Guides
Indian defence, naval and marine engineering, answered
Plain answers to the questions buyers, new vendors and engineers ask about selling to Indian defence, type approval, indigenisation, naval power and ship repair. Each one names the documents it was checked against.
- Guides
- 55
- Topics
- 9
- Questions answered
- 307
- Also see
- FAQ and glossary
01
Selling to Indian defence
Vendor registration with the Navy, Army, Air Force, the quality assurance directorates, shipyards and defence PSUs: who registers whom, and what they ask for.
- How to register as a vendor with the Indian Navy
How Indian Navy vendor registration works: naval dockyards, DQA(N) quality assurance, e-procurement portals and the documents a new supplier needs.
- DGQA and DGAQA vendor registration explained
DGQA covers land and naval defence stores; DGAQA covers military aviation. What each does, and how vendor registration and quality checks differ.
- Vendor registration with defence shipyards and DPSUs
How to register as a vendor with India's defence shipyards and PSUs: Mazagon Dock, GRSE, Cochin Shipyard, BEL, HAL, BDL and MIDHANI, verified facts only.
- What documents does a defence buyer ask a new supplier for?
The core document set Indian defence buyers ask new vendors for: PAN, GST, incorporation papers, financial statements, past orders and quality systems.
02
Quality assurance and type approval
DQA(N), DGQA, type approval certificates, quality assurance plans, type tests and the JSS and NES standards naval equipment is qualified against.
- What is JSS 55555, the environmental test specification?
JSS 55555 is the Joint Services Specification for environmental testing of defence equipment: its test families and where testing is done in India.
- What are NSS shock grades and how is naval equipment shock tested?
NSS Grade I and Grade II are India's naval shock standard grades, used with the UK's BR 3021 manual, for equipment that must survive underwater shock.
- What do vibration, bump and inclination tests check on shipboard equipment?
Vibration, bump and inclination tests check shipboard equipment works under running machinery, handling and the angles a ship lists, rolls and pitches to.
- What do damp heat, mould growth and salt fog tests simulate?
Damp heat, mould growth and salt fog tests each simulate a different way humid, tropical, coastal air attacks equipment: moisture, fungus and salt corrosion.
- What is a DQA(N) type approval certificate, and what does it contain?
A DQA(N) type approval certificate is issued once a design passes qualification testing: what the Directorate of Quality Assurance (Naval) checks first.
- What are a QAP, a FAT and an ATP in defence supply?
A quality assurance plan lists inspection and test stages for an item, a factory acceptance test proves it before dispatch, and an ATP is the test procedure.
- How is defence equipment type testing organised through accredited laboratories?
Defence equipment type testing runs through DGQA's own labs and NABL-accredited private labs, and the inspecting authority decides which report to accept.
03
Indigenisation and Make in India
Reverse engineering obsolete spares, the SRIJAN portal, positive indigenisation lists, iDEX and the routes that turn an imported part into an Indian one.
- What is the SRIJAN portal and how do vendors use it?
SRIJAN lists items the Ministry of Defence wants indigenised. How the portal actually works, who can respond, and where vendor registration happens instead.
- What is a Positive Indigenisation List, and what is in the sixth list?
What a Positive Indigenisation List is, how many exist, and what the sixth list, notified in August 2026 with 405 items, actually covers.
- How do iDEX, DISC and ADITI fund defence startups and MSMEs?
How iDEX funds defence startups and MSMEs through DISC, ADITI and Open Challenge grants, who is eligible, and how the milestone payments work.
- What is the Technology Development Fund, and who can apply?
What the DRDO-run Technology Development Fund pays for, who can apply, the current Rs 50 crore ceiling, and the separate deep-tech funding line.
- What is the Make-II procedure, and how does it differ from Make-I?
How the Make-II procedure works, how it differs from Make-I, what assured orders and liquidated damages actually mean for an indigenisation contract.
- How is an obsolete spare reverse engineered and qualified?
How an obsolete spare is reverse engineered: material identification by XRF and OES, first article inspection, and the approval it still needs.
- How does a naval spare go from sample to an approved indigenised item?
The verified stages a naval spare goes through, from being listed on SRIJAN to DQA(N) approval and an assured order under DPM 2025.
04
Procurement and tendering
DAP 2020, the Defence Procurement Manual, GeM, the tender portals, earnest money, performance guarantees and what MSMEs are entitled to.
- DAP 2020 procurement categories explained, and the DAP 2026 draft
DAP 2020 still governs India's defence capital acquisition as of September 2026: the categories, Buy Indian-IDDM content rules, and the draft DAP 2026.
- What changed in the Defence Procurement Manual 2025 (DPM 2025)
DPM 2025 governs revenue procurement from 1 November 2025: liquidated damages, limited tender limits, assured orders and ship refit provisions explained.
- How GeM works for defence suppliers
GeM is mandatory for government buyers under GFR Rule 149. What defence suppliers need to know: caution money, seller registration and DPSU practice.
- Where Indian defence tenders are published, and how to bid
Where Indian defence tenders appear: the Defence e-Procurement portal, CPPP and GeM, and what a first-time bidder needs to register and bid.
- EMD and performance bank guarantee rules in defence tenders
How earnest money deposit and performance bank guarantees work in Indian defence tenders, and which of these an MSME is exempt from under current rules.
