Thanking the efforts of the workers involved in the construction of the Submarine, PM Modi termed INS Kalvari the best example of the “Make in India” initiative. Here is a look at the key developments.

1. The diesel-electric submarine is designed by French naval defence and energy company DCNS.

2. The 1,565-tonne submarine is named after the dreaded tiger shark, a deadly deep sea predator of the Indian Ocean.

3. The submarine boasts of superior stealth features such as advanced acoustic silencing techniques, low radiated noise levels, hydro-dynamically optimised shape and the ability to launch a crippling attack on the enemy using precision-guided weapons, according to MDL.

4. The submarine, which has a speed of 20 knots, is equipped with sea-skimming SM-39 Exocet missiles and heavy-weight wire-guided surface and underwater target torpedoes.

5. The submarine was handed over to the Indian Navy by MDL in September this year. It underwent around 120 days of extensive sea trials and tests for various equipment.

6. This is first of the six Scorpene-class submarines handed over by MDL in Mumbai.

7. The six submarines are being built as part of the Rs 23,652 crore “Project-75” of the Indian Navy.

8. The second one INS Khanderi is expected to be commissioned by mid-2018, with the third INS Karanj following by early-2019. All the six are to be inducted by 2020-2021.

9. Kalvari will be the first conventional submarine to be commissioned in 17 years. The first-ever submarine was inducted into the Indian Navy from Russia in 1967.

10. Currently, the naval fleet has only 13 ageing conventional submarines in its arsenal.