Bridges do not collapse, they fail. Their parts erode silently, until what is left no longer has the strength to fulfill its purpose. They remain bridges in name, and when the ground beneath our feet gives way, that too is washed away.
India has lost at least five bridges, or some part of them, in the six weeks gone by. In Assam, floods swallowed a bridge. One near Ranchi shattered when it rained a little harder, plunging into a river. A pillar holding railway tracks above a seasonal river in Bijnor collapsed because the soil that embraced it had been removed. One midnight last week a bridge’s invisible stresses shifted from pier to pier as rapids pushed past them, before the lightest load sent the whole thing toppling. People vanished.
But this last bridge, in Maharashtra’s Raigad district, had been inspected recently, and its safety was vouched for. It was not at the end of its natural life. So why, then? An inquiry was begun. For good measure, to calm nerves, people in charge added that every bridge in the area would be inspected urgently.
The world of bridge maintenance is large and sprawling. Highway bridges are managed by the National Highways Authority of India, the Border Roads Organisation handles bridges on the border, and the railways takes care of its own. Bridges everywhere else belong to the Public Works Department of the state. Their collective domain extends to around 200,000 bridges made of concrete, steel, iron, stone, wood, and plastic.
Almost 25 years ago, it became clear that India was looking ahead by building bridges, but hadn’t turned back to see how its previous creations were doing. In a paper about bridge maintenance in 1992, engineers at STUP Consultants wrote, “About 6,400 road bridges were listed in a recent survey only on national highways and of these about 50% were reported to need some form of repairs or rehabilitation.”
The engineers looked at the condition of bridges across India with growing alarm. “The other major road network is about eight times as large as the national highway network and is likely to have correspondingly more number of bridges which are in distress,” they wrote. “It has also been reported that more than half the bridges have an age of above 40 years and bridge planning so far has been done with the assumption of an average life of about 50 years. Systematic maintenance of bridges has not been followed so far…”
Step back and take it in. Bridges built to last 50 years were 40 years old in 1992 – 24 years ago – and they were standing despite irregular maintenance.
A matter of trust
A bridge, however permanent, is temporary ground. It imitates land, a duplication of stability that is accepted without question. We cross bridges thousands of times, oblivious to their age, their health, the skills needed in their raising, and the money and duty required to keep them in good health. A bridge, then, is blind trust itself.
It takes a parent, a person in charge, to keep up the illusion.
NK Sinha, a consultant who was once the director general for roads in the Ministry of Road Transport and Highways, wrote in 1990 about the need to improve highway bridge inspection systems.
In 2013, he told me about a bridge management system purchased at great expense in the ’90s, loaded on exactly one computer in the ministry’s offices, and soon misplaced.
Since the nineties, Indian authorities have extensively discussed the need for a smart bridge management system that estimates the life of a bridge based on parameters that detail its condition. Finally, earlier this year, the minister of state for road transport and highways announced that his ministry would count and assess every bridge on national highways within three years. The ministry set aside Rs 300 crore for the project.
That’s the good news.
When generalists rule
In reality, an effective bridge management system depends on accurate data from the location of the bridge. This task is discharged by the engineers and personnel of public works departments –generalists who may not know how to maintain bridges, or who may not read the Indian Roads Congress codes that govern the creation and preservation of roads and bridges.
I learned in the aftermath of one devastating collapse – in which 28 school children and two adults died – that the company charged with repairing the bridge before its failure had no experience with bridges. The executive engineer of the local public works department said that for his single inspection, he “generally walked over the bridge and had seen from both abutments that the work which was done was satisfactory”.
The safety of India’s bridges – most of them, anyway – is in the hands of these engineers. A better way to think about it is this: Each time we use a bridge, we put our faith in engineers of a department frequently in the news for bribery, and personal assets that would take several lives to attain.