The Pakistan Navy Rises (Part 4): The Silent Service Will Grow

In 2015, Pakistan’s announcement about procuring eight new air-independent propulsion (AIP)-powered submarines from China kicked-off the Pakistan Navy’s (PN) modernization efforts.

Initially, it had appeared that the new submarines – designated the Hangor-class – would form the entirety of the PN’s big-ticket procurement, largely due to the fact that Pakistan is fiscally constrained and that the PN typically does not receive as much in procurement funding compared to the Army or Air Force.

However, while the PN added large surface ships to its procurement pipeline, there is little doubt that its new Hangor-class submarines will, ultimately, have the greatest impact in South Asia’s maritime domain.

As discussed in previous Quwa articles, this is due to the fact that the Hangor-class will likely (1) carry the PN’s strategic deterrence element through submarine-launched cruise missiles (SLCM), (2) offer credible anti-ship warfare (AShW) and anti-submarine warfare (ASW) capabilities, and (3) leverage both numbers and low detectability to serve as a threatening anti-access and area-denial (A2/AD) asset.

Supporting the Hangor-class submarines, the PN’s existing three Khalid-class (Agosta 90B) AIP submarines will have undergone major upgrades by 2028. In sum, the PN would have 11 AIP-powered submarines as well as, potentially, a submarine rescue and salvaging vessel by 2028.

Not only will the PN’s submarine fleet expand, but it will join among Asia’s largest sub-surface fleets. That fact alone is an altering factor in the region. ASW, especially in shallow water environments (where SSKs can mask themselves under the acoustic noise of merchant ships passing through), is resource-intensive.

For Pakistan, a strength in numbers will require the Indian Navy (IN) to stretch its ASW coverage relatively thinly (e.g., across a wider location, stretching the IN’s supply channels and the ability of its fighter aircraft to support surface and airborne ASW assets). Increasing the cost, difficulty, and potential of loss is key.

Besides posing a risk to enemy surface ships, the PN’s submarines would, arguably, be its best submarine hunters as well. Investment in quantity enables the PN to free more ships to focus on potentially intruding enemy submarines in addition to taking on land-strike or AShW missions.

Granted, this cannot be done by submarines alone. The PN must look at improving its AShW capabilities as well, notably through supersonic-cruising anti-ship cruising missiles (ASCM). However, large submarine fleets are essentials that few other countries, especially in Asia, benefit from atop of other pieces.

One area the PN is evidently studying, at least based on the Ministry of Defence Production’s most recent yearbook, is the construction of a miniature submarine at Karachi Shipyards & Engineering Works (KSEW).

This program was listed in the Ministry’s 2015-2016 and 2016-2017 yearbooks. It is unclear if the PN hopes for a domestic, original design or an off-the-shelf one. However, there are no details at this time indicating that domestic design work is underway; rather, off-the-shelf procurement is likelier.

Cost is still a factor. In fact, cost could limit the scope of a miniature submarine to something akin to the PN’s current Cosmos ships. But the market does have designs that can provide credible AShW and ASW – the addition of such capability, especially in shallow waters, would deepen Pakistan’s A2/AD profile.

However, the more complex the scope, the costlier the design. The PN would have to weigh whether the benefit of such a submarine outweighs the cost and, more importantly, if its need would be better served through additional Hangor-class submarines instead (in the AShW and ASW roles).

On the other hand, miniature submarines could have a specific role, such as infiltration and mine-laying in shallow waters, which may see the PN both limit its design scope or commit to a few ships only. Still, it would be a valuable capability and improve the PN’s ability to undertake asymmetrical operations via the Special Service Group (SSG) Navy’s combat diver operatives, such as intelligence.

Interestingly, one area that has not seen much discussion is whether the PN is interested in procuring or developing unmanned undersea vehicles (UUV), especially autonomous undersea vehicles (AUV).

In theory, one can configures submarines with UUV/AUV to execute ASW and AShW operations, but, potentially, with much lower risk to the manned submarine. For example, a UUV armed with a torpedo can operate at a distance from its mothership; if compromised, it would not expose the mother ship.

Overall, the PN has made building its sub-surface fleet a priority, and the emphasis on numbers signals an intent to reduce its main adversary’s ability to impose itself onto the PN’s interests.