submarine

A Royal Navy submarine carrying Trident nuclear missiles has returned to its Scottish base after a record-breaking 217 days spent submerged on patrol.

The 140-strong crew of HMS Vengeance have spent the tour in almost total isolation beneath the surface after setting out from Faslane, near Helensburgh, Argyll and Bute, on 12 April.

Defence Secretary Wes Streeting was at HM Naval Base Clyde to welcome them home after the longest deployment at sea for a British vessel.

The typical patrol length for the UK’s Vanguard-class ballistic missile submarines has more than doubled in recent years, with six-month durations now routine due to a shortage of seaworthy vessels.

Crew members could be seen standing on HMS Vengeance as it travelled up Gare Loch earlier, accompanied by some smaller Naval support vessels and tug boats.

The vessel was encrusted in marine growth and some of its sound-absorbing tiles were missing.

HMS Vengeance was expected back at Faslane last weekend, but that was reported to have been delayed, external when the submarine replacing it on patrol had to return to base to fix a technical fault.

The head of the navy, First Sea Lord Gen Sir Gwyn Jenkins, praised the dedication of submariners in keeping Nato safe at a conference last week in Oslo, but said the UK must do better at maintaining the fleet.

North Korea says it has test-fired two types of submarine-launched strategic cruise missiles off its east coast, in what appears to be the first time its bizarre Hero Kim Kun Ok submarine has been seen at sea in a publicized manner. If the vessel truly was the launch platform, the tests would mark its first confirmed weapons trials and a potential step toward operational service. Unveiled with considerable fanfare in 2023, the Hero Kim Kun Ok has been billed by Pyongyang as a centerpiece of its future nuclear-armed navy, but its operational status and actual capabilities have remained unclear.

The launches took place Wednesday, October 14, with state media Korean Central News Agency (KCNA) reporting the activity earlier today. North Korea said the tests were intended to assess the readiness of its underwater combat systems, improve the Navy’s ability to execute strategic missions, and demonstrate the reliability of its deterrent. Along with imagery of the cruise missiles, KCNA released one photo of the Hero Kim Kun Ok underway, which you can see at the top of this story.

KCNA did not otherwise identify the submarine involved or disclose the missiles’ ranges, flight paths, or performance. South Korea’s Joint Chiefs of Staff (JCS) said it had detected and tracked the launches from before firing through the cruise and terminal phases. A JCS spokesperson said one missile type was launched from a vertical launch system and another from a torpedo tube. This would match the imagery we are seeing, it would also match the Hero Kim Kun Ok’s unique capabilities. The South Korean military assessed that the launches came from a submarine but did not initially identify the vessel publicly.

There remains a possibility that the 3,000-ton-class Hero Kim Kun Ok was not actually involved in launching the missiles. North Korea has long used underwater platforms for test missile launches and has paired these with images of an actual submarine for propaganda purposes. However, the JCS confirming they came from a submarine would lend additional credence to the possibility Hero Kim Kun Ok did indeed launch the missiles. If this is the case, it would indicate that North Korea has begun validating weapons systems aboard the submarine ahead of deployment. At the very least, we can confirm that the Hero Kim Kun Ok is now sailing, although South Korean and U.S. intelligence would be acutely aware of its movements and it could have been in at-sea testing for years now, we just don’t know.

North Korea unveiled the submarine in September 2023, describing it as its first “tactical nuclear attack submarine” and one of the Navy’s core offensive platforms. At the launching ceremony, North Korean leader Kim Jong Un was quoted as saying that arming the Navy with nuclear weapons “brooks no further delay.”

Nevertheless, many questions remain about the submarine’s design and operational prospects. Overall, it remains a heavily modified derivative of a Cold War-era Romeo class diesel-electric submarine — nearly an antique by today’s standards — rather than a purpose-built guided missile submarine. Previous imagery shows 10 missile launch tubes concealed in the prominent ‘turtle back’ aft of the sail, in addition to torpedo tubes, although the precise configuration, usable capacity, and operational status of those systems remain uncertain.

