I just saw G’s Q and A 28123 1 Europe trains do not have noses and USA have? Funny Q and A; I have travelled in both with noses. Wire magazine had spoken about it long ago about the reason for noses when travelling through tunnels and increasing the speeds. “
*The dream of high-speed trains is already coming off the rails* *From China to Europe, trillions are being pumped into high-speed rail networks. But as squeezing more speed out of them becomes harder, it's looking like high-speed rail isn't the solution to our transport dilemma* On April 3, 2007, a sleek train raced across the countryside of northeast France, pursued by a small jet aircraft. On an open stretch of track between Prény and Bezannes, the train galloped ahead – eventually reaching 500kph. Officially, no train operated by TGV, the French state-owned high-speed service, had ever ever surpassed 515kph, the speed record set by the same firm 17 years earlier. This attempt, christened Operation TGV 150, was aiming to reach 150 metres per second, or 540kph. As the chase aircraft beamed data and video to pensive engineers, the train pushed beyond 540kph, before setting a new world speed record: 574.8kph. Since then the world has seen a boom in high-speed rail. In 2011, the EU set out to triple the length of the European network by 2030 <https://www.eca.europa.eu/en/Pages/DocItem.aspx?did=46398>, and since 2000 has invested €23.7bn (£20.42bn) in the development of high-speed rail infrastructure. In the last ten years alone, the number of passenger-kilometres travelled annually on high-speed trains (those operating at speeds over 250kph) has increased 350 per cent, to 845 billion. The lion’s share of this growth has taken place in China. Since the country inaugurated its first high speed service, a 120 km route between Beijing and Tianjin, in 2008, it has built over 20,000km of track <https://www.uic.org/com/uic-e-news/301/article/new-uic-brochure-high-speed-rail?page=thickbox_enews>, served by 1,200 trains. With air travel under increasing scrutiny as a dangerously indulgent mode of transport, rail is often touted as the greenest form of mass transit available. Across Europe and Asia, ultra-fast trains are racing to capture overland routes back from the air industry. Can high speed rail make long distance travel green again? “The big issue is power,” says Alan Vardy, emeritus professor of engineering at the University of Dundee. “The power required increases with the cube of the train speed.” That makes squeezing each additional boost in speed exponentially more difficult – and expensive. “You’ve got to have the electricity to provide that power, and the motors of the vehicle have to cope with that power,” he says. Typically, that power (around 15,000 to 25,000 volts worth) is supplied by catenaries, overhead wires that a train contacts to via a raised arm called a pantograph. These wires are not rigid, but draped between support pillars. “As the train goes under, it distorts the shape of wire, and the whole thing shifts,” says Vardy. The faster they go, the more the wire sways. “There is a fair amount of technology just keeping the pantograph in reasonable contact with the wire.” And as trains get faster, increasing that speed becomes even harder. *Air resistance become a major factor with increased speeds. “Double the speed leads to four times as much loss to drag,” says Hugh Hunt, researcher in engineering at Cambridge. “So high speed trains have really sharp pointy noses.” *The famously long noses of Japan’s Shinkansen ‘bullet’ trains are actually there for a different purpose, however: preventing sonic booms. As a train enters a tunnel, it acts like a piston, creating a shockwave that races ahead of the train. The aerodynamics of long, narrow tunnels can result in a cacophonous bang at the far end – to the irritation of those living within earshot. The problem is particularly acute in Japan, where tunnels were built before the effect was understood. Engineers designed trains with elongated nose cones to soften the sudden increase in air pressure. High-speed trains in Europe go just as fast as Japanese bullet trains <https://www.wired.co.uk/article/japan-bullet-train-alfa-x-nose> – if not faster – but the phenomenon is rarer due to larger bore tunnels. Where it does occur, engineers usually tackle the problem by adding a long hood to the tunnel. “Just like the long nose makes it possible to operate in tunnels without any hood, the hood makes it possible to operate without a nose cone,” explains Vardy. Sudden pressure changes in tunnels are also uncomfortable for passengers, and for this reason all high-speed trains are pressured to some degree. But this creates a new problem: the pressure difference has to be shouldered by the chassis of the train, and over time, leads to fatigue issues. At high speeds, noise also becomes a big issue. Narrow tunnels are also a problem in the UK, where