Building Defences in the Face of Extremes: A Precast Concrete Triumph

Imagine constructing a critical observation tower on a remote island, just 5 km wide, situated at the India-Pakistan border. Now, imagine that island is only accessible by a 25 km journey across the Arabian Sea. Add to those challenges like incredibly poor soil, high water tables, significant tide levels, a highly corrosive environment, and absolutely no existing infrastructure for power, housing, or sanitation. This was the reality for the Border Security Forces and CPWD, needing a robust solution for Observation Point (O.P.) Towers at Lakhpatwari, Narayan Sarovar, Kutch, Gujarat.

This site is not just remote; it’s classified as a high cyclone and high earthquake zone (Zone V). Traditional construction methods simply weren’t feasible.

Fuji Silvertech, in collaboration with CPWD, devised a complete precast concrete solution. The approach was ingenious: manufacture all components off-site in Bagodara facility, ensuring zero-millimeter tolerance for a perfect fit. These components included precast base slabs, raft footings, wall panels with couplers for the foundation, wall panels with door and window openings for observation, and precast slabs. The entire structure was then assembled on-site using bolted connections.

The result? A four-story O.P. Tower, built from 272 precast products of 29 variations, installed and finished in just 24 days. Each product weighed less than 1.5 tonnes, making transportation and handling manageable in such a challenging environment. The wall panels and floor slabs were 200 mm thick, designed to resist bullet penetration. Special attention was paid to protecting the foundation from the corrosive saline environment with bitumen paint.

The true test of these structures came shortly after installation. On June 15-17, 2023, cyclone Biparjoy, a very severe cyclone with sustained wind speeds of 125 kmph and gusts up to 140 kmph, along with a storm surge of 2 to 3 meters, hit the area directly. Not only did the towers withstand the combined force of the wind and tide, but they also encountered a minor earthquake during this period. Crucially, there was no damage.

This project stands as a powerful demonstration of the possibility and success of precast buildings in the most extreme and challenging conditions. The O.P. Towers were inaugurated by Shri Amit Shah, the Union Home Minister, and even received a Certificate of Merit as a “Best Completed Project” from the Director General, CPWD.

This case study is a testament to how innovative precast concrete solutions can overcome significant logistical and environmental hurdles, delivering resilient and crucial infrastructure for national defence.