 The Arihant @-@ class submarines are nuclear powered ballistic missile submarines built under the Advanced Technology Vessel ( ATV ) project . They will be the first nuclear submarines designed and built by India . The submarines are 112 m ( 367 ft ) long with a beam of 11 m ( 36 ft ) , a draught of 10 m ( 33 ft ) , displacement of 6 @,@ 000 tonnes ( 5 @,@ 900 long tons ; 6 @,@ 600 short tons ) and a diving depth of 300 m ( 980 ft ) . The complement is about 95 , including officers and sailors . The boats are powered by a single seven blade propeller powered by an 83 MW ( 111 @,@ 000 hp ) <unk> water reactor and can achieve a maximum speed of 12 – 15 knots ( 22 – 28 km / h ) when surfaced and 24 knots ( 44 km / h ) when submerged . 
