Why in News? Pakistan recently launched the Hangor class submarine (built by China) at a Wuhan shipyard. This was the first of eight submarines that the Pakistan Navy is set to induct into its fleet by 2028.

Basic Characteristics- The Hangor-class, an export variant of the Chinese Type 039A Yuan class, is a diesel-electric attack submarine named after PNS Hangor (now decommissioned), which famously sank Indian frigate INS Khukri during 1971 war. It boasts four diesel engines, is equipped with an Air Independent Propulsion (AIP) system to increase its endurance underwater, has six 21-inch torpedo tubes, and is capable to launch anti-ship missiles, as well as the Babur-3 subsonic cruise missile (with 450km range).

Comparison with India’s Kalavari Class-

1. Hangor class is significantly bigger in size than the Kalavari class which is based on French Scorpene-class, but small size makes Kalavari class much more maneuverable.
2. Both the submarines have same top speed of 20 knots (37 kmph).
3. Kalavari class doesn't come with built-in AIP as the Hangor. This matters because submarines’ USP is their ability to be stealthy, which comes from their capability of remaining underwater for extended time period. An AIP system can increase submarines’ underwater endurance manifold (upwards of 15-20 days).
4. In terms of armament, Kalavari class carries six 21 inch, German-made torpedoes, and missile systems like French Exocet anti-ship missiles, and MICA anti-air missiles. This is likely superior, and more battle tested than Hangor’s armament.
5. Both submarines don’t have vertical launch systems (like the ones in India’s nuclear Arihant class), which would allow it to carry bigger cruise missiles.
6. Both submarine classes carry state of art sensor suites, although details of Hangor’s capabilities are not known yet.