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 Defense industry, defence shipyards, located in Kolkata. It builds and repairs merchant shipping, commercial and warship, naval vessels. GRSE also expor ...

(GRSE),

Kolkata Kolkata, also known as Calcutta ( its official name until 2001), is the capital and largest city of the Indian state of West Bengal. It lies on the eastern bank of the Hooghly River, west of the border with Bangladesh. It is the primary ...

and

Goa Shipyard Goa Shipyard Limited (GSL) is a public sector undertaking for defence ship building located on the West Coast of India at Vasco da Gama, Goa. It was established in 1957, originally by the colonial government of the Portuguese in India as the "E ...

, Vasco for the

Indian Navy The Indian Navy (IN) (ISO 15919, ISO: ) is the Navy, maritime and Amphibious warfare, amphibious branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of the Naval Staff (India), Chief ...

. 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 or powerboat is a boat that is exclusively powered by an engine; faster examples may be called "speedboats". Some motorboats are fitted with inboard engines, others have an outboard motor installed on the rear, containing the inter ...

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 or capacity, its shape, or its ability to carry boats. Small boats are typically used on inland waterways s ...

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 lis ...

sounding system, differential

GPS The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide geol ...

motion sensors A motion detector is an electrical device that utilizes a sensor to detect nearby motion (motion detection). Such a device is often integrated as a component of a system that automatically performs a task or alerts a user of motion in an area. T ...

, 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. The study of gravity c ...

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, ...

, oceanographic

sensor A sensor is often defined as a device that receives and responds to a signal or stimulus. The stimulus is the quantity, property, or condition that is sensed and converted into electrical signal. In the broadest definition, a sensor is a devi ...

s, 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 o ...

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 the

Indian Naval Hydrographic Department A hydrographic office is an organization which is devoted to acquiring and publishing hydrographic information. Historically, the main tasks of hydrographic offices were the conduction of hydrographic surveys and the publication of nautical cha ...

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 pu ...

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, a financial discipline that uses option valuation techniques to analyse capital budgeting decisions *''Realm of Valor'', Thai-marketed version of multiplayer online video game ''Arena of Valor'' *Remotely ...

, AUV & USV.

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 Visakhapatnam (; List of renamed places in India, formerly known as Vizagapatam, and also referred to as Vizag, Visakha, and Waltair) is the largest and most populous metropolitan city in the States and union territories of India, Indian stat ...

Ships in the class

Gallery

Citations

References

External links