CDS (II) 2022 General Knowledge · Question 100 of 120

Correct — A, Diesel-electric submarines. Project 75(I) is the Indian Navy's programme for six conventional diesel-electric attack submarines of about 3,000 tonnes, fitted with air-independent propulsion so they can stay submerged far longer than an ordinary conventional boat. The 'I' stands for India and marks it as the follow-on to Project 75, under which the six Scorpène-class boats of the Kalvari class were built at Mazagon Dock. It is being run under the Strategic Partnership model, in which an Indian shipyard cleared by the Ministry of Defence ties up with a foreign original equipment manufacturer also cleared by the Ministry, and the submarines are built in India with transfer of technology. The armament planned is heavyweight torpedoes together with land-attack and anti-ship cruise missiles.

• (b)Nuclear-powered submarines. — India's nuclear boats run on a different track entirely — the Arihant class of ballistic-missile submarines under the Advanced Technology Vessel programme, and the separately sanctioned nuclear attack submarine project. Project 75(I) is explicitly conventional, which is why air-independent propulsion matters to it at all; a nuclear boat has no need of it.
• (c)Aircraft carrier warships. — The indigenous carrier programme is the Indigenous Aircraft Carrier line, built at Cochin Shipyard — INS Vikrant was commissioned on 2 September 2022, two days before this paper was written. Carriers and submarines are separate programmes with separate numbering.
• (d)Field guns. — Artillery projects carry their own names — the Dhanush 155 mm towed gun, the Advanced Towed Artillery Gun System, the K9 Vajra self-propelled gun. The 'P' numbering in P-75 and P-75(I) is naval project numbering.

A conventional submarine has to surface, or raise a snorkel, to run its diesels and recharge its batteries, and that is when it is most likely to be detected. Air-independent propulsion — a fuel cell or a closed-cycle engine that generates power without atmospheric oxygen — lets the boat stay down for a week or more at low speed, closing much of the gap with a nuclear submarine at a fraction of the cost and without the safeguards a reactor demands. This is why India's conventional submarine plans are written around it.

The question is really testing whether you can separate India's several submarine and shipbuilding lines. Read the number: P-75 delivered the Scorpène boats, so P-75(I) is its successor and must also be conventional. As of the September 2022 exam, Project 75(I) was still in procurement — the request for proposals had gone out in 2021 and no builder had been chosen. The position has since moved a long way. Mazagon Dock Shipbuilders paired with ThyssenKrupp Marine Systems of Germany, offering an enlarged Type 214 design; an inter-governmental agreement was signed during Chancellor Friedrich Merz's visit in January 2026, with the final contract, worth roughly ten billion dollars, expected by March 2026. If you meet this question again, answer the type from the project number and treat the builder as a separate fact with its own date.

• Project 75(I) covers six conventional diesel-electric attack submarines of about 3,000 tonnes with air-independent propulsion, with an option for three more.
• It follows Project 75, the six Scorpène-class boats of the Kalvari class built at Mazagon Dock Shipbuilders.
• It is being procured under the Strategic Partnership model, pairing a cleared Indian shipyard with a cleared foreign equipment manufacturer.
• Mazagon Dock Shipbuilders is partnered with ThyssenKrupp Marine Systems of Germany, offering an enlarged Type 214 design.
• Planned armament is 18 heavyweight torpedoes together with land-attack and anti-ship cruise missiles.

• Reading the 'I' in P-75(I) as anything other than India — it does not stand for an improved or a nuclear variant.
• Assuming air-independent propulsion means nuclear propulsion; it is a way of running a conventional boat without surfacing.
• Attaching Project 75(I) to Cochin Shipyard, which builds the carriers, rather than to Mazagon Dock.

As a one-line identification of a defence project, or as a match between project names and the platforms they deliver.

• practice — not a real PYQ

  The submarines of the Kalvari class, commissioned into the Indian Navy from 2017, are based on which foreign design?

  • (a)Type 214
  • (b)Scorpène
  • (c)Kilo
  • (d)Soryu

  Answer(b) Scorpène — built at Mazagon Dock Shipbuilders under Project 75 with French collaboration; the Kilo class boats are the earlier Sindhughosh class of Russian origin.

• practice — not a real PYQ

  Air-independent propulsion gives a conventional submarine which one of the following advantages?

  • (a)Higher maximum speed on the surface
  • (b)The ability to remain submerged for much longer without snorkelling
  • (c)Unlimited range without refuelling
  • (d)The ability to launch ballistic missiles

  Answer(b) The ability to remain submerged for much longer without snorkelling — it generates power without atmospheric oxygen, so the boat need not surface to recharge its batteries.