On Tuesday, amid heavy rain, a road overbridge collapsed on railway tracks in Andheri in Mumbai. Five people were injured, and it is providential no lives were lost. Train schedules were disrupted, putting millions of people to inconvenience.
Bengaluru has 10 road overbridges (roads with railway tracks underneath) and 20-foot overbridges (for pedestrians, again with railway tracks underneath). Some are maintained by the railways and others by the BBMP.
The road overbridges are what the engineers call ‘prestressed’ concrete structures. “Steel bridges are few in number in this city. The Yeshwanthpur railway station has a couple of steel bridges. Bengaluru, unlike Mumbai, does not have vast stretches of rail tracks,” an official of South Western Railways explains.
“The foundation is thoroughly checked. We also inspect the steel structures for possible corrosion. If we find any damage, then we order the structure to be replaced and repainted,” he says.
Safety measures
The road and foot overbridges are inspected by supervisors every month and by senior staff three times a year.
“We make sure the quality of inspection is not compromised. The steel structures are most vulnerable to corrosion because of people urinating near them. This leads to rapid deterioration,” he says.
Inspectors check the foundation to gauge vertical strength.
Another official in charge of bridge construction says, “For some bridges, the BBMP pays a fee to the railways for the land. The railways and the BBMP jointly maintain these structures.
What happened on Tuesday
A senior official with South Western Railway told Metrolife, “The bridge that collapsed in Mumbai is a road overbridge. It was intact but the foot over bridge attached to it, with the help of a cantilever system (no supporting system to the ground but attached to road overbridge) collapsed. In Bengaluru, we don’t have any bridge like that. All existing foot overbridges in the city are independent structures.”
3 levels of inspection
Railway road and foot overbridges are checked for cracks in the foundation, and also for loose joints and corrosion.
City’s road overbridges
(Railway tracks underneath)
- Near ITC factory
- Banaswadi railway station
- Whitefield
- Yeshwanthpur railway station
- Hebbal
- Devanahalli
- Rajankunte in Yelahanka