:22 AM Personally, I don't believe it will cause you any problems whatsoever. Much better (as I assume they're much quieter) than being 20m away from a traditional train. You'll still need double-glazing though to keep the noise out. If you notice metal objects being slowly dragged across your table and clinging to the window closest to the track, then you may have problems. People in the UK (and everywhere else I imagine, but I tend to stick to reading UK news for non-headline stuff) complain about living under powerlines. They say it causes depression and they also blame it for increased cancer risk. Same for mobile phone transmitters. Again, I've not seen any scientific proof of this and hence tend to discount it. However, I don't live close to any of those things so it's easy for me to be dismissive. Power supply lines humm, and that noise would drive me crazy hearing that 24 hours a day. Quote
gato Posted January 8, 2008 at 12:56 PM Report Posted January 8, 2008 at 12:56 PM Much better (as I assume they're much quieter) than being 20m away from a traditional train. Take a look at this about the noise. The maglev trains are traveling up to 450 km/hr, so they are quite a bit noisier than normal speed trains. http://ntlsearch.bts.gov/tris/record/tris/01076476.html High-speed maglev noise impacts on residents: A case study in Shanghai High-speed maglev trains offer competitive journey-times to automobile and air transport in markets of 60-1000 miles but they have potentially adverse noise impacts. This paper considers the noise characteristics of the Shanghai Maglev Train on residents within 300 m to the track. It shows that the system is about 4-8 dBA quieter than other high-speed systems at comparable speeds with their guideways at a similar distance. The onset rate within 30 m-distance to the maglev track is more than 20 dB/s, and 86.5% of respondents complained they had been startled when traveling beneath the guideway when it was in use. High speed maglev noise annoyance is not found to be strongly related to demographic variables, other than that home owners are more annoyed than renters. http://www.railpage.com.au/f-t11305308.htm Levitating trains make a racket; Magnetic trains more annoyingly noisy than the old-fashioned kind. Nature Science Update April 9, 2004 Magnetically levitated (maglev) trains cause more noise pollution than today 's intercity trains, according to a report by Joos Vos of the Dutch research institute TNO Human Factors, Soesterberg, in the Journal of the Acoustical Society of America (1). Vos played people recordings of maglev and normal trains that mimicked the sound levels in houses near railway lines. When asked how annoying they would find the sound if regularly exposed to it at home, participants rated the maglev noise as more disturbing than standard intercity trains. At high speeds, says Vos, "the maglev sound is similar to that of aircraft". Vos's subjects found the maglev and road noise equally annoying, and considered both worse than intercity trains. Many said that the maglev noise made them feel insecure, some found it startling, and disliked the occasional shrill sound the maglevs produced. Quote
adrianlondon Posted January 8, 2008 at 01:13 PM Report Posted January 8, 2008 at 01:13 PM Seems I was wrong. Having lived next to a train line and hearing teh thing make loads of noise as it screeched along the tracks, I assumed that a maglev train, almost floating along, would be much quieter. In which case, 20m away isn't going to be pleasant. I'd love to know what one sounds like. Quote
Velgam Posted January 9, 2008 at 12:28 AM Author Report Posted January 9, 2008 at 12:28 AM Thanks for your replies. Actually the noise is not my biggest concern. What I worry about is Electromagnetic Radiation. As I known the safe distance which was suggested by Germany(the original designer) is 300 meters!!! I don't know why the safe distance is so short here, in Shanghai Minhang district, very close to many people's house! The only thing can give me a little hope is that maglev train plan is still a draft, even it is from official homepage. Quote
gato Posted January 9, 2008 at 12:49 AM Report Posted January 9, 2008 at 12:49 AM As I known the safe distance which was suggested by Germany(the original designer) is 300 meters!!! I don't know why the safe distance is so short here, in Shanghai Minhang district, very close to many people's house! To reduce the cost of having to pay people to move. http://finance.sina.com.cn/china/dfjj/20070627/20153730897.shtml 上海磁浮:待解的疑问 控制搬迁费用,更有效的办法是控制项目所要求的搬迁距离。据测算,仅以涵盖了一半以下线路长度的闵行区为例,如拆迁距离控制在22.5米内(即铁路两侧22.5米范围内都要拆迁),总拆迁量约有1000户;以户均100平方米、均价12000元的补偿标准计,其拆迁成本将在12亿元左右;而一旦将“控制线”放到50米,仅闵行一区,拆迁户数就将激增到6000户,可能产生的拆迁成本,将相当于现在整个项目规划的总投资额度。 Quote
gougou Posted January 9, 2008 at 02:45 AM Report Posted January 9, 2008 at 02:45 AM Seems you are not the only one worried. Quote
flameproof Posted January 13, 2008 at 03:14 AM Report Posted January 13, 2008 at 03:14 AM You'll still need double-glazing though to keep the noise out. Normal double-glazing do have some better noise protection then normal windows, no question about that, however, they are primarily designed as a thermal protection (which is of course no use if the rest of the building is crap). To protect better against noise you need at least a double-glazing were each glass sheet has a different thickness to avoid resonance. Better would be triple glazing. But as buildings in China are mainly solid concrete you have also sounds traveling through the concrete. I don't believe that the Maglev disturbs more then a train. Trains run 24h, the Maglev stops at 21:00 - I would be more comfortable with that. It should be also noted that the max speed before 9:00 and after 17:00 is only 300Km/h PS: that renters bother less then owners shows that this is more about property value. Quote
