Elio Calcagno and Michelangelo Freyrie join the program to discuss the European undersea environment, security, and defense.
Elio is Researcher in the Defence Programme at the Istituto Affari Internazionali (IAI). Michelangelo is a junior researcher in IAI’s Defence and Security Programs.
In the race against time, recent history demonstrates that technology remains limited for submarine search and rescue efforts. The November 2017 disappearance of the Argentinian Navy submarine, the ARA San Juan (S-42), highlights the particular hardship confronting submarine recovery. After completing a naval exercise near Tierra del Fuego, the diesel-electric submarine ARA San Juan (S-42) departed from the city of Ushuaia to return to its home port in Mar de Plata. The boat transmitted its last signal on November 15th, 2017 and its failure to report twice to its command the next day prompted an international search and rescue operation starting November 17th.1 This case study examines the limits of aquatic-based forensic methods along with institutional shortcomings that inhibited the investigation. It furthermore underlines how contemporary submarine search tools – for rescue, post-mishap investigation, or espionage – remain underdeveloped and require further attention.
Searching for the ARA San Juan(S-42)
On its one-year anniversary of the San Juan’s disappearance, Ocean Infinity – an American private seabed explorer company contracted by Buenos Aires – located the missing submarine 270 nautical miles off Argentina’s nearest coastal city at a depth of 2,976 feet – roughly three times the nominal test depth.2 Photographs taken by Ocean Infinity’s ROVs portrayed a compromised hull with propellers and a bow section discernibly separated.3 Although presumed beforehand, the imagery eliminated any possibilities that there had been survivors on the ARA San Juan.
Revisiting the initial search operations on the 17th sheds light into the immediate challenges of the submarine search and rescue operations. Argentinian Navy helicopters, U.S Navy P-8A Poseidon, and NASA P-3 Orion aircraft began search efforts with sonobuoys that possessed limited range, but which could be rapidly and widely deployed. It became apparent that space and time disadvantaged the emergency responders: The initial search box was larger than the size of Iraq.4 The ARA San Juan only had a submerged oxygen supply of seven days, giving a five-day rescue window after the last communication. Moreover, the remoteness of the search area and the tardiness in support diminished the probability of success. Over 11 countries sent nine ships and 13 aircraft to the search area, but the additional manpower and vessels arrived by November 21st (T-3 rescue window), requiring aerial-deployed sonobuoys to spearhead localization efforts – not side-scan sonars. 5 These sonobuoys offered a medium to hear distress transmissions from submarine, including via active sonar, underwater telephone, echo sounder, emergency location beacons, and hull tapping.
Other obstacles included unfavorable weather conditions. In the rescue window, investigators battled swells that reached 10 meters and wind speeds in the South Atlantic recorded around 100km/h.6 Yet, the most disappointing element to the abrupt search operation was the abundance of false signatures. In the critical rescue window, multiple incidents hindered search progress by draining resources from follow-up investigations. Table 1 summarizes these sources of hope that were later met with frustration.7
Table 1: Summary of False Leads and Later Determined True Origin
Date
Observed Incident
Later Determined Cause
Location
NOV 20
Satellite Calls on same frequency used by San Juan
Commercial Vessel
Unspecified
NOV 21
Faulty identification of possible banging on metal from passive sonar
Biological
Unspecified
NOV 21
Magnetic anomaly with heat signature
Equipment
430km from coast
NOV 21
3 Flares seen in vicinity of last location
Not Same Color Flares
Unspecified
NOV 22
Object found near area of San Juan’s last signal
Unrelated debris
270km from coast
The Argentinian Navy declared the rescue aspect of the search operation to be over on November 30th, 2017 after planners eliminated an extreme survival situation. At its height, the search operation constituted over 4,000 personnel from over 13 countries and surveyed over 200,000 square miles.8 On November 16th, 2018, a Houston-based hydrographic survey company, Ocean Infinity, used a Norwegian multipurpose ship to investigate a possible ping on the San Juan’s potential position in the middle of a sea canyon.9 Finally, Ocean Infinity confirmed discovery of the San Juan on November 17th, 2018 and handed over data and visual evidence of the wreckage for forensic investigators to determine cause. Ocean Infinity’s use of five autonomous undersea vehicles (AUVs) for exploring the wreck site suggested that extensive use of AUVs was integral to the mission’s success.