The absence of publicly reported weapons tests from the vessel over the following years raised questions about its development. Analyst Shin Jong-woo of South Korea’s Defense and Security Forum told Reuters that the latest launches suggested combat-system testing for operational deployment was underway. He also suggested that North Korea may have resolved technical problems and could also test a submarine-launched ballistic missile (SLBM) before the vessel enters service. North Korea has previously presented SLBMs of increasing size, but has lacked a suitable submarine to launch them from.

Missile launches while the submarine is submerged represent a more demanding and operationally relevant capability than firing from the surface.

At the same time, a missile launch of any kind demonstrates only part of the capability required for a submarine like this to be effective at all. An operational submarine must also be able to deploy reliably, remain sufficiently difficult to detect, maintain its weapons, and execute missions under realistic conditions.

A vertical launch system (VLS) can provide dedicated capacity for certain missile types — potentially much larger ones — and may enable faster launches or larger salvos than a configuration relying exclusively on torpedo tubes. Torpedo tubes offer an alternative launch method, but with different constraints on weapon dimensions, handling, and firing procedures.

The forward four tubes are larger than the rear six on the submarine’s ‘turtle back.’ This would allow the boat to carry multiple types of missiles, possibly including a mix of short-range and longer-range submarine-launched ballistic missiles (SLBMs) and submarine-launched cruise missiles (SLCMs).

Testing both systems would be consistent with an effort to validate multiple elements of the submarine’s weapons architecture.

North Korea has pursued submarine-launched missiles for years. In March 2023, it reported a submarine-launched cruise missile test from the older 8.24 Yongung submarine. In January 2024, Pyongyang said it had fired Pulhwasal-3-31 strategic cruise missiles from that same vessel. The earlier sub is in the 2,000-ton-class and is understood to have only one or two vertical launch tubes.

North Korea’s description of the weapons as “strategic” cruise missiles should also be treated cautiously. North Korea’s long-range cruise missile program is well established and a nuclear payload is a major part of its ambitions, but how mature or reliable a nuclear warhead is for this application at this time isn’t clear. Regardless, ground, surface, and now subsurface-launched cruise missiles are a key part of North Korea’s broader deterrent architecture.

According to reports, Wednesday’s activity was the first publicly reported underwater North Korean missile-testing event since the January 2024 launch.

Compared to the 8.24 Yongung submarine, the Hero Kim Kun Ok has a larger hull and additional vertical launch tubes, but it still uses very dated diesel-electric propulsion, which presents hugely different endurance, acoustic, and operating constraints compared with nuclear propulsion or even modern diesel-electric submarine capabilities.

As to the expectation that Pyongyang may test an SLBM from the submarine before deployment, this would be a likely milestone toward North Korea fielding a credible sea-based nuclear deterrent.

North Korea is also pursuing a separate nuclear-powered submarine project, unveiled as under construction in March 2025. Its completion and operational timeline remain uncertain. Nuclear propulsion is a much bigger challenge, but if perfected, such a boat would be of considerably greater value, especially as a second-strike capability.

The latest submarine tests come amid a broader series of North Korean weapons demonstrations, including reported hypersonic missile tests on September 20 and October 3, as well as tactical ballistic missile launches earlier in October.

The sequence is consistent with Pyongyang’s effort to diversify its delivery systems and complicate military planning for South Korea, the United States, and Japan.

The activity also carries a diplomatic message. North Korea has repeatedly insisted that it will not abandon its nuclear weapons while the United States maintains what Pyongyang calls a hostile policy. It has also rejected the suggestion that adjustments to U.S.-South Korean military exercises would be sufficient to change the underlying relationship.

The tests also follow North Korea’s rejection of an apparent diplomatic opening from U.S. President Donald Trump after Washington sought to reduce tensions surrounding a U.S.-South Korean military exercise.

A submarine able to launch missiles from less predictable locations complicates defensive planning for South Korea and the United States. The challenge extends beyond intercepting missiles after launch to detecting and tracking the submarine before it reaches a potential firing position. Even a partially capable vessel places additional demands on potential adversaries.

