More than two months after the collapse of the Himalaya foot overbridge (FOB) at CSMT, BMC departments continue to pass the buck to fix culpability, the latest supplementary chargesheet filed by the police in the chief metropolitan magistrate court on Thursday showed.
According to the chargesheet, the BMC’s A ward, which undertook the beautification of the bridge under Swachh Bharat Abhiyan in 2016, has told the Mumbai Police that it had written to the bridges department to carry out a structural stability assessment of the FOB before work could begin.
The civic body had planned to lay a fresh coat of tiles over the walking surface of the bridge, which carries commuters in and out of the station. Then BMC commissioner, Ajoy Mehta, had visited the bridge on October 25, 2016 and given instructions to carry out the beautification work. A contract was awarded to Vitrag Constructions on November 3.
The chargesheet quoted an A ward official as saying that Anil Patil, executive engineer (bridges department), who has been arrested in the bridge collapse case, did not respond to their letter. “We had written to the bridges department asking for an assessment of the bridge from the stability point of view. Anil Patil never responded to the letter and we went ahead with the beautification of the bridge,” the chargesheet said.
Neeraj Desai, the arrested director of Prof DD Desai’s Associated Engineering Consultant and Analyst Private Limited — which conducted a structural audit of the FOB — has claimed in his defence that the FOB collapsed as a result of the “dead weight” of the tiles, and “live weight” of the commuters.
The BMC has so far arrested Neeraj Desai, Anil Patil, assistant engineer S F Kakulte and retired chief engineer Shitalaprasad Kori of the bridges department in the case. In the chargesheet, Kakulte and Patil have been charged with failing to visit the bridge while the structural audit was underway and not inspect bridges under their jurisdiction in April and October, before and after the monsoon season.
But a report from Veermata Jijabai Technological Institute (VJTI), sought by the police for its opinion, stated that corrosion was the likely cause of the collapse. Experts at the college examined two steel plates and three steel rods taken from the wreckage and subjected the latter to tensile tests.
“In order to have adequate ductility in the structure IS 1786 (2008) table number 3, specifies that the percentage elongation should be 14.5 percent and above for FE 415 grade of steel. From the test result, it is observed that the percentage elongation is significantly lower than the permissible value. This indicates the possibility of loss in ductile property of reinforcement bars which may lead to brittle – failure,” stated the college’s findings.
On the corrosion of the steel components holding together the bridge, the report noted, “Pitting of steel, loss of material and reduction in thickness due to heavy corrosion has been observed. The variation in the thickness due to corrosion vary from minimum 2.8 mm to maximum 10.0 mm. Considering presently 10 mm as original thickness of plate (due to absence of actual data), there is significant reduction in effective cross section area of the structural member leading to decrease in load carrying capacity. Such significant reduction in load carrying capacity may lead to loss of structural integrity…it is necessary to inspect all structural steel members as well as joints (connections) so that corrective measures can be taken in due course of time.”
The 306-page chargesheet filed by the Azad Maidan police station included statements of A ward officials, Vitrag Enterprises (contractor that had taken up the beautification of the FOB), and authorities at J J Hospital, G T Hospital St George Hospital, where the injured were rushed when FOB crashed on March 14.
Seven persons were killed and 31 injured. A police officer said that the reason for the collapse is yet to be determined. “The auditor claims it was due to the load of the beautification work, the VJTI report states that it may be due to corrosion and the BMC claims that it is yet to receive a definitive conclusion,” he added.