Was it the bridge, or the bogies?

The Railway authorities blame nature and an overaged bridge for the Kadalundi train accident; many experts, however, say that evidence points to a systemic neglect of rail safety.

THERE is widespread apprehension that the inquiry into the recent train accident in which bogies of the Chennai-bound Mangalore-Chennai Mail fell from a 139-year-old bridge into the Kadalundi river near Kozhikode on June 22 may conceal rather than reveal the proximate causes of the accident.

Faced with mounting criticism about its lack of sufficient concern for passenger safety, the Railways, in its first reaction, seemed to blame nature for the tragedy. Union Minister of State for Railways O. Rajagopal said on June 28 that "unusual" geological activity in the region, confirmed by the "disappearance" of some wells, could have caused the accident. Citing as yet unconfirmed reports, he said that the third pier of the bridge had sunk by two feet.

To sceptics this rang a familiar bell. An inquiry conducted by the Commissioner for Railway Safety into the 1988 rail accident at Perumon in Kerala, when several bogies plunged into the Ashtamudi lake killing more than 100 persons, attributed it to a tornado. A second inquiry, prompted by public outrage, revealed that problems in track alignment and faulty wheels of coaches were responsible for the tragedy. Curiously, the Commissioner functions under the Union Ministry of Civil Aviation, not the Railways.

Experts who support the "geological activity" theory say the large-scale construction activity and the disappearance of water-logged areas in the region had increased the percolation of water, resulting in the rise of the water table, This in turn resulted in the collapse of wells in the area. However, other experts, among them scientists from the Centre for Earth Science Studies, point out that drawing a parallel between the sinking of wells and that of bridges and their piers was inappropriate. Instead, they asserted that the well collapse had more to do with human activity than an act of nature.

The "geological activity" hypothesis was followed by the theory that a pier on the eastern side of the bridge sank as the train ran on the bridge in the north-south direction. Railway Minister Nitish Kumar was among the early proponents of this theory. However, this was contradicted by investigations commissioned by the Railways as also by other scientific opinion. A team of naval divers, which inspected the bridge on June 30, ruled that the pier collapsed under the weight of the passing train. It also categorically dismissed the theory that the pile sank. The team from the Naval Base at Kochi, led by T.N. Srikumar, observed that the top portion of the broken pier was inclined at an angle of 50 to 60 and that there were no "hit (marks) or external damage" on the pier. The naval team's inspection suggested that the accident was caused by the collapse of the bridge as the train ran on it. This appeared to be a plausible explanation, given the fact that the replacement of the bridge was overdue. Around the same time reports of an earlier breakage on the bridge, which had escaped the attention of the Railways' Civil Engineering Department, appeared in the media.

However, critics see ulterior motives behind the Railways' belated attempt to fix the blame on an overaged bridge. They point to other evidence, circumstantial as well as material, suggesting that the train and its bogies were to blame. Having to accept that the tracks were bad and inadequately maintained and monitored, and that the coaches were in a dilapidated condition owing to poor maintenance would suggest a systemic failure in the Indian rail network.

Vishnu Potti, Director of the Forensic Department in Kerala, who visited the accident site for a few days from June 28 and again on July 6, said that he "examined all the material involved in the accident", including the coaches, piers, girders, sleepers and rails. He "specifically noticed certain marks and damages indicating a leftward tilt." He also "did not find any hit marks indicating a derailment of the train." There was also no indication that the wheels had "dragged" prior to the accident.

Potti's observation that the train fell leftward, to the east, has been contradicted by eyewitnesses as well as by other experts. They have said that the bogies had fallen on either side of the bridge. Photographs taken immediately after the accident confirm this.

The Principal of the Regional Engineering College (REC) near Kozhikode, Dr. M.P. Chandrasekharan, was among those who went to the spot soon after the accident. He had a special reason to do this: Somrup Mazumdar and Nirmal Jyothi Bhattacharya, two final- year students of the REC, were among those who died in the accident. Chandrasekharan, a mechanical engineer, is sceptical about the bridge being blamed as the proximate cause for the accident. He disagreed with Vishnu Potti's assessment of the "cause and effect" of the accident. He said that a team of experts in structural engineering, soil mechanics and foundation engineering and mechanics from the REC had gone to the site on June 25. It noticed several coaches lying on either side of the bridge. The experts, who went in a boat, "clung to a broken cross girder slanting to the east and felt the pier with bare feet and made an approximate measurement."