Argentine Navy photos showing the submarine’s bow section, sail, and propeller that were torn off in the implosion. (Argentine Navy photo)
Forensic Shortcomings and New Questions
In the case of the San Juan’s disappearance, investigators must ask themselves about failures in the search phase and prescribe future procedures to avoid such pitfalls. The disappearance of the ARA San Juan disturbingly mirrors the loss of the Kursk in 2003, apart from the evidence that the Kursk had initial survivors post-implosion. First, the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) in Vienna did detect a hydro-acoustic anomaly from its Ascension Island and Crozet Island stations that seemed consistent with an underwater explosion on November 15th around 30 nautical miles from the San Juan’s last known bearing in the morning.10
Unfortunately, the CTBTO’s automatic processing algorithm used to detect nuclear explosions did not flag the registration of the two hydrophone station’s recording.47 In an effort to minimize false alarms, the CTBTO incidentally failed to exploit data that could have been used towards the calculation of a coverage ellipse for the San Juan. CTBTO could have directed their waveform analysts to immediately deploy their standard iterative dual correspondence (IDC) automatic localization algorithm to produce a spatial diagram of the detonation’s coordinates from iterative minimization of the origin time and azimuth residuals from the seismic data.
This had been done before as Koper details how four land-based seismometers detected the Kursk’s torpedo misfire on August 10th, 2000.11 Collation of the data in the Kursk case allowed for there to be a preliminary ellipse-shaped search parameter for the Kursk. The ARA San Juan’s implosion likely mimicked features of the Kursk’s explosion – compressive first motion, significant variation and high ratio of Sn to Lg, and shear wave generation in the seismic record. The oversight in the hydroacoustic anomaly, although eventually rectified through manual processing, caused the CTBTO to inform Argentina on November 22nd about a possible localization tardy in the search phase.12 Earlier consultation between Argentina and CTBTO and better automated processing for significant non-nuclear seismic events could have produced a more refined search box sooner.
State capabilities also hampered search execution. Ocean Infinity discovered the San Juan in a grid site that had a 90 percent probability of wreckage to be found – at the beginning of search planning.13 Argentinian officials defended themselves by stating that sub-canyons presented a hazard that its Navy could not outmaneuver. In other words, even if the crew was deemed to be alive, Argentina lacked methods and technology like a McCann Rescue Chamber or Deep Submergence Rescue Vehicle (DSRVs) required for a delicate retrieval operation. This deflection of blame, however, shared no merit as U.S operators from Undersea Rescue Command in San Diego arrived with Submarine Rescue Diving and Recompression System and a tethered Pressurized Rescue Module Remotely Operated Vehicle (ROV) in only two days.14
Comodoro Rivadavia, Argentina (Nov. 26, 2017) U.S. Navy Undersea Rescue Command (URC) sailors and Argentine construction workers prepare the motor vessel Sophie Siem for the installation of the Submarine Rescue Diving and Recompression System (SRDRS) which operates the deep diving rescue vehicle, the Pressurized Rescue Module (PRM). (U.S. Navy photo by Mass Communication Specialist Christopher Lange)
Lastly, the relegation and sidelining of side-scan sonar and UUVs contributed to inefficiency and lack of coverage. Tardiness in the arrival of logistical support signified that these methods could not be practically implemented so total blame could not be place on the planners. Absence in information regarding scenarios and hypotheses did not allow for Bayesian search strategies to be fully utilized, although submarine officers blame a short-circuit in the battery tray in the prow due to water intake from the submarine’s snorkel as a precedent event to the suspected implosion.
