Monday, August 6, 2007


To read and write in Bengali, please download FREE Fonts and FREE Keaboard Software by clicking the links given under "You must visit" and Set your Browser Encoding to Unicode (UTF-8 ). Thank you.

In our college life, in the traction paper, we came to know that an electric locomotive would follow a total period divided into 4 zones while going from one station to another. These zones are accelerating zone, where the engine gains speed starting from zero to come to the highest speed, coasting zone, where the engine takes only little power to maintain its speed, regenerative zone where the engine gradually reduces speed and the resultant power is fed back to the traction overhead electric line, breaking zone where break is applied for fast speed reduction, before the train stops. ......

Please give your COMMENTS on this topic written by Pranab Ray Chaudhuri.

To read and write in Bengali, please download FREE Fonts and FREE Keaboard Software by clicking the links given under "You must visit" and Set your Browser Encoding to Unicode (UTF-8 ). Thank you.


  1. This analogy - between the functioning of a locomotive with human life is definitely praiseworthy. The writer is an Electical Engineer who passed out of JU 40 years ago, but still remembers the cycles of locomotive engine - and can draw such an interesting analogy with our life cycle. Such brilliant article definitely needs a citation. I wish him all success in his writing ventures. =Subhas Chatterjee=

  2. Thanks to Subhas for such personal praise. However, I shall be more interested in his and others thoughts not only on this subject but also on other such subjects in this column .

  3. Traction niey amar bondhu Pranab(Bua) ekta lekha pathiechey. Amar motamot holo ei prakar:

    Traction man made thing by drawing inference from "electric locomotive
    engine". He has comapred man made thing with a human being who are God's creation.

    May be both have some similarity as compared to 4 zones as mentioned by Bua (Pranab)in Traction. Human being or any animal have the natural ageing process but for Traction they are made by man, as any of the 4 zones may be increased or decreased according to the wish or the desire of the pilot. But for human being none of us can hardly make any change of the time period mentioned in the matter or graph. Though all of us can make a marginal change in those 4 zones of our lives.

    Final stopping of electric loco motive and restart of the same can be done as per wish of pilot. But for the human being once the cycle is complete it can not be restarted.

    Actually for locomotive there are 4 zones where as for a human being
    there are ten stages "Manusher dosh dasha" from birth to natural death of a human being.

    I do not know why he wanted to compare our lives with Traction & what he wanted to achieve?

    For traction there is no natural process except for the breaking zone where friction will play a very important role to come to a hault.

    I think it is waste of time by comparing human being with Traction, as I do not find/get anything new in the subject.

    Let us disuss some thing more on any lively subject.

  4. 1.I have never compared electric locomotive with man. I compared ,in fact that is also not correct , I tried to give an analogy between the speed-time characteristic of an electric locomotive with that of various stages of man. It is correct locomotive is man-made but there is no proof that man is god-created as it is not even proved whether god exists. In any case such debate is besides this particular topic.
    2. It is not correct that pilot can change the duration of the 4 zones as he pleases as it actually depends on the design of the locomotive engine which is based on the service reqirements with an eye to obtain the maximum efficiency of the engine for one cycle . In fact it is always designed to maximise the area within the trapizoidal curve which has four definite areas initial and the last two almost triangular and the middle one rectangular.So the middle part i.e coasting zone is always the maximum as area of rectangle is dobble of a triangle of equal height and base. The acceralating zone, regenarative zone and breaking zone are all restricted by the design parameters , rail line specification, brake efficiency etc. In any case these three zones can only be triangular. Pilot can only be guided by the speed limits specified by the particular design and can neither increase or decrease the areas of these zones as he pleases .
    3. It is correct we cannot change any of these zones in the case of human beings. But we are initially wasting much of the coasting zone which starts around 18years and ends around 45 years and then trying to extend that period later than 45 years when we are already in regenarating or breaking zone. Since we cannot increase these timeperiods we can at least make an effort to utilise these zones to our maximum. Alas we do not do that. As we are advancing we are keeping on wasting more of the coasting zone.
    4.It is correct same engine can start again in the next cycle after stopping but the same man cannot live once he dies. But we also know that life force goes on from one generation to next, from parents to their issues.
    5.I am only aware about 3/4 stages in human life as supported by medical science . I do not understand why and how 'ten stages of a man's life ' is brought by Robin unless he is depending for proof of that on mythical and religious scriptures.
    6. It is not comparison. It is analogy to take advantage for our betterment.
    7.Both processes are natural processes as both are strictly guided by natural laws.
    8 I consider this to be a very lively subject for discussion as development of entire mankind depends on proper analysis of these zones and following same with maximum advantage for us.