Accidents do not happen ...

When simple engineering mechanics make the sequence (of the train accident at Kadalundi on June 22) amply clear, the Railways and their remote sensing apologists are looking for explanations on how geological phenomena could be superimposed on an extremely localised event such as the collapse of a pier. SPECULATION AND opinions on accidents tend to project them as part of natural phenomena. This is a very convenient way of absolving all concerned, of their responsibility, accountability and even culpability. Thus, over the years, the general public and the media have begun to consider accidents as natural disasters. Most of the investigations proceed on the assumption that some natural phenomenon has triggered the accident. Thus, concrete evidences are bypassed, proper modelling and analysis of the process ignored and ridiculous but convenient conclusions arrived at. A classic example is the "Tornado Theory'' attributed to the infamous Peruman rail disaster. "Tornado'' was confirmed finally by the Railways, although the neighbourhood of the accident did not even experience a breeze to speak of. It was for the first time that a tornado overturned a passing train, leaving all the tress, huts and fishing boats intact.

The recent accident at Kadalundi near Kozhikode on June 22 was initially dubbed as due to the sinking of the eastern pier of the third pair of piers from the south (last but two, in the direction of running of the fateful 6602 mail). Railway officials can be pardoned for this hasty conclusion, as they would like to save the face of the organisation and those of their erring colleagues. But some of the "geologists'' and "scientists'' living far away from the site try to assert that some geological phenomena, akin to the sinking of wells in some parts of Kerala, caused the accident. These "remote sensing scientists'' have neither visited the site nor analysed the mechanics of failure of the pier. The pedantry and conceit associated with deep knowledge in narrow fields make such people assert that every phenomenon has something to do with their area of expertise. One is reminded of Mark Twain's famous statement "If you have a hammer in your hand every problem looks like a nail on the wall''. This is precisely what happened to the remote-sensing scientists who have thoughtlessly associated the accident with geological phenomena, far away in space and time.

One such scientist has assigned the cause to the geological faults dating back to the continental drift that resulted in the separation of Madagaskar from the Indian peninsula (The Hindu, June 29). Attempts to relate the failure of the eastern member of the third pair of piers to the position of stars and planets should sound equally logical.

Not a geological phenomenon

It is true that no plausible arguments should be rejected at the outset in scientific reasoning. Many people had a doubt whether the "pier sinking'' had some relation to the disappearance of wells in certain parts of Kerala. The team of scientists from Geological Survey of India, CESS and other organisations have closely examined the wells and reported that the prevention of surface flow of rain water due to massive land filling and construction activity in Kerala has increased the percolation of rain water, raising the water table around the wells. As the concrete ring type of wells do not permit cross flow through the well, the differential pressure between the interior and exterior of the rings causes the rings to collapse and the wells to cave in. This occurs during the beginning of monsoon and stops once the water table is stabilised. This can hardly be called a geological phenomenon, as the human error in the construction of wells is the assignable cause.

Most people thought, and the Railways conveniently publicised, that the eastern pier of the third row has `sunk' to the ground. The cross girder on the pier was resting on it at an inclination of 25{+o} after the accident, with the eastern end completely submerged. This appearance gave credence to the story that the pier had sunk, and that the possible reason could be some unknown geological phenomenon, over which Indian Railways had no control. By examining the pier under water, it was clear that the pier had broken into two or more pieces, the top piece of 2.73 metres length lying at an angle of about 40{+o} to the horizontal, and its top edge still supporting the eastern end of the cross girder. The immediate thing that the Railways should have done was to take out all the broken pieces of the pier, put them together on the ground and measure its length. It is fairly certain that the result of adding this to the bottom stub will give the original height of the pier. Such measurement is just common sense, and no great technology is involved.

As it is already known that the pier has broken into two or three pieces, the "sinking pier hypothesis'' can be rejected straightaway. A pier that sinks into soft soil cannot break due to a force from the top, because the soft soil does not provide the necessary upward reaction to break the pier. Moreover, a 140 year old pier cannot sink all of a sudden, after allowing the engine and nine coaches to pass without any problem. But, its collapse is possible if it stays without sinking, provided a coach overturns and gives the necessary eccentric impact load. Thus the only reason why the pier broke is that a coach overturned on the cross girder, hit the main girder providing necessary bending moment to break the pier. In such a case, even eccentric loading of the pier is not a must, as the bending moment could be provided by the lateral load on the longitudinal girder. It could be seen that the northern span of the plate girder resting on this pier had moved away to the east at the end of the accident, possibly due to this impact. Once the capsizing of coaches starts, chaos sets in, and the mechanics of the further process is beyond any modelling and analysis. In short, it is clear that a coach capsized, fell on the cross girder, hit the plate girder, causing the pier to break into two or more pieces.

The Rail Safety people hold that capsizing will be preceded by derailing: and derailing will be taken care of by `guard rails', enabling the driver to drag the affected coach away from the bridge. If a `rogue' compartment is involved in the derailing, it is unlikely that it could be dragged out before overturning unless the train moves at painfully slow speed. If the `rogue' compartment has a defective undercarriage with defective springs, malfunctioning bearings or loose brackets and clamps, the excitation given by the reactive forces by the rail can lead to amplitudes of oscillations beyond acceptable limits. Remember, the wheel flange radius is only 38 millimetres, and a defective undercarriage can cause not just derailing, but overturning also.

`Rogue' compartment

It is clear that the train overturned, fell on the girder and damaged the bridge. The interested parties try to change the sequence of events the other way that the bridge collapsed before the train capsized. When simple engineering mechanics make the sequence amply clear, the Railways and their remote sensing apologists are looking for explanations on how geological phenomena could be superimposed on an extremely localised event such as the collapse of a pier. It is obvious that somebody is afraid of the truth. If the rogue compartment is identified, its defects and dynamic characteristics understood, it should be possible to reconstruct the accident by computer simulation. When such a study follows the trail and locates the First Cause of the accident, the responsibility (culpability?) of those involved can be fixed. A callous indifference and criminal negligence alone can allow such a rogue compartment to find a place in an important train such as the Chennai Mail.

Warning ignored

Among the non-technical arguments and evidence the observation of a school girl named K.T. Sabitha who watched the train between the points 677/8 and 677/7 near the Korappuzha bridge shines like a silverline amidst the obscurities. She watched with a great deal of concern and anxiety the swaying of a coach with one of its wheels not rolling at all. She told her parents, and learnt later that the train had capsized at Kadalundi the same evening. Some of the passengers travelling in the coach had also reported the matter but the Railways chose to ignore the warning.

If truth has to come out, the Railways have to identify the rogue compartment and subject its undercarriage to rigorous dynamic analysis without further delay. The maintenance history of the coach will narrate a few tales. There will be many eye-openers from which all of us can learn useful lessons. The sad part of the story is not that a driver, a stationmaster or a few mechanics shirked their responsibility and allowed the defective train to pass, but that the Railways chose to ignore the warnings, loud and clear. It appears that they prefer the First Cause to be of natural origin rather than human error. The Railways can utilise the services of the rich galaxy of technical personnel in the country to find out the truth. Alternatively, they can sweep the problem under the carpet and take shelter under the theory of continental drift proposed by their apologists. They can continue to believe that in an organisation of perfect human beings, accidents are, after all, acts of God.

M. P. CHANDRASEKHARAN

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