That being said, forensic investigators still confront distinct challenges irrelevant to traditional geophysical investigations. Unlike terrestrial-based forensics, pre-established knowledge of a local maritime environment is sparse. Scientists have mapped 1/5th of the sea floor to modern standards with 100m resolution, but that means almost 290 million square kilometers of seafloor – twice the surface area of Mars – has not yet been surveyed. The absence of existing charts, therefore, necessitates simultaneous 4-D mapping of the area.15 Submarine debris are unidentifiable in satellite and aerial images due to surface opacity and the extreme depth of wrecks. Stratification conceals wrecks and clearing sedimentary buildup becomes extremely complicated due to sheer volume. An onsite “walk-over” survey, as described by Fenning and Donnelly in their description of geophysical methodologies, is simply impossible in a marine environment.16 Acidity and pH levels of the water also influence rates of decomposition, and must be considered for a simulation in the casualty scenario. In the future, the undersea recovery field must overcome these variables in order to find any success in submarine search and rescue.
A screenshot showing the wreckage of the ARA San Juan laying 920 meters below the surface. (Argentine Navy photo)
The loss of the ARA San Juan devastated the Argentinian public and had harmful repercussions on its naval service. Not only did Argentina lose 44 sailors, but one of the San Juan’s crewmembers was the first female submarine officer (Lieutenant Eliana Krawczyk) in Argentina’s history.17 Federal policemen raided the Navy’s headquarters for document requisition to piece together culpability and allocate responsibility. Argentina’s Minister of Defense unceremoniously fired Marcelo Srur, the Navy’s Chief of the General Staff, and the events surrounding the ARA San Juan’s mission — tracking British assets near the Falkland Islands — was publicly leaked by an Argentinian media source, further embarrassing the Navy.18
Conclusion
The task of finding lost submarines is an enigma complicated even further by the very reason these boats exist: to be undetectable assets for national security. Unlike their geologist peers, marine forensic investigators rely on robotics and invisible sound waves as surrogate sensors to hands and eyes. The development of side-scan sonar systems, and the consolidation of UUVs for search operations and site verification amalgamate the practice of maritime search into a forensic field heavily invested and intertwined with technological innovation. When establishing an inaugural search parameter, best practices in Bayesian search strategy call for officers and scientists to weigh qualitative hypotheses in order to allocate priorities to search boxes that will offer maximum efficiency.
The ARA San Juan represents a recent case, where these methods did not seem utilized to the fullest capacity. Prior success in the history of these methodologies being used for finding WWII vessels demonstrate that perhaps governments must rethink quick reaction plans to lost submarines. In order to save lives and honor the gravesites of individuals lost in times of conflict, advancement of these methods and a reevaluation of the ARA San Juan’s loss will be beneficial for the global submarine community and for navies around the world.
Ensign Andrew Song is a U.S. Navy submarine officer assigned to the USS San Francisco (MTS-711). His past publications have appeared in peer-reviewed military journals and outlets including Military Review, Journal of Indo-Pacific Affairs, USNI Proceedings, Yale Review for International Studies and the Wall Street Journal. He graduated from Yale University with a B.A. in Global Affairs.
10. Nielsen, P.L., Zampolli, M., Le Bras, R. “CTBTO’s Data and Analysis Pertaining to the Search for the Missing Argentine Submarine ARA San Juan.” Pure Appl. Geophys.https://doi.org/10.1007/s00024-020-02445-9. January 31 2020.
11. Koper, K. D., et al., 2001. Forensic seismology and the sinking of the Kursk, Eos, 82, 45-46.
16. Fenning, P. J., Donnelly, L. J., 2004. Geophysical techniques for forensic investigation. Geological Society of London Special Publications, 232, 11-20.
For the past two weeks, CIMSEC featured short articles submitted in response to our Call for Notes to the New CNO. In this special series, authors conveyed their thoughts on what they believe are the most pressing issues for the U.S. Navy’s new top leader, Acting Chief of Naval Operations Admiral Lisa Franchetti.
Authors recommended new naval strategies and approaches to force design, as well as specific efforts to manage personnel retention issues. Authors also offered recommendations on how the Navy can become a better learning organization and seize opportunities posed by emerging capabilities. The U.S. Navy’s new leadership is confronting myriad challenges that could affect the Navy’s competitiveness for years to come.
The featured authors are listed below, and we thank them for their excellent contributions. This is an independent CIMSEC initiative and is not produced in partnership with any U.S. Navy organization or entity.
