Pakistan’s KSEW Cuts Steel of Fifth Hangor Submarine

On 09 December 2021, Karachi Shipyards & Engineering Works (KSEW) cut the steel of the fifth Hangor-class submarine for the Pakistan Navy (PN).

Pakistan bought eight Hangor submarines from China Shipbuilding & Offshore International Co. Ltd (CSOC) in 2015. Under the contract, KSEW would manufacture four of the boats, while China will supply the rest.

Collectively, the PN is slated to receive the eight Hangor-class submarines from 2022 to 2028. The Chinese-built boats will arrive first, while the final KSEW-built submarine is due for completion by 2028.

Named in honour of the original PNS Hangor (which sank the Indian Navy frigate INS Khukri in the 1971 War), the Hangor-class is the centerpiece of the PN’s submarine modernization program. Similar in scope to the surface warship acquisitions, the PN is aiming to both revitalize and expand its sub-surface fleet.

Currently, the PN operates three Agosta 90B air-independent propulsion (AIP)-equipped submarines (SSP) and two Agosta 70 diesel-electric submarines (SSK). Previously, the PN also operated four Daphne SSKs, which it acquired in the late 1960s, but it has retired these boats. With the Hangor SSPs, the PN will have a fleet of 11 AIP-equipped boats, which is a relatively significant jump in numbers and capabilities.

Based on the information available, it seems that the Hangor is a variant of CSOC’s S26, an export-centric design that draws on the Type 039A/041 Yuan-class submarine.

The clearest connection between the two programs came from the previous PN Chief of Naval Staff (CNS), Admiral Zafar Mahmoud Abbasi, who said that the PN will get a Yuan-class submarine from the People’s Liberation Army Navy (PLAN) fleet for training and acclimation purposes.

Like the Yuan-class, the S26 uses a Stirling-based AIP system. However, compared to the standard S26, the Hangor has several differences. It is shorter (76 m to the S26’s 77.7 m) and has a heavier displacement (2,800 tons to the S26’s 2,550 tons). The reasons for these differences are not publicly known. Otherwise, the Hangor seems to be similar to the S26 and Yuan-class, especially in terms of armament load (through six 533 mm torpedo tubes) and general design approach.

One other interesting aspect of the Hangor program is that neither CSOC nor the PN are publicizing the Chinese-produced boats. To date, there have been no reports of steel-cutting ceremonies or other major milestones. It is unclear why there is such secrecy over the Pakistani program. Interestingly, this is not the case with Thailand’s S26T acquisition – China has been covering its milestones as normally would.

The PN did not disclose how it will configure the Hangor submarines in terms of sensors and other critical subsystems. Given its approach to surface warships and maritime patrol aircraft, the PN has been open to custom project work. It could, theoretically, look to equip the Hangor along similar lines to the upgraded Agosta 90B so as to leverage commonality in training, integration, and maintenance. However, the PN has also focused on controlling cost and mitigating risk. Like the Type 054A/P, it probably opted for available Chinese subsystems, weapons, and other inputs for the Hangor.

Operationally, the PN will likely use the Hangor for mostly anti-access and area-denial (A2/AD). In other words, the missions of the Hangor will likely involve anti-ship warfare (AShW) and anti-submarine warfare (ASW). Granted, the Babur-3 submarine-launched cruise missile (SLCM) tests show that Pakistan wants to build a deterrence triad and strategic second-strike capability. However, given its geographic proximity to India, Pakistan has no shortage of suitable launch points on land for cruise missiles. Strategic deterrence could be a secondary or tertiary capability of the Hangor, but the main mission will be A2/AD.

The inclusion of AIP will let the PN to deploy the Hangor boats throughout Pakistan’s exclusive economic zone (EEZ) for longer durations than non-AIP SSKs. The PN will likely station Hangor SSPs at key sea-lines-of-communication (SLOC) to deter Indian Navy ship and submarine activity along sea lanes important to Pakistan’s economy. Doing ASW in hostile waters is exceptionally difficult due to the acoustic noise busy waters create (from freighter activity). The Hangor boats can ‘mask’ their presence using that noise and, thanks to AIP, stay silent without snorkeling for weeks. Though India could theoretically use ASW aircraft, the Pakistan Air Force (PAF) will be on station to deter that activity. Moreover, the PN would use its own ASW aircraft and ASW corvettes (the latter being the Babur-class, which will have a capable self-protection suite comprising of an advanced air defence system and electronic countermeasures) to deter submarine activity from India. Finally, Pakistan will also deploy long-range anti-ship cruising missiles (ASCM) from its fighter aircraft and land-based batteries to further deter IN activity along Pakistan’s EEZ. There is also an anti-ship ballistic missile (ASBM) in the works which could see both ship and land-based deployment.

In its announcement, the PN also revealed that it will induct shallow-water attack submarines (SWATS) in the 2020s. The PN spoke about its pursuit of SWATS for several years, but the PN’s statement implies that a program is now actively underway. In other words, the PN signed for a SWATS and is awaiting delivery.

The actual details of the design, make or origin of the SWATS are not known. However, in 2016, Turkey’s Savunma Teknolojileri Mühendislik ve Ticaret AŞ (STM) said that it was designing a SWATS concept for the PN as a replacement for the Cosmos MG110. In 2021, STM revealed a SWATS concept called the STM500.

Displacing 540 tons, the STM500 is smaller than the PN’s required specifications (700 tons). However, the design meets all of the PN’s other requirements, such as space for AIP, electronic support measures (ESM), and other features. It would not be surprising if the PN opted for the STM500. However, a source had told Quwa that the PN favoured SWATS designs from vendors with prior experience, such as Italy’s DRASS.

The PN will likely use SWATS to reinforce its A2/AD, especially in littoral waters. One mission would be to use these SWATS to carry ASW in littoral waters while the larger AIP boats operate further out. The other mission would be deterring enemy surface warships, especially amphibious assault ships.

However, the SWATS could also have a strategic role. Since the SWATS are replacing the MG110s, the PN may integrate its Special Operations Forces (SOF) to the SWATS (e.g., frogmen operations).

In any case, the SWATS will add to the PN’s sub-surface fleet growth. Unlike the MG110s, the SWATS are practically as capable as full-sized submarines, though with less range and endurance. But as far as India is concerned, a SWATS is as much of an anti-ship and anti-submarine threat as the Hangor or Agosta 90B.

Collectively, the PN could have at least 11 full-sized AIP submarines and potentially three to four additional SWATS with AIP. For a country those navy was traditionally a small service arm, this growth is exponential and makes the PN one of the largest submarine operators in Asia and the Middle East.