No stone left unturned: The engineering excellence of Ayodhya Ram Mandir

The meticulous construction of the Ram Mandir in Ayodhya stands as a beacon of engineering excellence and unwavering devotion. At the heart of this monumental project is the use of specially chosen stones subjected to rigorous testing — a process overseen by the National Institute of Rock Mechanics (NIRM) in Bengaluru. Special technology is employed to place the carved stones in the construction, and NIRM played a pivotal role in ensuring that every aspect of the temple, from its foundation to the superstructure, adheres to the highest quality and durability standards.

The strength of the Ram Temple comes from the rocks used in its construction. Around 20,700 large blocks of granite, 32,800 blocks of sandstone, and 7,200 blocks of marble, certified by the scientists of NIRM, have been used in the construction, said VK Mehta, project engineer of Ram Temple.

Mehta added that the temple’s construction showcases a meticulous engineering feat, with a foundation rooted in a 15-metre-thick layer of rolled compacted concrete. This formidable base, consisting of 54 layers of the compacted concrete made from fly ash, dust, and chemicals, provides a solid footing to the structure. Also strengthening the foundation is a 21-foot-thick plinth of granite, strategically designed to shield the temple from moisture.

“On the advice of the Indian Institute of Technology, Chennai, engineers excavated the land up till 15 metres to remove the clayey topsoil. This void was filled with re-engineered soil, a substance capable of solidifying into stone within 14 days,” he said, adding that innovative approach was crucial in overcoming the challenges during construction.

“We adopted an innovative construction approach, avoiding the use of iron and minimising the use of cement. The stones are intricately interlocked, forming a robust structure. To enhance stability, sheer keys are strategically employed at male-female joints. Copper clamps and pins further fortify the assembly, creating a durable and interconnected framework without the traditional reliance on iron or excessive cement. This method not only demonstrates a commitment to resource efficiency but also results in a distinctive and resilient architectural outcome designed to last for more than 1,000 years,” Mehta added.

Meanwhile, VK Shukla, project director, Ram Temple said, “The temple can withstand major earthquakes. The collaborative effort of a dedicated team comprising 150 engineers and thousands of workers underscores the temple’s architectural marvel, projected to remain free of repairs for over 1,000 years.”

Elaborating on the endurance of stones used in the temple, Dr HS Venkatesh, NIRM director, said, “The grey granites, aged at least 2,100 million years, were meticulously sourced from Ongole, Chimakurti, Warangal, and Karimnagar mines and their hardness was scientifically determined using advanced tools like the Schmidt Hammer.”

“The superstructure is crafted from specially selected pink Bansi Paharpur sandstone from Rajasthan. This type of sandstone, aged between 700 and 1,000 million years, is renowned for its unique combination of carving ease and resistance to weathering. The careful choice of this material ensures the temple’s aesthetic appeal and its ability to withstand the ravages of time and environmental elements,” he added.

Sharing further details, Venkatesh said, “Adding to the opulence of the temple is the decorative marble sourced from the mines of Makrana in Rajasthan, which plays a crucial role in enhancing the overall grandeur of the structure, particularly in the sanctum sanctorum. The marble’s age, at least 1,450 million years, speaks to the enduring legacy embedded within the temple’s fabric.”

NIRM’s senior scientist, Dr A Rajan Babu, who is responsible for assessing the density, porosity, compressive strength, structural strength, tensile strength, water absorption, and modulus of rupture of stones, said that the comprehensive testing regime not only guaranteed the structural integrity of the temple but also ensured its longevity, standing as a formidable structure for generations to come.

“Even the intricately carved pillars, a hallmark of the temple’s architectural beauty, underwent non-destructive testing (NDT) using cutting-edge techniques such as ultrasonic and infrared thermography,” he said.

Expressing satisfaction in his role in the construction of this national landmark, Dr Venkatesh, asserted with confidence that the rocks utilised in the construction of the Ram temple would endure for more than thousand years.