“Admiral Lisa Franchetti should take the initiative to develop a comprehensive, operational level of war maritime strategy that will determine fleet missions, which will subsequently inform a specific fleet size and force design. Forging a stronger connection between warfighting strategy and force design will remain among the most pressing matters for the leadership of the United States Navy.”
“A revised NDP-1 will go beyond teaching warfare principles as an instrument of national power. Indeed, it would provide a timeless model for how to approach complex warfighting challenges with specific learning strategies and campaigns.”
“Successful AI culture is a departure from Navy norms. Military culture is based around assured success, but compared to aviation or weaponeering, AI requires far more failure before reaching success.”
“The traditional benefits of naval service – adventure, camaraderie, leadership experience, stable pay, and robust benefits – no longer match the costs associated with a sea-going career. While this may not be the case for every Sailor, personnel numbers indicate a strong correlation. So what do we do?”
“To support its goals, China is creating a navy that it hopes can directly challenge the U.S. Navy for supremacy on the world ocean, something the USSR never aspired to do. The combination of China’s economic and industrial power, and its sweeping global objectives, presents the U.S. with a new and more difficult challenge that previous approaches to security will not properly address.”
“These two areas of focus – empowering division officers and enhancing sailor stability – are interconnected. A more empowered division officer will better understand and address the unique needs of their sailors, including their need for stability. More content and stable sailors will be more responsive to their officers, creating a more trusting and effective chain of command.”
“The Navy needs to divorce itself from its affinity of conceiving capability as a function of traditional naval platforms, such as surface combatants or range-hobbled carrier air wings, and pursue a more holistic concept.”
“The Navy must recommit to the vital role of small ships in meeting its obligations. A commitment to smaller combatants offers benefits for naval operations, the supporting industrial base, and for leadership development.”
“With an increasingly complex strategic environment, and a fleet struggling to meet its many operational requirements, the next CNO must strive to find new ways to capitalize on allied naval capabilities to succeed at sea. Prominent options include strengthening naval cooperation with partners to ensure a permanent presence in all strategically relevant theaters, and bolstering the sharing of naval knowledge among allied naval war colleges.”
“Today we have a forward-based navy, not an expeditionary navy. This distinction is important for remaining competitive against modern threats and guiding force design.”
“Whether it is maintenance and administration, training and education, at-sea exercises, engagement with adversaries and partners (e.g., FONOPS), or creating antifragile naval architectures, if the participants are simply box-checking rather than learning, the effort is falling short. The Navy must be more deliberate about being a learning organization and how it structures its campaigns of learning.”
“In the pursuit of maritime superiority, the U.S. Navy must prioritize the education and empowerment of its enlisted Sailors. These dedicated individuals are the backbone of the U.S. Navy, and their success directly contributes to the U.S. Navy’s overall readiness and effectiveness. By reinforcing and expanding educational opportunities for enlisted Sailors, the U.S. Navy can ensure that they become full, active, and informed participants in the mission.”
“Consistent errors in their HR experience, often driven by these unreliable digital HR tools, push many Sailors out of the service. Sailors’ digital HR experience is not a quality of service or quality of life issue. Getting HR digital implementation right is a warfighting and readiness imperative.”
“After almost a decade of demonstrating the capabilities of MUSVs, the Navy has been slow to establish programs of record to populate the fleet with these workhorses. The Navy should now shift its efforts from prototyping to serial production, given how these vessels have demonstrated their potential.”
“In the end, it comes down to setting firm priorities and making the tradeoffs. The best weapons in the world will fall short if they are manned by overworked and exhausted Sailors.”
“All members of the sea services must help maintain and hone their intellectual edge. They must be able to out-think and out-learn any opponent, especially in dynamic and rapidly changing situations. This is their greatest advantage, but it is also perishable. If it is neglected due to other priorities, it will atrophy and wither away.”
“Climate change is transforming the security landscape in the Indian Ocean. It is having a profound impact in fomenting transnational maritime crimes, particularly illegal fishing, human smuggling, drug trafficking, and piracy. Island states are specifically vulnerable to these crimes, which often exploit their maritime boundaries and limited capacity. Recognizing these strategic vulnerabilities and their potential to destabilize the region is paramount.”