adrianlondon Posted January 13, 2008 at 11:39 AM Report Posted January 13, 2008 at 11:39 AM that renters bother less then owners shows that this is more about property value Not necessarily; it's likely to be that renters know they can easily move if it gets too much, and that they will only be living there temporarily anyway. If you hire a car and its engine makes a strange noise, you might decide you can't be bothered to return it, as once the rental period is over, it's not your problem any more. If you bought a faulty car you're going to be pretty angry and demanding a refund/fix ;) Quote
gougou Posted January 13, 2008 at 02:59 PM Report Posted January 13, 2008 at 02:59 PM PS: that renters bother less then owners shows that this is more about property value.But if the maglev didn't have any adverse effects on living conditions, why would property value decrease? Quote
gato Posted January 13, 2008 at 03:16 PM Report Posted January 13, 2008 at 03:16 PM Property prices usually rise when a subway station is built nearby, which shows how smart this maglev idea is. Quote
adrianlondon Posted January 13, 2008 at 06:13 PM Report Posted January 13, 2008 at 06:13 PM If the trains are whizzing past at 300kmh and your house isn't near a station, I doubt that'd help property prices ;) Quote
flameproof Posted January 14, 2008 at 03:29 AM Report Posted January 14, 2008 at 03:29 AM But if the maglev didn't have any adverse effects on living conditions, why would property value decrease? Because people are people and can have all sort of wrong believes. Look i.e. at superstition, fengshui can effect property values too for no real reason. Shanghai police break up "maglev" train protest http://www.reuters.com/article/latestCrisis/idUSSHA328582 The demo was on Nanjing Lu, they certainly start to learn how to demonstrate. Quote
Loriquero Posted January 14, 2008 at 01:03 PM Report Posted January 14, 2008 at 01:03 PM strange, I were in maglev just once and didn't feel really noisy, perhaps is because the speed strongly reduces when is arriving to the station Quote
flameproof Posted January 14, 2008 at 03:03 PM Report Posted January 14, 2008 at 03:03 PM 2 links about the protest: http://shanghaiist.com/2008/01/14/maglev_protest_1.php (has videos) http://shanghaiist.com/2008/01/12/antimaglev_prot.php I still believe it's only and only about property values - which is of course still a legitimate concern. Quote
simonlaing Posted January 15, 2008 at 01:39 AM Report Posted January 15, 2008 at 01:39 AM I think it is more than just property values. The line that goes to Hangzhou is very long. People are very worried about the noise and the relocation. Also if you have lived next to a building site you know for 1-2 years it will be noisy and dusty everyday. Think of that but with the knowledge it will still be noisy after it's finished. Even in the train you can hear the noise the train makes when it's going so fast. In Fujian they had a similar middle class protest over the zoning of a chemical plant. These are important quality of life issues that the government has messed up before and now people realize they can influence it now. These are key issues I think. Quote
flameproof Posted January 17, 2008 at 06:55 AM Report Posted January 17, 2008 at 06:55 AM Out of curiosity I checked about magnetic radiation. The magnetic radiation field 10m away from the track is about 100mG. The exposure to the earth magnetic field ranges from 300-800mG, depending where you are. G is for Gauss, if you studied electronics you know, it's the small brother of Tesla. The demonstrations in Shanghai have certainly no scientific base when it comes to magnetic field radiation. Strangely enough, there are lots of magnetic health products: http://www.xionghaimagnets.com/productlist_l3.asp?classcode=21&h=4 If they maglev protesters were right those would most certainly cause instant death. Noise is another issue. But I would worry more about all the other noise sources in China rather then the train which passes once in a while. Who would hear that with the TV on full power all day anyway? Quote
cdn_in_bj Posted January 17, 2008 at 07:32 AM Report Posted January 17, 2008 at 07:32 AM Strangely enough, there are lots of magnetic health products Not to mention the magnetic-induction cooking things, which I've never seen in North America (presumably because their E-M emissions exceeds the standards there). I've noticed an interesting "obsession" or rather, phobia when it comes to electromagnetic radiation. I don't know if any of this is due to TCM influences, but I've heard stories of pregnant women not going near refrigerators or microwave ovens due to the electromagnetic radiation. Some even stop using their cell phones. While I'm not going to argue that exposure to E-M is perfectly safe, what gets me is the seemingly arbitrary manner in which things are determined to be "bad" or "ok", ie - won't open fridges, but can still use cellphone. But what I find most amazing is that carcinogenic second-hand smoke (or air pollution in general) doesn't seem to worry these moms-to-be in the least. Quote
Quest Posted January 17, 2008 at 09:31 AM Report Posted January 17, 2008 at 09:31 AM I lived next to a railroad for years in China. I don't know how I coped with it, but it didn't seem to bother me then... maybe I was too young to realize it was supposed to be a bad thing. I looked up wiki, the noise of a maglev train is given as 5dB higher than a traditional train, or about 1.8 times higher. Wiki also gives: Source of sound | RMS sound pressure sound (Pa) | pressure level (dB re 20 µPa) hearing damage during short-term effect 20 approx. 120 jet engine, 100 m distant 6–200 110–140 jack hammer, 1 m distant / discotheque 2 approx. 100 hearing damage from long-term exposure 0.6 approx. 85 traffic noise on major road, 10 m distant 0.2–0.6 80–90 Long-term exposure to 1.8 times a major road noise at 10 meters, which is perhaps lower than a traditional train, is probably cause for concern. However, not sure how that'd translate to intermittent long-term exposure though, since trains don't run continuously. It probably hurts more psychologically than physically. Quote
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