Were things to ‘go hot’ on the Korean Peninsula, any submarine capable of carrying strategic weapons would be at the top of the targeting list for Pyongyang’s adversaries. A submarine based on the archaic Romeo class design would be fairly easy to track from the time it leaves its berth. This is especially the case bearing in mind the sophisticated nature of South Korea’s anti-submarine capabilities.

Future submarines will become increasingly more challenging, however. That problem could intensify if future North Korean boats make more use of Russian assistance in developing their capabilities. Submarine technology is supposedly part of the payment to Pyongyang for its help in the war in Ukraine. This could become a much larger problem, even if Moscow were to provide North Korea with advanced Kilo class boats, for example.

For now, provided that the Hero Kim Kun Ok launched the missiles, which seems most likely, this would indicate that North Korea is advancing weapons integration aboard a submarine intended to expand its offensive naval capabilities. The fact that the Hero Kim Kun Ok is now at sea also signals progress toward deployment.

Whatever the ultimate operational effectiveness of the Hero Kim Kun Ok and its emerging missile armament, Pyongyang continues to demonstrate incremental improvements to its submarine forces.

Contact the author: thomas@thewarzone.com

New footage of Australia’s Ghost Shark extra-large autonomous underwater vehicle (XL-AUV) provides the first look at how the vehicle launches aerial drones, while also revealing a pair of deployable masts not previously seen on the platform. The video comes soon after we got a glimpse of some of the payloads that the Royal Australian Navy plans to integrate on the new uncrewed submarine, as you can read more about in our coverage here.

Published by manufacturer Anduril, the footage shows a Ghost Shark surfacing before doors on the top of its hull slide open. A launcher consisting of 12 angled tubes then emerges from a drone sub. Another launcher is seen in the other upper payload bay, but is not raised in the video. While it appears to be of the same type, the second launcher could also have a different arrangement of tubes.

The footage subsequently cuts to an ALTIUS-type drone being launched from one of the tubes, with Ghost Shark itself remaining surfaced.

The sequence provides a much more concrete look at the aerial-drone deployment concept — or one of them — than the photographs released previously, which offered the first public view inside Ghost Shark’s side payload bay.

The Australian government has said the vehicle is being developed for missions including persistent intelligence, surveillance, reconnaissance (ISR) and strike, but the precise configuration and operational capabilities of its weapons and how they are launched had not previously been disclosed.

The video does not identify which ALTIUS variant is being launched. However, Ghost Shark has previously been displayed at the Altus factory in Australia alongside derivatives of the ALTIUS-600 family. This includes the ALTIUS-600 for ISR, as well as the ALTIUS-600M, which is designed for strike missions. You can read more about this family of drones here. As we noted before, unarmed variants of the ALTIUS-600 are designed to be optionally expendable, and can be reused, although in many scenarios that isn’t possible. In terms of capabilities, the ALTIUS-600 has a maximum range of around 275 miles and can remain airborne for at least four hours, according to Anduril.

ALTIUS-600M Loitering Munition

Ghost Shark can clearly deploy a substantial number of aerial drones — two dozen in this case – in a single sortie, enabling swarms to be launched far from an adversary’s coastline. Depending on the drones carried and how they are employed, such a swarm could provide broad-area surveillance, wreak havoc on enemy air defenses via electronic warfare, or attack targets.

The concept could also have value below the threshold of open conflict. A mass launch of relatively inexpensive drones could be used to probe or stimulate an adversary’s air defenses, prompting them to reveal their locations, signatures and operating procedures for collection by other intelligence assets or even some of the drones themselves. There is a precedent for exactly this going back to the early Cold War years, which you can read all about here.

Ghost Shark could carry these capabilities deep into contested waters clandestinely without putting a crew at risk, unleashing their payload even at standoff distances or right next to the shore to give the drones maximum penetration and loitering time over target, depend on the risk profile.

