The Indian Navy has a fleet of 16 diesel-electric submarines leased from Russia and Germany. However, the disadvantage with diesel electric submarines is that they cannot stay under water for an extended period.
Arihant's design is based on the Russian Akula-1 Class submarine.
It weighs 6,000t. At a length of 110m and breadth of 11m, Arihant is the longest in the Indian Navy's fleet of submarines and can accommodate a crew of 95.
It can reach a speed of 12kt-15kt on surface and up to 24kt when submerged.
Arihant is able to stay under water for long periods undetected due to the nuclear-powered 80MW pressurised water reactor (PWR).
Arihant is fitted with a combination of two sonar systems – Ushus and Panchendriya. Ushus is state-of-the-art sonar meant for Kilo Class submarines.
Panchendriya is a unified submarine sonar and tactical control system, which includes all types of sonar (passive, surveillance, ranging, intercept and active).
It also features an underwater communications system.Its exterior is uneven and the hull is placed on a mat covered with tiles.