they were built for smaller nineteenth century vehicles, and limit the amount of noise insulation that can be added to a modern train. Noise increases with speed, and high-speed trains are usually fitted with skirts to muffle the shriek of steel wheels on steel tracks. This sound is especially bad if the rail isn’t constantly ground down. “High speed tracks have got to be very, very smooth,” says Vardy. “You can hear it if you go on the Underground in London, or any city, sometimes it becomes really noisy because that section of track has become corrugated.” At 400kph, high speed transport is a moving experience for more than just the passengers. The speed of a train is dictated by the rail it runs on, which is set down in stone – literally – when the track is laid. The sharpness of curves – as well as the tilt they are given, to allow the train to lean into the turn – sets a cap on the maximum speed a train can pass safely. Tilting trains can squeeze a little extra speed from the existing track, but then any existing track must be redesigned or replaced with a purpose built high speed line. Costing around $30m (£23m) per kilometre, this soon adds up. Xxxxxxxxxxxxxxxxxx Q4 Chennai is still the oldest city unlike Mumbai, Delhi and Calcutta because even Trivandrum and Cochin had changed completely. I endorse the Sekar view expressed. The writer sabha is not a sabha of older origin but converted as open by chettyar. Music academy, Narada Gana sabha , Vani mahal, Parthasarathy sabha etc are the oldest and even now functioning well. I was once an ardent lover of spending December Jan in sabha; because of my shift to the USA it is now becoming a far away place. I am a regular member who always takes a season ticket for Row 3 . One who knows cine music and seeing from bs while crossing the mount Rd may not know about it. Stalin, as his father did, wishes to crush Chennai and T Nagar. Let's see in the future. Xxxxxxxxxxxxxxxxxxxxxxxxxxxx - On Sat, Jan 28, 2023, 6:36 PM 'gopala krishnan' via iyer123 < [email protected]> wrote: > *CULTURAL QA 01-2023-29* > > *BEING A COMPILATION THERE MAY BE ERRORS* > > Q1 Why do American trains have "noses" at the front of the > locomotives but European, for example, don't? > > A1 Jay Snead, retired researcher, amateur philosopher Jan 21 > > *American trains are typically longer and wider to accommodate more > freight**, while European trains are shorter and narrower to allow for > more nimble movements and quicker acceleration*. European railways have > tighter curves and the tunnels and bridges have smaller clearances. > Likewise, American locomotives are longer, taller, and wider than their > European counterparts. *The American locomotives have much greater > distances to travel, and are pulling much heavier trains than their > European counterparts.* > > The hood on American Locomotives is there because the longer frame has > room for it. Engineers like having some crumple space in front of the cab > in case of collisions with vehicles and other trains. The shorter > European trains seldom have the length needed to add this safety measure. > > For the same reason most American semi-trucks have a hood, while most > European trucks do not. European cities have tighter turning requirements > and require a shorter truck. > > *My note- I recollect buses in Kerala had the hood in* front, difficult > to read the destination, petrol engine and many could get vomiting > sensation, when I was about 7-10. We used to call it Mookranchi > > Q2 What foods did potatoes replace when they were brought to > Europe? > > A2 Matt Riggsby, MA Archaeological Studies, Boston University Wed > > They didn’t really replace anything. That is, *there’s nothing people > stopped eating because potatoes were available instead.* > > That said, *potatoes grew into a niche leading to a relative decline in > the consumption of some other crop*s. Notably, whereas before the > introduction of the potato most people got most of their calories from > starchy cereal grains like wheat and barley, potatoes moved into that > niche, with some people getting most of their calories from potatoes and > many getting a substantial portion of their calories from them, accompanied > by grains. > > *Human consumption of turnips probably declined somewhat, but it was > usually a food for the poor anyway*. It just so happens that potatoes > started to come in around the time Europeans started using four-field crop > rotation techniques, which involved growing more turnips, which were fed > to livestock, so there was something of a shift in turnip usage, but not > necessarily because of the introduction of the potato. > > Q3 What is the reason that the maximum cooling temperature of air > conditioners is 17°C only? > > A3 Pradip Chandra Bhattacharyya,PhD in Mechanical Engineering, > University of Strathclyde (Graduated 1977)Updated 3y > > In 1963, the ASHRAE - KSU sponsored