At the same time, while the 12-tube launchers fit neatly into Ghost Shark’s hull architecture, the modular nature of the design means that the same space can accommodate many other payloads, which might include alternative types of aerial drones. This could be fewer larger, more capable types, or far more plentiful smaller, less capable ones.

The other notable development in the video is the appearance of two deployable masts. Their presence is particularly interesting given Anduril’s emphasis on designing uncrewed underwater vehicles without the kinds of protruding mast arrangements associated with traditional submarine designs. On UUVs, masts like these are generally used to support sensors, communications, and propulsion systems.

“We don’t have big masts running down the backbone of our vehicle that a lot of other designs do that then preclude the ability for the payloads to come out in different directions… of the payload module itself,” Dr. Shane Arnott, Senior Vice President for Engineering at Anduril and the company’s maritime lead, told TWZ back in 2024.

“So we have… in effect, unlimited flexibility in this design, just the way that we’ve configured the vehicle and the payload bay itself could be almost anything within a size configuration that you can dream up,” Arnott added. “We haven’t encountered a crazy idea yet from a customer that … we can’t fit.”

The larger mast that lies flat is actually a fairly traditional one for large UUVs. It lies along the centerline of the hull when stowed, between the upper payload bays. It then deploys upward in an arm-like motion and carries an antenna. The smaller mast is located farther aft and rises vertically from its own housing. Potentially, the tall mast supports a line-of-sight datalink to the drones, while the other being a satcom array, such as one connected to Starlink/Starshield, sends drone feed to controllers anywhere in the world. It’s also worth noting that Ghost Shark could just launch the drones and send them on their missions autonomously, without needing to stay surfaced at all. Other arrangements could exist, as well, such as Ghost Shark launching a dozen drones and one larger one capable of carrying its own satcom terminal. This would allow direct control of the drones by operators anywhere in the world without Ghost Shark remaining present near the surface.

Ghost Shark also has a lower-profile swept-back sail on top of its nose section, not visible in the video. Overall, the vessel would retain a very small signature above the waterline while connected to the drones, making it hard to detect by radar and electro-optical imaging systems.

The new video follows the recent disclosure of three payload concepts for the Royal Australian Navy’s Ghost Shark: the deployment of up to 12 sea mines in a mission, the placement of supply caches on the seabed, and the launch of aerial drones. Those capabilities expand the vehicle beyond conventional underwater surveillance into a broader range of undersea warfare missions.

The mine-delivery option could support operations in strategically important maritime areas, while seabed caches could provide a means of positioning equipment and supplies for later retrieval. The aerial-drone capability, as seen in the new video, would allow Ghost Shark to extend surveillance beyond the reach of its own sensors or potentially deliver strike effects without exposing crewed platforms to the same risks. Having 12 ALTIUS drones ready to launch (and potentially the same number in the adjacent upper payload bay) would allow multiple missions to be undertaken.

The modular design is central to Ghost Shark. As we have discussed, the payload section can be configured using different hull sections and mission-specific systems, allowing the same underlying vehicle design to accommodate different requirements. The newly revealed launcher provides a first look at how at least one of those payload concepts may be implemented in practice.

Australia has committed substantial resources to autonomous and uncrewed undersea warfare capabilities, with a planned fleet of Australian-designed and built Ghost Shark vehicles serving alongside the Speartooth large uncrewed underwater vehicle (LUUV) and the BlueBottle uncrewed surface vessel (USV). The Ghost Shark program is also part of the broader AUKUS effort to develop advanced maritime technologies alongside the United Kingdom and the United States.

The new footage provides a clearer picture of the practical design choices behind that effort. Most notably, how the underwater vehicle can operationalize its aerial drone launching capability and the quantity of those systems it could potentially deploy very quickly before slipping back below the waves.

Contact the author: thomas@thewarzone.com

Nearly a month ago, we reported on a uniquely configured vessel that was far along in its construction at Hudong-Zhonghua Shipyard on Changxing Island in Shanghai. The intentions behind this design appeared to be as an uncrewed underwater vehicle (UUV) mothership, capable of deploying a handful of very large vehicles or many more smaller ones via its stern garage door and well deck. Its large pylons would be used to lift the vessels up and down out of the water and to different levels in the ship. Now it appears China has not just one, but two of these vessels nearly complete.

