Indian Naval Submarine Wet-Dock Construction MEP — Naval Engineering + IACS + IMO + MIL-STD

Indian Scorpene-class 1800 t submarine wet-dock construction MEP demands ₹2010 Cr (or ₹2985 Cr for SSBN nuclear) capex with wet/dry dock + 600 t crane + dehumidified hull-storage + helium leak test + anechoic acoustic test + battery refit + reactor compartment (SSBN). Indian Navy Naval Engineering Manual + IACS + IMO + MIL-STD + NORSOK + MES SSR + AERB (nuclear) govern. India operational/planned fleet 26-34 submarines. Three failures: RH > 50 % hull-section storage causing pressure-hull corrosion + ₹120-180 Cr rework, helium leak detection skipped, acoustic signature chamber shared with industrial test.

Indian submarine yard wet-dock framework

Indian Navy submarine — INS Kalvari + Khanderi + Karanj + Vela + Vagir + Vagsheer (Project 75 Scorpene-class) + INS Arihant + Arighaat + Aridhaman (Project 75-I + SSBN). Built/refit at MDL Mazagon Dock + GRSE Garden Reach Shipbuilders + Hindustan Shipyard. Standards stack — IMO + IACS + Indian Navy Naval Engineering Manual + NORSOK + MES SSR + IS 7016 + AERB safety (for nuclear) + DRDO + worldreknown Naval Group France + Thyssenkrupp Marine Systems.

Indian Naval submarine wet-dock construction MEP scope — Scorpene-class 1800 t

Three Indian submarine yard MEP failures

1. RH > 50 % in hull-section storage causing pressure-hull corrosion — submarine pressure-hull HY-80/HY-100 steel corrodes at RH > 50 %. Indian yards sometimes use tarpaulin instead of dehumidified covered berth — face ₹120-180 Cr rework (Submarine 2024 batch).
2. Helium leak detection skipped — pressure-hull integrity verified by helium leak at 10⁻¹⁰ mbar L/s. Skipping = mid-cycle hull failure during diving test. Specify per MIL-STD-883 + Naval Engineering Manual.
3. Acoustic signature test chamber inadequate — submarine survival depends on acoustic stealth. Test chamber needs anechoic + < 25 dB-rel background. Indian yards sometimes share with industrial test = signal-to-noise inadequate.