The cannons at Dindigul Fort exemplify a remarkable accomplishment in the field of Indian Metallurgy-Exempt from corrosion

Abstract

Dindigul Fort is situated approximately 400 kilometers from Chennai in the state of Tamil Nadu, India. The fort's geographical coordinates are 10.36109°N latitude and 77.96167°E longitude. Standing at an elevation of 900 feet, the structure is predominantly constructed from granite. At this height, one can observe several brick buildings, which were likely constructed during the British colonial era. The fort is strategically located and features a circular freestanding bastion that historically housed numerous cannons. The introduction of artillery to the site can be traced back to the 17th century, and notably, these cannons have remained free from corrosion. A comprehensive examination of a rust sample collected from one of the cannons at Dindigul Rock Fort was conducted utilizing scanning electron microscopy (SEM), dynamic light scattering (DLS), EDX and Fourier-transform infrared (FTIR) spectroscopy. This investigation identified a range of elements, such as carbon, oxygen, silicon, phosphorus, sulfur, calcium, and iron, along with the presence of nanoparticles. The FTIR spectrum served to validate the presence of γ FeOOH, α FeOOH, and Fe₃O₄.