Make sure to read our initial report on this vessel configuration for full context by clicking here.

The new image was taken in Guangzhou and the vessel has a near identical shape, but with smaller proportions and minor changes to its overall moldline, compared to the larger one in Shanghai. This new vessel appears to be about a third smaller overall than its counterpart. The lift towers number six in total instead of six larger ones and six smaller ones on the Shanghai vessel. Regardless, the major design features are all there, including the flight deck and hangar behind the forward superstructure, the location of the smokestacks, and so on.

While two of these assets could still be considered largely intended for experimental use, a growing fleet would have increasing tactical and even strategic importance. Being able to easily launch and recover large numbers of UUVs, or a few very large ones, far from Chinese shores would provide an asymmetric capability. A fleet of ships that is dedicated to deploying, recovering, and tending to these systems, some of which can remain on patrol for very long periods, would be a major indication of how important China sees UUV operations as part of its future strategy.

There have been rumors that these vessels are part of a larger overall program that will see more ships with similar capabilities constructed. Once again, this would be a strong indication that these vessels’ utility will go beyond testing and limited operational use cases. The launch and recovery of large UUVs remains a conceptual work in progress for the U.S., with nothing similar in the U.S. Navy’s inventory, as we discussed in our original post.

Large long-range UUVs can be used for many tasks, from mapping the sea floor to hunting submarines and ships to searching for mines to launching cruise missiles and drones to being turned into immensely destructive weapons in their own right that can circumvent traditional strategic defenses. For China, providing a credible threat to America’s outposts deep in the Pacific and even the U.S. seaboard would be on the table.

There is speculation online as to where exactly this vessel was built. The first place that came to mind is Guangzhou Shipyard International’s (GSI) facilities on Longxue Island, just southeast of the city of Guangzhou. GSI is a subsidiary of the China State Shipbuilding Corporation (CSSC). It is here that many of China’s most unique vessels are born. These include drone test ships of various kinds, massive beach landing barges, and giant supply ships. Upon closer review of archival satellite imagery, we can say for certain that GSI did build this ship. An image from October 2nd shows it peeking out of a covered graving yard area at the facility prior to launch.

The emergence of two of these large UUV tenders in such a short period of time underscores China’s major bet on the technologies they will support. If more ships are added to the currently known fleet of two, a clearer picture of the People’s Liberation Army Navy’s large UUV plans, and its expeditionary potential, will come into focus.

Contact the author: Tyler@twz.com

The U.S. Navy has taken delivery of the first C-130J-30 Hercules airframe destined to become an E-130J Phoenix II, the service’s next-generation aircraft for maintaining communications with its nuclear ballistic submarines. The aircraft will now undergo extensive mission-systems integration before it can begin testing for the Take Charge and Move Out (TACAMO) mission.

Lockheed Martin handed over the newly built aircraft at its facility in Marietta, Georgia, on October 15. The delivery marks the start of the transition from the Navy’s aging E-6B Mercury fleet to the turboprop-powered E-130J, which is intended to provide a survivable communications link between national leadership and U.S. Navy nuclear ballistic missile submarines, including the ability to send them orders to launch strikes while they are submerged.

“Today’s delivery from the historic Marietta line represents far more than a new airframe; it marks the foundation of our future strategic deterrence posture,” Capt. Roger Davis, program manager for the Navy’s Airborne Strategic Command, Control, and Communications program office (PMA-271), said in a statement.

“Through our close partnership with Lockheed Martin and our industry team, we are ensuring our nation maintains an unshakeable communications lifeline to our ballistic missile submarine fleet.”

The aircraft is the first of three C-130J-30s initially procured by the Navy in September 2024. It will be transferred to Northrop Grumman, the E-130J program’s prime contractor and mission-systems integrator, for conversion. Collins Aerospace is providing the very low frequency (VLF) communications system, a key component of the TACAMO mission.

