“Papa, I read that this new bridge inaugurated in Panaji across the river Mandovi is a cable-stayed bridge, and is the third longest of this type in India. There is so much talk about it. What is a cable-stayed bridge and what about the other two old bridges which connect Panaji to Porvorim?” Raju asked his father after reading a piece about the new bridge.
“Raju, we know that bridges are connecting links on paths – either roadway or railway – and give continuity to travel by that way of transport. It basically takes us over any obstacle in our path. We have seen that there are different types of bridges today. Crossover bridges are for pedestrians only and are built only for people to walk across the road safely without affecting the flow of traffic. Take for example the bridges on railway stations. We cross from one platform to another using them thus avoiding the railway tracks. We see so many flyovers in a city which connect one road to another, going over other roads or railway tracks. They help reduce the traffic congestion and reduce the distance and hardships and thereby time and cost of travel. Imagine, Raju, before the Zuari bridge was built at Cortalim, there were thousands of daily commuters from Margao to Panaji, who used to travel up to the Cortalim side of the river, take a ferry to reach Agassaim and then travel from there to Panaji or further. Imagine the reduction in their time of travel once the bridge was constructed,” said his father.
“Yes papa. I wonder how they travelled during the rains. It must have been hectic.” Raju said.
“Yes, today one can reach Panaji in 30 to 40 minutes. It is one of the busiest routes. The other one from the Ponda side is a much longer route from Margao to Panaji. The other one at Canacona reduces the distance between Karwar and Margao by almost 13 kilometres.”
His father continued, “You must have seen the slab across the canal near the market which allows us to cross over. These bridges are known as ‘sakav’. The oldest bridges must have been the fallen trees over which people walked to avoid a river. We know the story of how Hanuman and his vanar sena built the bridge in the sea for Rama to cross over to Lanka.”
“Today we have various types of methods of constructing bridges depending upon the lengths required, the space available, cost of construction, frequency of use, etc. As we know there are several marvelous bridges built on the Konkan railway taking the train over the valleys and rivers, and today it is one of the busiest routes connecting the coastal towns by rail. The bridges can be of the cantilever type, cable-stayed type, arch bridges, suspension bridges and so on. I will explain each one by one.” said Raju’s father.
(Writer is a mechanical engineer and runs a hands-on science activity centre at Margao)