The ''Sandhayak''-class survey ships are a series of eight vessels built by

Garden Reach Shipbuilders and Engineers Garden Reach Shipbuilders & Engineers Ltd, abbreviated as GRSE, is one of India's leading shipyards, located in Kolkata. It builds and repairs merchant shipping, commercial and warship, naval vessels. GRSE also builds export ships. Founded in ...

(GRSE),

Kolkata Kolkata (, or , ; also known as Calcutta , List of renamed places in India#West Bengal, the official name until 2001) is the Capital city, capital of the Indian States and union territories of India, state of West Bengal, on the eastern ba ...

and Goa Shipyard, Ltd., Vasco for the

Indian Navy The Indian Navy is the maritime branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of Naval Staff, a four-star admiral, commands the navy. As a blue-water navy, it operates sig ...

. While ''Sandhayak'', ''Investigator'', ''Nirdeshak'', ''Nirupak'' were built in GRSE; ''Sarveshak'', ''Jamuna'', ''Darshak'', ''Sutlej'' were built by Goa Shipyard.Saunders 2002, p. 316. The vessels equipped with four survey

motorboat A motorboat, speedboat or powerboat is a boat that is exclusively powered by an engine. Some motorboats are fitted with inboard motor, inboard engines, others have an outboard motor installed on the rear, containing the internal combustion ...

s, two small

boat A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size, shape, cargo or passenger capacity, or its ability to carry boats. Small boats are typically found on i ...

s and are powered by two diesel engines with a top speed of . They have a helicopter deck and are also armed with a Bofors 40 mm/60 gun mount for self-defense. The ships are equipped with variety of next-generation surveying systems fitted onboard including multi-beam swath

echo In audio signal processing and acoustics, an echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the li ...

sounding system, differential

gps The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...

motion sensors Motion detection is the process of detecting a change in the position of an object relative to its surroundings or a change in the surroundings relative to an object. It can be achieved by either mechanical or electronic methods. When it is done by ...

, sea

gravimeter Gravimetry is the measurement of the strength of a gravitational field. Gravimetry may be used when either the magnitude of a gravitational field or the properties of matter responsible for its creation are of interest. Units of measurement G ...

magnetometer A magnetometer is a device that measures magnetic field or magnetic dipole moment. Different types of magnetometers measure the direction, strength, or relative change of a magnetic field at a particular location. A compass is one such device, o ...

, oceanographic sensors, side scan

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects on ...

s, automated

data logging A data logger (also datalogger or data recorder) is an electronic device that records data over time or about location either with a built-in instrument or sensor or via external instruments and sensors. Increasingly, but not entirely, they a ...

system, sound velocity profiling system, digital survey and processing system, amongst others. Working as part of Indian Naval Hydrographic Department the ''Sandhayak''-class

survey ship A survey vessel is any type of ship or boat that is used for underwater surveys, usually to collect data for mapping or planning underwater construction or mineral extraction. It is a type of research vessel, and may be designed for the purp ...

s are equipped with a range of surveying, navigational and communication systems. The ships are designed to undertake shallow coastal and deep oceanic hydrographic survey and collect oceanographic and geophysical data required for the production of digital navigational charts and publications. Besides carrying out their primary role of hydrographic survey, they can also assist in times of war and natural calamities as troop transports and casualty holding ships. The ships are also equipped with

ROV ROV may refer to: *Real options valuation *Recreational Off highway Vehicle, also known as ''Side by side'' or UTV (''Utility Task Vehicle'') *''Realm of Valor'', Thai-marketed version of multiplayer online video game ''Arena of Valor'' *Remotely ...

AUV An autonomous underwater vehicle (AUV) is a robot that travels underwater without requiring input from an operator. AUVs constitute part of a larger group of undersea systems known as unmanned underwater vehicles, a classification that includes ...

& USV. Nirdeshak was decommissioned in 2014.

Service history

was decommissioned on 19 December 2014. The lead ship of the class was decommissioned on 4 June 2021 after 40 years in service. The third ship in the class was decommissioned after 38 years of service on 29 January 2024 in

Visakhapatnam , image_alt = , image_caption = From top, left to right: Visakhapatnam aerial view, Vizag seaport, Simhachalam Temple, Aerial view of Rushikonda Beach, Beach road, Novotel Visakhapatnam, INS Kursura submarine museu ...

Ships in the class

Gallery

Citations

References

External links