Two IIT Kharagpur professors who have designed the shelters that saved thousands of lives after Cyclone Fani hit Odisha last Friday said the lessons of the 1999 supercyclone were the trigger behind their project.

Sriman Kumar Bhattacharyya, professor of civil engineering department at the institute, and Gopal Chandra Mitra, a visiting professor at the department, took one-and-a-half years to design the project and built a prototype structure in 2004.

The structure was built with reinforced concrete and had open spaces between the pillars on the ground floor.

The project, funded by the Prime Minister’s relief, was taken up to prevent a recurrence of the 1999 tragedy, Bhattacharyya said. The supercyclone had claimed as many as 10,000 lives.

“The supercyclone that had ravaged Odisha was the trigger. The Odisha State Disaster Mitigation Authority, a wing of the state government, took up the project in association with the IIT. We are happy the facilities have succeeded in achieving what they were meant for,” Bhattacharyya, also deputy director of the institute, told Metro.

An engineer with the public works department of Odisha said about 600 such shelters had been built since 2004 to accommodate people during cyclones. Each shelter can accommodate 1,000 people.

The two-storey structures stand on stilts and are built with reinforced concrete and masonry infill walls. An infill wall — a wall between two columns of reinforced concrete — increases the strength of the columns.

Bhattacharyya explained why they kept the ground floor of the storm shelters open.

“If we had designed an entirely closed structure, it would have suffered immense stress after being buffeted by wind. So, we have kept a lot of open space on the ground floor for the wind to pass without facing any resistance,” Bhattacharyya said.

The shelter is housed on the first and second floors, which have some open space, too, to let air pass.

The buildings also have ramps for the benefit of disabled people.