TACAMO aircraft provide a means for the president, secretary of defense, and U.S. Strategic Command to communicate with nuclear forces, including submarines submerged at sea. The mission is designed to preserve the ability to transmit emergency action messages even if conventional communications infrastructure is disrupted or destroyed.

The E-6B accomplishes this in part through a long, trailing wire antenna that enables VLF transmissions to submerged submarines. The E-130J will receive a comparable system as part of its conversion.

Hardening against the effects of electromagnetic pulse (EMP), which occurs during the detonation of nuclear warheads, is another key requirement for these planes.

The Navy plans to acquire 31 E-130Js, nearly doubling the 16 E-6Bs currently in service. That total includes six developmental aircraft and 25 production examples, although it remains unclear how many of the developmental aircraft will ultimately be available for operational use.

The larger planned fleet should provide additional aircraft to support training, maintenance, and operational demands. However, the transition also brings technical challenges. The Government Accountability Office (GAO) has previously warned that integrating the specialized mission equipment into the smaller C-130J-30 airframe could affect operational availability and create additional engineering and manufacturing difficulties.

In the past, TWZ has discussed the potential operational readiness and other trade-offs that could come from selecting a C-130-based platform to replace the E-6B in the TACAMO role. As we wrote previously:

“It’s certainly worth pointing out that the E-6Bs, conversions of what were some of the last and most modern 707 airliners built, were larger and higher performance platforms than the EC-130Qs. The C-130J-30 is certainly a more capable aircraft than the C-130H on which the EC-130Q was based, but it won’t have the base speed and altitude capabilities of an airliner-sized multi-engine jet. Compared to the Mercuries, any TACAMO-configured C-130J-30 would not be able to get on station as quickly, or fly as high, limiting its ability to get above bad weather or establish a better line of sight for its communications systems.”

“At the same time, as the Navy itself has noted, the C-130J-30 platform does immediately open up the ability to use a larger number of air bases, airports, and airfields, including austere ones that the E-6B cannot operate from. This could be very useful in a contingency scenario where an opponent may have destroyed or otherwise rendered unusable many well-established bases, as well as larger secondary dispersal sites, which include large commercial airports. Being able to fly from smaller, tertiary locations could help to ensure that the TACAMO mission continues without significant disruption under such circumstances. This is also true during peacetime, as targeting the TACAMOs on the ground would be much harder if they could easily operate from and sit alert at a much larger number of airports.”

“A C-130J-30 configured for the TACAMO mission would certainly have a mid-air refueling capability, and the Hercules is already a platform that has demonstrated the ability to loiter over particular areas for long periods of time. Unlike the Boeing 707, the C-130J is still in production, as well, meaning that TACAMO aircraft based on this plane would be inherently easier to maintain and support logistically, and may also be easier to convert to this specialized configuration to begin with. As time goes on, the J looks set to increasingly become the default base C-130 model across the U.S. military, as well. Compared to the long out-of-production 707-based E-6, support for the C-130J is already distributed across the U.S. and beyond. Training C-130J crews is even an easier proposition.”

The E-130J also represents a return to the Hercules family for the Navy’s TACAMO mission. The EC-130Q performed the role from 1963 to 1993, before the E-6A Mercury took over. The E-6B subsequently added an airborne command post mission known as Looking Glass, supporting U.S. strategic forces beyond the submarine communications role.

The Navy’s current plan is for the E-130J to assume the TACAMO mission, while the Air Force pursues a separate effort to replace the Looking Glass airborne command post capability.

Following its delivery, the first E-130J airframe will enter mission-systems modification, ground testing, and developmental flight testing. The aircraft is not yet an operational TACAMO platform, and further integration and testing will be required before the Navy can begin fielding the new fleet.

The transition is intended to preserve one of the most critical links in the U.S. nuclear command, control, and communications architecture as the E-6B fleet becomes increasingly difficult to sustain.

Contact the author: thomas@thewarzone.com