SIT in preliminary investigation report: Corroded wires, welded suspenders behind Morbi bridge tragedy

One of the major flaws that caused the collapse of the suspension bridge in Morbi last year, which resulted in the deaths of 135 people, was the welding of old suspenders with new ones, according to the Special Investigation Team (SIT) that the Gujarat government appointed.

The five-member SIT included these conclusions in its ‘Preliminary Report on Morbi Bridge Incident,’ which was turned in in December 2022. The state Urban Development Department recently provided the Morbi Municipality with the report.

The suspension bridge over the Machchu River built in the British era was operated and maintained by Ajanta Manufacturing Limited (Oreva Group), which is also responsible for the collapse on October 30, 2017. The SIT had found numerous flaws in the bridge’s operation, maintenance, and repairs.

Members of the SIT included an IAS officer named Rajkumar Beniwal, an IPS officer named Subhash Trivedi, a secretary and chief engineer from the state’s department of roads and buildings, as well as a structural engineering professor.

One of the two main cables of the bridge, which the former rulers built over the river Machchhu in 1887, had corrosion problems, and nearly half of its wires ‘may have already broken,’ according to the SIT, even before the cable broke on October 30 in the evening.

The SIT claims that the main cable on the river’s upstream side broke, causing the tragedy.

Seven strands, each made up of seven steel wires, made up each cable. According to the SIT report, a total of 49 wires were bundled into seven strands to create this cable.

‘It was observed that out of the 49 wires [of that cable], 22 were corroded, which indicates that those wires may have already broken before the incident. The remaining 27 wires recently broke,’ the SIT said in its report.

The SIT also found that during the renovation work, ‘old suspenders (steel rods which connect the cable with the platform deck) were welded with the new suspenders. Hence, the behaviour of suspenders changed. In these types of bridges, single rod suspenders should be used to bear the load.’

Notably, the Oreva Group (Ajanta Manufacturing Limited), which had closed the bridge in March 2022 for renovations and opened it on October 26 without any prior approval or inspection, had been given the contract to maintain and operate the bridge by the Morbi Municipality without the approval of the general board.

Nearly 300 people were on the bridge at the time of collapse, which the SIT claims was ‘far more’ than the load the bridge could support. However, it stated that laboratory results would confirm the bridge’s actual carrying capacity.