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| SCIENCE & TECHNOLOGY |
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Which MRTS will be the most suitable?
UNDERSTANDING THE
UNIVERSE |
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Which MRTS will be the most suitable? The traffic jams cause accumulation of exhaust fumes in the air and time delays. The problem of exhaust fumes has been partly controlled in Delhi as a result of switchover to CNG and coming of Euro-2000 engines. But the other problem stays. The problem is three dimensional. Besides traffic congestion, parking of cars has become an equally serious problem. Thirdly, the large-scale consumption of petrol by cars is a big drain on foreign exchange. Therefore, a foolproof system is one which tackles all three. History shows that only public transport system has been able to solve the problem and individual transport only aggravates it. Five solutions come to mind. The next best solution is the introduction of single seater cars. But unfortunately, such a petrol driven car has not been manufactured in India so far. However, a battery driven car has been manufactured but it has not found popularity with the people. B. Construction of flyovers across all the crossings:
This is a costly solution. If we construct unidirectional flyovers across all the crossings, 50 per cent traffic will move without any
hindrance. The holding time of remaining 50 per cent traffic will also be reduced by half. But the number of flyovers required is so large (500 in Delhi) that it may take 50 years to construct these across all the crossings in a city like Delhi or Mumbai. The cost of one six-lane flyover may be Rs 200 crore and time of completion may be two years. But if we provide two-tier flyovers only for light vehicles, the cost and time of execution can come down substantially and holding time of traffic may also improve. The cost of one two-tier flyover would be Rs 25 crore and cost of 500 flyovers would be Rs 12,500 crore only. C. Construction of elevated tracks:
80 per cent of the traffic consists of cars, three-wheelers and two-wheelers. If we construct four-lane concrete tracks for the light vehicles on all major roads (with slip roads at all major crossings), it may turn out to be a better solution. The beauty of this solution is that it is cost effective as a 12" thick slab of 50 ft span may be sufficient to take the load of light moving vehicles. The cost per km will be only Rs 10 crore. Once 80 per cent traffic is segregated and runs on elevated tracks, the existing surface roads will be able to provide very fast movement to remaining 20% four wheelers (buses and trucks). The roads can also take additional busload and provide what is called Mass Rapid Transport System (MRTS). For example, an elevated concrete track from Panchkula to PGI may completely solve the traffic problem on Madhya Marg. The track length of major roads in Delhi (which remain choked with traffic) is 1500 km. Hence a sum of Rs 150,000 crore will provide the elevated tracks for the entire Delhi Territory and some parts of Gurgaon and Faridabad. D. Metro System:
This system consists of two categories: I. Construction of elevated tracks for trains: This system consists of construction of an elevated track provided with double railway track. This system is also known as Elevated Rail Track System (ERTS). This system has been taken up in New Delhi where 13 km track between Tri-Nagar and Shahdara has been operationalised. Electric trains (600 persons capacity) run on this track at an average speed of 50 km/hour with a frequency of one train after every nine minutes. This system can carry 140,000 passengers per day from two ends. But the cost of this system is a whopping Rs 130 crore per km. This system is also under construction in Chennai and may be taken up in Hyderabad also. With the indigenisation of this technology, the cost of system may come down to Rs 100 crore per km. At present, the occupancy rate has gone up to 60 per cent and will increase up to 90 per cent once the track is fully laid up to Rithala. The other track between Dwarka and Connaught Place is under construction and two are likely to be fully operational by December, 2005. The time saving is tremendous. Even with 50 km per hours speed, the train is able to reach ISBT from Shahadra in 13 minutes whereas a bus takes minimum 45 minutes. II. Underground Metro System: Kolkata is the first city where an underground railway line was laid between the airport and Tollygunj, over a distance of 32 km. Underground metro is being laid in Delhi from the university area to Udyog Bhavan over a distance of about 15 km. The present day cost is Rs 300 crore per km. The total cost for 65 km for elevated track and the underground system is Rs 11600 crore giving an average cost of Rs 160 crore per km. Economics The cost of Rs 160 crore per km is huge and no state/municipality can afford this heavy investment. In case of Delhi and Kolkata, the funding is mostly from the central allocations. This huge cost prevents private agencies from executing such projects on BOT basis. There are two aspects of this project which need to be carefully observed. In Kolkata, the underground metro with the present-day cost of Rs 10,000 crore serves only a distance of 32 km. The relief in surface traffic volume on this route is substantial. (The density of cars in Kolkata is much less than in Delhi). But on the other routes, the situation is as chaotic as ever in the form of traffic jams and overcrowding in buses. The total route length along all major roads may be 2000 km. So what we have achieved at a huge cost of Rs 10,000 crore is partial relief in a distance of 1.5 per cent. Similarly, the length of major roads in Delhi is also 1500 km. So metro system over a distance of 65 km brings relief only in 4.3 per cent area. To cover major roads in Delhi with combined elevated and underground system will require an investment of 1.8 lakh crores of rupees. The real success of this system will be achieved if at least 50 per cent people stop using their personal vehicles and start travelling by the metro system. Only then metro system will give the triple benefit i.e. parking and traffic problem will be reduced by 70 per cent and saving in petrol consumption by 50 per cent. There are 30 lakh cars in Delhi and average consumption of petrol may be 75 lakh litres per day, costing Rs 15 crore. Petrol is imported and electricity is indigenous. Hence this system will save a foreign exchange of Rs 7.50 crore per day. The response of people travelling by elevated track metro system form Shahadra to Tri Nagar is overwhelming. They come from adjoining areas by their personal vehicles and park at the metro station and then make to and fro journey by metro. DTC has also stopped the plying of many buses coming to ISBT and Tis Hazari Station. But from where to bring Rs 1.8 lakh crore to achieve this triple objective in the remaining area (95.7 per cent) in Delhi? The sheer heavy cost is responsible for not extending the metro project in Kolkata even after 10 years. E. Skybus System:
The benefits of metro system are tremendous and wonderful; but skyrocketing cost is a great impediment for future expansion of the project. To solve this issue partially, Konkan Railways has come out with a new solution of skybus system. This system consists of running an AC coach of 150-person capacity under an elevated track instead of over the track — something like a ropeway. The reason of running the coach below the track is to avoid any possibility of derailment. The cost of this system is Rs 50 crore per km against Rs 130 crore in the case of elevated railway track system. The substantial cost saving in the new system is due to the economy in construction of small station building and other allied works because of low axle load. In the existing system, a big structure of railway station having a platform of 350 m length has to be provided to accommodate the length of the train. In the new system, length of station is reduced to 50 m to suit the requirement of the single coach. The reduction in carrying capacity is compensated by increasing the frequency to one coach per minute against one train of four coaches after every nine minutes. The other
superior, features of this system against the metro system are fast construction (two years), substantial maintenance cost reduction, execution in crowded areas and over the flyovers. Therefore, this new system promises better prospects for adoption than the existing metro system. The Maharashtra Government has signed an MoU with Konkan Railways to lay this system over a distance of 18 km in Mumbai. Mono rail system is suitable (cost Rs 70 crore per km) where traffic problem is not so acute as in Singapore. However, Konkan Railways is doing research to bring down the cost. A system of electric trains (as in Kolkata) on an elevated track will be the cheapest and research is needed to be done in this direction. The writer is Engineer-in-Chief, HSIDC, Panchkula |
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UNDERSTANDING
THE UNIVERSE Clapping under water does not produce any sound. Why?
But your question could be interpreted as saying: “what is so special about the sound made by clapping in air”? How is this sound produced? Its loudness does not depend only on the force with which we hit one hand with the other to set it vibrating. We don not get much of a sound when we hit the base of one hand with that of the other. We do not call hitting the backs of palms together as clapping because that also does not produce much of a sound. I believe that clapping is a special trick we humans discovered because of the special construction of our hands. By smartly hitting the hollow on one palm by a flexible hollow made by the joined fingers of the other we compress a volume of air in between which escapes with an explosive force. It is this explosion that makes most of the sound. Just try clapping by hitting the hollow of one hand with claw of the other with fingers spread out. You would not get much of a sound, because the air does not get compressed — it escapes through the gaps between the fingers. The sound produced in vigorous clapping is physically akin to that you get by bursting a balloon with a needle! Since horses, dogs or monkeys do not have the capability of making matching hollows on the ends of their limbs they can never clap like us. In that sense at least we are far superior. Imagine a world in which we could not express our appreciation after a good music or dance performance by clapping.
Some stars are seen moving in the sky. Why is this so?
All the heavenly bodies are moving all the time. This is their natural state. All the so-called fixed stars are also moving. All of them also share the rotational motion of our galaxy. These motions are not easily sensed because everything is so far away. But I have a feeling that you might be referring to the planets of the solar system and not the fixed stars. We know that the earth moves. That is how we have our seasons. But it also rotates. That gives us day and night. The moon clearly moves around the earth. That is what causes the phases of the moon, from new moon to the full moon and back. Similarly all the other planets also have orbits around the sun and their motion in their orbits can be sensed because of the background of stars and their constellations we recognise in the sky. As I mentioned earlier, the constellations are also not fixed, but they are so far away that we cannot sense the change in their positions in our life times. Perhaps you are not even referring to planets but meteorites. These are not stars but small pieces of matter that hit our atmosphere and burn away. Yes they also represent constituents of the solar floating around space that have accidentally ventured into our neighbourhood. Then there are comets that come from very far away to go around the sun, developing a tail when in its neighbourhood. You ask why must they move. I would reply: “Why not”. Zero movement with respect to any other object has zero probability. The other thing we have to remember is that things that do not have any motion near another heavenly body would be sucked into that body and disappear. The only way to survive in a universe of heavenly bodies is to have some motion of your own.
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Almost every city is suffering from traffic blues. This is primarily due to the sharp increase in the population of cars and two-wheelers. The situation is worst during office hours. In cities like Mumbai, Delhi and Kolkata, the situation is alarming and chaotic. At some crossings, only one-third vehicles are able to cross before the light turns red. 
A. Simple solutions:
If the government or the municipal authority bans the use of cars during rush hours and introduces semi or
deluxe buses in large number, the problem of traffic congestion is solved substantially. A bus carrying 60 passengers saves the space occupied by 50 cars, resulting in 95 per cent space saving. But this solution is somewhat impractical because no government or municipal authority has the willpower to pass such a fiat, otherwise, this step solves the problem of car parking and petrol consumption also. 
Let me confess that till the time I started thinking about your question I had not wondered about this. A superficial answer might be that under water we cannot move our hands fast enough to hit each other with enough force — such as would cause our hands and the water around to vibrate. We need vibration because sound is nothing but that. We know that vibrations propagate through water very well. That is how we hear the sound of the screw of a motorised boat or ship from far away if we have our ear inside water. That is why whales can hear each other in the oceans from hundreds of kilometers away.