The “Silent Service” is Still the Future of Pakistan’s Navy

In a way, an original submarine program would be more important than any of the surface vWith a vision of a 50-ship fleet with over 20 “major surface vessels,” like frigates, one might assume that the Pakistan Navy (PN) is building towards a traditional naval set-up.

However, while it has a notably larger requirement for surface vessels, the actual future of its naval edge still rests in its submarine development, i.e., its “silent service.”

The nature of the “silent service” is that its programs are opaquer.

For example, the Hangor-class submarine, is certainly active. In fact, Karachi Shipyards and Engineering Works (KSEW) laid the keel of the fifth Hangor-class submarine (PNS Tasnim) and cut the steel of the sixth boat towards the end of December 2022.

However, the PN has been reluctant to release other details, like the status of the first four boats (other than previously stating that all eight Hangor-class submarines will come by 2028).

The Hangor program had seemingly hit an obstacle several years ago when Germany refused to release export licenses for MTU diesel engines. In April 2022, Pakistan’s previous Chief of Army Staff, Gen. Qamar Javed Bajwa publicly stated that the Hangor-class submarine was to use German engines, but the PN was unable to secure the export licenses from Berlin.

Originally, China had apparently marketed its export submarines with MTU 12V 396 SE84 engine. In fact, it had also sold the S26-series to the Royal Thai Navy (RTN) on this premise of securing the MTU engines. But with Germany refusing to release these engines, the RTN deal is not proceeding as scheduled.

China had offered the RTN an alternative engine – i.e., the domestically built CHD620. While the RTN has not taken China up on this option, it seems that the PN has with its Hangor-class project. If accurate, then the Hangor-class submarine is probably a stock configuration comprising of Chinese solutions across the engine, AIP, electronics, and weapons stacks.

There are some design modifications, and that can be seen in the Hangor having a heavier displacement (2,800 tons to the S26’s 2,550 tons) and a slightly shorter length (76 m to the S26’s 77.7 m). But otherwise, the Hangor-class is probably similar to the S26 in its most important areas, like critical subsystems (e.g., AIP, engines, etc). It is possible that the more significant changes could be a result of making the Hangor-class compatible with the Babur-series cruise missile, for example.

Overall, the benefit of sticking to a stock configuration (i.e., with minimal customization work) is that the PN can aggressively control the cost of the submarines. In addition, proceeding with a stock model could also help prevent delays and technical complications with the program.

For the PN, controlling cost and reducing the technical risk were likely key goals with the Hangor project. It wants to induct a large number of submarines in a relatively short period of time, and with limited fiscal resources available on hand to support the project.

Interestingly, the Hangor-class submarine is not the only ‘stock’ project.

The Tughril-class frigate is also a stock configuration of the Type 054A frigate. Of course, compared to the People’s Liberation Army Navy (PLAN) version, the Tughril-class frigate has a number of key changes, but these mostly relate to the sensor and weapons suite.

However, even with the weapons, the PN was conservative by restricting its changes to the ASCM solution (by adding a supersonic-cruising missile). Though it could have sought a different Chinese anti-air warfare (AAW) suite, it stuck with the LY-80N. It did not go for another, longer-ranged Chinese AAW suite.

Quwa believes that the PN likely froze both the Hangor-class submarine and Tughril-class frigate programs around the same time period, i.e., in 2015. The initial news reports about the Hangor submarine deal had quoted a price range of $4 billion to $5 billion U.S. However, this price figure was far too high for the eight submarines alone; the PN had likely slotted in the Type 054A/P frigates in that original agreement too.

It would not be surprising if the PN had originally planned to get both the S26 submarine and Type 054A frigate in largely stock configurations. These two programs were the first big-ticket additions to Pakistan’s naval modernization plans. It made sense to reduce cost and risk at the initial stages as much as possible at the start so as to ensure the PN could acquire the baseline capabilities as early as possible.

An Original Submarine Design Incoming?

However, one can also see from later programs that the PN began to delve into either heavily customized designs, or original projects. The Jinnah-class frigate and the Sea Sultan long-range maritime patrol aircraft (LRMPA) headline these efforts. These are far more high-risk and high-cost endeavours. The Jinnah-class project came into being after the Tughril-class frigate (i.e., the “safe” option) was finalized.

Quwa believes that the PN will take a similar approach with submarines. While the Hangor-class provides a “safe” baseline, a more advanced and capable project is likely on the PN’s roadmap. Starting in the mid-2030s, the Agosta 90Bs will start showing their age. With no lifecycle support from France, the PN would likely have to consider replacing the Agosta 90Bs by the 2040s.

In fact, the previous Chief of Naval Staff, Adm. Zafar Mahmoud Abbasi, said that the PN will become a “submarine-building navy.” Thus, there is an emphasis on domestically producing submarines.

The ‘intermediary’ step would be the miniature submarine project. In 2016, Turkey’s STM had invited the PN to co-develop an original miniature submarine. However, STM added that the program could expand into a “different and strategic” initiative. In 2018, STM began offering both a 500-ton shallow-water attack submarine (SWATS), i.e., STM500, and a full-sized 1,700 AIP-equipped submarine, xTS1700.

The next phase of the PN’s submarine program could involve an original design, perhaps in collaboration with Turkey. It would likely start with a SWATS, which is an existing PN requirement, and then expand into a full-sized AIP-equipped program. The latter would be more ambitious in scope than the Hangor project and drive further growth of the PN’s submarine fleet.

The PN understands that its best chance to deter the Indian Navy (IN) is through its sub-surface fleet and long-range anti-shipping capabilities. In fact, not only does the PN need more submarines to deter the IN surface fleet, but to bolster its anti-submarine warfare (ASW) capabilities as well (the IN will also invest in additional submarines). Basically, additional submarines are a must.

Of course, an original design is not a license for liberal spending. Even with an original design, the PN will likely focus on core mission goals, i.e., anti-ship warfare (AShW) and ASW. Strategic attack features, like a vertical launch system (VLS) for missiles, are unlikely. Rather, the PN’s focus will go towards reducing the acoustic signature, extending the loitering time, and using emerging technologies, especially unmanned underwater vehicles (UUV). Basically, one should expect a conservative design, but with greater emphasis on stealth, endurance, and leveraging expendable assets (like UUV).