“The bi-modal fleet structure includes a combination of small, crewed, and autonomous systems working as a networked flotilla. The crewed LMACCs and uncrewed autonomous surface vessels can be built and armed for much lower costs and greater capability than the cost of building one or two more destroyers or frigates. In this systems view, it is the holistic flotilla network that is the capability, rather than the individual platform.”
“A key contributor to unit success includes the intentional creation of organizational and cultural environments conducive to learning. The ability to learn is arguably the main attribute with the potential to produce warfighting victory.”
“Even the people of a famously tax-averse country like the United States might accept financial sacrifice to help the troops. While today’s Americans do not have to sacrifice to nearly the extent the World War II generation did, direct requests for contribution to the armed services could help revive some of the spirit of America’s greatest military triumph.”
“The Joint All-Domain Command and Control (JADC2) concept is totally dependent on radiofrequency (RF) communications to connect military assets across the space, air, land, and sea domains. This plethora of RF emissions from U.S. radars, communications systems, data links, and navigation aids presents a lucrative signals intelligence target that could undermine JADC2.”
Dmitry Filipoff is CIMSEC’s Director of Online Content. Contact him at Content@cimsec.org.
Featured Image: WASHINGTON (Sep. 14, 2023) – Vice Chief of Naval Operations Adm. Lisa Franchetti answers questions from members of the Senate Armed Services Committee during her confirmation hearing at the Dirksen Senate Office Building. (U.S. Navy photo by Chief Mass Communication Specialist Amanda R. Gray)
The Joint All-Domain Command and Control (JADC2) concept is totally dependent on radiofrequency (RF) communications to connect military assets across the space, air, land, and sea domains. This plethora of RF emissions from U.S. radars, communications systems, data links, and navigation aids presents a lucrative signals intelligence target that could undermine JADC2.
While net-centric concepts such as JADC2 enjoy broad endorsement, the elephant in the room is the underlying risk associated with adversary intelligence collection and exploitation. RF emissions present the best source for channeling enemy wide-area search, classification, and tracking. If U.S. emissions are sufficiently frequent, they provide the basis for maintaining the track continuity required for targeting long-range anti-ship missile strikes. The U.S. should not underestimate the ability of adversaries to take full advantage of the RF opportunity presented by U.S. net-centric operations.
In contrast with the JADC2 concept, service concepts such as Distributed Maritime Operations (DMO) and Expeditionary Advanced Base Operations (EABO) are based on the force being hard-to-find. Recognizing the risk of enemy exploitation of RF emissions, the hard-to-find objective is achieved in large measure through operating in RF silence.
The JADC2 net-centric concept and concepts based on being hard-to-find both make sense, but need to be made more complementary. If the enemy does not know where U.S. units are located, the strategy would be to operate in RF silence to remain hard-to-find, thereby avoiding premature engagements and maintaining the advantage of surprise. When the hard-to-find strategy fails and the U.S. force is facing attack, the strategy would be to rapidly transition to unconstrained RF emissions to leverage the substantial advantage of net-centric operations.
The Navy should request that the Defense Intelligence Agency conduct an assessment, with Navy, NSA, and NRO participation, of the risk of Chinese exploitation of JADC2 RF emissions. If the risk is assessed as high, it would serve to persuade JADC2 advocates of the risks of enemy exploitation of RF emissions, the necessity to conduct some phases of operations in RF silence, and the need for modifications to the JADC2 concept to integrate both.
Richard Mosier is a retired defense contractor systems engineer, Naval Flight Officer, OPNAV N2 civilian analyst, and OSD SES 4 responsible for oversight of tactical intelligence systems and leadership of major defense analyses on UAVs, signals intelligence, and C4ISR.
Featured Image: ATLANTIC OCEAN (Feb. 18, 2019) An E-2D Hawkeye assigned to the “Bluetails” of Carrier Airborne Early Warning Squadron (VAW) 121 performs an arrested landing on the flight deck of the Nimitz-class aircraft carrier USS Abraham Lincoln (CVN 72). (U.S. Navy photo by Mass Communication Specialist 3rd Class Amber Smalley/Released)