- MSME benefits in Indian public procurement, and what is excluded
Purchase preference, EMD exemption, 358 reserved items and the works-contract exclusion: what Udyam-registered MSMEs actually get in public procurement.
- How L1 evaluation and reverse auctions work in government tenders
L1 is the lowest technically qualified bid. How L1 is decided, how a GeM reverse auction runs, and how MSE and local-supplier preference change it.
- How Udyam registration helps a defence supplier
Udyam registration is free and unlocks EMD exemption, price matching and reserved items in defence procurement, for micro and small enterprises.
06
Marine engineering and ship repair
Dry docking, hull plating and coatings, sea chests, shaft line alignment, stern tubes, and propulsion and hydraulic overhaul on ships and tugs.
- Marine shaft alignment explained
How marine propulsion shaft alignment works: sag and gap checks, jack-up tests, and why dry-dock and afloat readings differ, explained with sources.
- Propeller shaft survey intervals under IACS UR Z21
How IACS UR Z21 sets propeller and tube shaft survey scope, methods and intervals: 5-year cycles, keyless propellers to 15 years, and extensions.
- Stern tube seals and bearings: types and wear
Stern tube seals and bearings explained: lip seals against face seals, oil against water lubrication, and how weardown and propeller drop are measured.
- Dry docking intervals and extended dry docking (IRS)
How often ships need dry docking, what an in-water survey checks instead, and how the IRS Extended Dry-Docking scheme stretches the interval to 7.5 years.
- Hull plate renewal and thickness gauging basics
How ultrasonic thickness gauging works, what counts as substantial corrosion in a survey, and how the renewal decision on ship hull plating is made.
- Sea chest maintenance
What a ship's sea chest is, how it is cleaned and inspected in dry dock, and why it counts as a biofouling risk area under IMO guidance.
- Cathodic protection on ships: anodes vs ICCP
Sacrificial anodes compared with impressed current cathodic protection (ICCP) on ships: how each works, replacement intervals, and reference electrodes.
- Hull coating systems during dry dock
Surface preparation grades Sa 2½ and St 3 explained, the IMO ban on TBT and cybutryne antifouling paint, and who needs an anti-fouling certificate.
- Hydraulic system overhaul on tugs
Why tug propulsion depends on hydraulics, how ISO 4406 oil cleanliness codes are read, and the cleanliness servo valves need after an overhaul.
- Ship repair and dry dock facilities in India by port
A port-by-port look at India's main ship repair and dry docking facilities: Visakhapatnam, Kochi and Kolkata, with verified capacities and history.
07
Defence fabrication and interconnection
Handling trolleys and cradles, fabricated steelwork, cable harnesses, junction boxes and the test equipment that proves them.
- Which welding and structural steel standards apply to defence fabrication?
IS 2062 grades structural steel by yield strength and impact rating, while ISO 3834, 15614-1 and 9606-1 qualify the welding procedure and the welder.
- What do continuity, insulation resistance and hipot tests check on a cable harness?
Continuity, hipot and insulation resistance testing each check a different failure mode on a cable harness; IPC/WHMA-A-620 sets defaults by class.
08
Building operation and maintenance
Operation and maintenance of substations, DG sets, lifts, fire systems, air conditioning and pumps under CPWD contracts.
- How often should fire extinguishers be refilled and pressure tested?
IS 2190:2010 sets separate refill and hydraulic test intervals by extinguisher type, not the flat five years several websites still claim for every type.
- What is the right maintenance schedule for a standby DG set?
A standby diesel generator needs daily checks, a monthly load run and scheduled servicing; running it unloaded for long periods causes wet stacking.
- What is the maintenance schedule for an 11 kV substation transformer?
IS 10028 sets hourly, daily, monthly, quarterly, half yearly and yearly transformer checks, tightening further for transformers of 1000 kVA and above.
- What is included in a building E&M operation and maintenance contract?
A CPWD-style building E&M operation and maintenance contract covers round-the-clock plant operation, preventive schedules and breakdown response.
09
The Indian defence industry
Defence corridors, the Hyderabad and Visakhapatnam ecosystems, industrial licences and export authorisation for defence items.
- When does a defence manufacturer need an industrial licence?
Which defence items actually need an industrial licence under the IDR Act or Arms Act, how long it lasts, and who is exempt as a parts maker.
- How much foreign investment is allowed in Indian defence manufacturing?
How much foreign investment is allowed in Indian defence manufacturing, the automatic and government routes, and the security review that still applies.
- How does a company get authorisation to export defence items from India?
How a company gets authorisation to export a defence item from India, what SCOMET Category 6 covers, and how large India's exports now are.
- What are India's defence industrial corridors, in Uttar Pradesh and Tamil Nadu?
India's two Defence Industrial Corridors, their nodes in Uttar Pradesh and Tamil Nadu, the nodal agencies, and what investment they have attracted.
- What does the defence and aerospace ecosystem in Hyderabad and Visakhapatnam look like?
The defence and naval organisations actually based in Hyderabad and Visakhapatnam, and why neither city sits inside a national defence corridor.
Reference
Short answers and definitions
Looking for a supplier rather than an answer?
Two DQA(N) type approvals, ISO 9001:2015, and offices in Hyderabad and Visakhapatnam. Send the requirement.