Ibn-e-Azan
The Hangor-class submarines being supplied to Pakistan are export versions of China’s Yuan-class platform, with sensitive systems removed or downgraded before delivery. Pakistan is paying nearly $5 billion for a product China itself does not deploy in its frontline fleet — a distinction that carries significant implications for the programme’s actual strategic value in the Arabian Sea.
The CHD620 diesel engine fitted to the Hangors is a licensed Chinese-manufactured version of the German MTU 396, produced to Chinese manufacturing standards and without independent validation of its combat performance in submarines. Its acoustic signature — which determines how detectable the submarine is to enemy sonar arrays and maritime patrol aircraft — is assessed by naval analysts as inferior to the MTU it replaced. In submarine warfare, noise profile is not a secondary concern. It is often the determining factor in whether a vessel survives first contact with a hostile anti-submarine warfare asset.
India’s Kalvari-class submarines, built to French Scorpène design specifications, carry SM.39 Exocet anti-ship missiles and wire-guided torpedoes integrated into a French combat management system with an extensive operational history. The Hangors’ weapons fit, by contrast, is drawn from a Chinese export catalogue operating without a comparable level of independent operational validation. In a direct underwater engagement, the armaments gap matters as much as the platform gap.
The Yuan-class, in its frontline People’s Liberation Army Navy configuration, incorporates advanced sonar suites and weapons management systems representing the cutting edge of Chinese submarine engineering. The export version supplied to Pakistan excludes several of those systems. This is standard practice in Chinese arms exports — Beijing preserves its technological edge by ensuring its most capable systems never leave direct Chinese control. Pakistan is buying a platform from which the most capable components have already been removed, at a price that does not reflect those omissions.
The gap between what China deploys in its own submarine fleet and what it supplies to export customers is a deliberate engineering and commercial choice, not an accident of supply chains or production timelines. Pakistan’s Hangors sit below that line by design.
The timing is particularly consequential given the Indian Navy’s ongoing expansion. India currently operates twelve P-8I maritime patrol aircraft, with six more approved, alongside a growing fleet of nuclear and conventional hunter-killer submarines and shore-based detection infrastructure specifically built to counter submarine threats in the Arabian Sea.
Against that expanding capability, the Hangor’s acoustic disadvantage and downgraded sensors are not marginal weaknesses. They are structural limitations built into the platform before it even entered the water.
Pakistan is paying a premium price for an export-grade product. The downgraded sensors, the acoustically compromised engine, the stripped-out systems China reserves for its own forces, and the weapons fit that has never been tested against a sophisticated adversary all point in the same direction. What Pakistan is receiving is a carefully calibrated export product — capable enough to justify the price, yet limited enough to ensure Pakistan never acquires the full measure of what Chinese submarine technology can actually do.
