2,500-year-old Persian technique powers Mahakumbh’s lifeline
Mahakumbh 2025 features innovative pontoon bridges, spanning 4,000 hectares, connecting 25 sectors, blending ancient techniques with modern engineering.
The floating marvels of Mahakumbh 2025—heavy-duty pontoon bridges spanning 4,000 hectares and connecting 25 vibrant sectors—are stealing the spotlight as the lifeline of this grand 45-day spiritual spectacle.

Inspired by a 2,500-year-old Persian technique first used in Europe around 480 BCE, it has taken over 15 months and a total of 2,213 black floating iron capsules, weighing 5 tons each, to construct the 30-odd pontoon bridges facilitating the movement of vehicles, pilgrims, sadhus, and workers at the world’s largest cultural-cum-spiritual event, according to officials.
Historians trace the origin of these pontoon bridges to China and Persia. “In China, temporary pontoon bridges were first used during the Zhou Dynasty in the 11th century BCE, with permanent versions developed under the Qin Dynasty in the 2nd century BCE. In Persia, engineers constructed pontoon bridges in 480 BCE across the Hellespont to facilitate Xerxes I’s military campaign into Greece. These structures relied on the principle of buoyancy, utilising floating platforms to create stable, temporary crossings over water bodies,” shared Prof Yogeshwar Tiwari, historian and former professor and head of Medieval and Modern History at Allahabad University.
Prof Tiwari added that in India, the first pontoon bridge opened to traffic in October 1874, connecting Howrah and Calcutta across the Hooghly. “Designed by Sir Bradford Leslie, the bridge was built using timber pontoons and was partially constructed in England before being shipped to India for assembly. However, it was damaged by a cyclone in the same year. Despite this, the bridge remained functional and was illuminated by electric lamps in 1879. To accommodate river traffic, the bridge was periodically unfastened,” he said.
However, due to increased traffic and harsh weather conditions, the bridge was decommissioned in 1943 and replaced by the Howrah Bridge, which was built to handle higher traffic volumes and withstand the region’s rough weather, he added.
Chief engineer of PWD-Prayagraj, AK Dwivedi, said the pontoon bridge, a blend of ancient innovation and modern practicality, is a floating structure supported by large hollow containers called pontoons capable of bearing significant loads. “These bridges are indispensable for the mega fair. We are working round the clock to maintain them. Though they require minimal maintenance, they need constant monitoring,” he stated.
PWD officials shared that in August 2023, the department was tasked with erecting these massive pontoon bridges for the mela area. “This huge task required constructing 2,213 pontoons within just 15 months. Over 1,000 workers, engineers, and officials worked tirelessly, often for 14 hours a day, to achieve this. By October 2024, we completed all the pontoon bridges and handed them over to the mela administration,” said officials.
Each pontoon bridge is designed to support up to 5 tons of weight at a time. Once constructed using thick iron sheets, the hollow iron capsules are transported with cranes and lowered into the river. Workers then set girders on top, secure them with nuts and bolts, and push the pontoons into the river using hydraulic machines.
The bridge deck is layered with wooden planks, loam soil, and sand, while strong iron angles and wires provide additional stability. Finally, checkered metal plates are installed to complete the surface. The pontoons resemble large boats, remaining buoyant and stable even under heavy weight.
“The bridges have been carefully designed to evenly distribute weight. Crowd movement is also managed to prevent excessive strain on any single section. Constructing the 30 pontoon bridges for the mega fair cost around ₹17.31 crore. The bridge connecting Nag Vasuki Temple to Jhusi is the costliest at ₹1.13 crore, while others, like Gangeshwar and Bhardwaj bridges, range from ₹50 to ₹89 lakh each,” officials shared.
Built using the principles of buoyancy and Archimedes’ law, these pontoon bridges will be dismantled after Mahakumbh concludes and stored in locations like Sarai Inayat near Kanihar, Trivenipuram, and the Parade Ground in Prayagraj. Some may also be sent to other districts for temporary bridge requirements, officials said.