Media reports, obviously based on railway sources, suggested, even as the official inquiry was on, that the bridge collapsed because the screw piles supporting it gave way. The REC study dismisses this theory as "absurd". "Even if there was a crack on the pier, a regular axle load passing on it would not cause such a collapse," Chandrasekharan said. He pointed out that several trains had passed through the bridge, as had the first seven coaches of the Chennai Mail.

He cites evidence to show that "a rogue compartment" would have provided the "necessary impact load" and possibly an additional load from the side of the bridge to trigger the accident. He postulated that a coach overturned on a cross girder and then proceeded to hit the plate girder, providing the force to brake the pier.

Chandrasekharan said that a derailment of the "rogue compartment" was not a necessary condition for triggering the kind of collapse that the REC team has postulated. "A rogue compartment could capsize without derailing." He said that the collapse was caused by "an impact load on the third cross girder and the plate girder on the bridge." Asked if the girders would not bear the marks left by bogies that derailed or were thrown off the tracks, he said that these would "leave marks on sleepers, not girders." Girders, he said, bore not just marks, but suffered deformation.

Pictures taken by the REC team show that not only had the plate girder shifted significantly to the left of the train but the rails had unhinged from the sleepers and the plate girder. Chandrasekharan said that the impact had "torn the sleepers to shreds." The photographs also show a rail resting on a cross girder, "where it has no business to be". He also pointed to a dent on the cross girder, indicating that "a heavy object had fallen on it."

He said that broken or stiff springs, malfunctioning bearings or loose clamps and brackets in the undercarriage of a "rogue compartment" could cause a bogie to be thrown off the track. He pointed out that since the radius of a rail wheel flange is just 38 mm, a bogie needs to be lifted only by that much to be thrown off-track.

Chandrasekharan argues that if the collapse of the pier on the eastern side of the third pair of piers was the "first cause" of the accident, all the coaches would have fallen on the eastern side. He argues that the fact that some of the coaches fell to the west, against the direction of tilt of the breaking pier, implies that "the tilt of the cross girder had taken place only after some of the coaches had fallen towards the west. He also pointed out that the top plate of the cross girder had undergone "local deformation", indicating the "impact of a heavy object on it". This deformation, he said, could not have happened after the pier tilted to the east by 25 degrees and when it was not in a horizontal position.

Vishnu Potti's claim that the pier took 11 seconds to collapse, has also been rebutted by Chandrasekharan. He said the pier collapsed as a result of what in engineering parlance is called "brittle failure". Such failure happens in a fraction of a second. He pointed out that cast iron and surki concrete, the bridge's main components, do not have ductile properties.

The REC team, he said, rushed to the accident site because the college was located at Chathamangalam, just 40 km away from bridge. His team deposed before the inquiry committee because the "Railways has a bad record of having twisted facts in an earlier case." He also alleged that the Railways "try to intimidate non-technical people who (give) direct evidence and we thought that it is our duty to bring out the truth before it is obliterated."

The fact that the forensic expert and the naval team went to the site almost a week after the accident has also been criticised. Chandrasekharan said that what he saw on June 25, and what the naval team observed five days later, were "very different". "The cross girder," he said, "had disappeared by the time the Navy team arrived." The heavy flow of water under the bridge also meant that evidence was fast disappearing. In fact, it has been pointed out that a small coffer should have been constructed at the accident site to examine the material evidence.

There is circumstantial evidence, from other sources, to suggest that the bogies were not sound. Several passengers said that the train jerked and rattled abnormally. Some of them said there was a continuous grating sound, particularly in Coach S-7. Others are reported to have seen a fire at the rear of the train. Union sources in the Southern Railway told Frontline that station masters at Neeleshwaram and Kannur had sent messages to onward stations at Kozhikode and Shoranur, informing them about "defective bogies". This implies that the train was allowed to run for more than three hours between Kannur and the accident spot after the messages were sent.

There have also been serious complaints about the manner in which the official probe was conducted. Several top Railway officials dealing with civil engineering were allowed free access to the proceedings. Chandrasekharan, who made a suo motu appearance before the Commission, said that several senior officials were present during his deposition and he assumed that they were part of the Commission.

The Kadalundi accident has once again put the safety record of the Indian Railways in the spotlight. The problems that the Railway Safety Review Committee, headed by Justice H.R. Khanna, highlighted remain largely unaddressed (see box). In the Southern Railway, for instance, one-third of the broad gauge electric locomotives are more than 15 years old; more than 20 per cent of the metre gauge coaches and nearly 15 per cent of the broad gauge ones are more than 20 years old. The problem is more acute with goods wagons.