project at the Institute for > Environmental Research, KSU, US, studied thermal comfort levels for > clothed sedentary subjects. > > Results showed that for such subjects comfortable situation ranged from 16.7 > to 36.7 deg C, (62 to 98 F). > > This might have motivated the AC manufacturers to adopt the lowest > temperature level as 17 deg C. This standard has come to India as well, > like many other things. > > My LG split AC has a setting range of 18–30 deg C only. > > Q4 How much has Chennai transformed in your lifetime? > > A4 Kadambi Seshasayee, Lives in Chennai, Tamil Nadu, India > (1962–present)Jan 14 > > *I have been in Chennai since 1962 till now, with some absences for 12 > years*. The absences only highlighted the changes since I had left. Let > me break this up into two parts: The city’s place in India and the world, > and a personal view as a Chennai-wasi. > > Chenai’s place in the world: > > In the 60’s and even the 70’s, Chennai was the leading metropolis of the > south. Bangalore was still a retiree’s haven, a PSU factories location, > and fairly compact. *Chennai had the only international airport, had > connectivity by sea to Singapore, Malaysia and Sri Lanka. *It was also a > place where most (say 90% ?) of all southern movies were shot in all > southern languages; Very conservative but influential on the national > scene. The first migrants to US had started, and IIT Madras (along with > IISc) was the premier engineering institution. most of whose students > made a beeline to US. Those days, people referred to the four metros- > Bombay, Delhi, Calcutta and Madras. > > Since 2010, Chennai has been losing its mojo and its premier place among > southern cities. Bangalore has pushed it to the second place in the > south. It is no more in a predominant position- people refer to the *three > metros- Mumbai, Delhi and Bengaluru*. In population too, it lags behind > Bangalore. At the center, Tamil Nādu has lost any influence it had before, > and it is basically ignored. International flights now take off from > about eight cities in the south, and Chennai with its thrid-rate airport > lags far behind Bangalore. > > But, Chennai, along with Tamil Nādu overall, leads on many fronts- GDP, > Civic consciousness and cleanliness, still-bearble traffic ( Approximately > one in two persons in Chennai owns a vehicle, and still it is not subject > to horrendous traffic as in Mumbai and Bangalore, but it is catching up…) > Industry-wise, > it is among the top preferred locations in the country. It is a major > center of Automotive and Engineering Industries and one of the leaders in > IT. > > *Chennai from the individual’s point of view:* > > In the 70’s. Madras was a peaceful, quiet and highly cultured place, where > the individual had a lot of space to achieve and shine. *As a student and > young engineer, I had a great time*- great food (Buhari's was a great > example); A cabaret where we would blow up our earnings- it was that costly > (but not indecent); *Many theaters showing English movies; The peaceful > beach and India’s first malls and hypermarket ( Alsa Mall and Spencers*) > even the first multiplex (Safire with its three screens and the only > non-stop movie house- walk in anytime and keep watching the movie as long > as you want) . Importantly, we were treated to visiting musicians and > Theater from abroad- jazz from USA, Symphonies from Germany etc. What not > to love ? > > *Now, Chennai is a large, cosmopolitan city. It* boasts on many 5-star > deluxe hotels, world cuisine- from Mediterranean, Singaporean and Japanese > to Korean (The largest number of the last two in Indian cities) apart from > the usual Thai, Chinese and ‘Pan-Indian” restaurants. You have a lot of > expats and a whole ecosystem catering to them and pushing up prices > (Restaurants again, Americal chain hotels, boutiques, high-end residences > etc., ) like the other metros. *In spite of the vehicle and human > population it still does not feel like a hurried metro like Mumbai or > Bangalore.* The hospitality and kindness to strangers and newcomers has > not gone down a bit. Leisure activities are many more- from the usual > mall-hopping to high-end resorts on the East Coast Road. > > A few major issues persist- the local airport, the only one of two under > Government control-and that is telling- is easily the worst among all > Metros. Long before, Hyderabad and Kochi were far superior , and now Mumbai > and Delhi and recently, Bangalore have joined them. But local transport > is great- three types of trains- Metro, local ‘electric train’ that after > 90 years carries a lot of traffic, and the MRTS. Even bus transport that > can surely improve, provides basic service to people. The multiplexes are > many, big and far cheaper than Mumbai or Delhi-prices controlled by the > Government. > > Medical care is top class- from the hospitals catering to the poor to the > high-end ones catering to foreigners, NRIs and expats. But for all this, > it somehow feels provincial and lacks the glamour and feel of the other > metros. But, there is great cultural and communal harmony, and a visitor > or newcomer is made welcome. > > All in all, a very livable place. > > Q5 Why have Mumbai trains been overcrowded for so many years, and > why is the government not doing anything about it? > > A5 Navnit Sourirajan,MURP in Transportation Planning, CEPT > University - School of Planning (Graduated 2017)Updated 5y > > Your question has 2 parts and so my answer shall also consist of 2 parts > > Part 1: > > *Since you mentioned “so many years”, I will take* the last 4 decades. > Let’s look at Mumbai’s population growth. > > 1971: 5,970,575 > > 1981: 8,227,382 > > 1991: 9,900,000 + 2,600,000 (Thané) = 12,500,000 (Greater Bombay) > > 2001: 16,368,084 (Greater Mumbai, incl. Thané) > > 2011: 18,394,912 Greater Mumbai, incl. Thane ) > > *Mumbai has grown phenomenally in terms of population and is one of the > most densely populated areas in the world today.*So demographically it is > a one of a kind place. > > *Now predominantly its a linear city in terms of its shape*. The island > city is long and runs from north to south, This makes commuting very > simple. You either go up or down, for the most part. This means that all > the people either go up or down the city everyday and there is nowhere else > to go, unlike Delhi. > > So the train services were running in the same direction, and it got > people close to their jobs, with simply two or three routes, again unlike > other cities, where people go everywhere and the city needs many different > routes for trains/metros. > > Now, almost the entire city travels up and down just these 3 lines > everyday. And as the city expanded so did the length of the lines, > servicing more and more people. Naturally it got crowded. > > Part 2: > > Contrary to your belief, the Railways has been doing its best to improve > it. > > First it increased the duration for how long the trains ran, today they > run almost round the clock. The last train ends its run at 2 in the > night, while the first train departs at 4 in the morning. > > Then they increased the number of services, and today *it runs 2500 > trains each day*. This meant a gap of 3 minutes between trains. *This > can’t be decreased, due to the signalling system and safety issue, so as to > maintain the minimum gap between trains.* > > They have also increased the speed of trains, and the latest trains can do > a top speed of 110 Kmph. Siemens rake fit and running at 100kmph since > 2007. Bombardier rake fit for 110kmph and already running at 110kmph > between Virar and Dahanu rd. > > *Then they increased the number of coaches in each train from 9 to 12 to > 15 in some cases*. They could not go beyond this because the platforms > are not long enough to accommodate the trains. > > What else can be done ? They can’t build new lines, because the demand is > along only these lines. So can’t we increase the number of tracks ? That > would be very difficult as that would involve acquiring land. (Considering > Mumbai, i feel its almost impossible) > > *So are they not doing anything ? No.* > > This is the CRs recently developed control room. This enable a control to > monitor the entire network at any point of time. And even more recently a > new scheduling and signalling program is being *developed with IIT Bombay > to reduce the frequency of the trains to 90 seconds.* > > All this will reduce the crowd to some extent, until more people move to > the city and start using the service, and it becomes just as crowded. > > It is the world’s busiest urban public transport system, except for > shanghai. And remember it is one of the oldest as well. Country’s first > train ran between Roorkee and Piran Kaliyar in 1851 while train between > Mumbai & Thane ran in year 1853 .Unless there is a complete over haul(which > is practically impossible) the crowds will remain. > > The Mumbai metro’s Line 3 , which is being built from Colaba to Seepz, > when opened, will take a little burden of the locals, but that is as far as > it gets. > > We can do all that we can, but Mumbai will remain Mumbai. > > *All the above QA are from Quora website on 28-01- 2023.* > > *Quora answers need not be 100% correct answers .* > > *Compiled **and posted by R. Gopala krishnan on 29-01-2023* > > > > -- > You received this message because you are subscribed to the Google Groups > "iyer123" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/iyer123/1242560303.537799.1674959804678%40mail.yahoo.com > <https://groups.google.com/d/msgid/iyer123/1242560303.537799.1674959804678%40mail.yahoo.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Thatha_Patty" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/thatha_patty/CAL5XZooLwtRuEnc2u70-j1z6BjE1eQD5-tCQi9B2Eh8e8QkCiA%40mail.gmail.com.
