The refurbished periscope is, at present, undergoing trials onboard the submarine

Far from the sea, in the foothills of the Himalayas, a critical naval system has found a new lease of life. For the first time, periscopes on the Navy’s attack submarines have been repaired and refurbished indigenously, with the Central Scientific Instruments Organisation (CSIO) in Chandigarh executing the project.

Periscopes are complex electro-optical devices that allow the crew to visually scan the surrounding sea surface while the submarine remains submerged just below the surface, thereby reducing the risk of detection. Submarines are equipped with different types of periscopes, which can be raised or retracted as per requirement.

“The project took us about one-and-a half years to carry out and the refurbished periscope is, at present, undergoing trials onboard the submarine,” CSIO Director Prof SA Ramakrishna said. “The work involved studying and analysing a large number of optical elements and associated components and then developing the methodology and technology to meet the Navy’s requirement,” he added.

The Navy’s 16 operational attack submarines are all of foreign origin. It has been trying to overhaul and refurbish periscopes within the country for the past several years and had approached CSIO for the same. CSIO has been involved in several defence related projects, including those in the field of optics.

Prof Ramakrishna said that the project has enabled CSIO to handle large optical systems and the technology and expertise so developed will not only be utilised for repairing and overhauling such systems in the existing fleet, but can also be applied in the Navy’s ongoing indigenous submarine construction program.

The Indian Navy’s submarine arm was established about 56 years ago, with the commissioning of INS Kalvari, a Soviet origin Foxtrot Class submarine on December 8, 1967 at Riga in the erstwhile USSR.

At present, the submarine fleet consists of two indigenously developed nuclear propelled ballistic missile submarines--INS Arihant that is operationally deployed and INS Arighat, which is undergoing trials.

Others in the fleet are attack submarines including four German-origin Type-209 Shishumar Class, seven Russian-origin Kilo Class and five French-origin Scorpene Class boats. A sixth Scorpene Class boat is under construction and three more are expected to be procured. Some of the submarines are in the process of undergoing upgrades and modernisation to enhance their operational capability.

India also has an ambitious indigenous programme to design and construct submarines. The plans call for three more Arihant Class ballistic missile submarines, two of which are reported to be under construction, six nuclear propelled attack submarines under Project 75-A and another six diesel-electric attack submarines under Project-75-I.

According to experts, the periscope could be replaced in the future by other technically advanced equipment that allows for greater stealth and wider coverage. The Navy is also exploring the feasibility of employing tethered drones that can be launched underwater by a submarine sailing at depths greater than just below the surface.