The Record
Argentine TR-1700-class diesel-electric submarine, on patrol off the Patagonian coast. Reported a seawater leak into her forward battery compartment at 07:30 on 15 November 2017; an acoustic event consistent with hydrogen explosion or implosion followed hours later. 44 dead. Located 907 metres down by Ocean Infinity on 17 November 2018, a year to the day after her loss, after a crowdfunded family campaign forced the Argentine Navy's hand.
The Vessel
The ARA San Juan (S-42) was an Argentine Navy diesel-electric submarine of the TR-1700 class, built at the Thyssen-Nordseewerke yard at Emden, West Germany between 1983 and 1985 and commissioned on 19 November 1985. She was 66 metres long, 2,264 tons surfaced displacement (2,336 tons submerged), and armed with six 21-inch torpedo tubes. Her propulsion was diesel-electric: four diesel engines for surface operation and one main electric motor for submerged operation.
The TR-1700 class was a specific German-designed submarine intended for the Argentine Navy's medium-range coastal patrol and territorial-waters mission. Her specific design was sophisticated for a 1980s submarine; her specific operational capability was comparable to contemporary German Type 209 submarines.
By 2017, San Juan was 32 years old. The specific maintenance condition of the submarine had been substantially variable; she had completed a major overhaul at the Argentine Navy's Tandanor shipyard in 2013-2014, which had substantially updated her systems but had also been the subject of various specific technical concerns.
Her master on her final voyage was Captain Pedro Martín Fernández, 40, a career Argentine Navy submariner. Her complement on 15 November 2017 was 44 officers and enlisted personnel.
The Voyage
On 15 November 2017, the ARA San Juan was on a routine training patrol in the South Atlantic. She had departed Ushuaia, Argentina on 13 November 2017 for a return voyage to her home base at Mar del Plata, Argentina. The specific route was approximately 3,000 kilometres of coastal transit along the Argentine continental shelf.
At approximately 07:30 on 15 November 2017, San Juan transmitted her final routine status report to the Argentine Navy. The specific report indicated: normal operational conditions; the ship's position was approximately 430 kilometres east of the Argentine coast; the specific weather conditions were rough but manageable.
At approximately 10:30 on 15 November 2017, San Juan transmitted an unusual message to the Argentine Navy reporting that seawater had entered the ship's battery compartment through the snorkel air-induction system. The specific message indicated: fire had occurred in the battery compartment; the fire had been extinguished; the battery compartment was isolated from the rest of the ship; the ship was returning to Mar del Plata.
The specific battery compartment fire was a significant concern. The specific lithium-based batteries of modern submarines can produce catastrophic fires when exposed to seawater; the specific combination of seawater ingestion and battery fire was substantially indicative of a serious operational emergency.
The Disaster
At approximately 11:15 on 15 November 2017, an unexplained acoustic event was recorded by multiple international hydrophone installations in the South Atlantic. The specific acoustic event was located at approximately 46 degrees south, 59 degrees west, approximately 432 kilometres east of Comodoro Rivadavia, Argentina. The specific event was consistent with a catastrophic structural failure or explosion.
The ARA San Juan was subsequently established to have sunk at approximately 11:15 on 15 November 2017 at the location of the acoustic event. The specific mechanism of the sinking was subsequently identified as a catastrophic implosion of the submarine's pressure hull at a depth substantially below her operational depth limit.
The specific causal chain leading to the implosion was: (i) the initial seawater ingestion through the snorkel system; (ii) the subsequent battery fire in the flooded battery compartment; (iii) the subsequent loss of electric propulsion and buoyancy control; (iv) the progressive uncontrolled descent of the submarine to depths exceeding her design operational limits; (v) the eventual implosion at approximately 900 metres depth.
The specific search operation for San Juan was one of the largest international submarine search operations in history. Multiple countries (Argentina, the United States, the United Kingdom, Brazil, Russia, Germany, and others) deployed submarine rescue equipment and search vessels over approximately 2 weeks (15 November through 30 November 2017). The specific search was substantially unsuccessful during the initial operations.
The specific wreck of San Juan was eventually located on 17 November 2018 (one year after the initial disappearance) by the American company Ocean Infinity using remotely operated search vehicles. The specific wreck was located at approximately 907 metres depth, approximately 500 kilometres east of the Argentine coast.
All 44 crew aboard died: the specific implosion would have killed all crew essentially instantaneously. No survivors were recovered. Captain Fernández died aboard the submarine.
The Legacy
The ARA San Juan disaster of 15 November 2017 was the most specifically significant Argentine Navy peacetime disaster of the 21st century. The specific 44 dead were all Argentine Navy personnel; the specific casualty represented the largest single-incident Argentine Navy loss since the Falklands War of 1982.
The subsequent Argentine Navy investigation, conducted through 2017 and 2018, identified a pattern of failures: (i) the specific 2013-2014 overhaul at the Tandanor shipyard that had introduced specific technical deficiencies; (ii) the specific inadequate maintenance of the snorkel system that had enabled the initial seawater ingestion; (iii) the specific inadequate emergency response procedures for the battery fire; (iv) the specific inadequate submarine rescue infrastructure of the Argentine Navy.
The specific criminal prosecution of specific Argentine Navy officials was extensive. Multiple senior Argentine Navy officers were charged with criminal negligence related to the submarine's maintenance and operational decisions. The specific prosecutions continued through 2019-2022.
The specific regulatory response in Argentine submarine operations was substantial. The Argentine Navy substantially reformed its submarine operational procedures; the specific submarine maintenance infrastructure was modernised; the specific international cooperation on submarine rescue was enhanced.
The specific cultural and political impact in Argentina was profound. The specific 2017-2018 Argentine political discourse was substantially shaped by the San Juan disaster; the specific political pressure on the Argentine government of President Mauricio Macri was significant. The specific annual 15 November commemoration has become an important reference point in Argentine national memory.
The specific international significance was the comprehensive demonstration of gaps in international submarine rescue coordination. The specific NATO and other international submarine rescue capabilities were subsequently enhanced based on the lessons of the San Juan search operation.
The wreck of San Juan remains at approximately 907 metres depth in the South Atlantic; she has not been raised. The specific wreck has been documented by subsequent international expeditions. The wreck is protected under Argentine cultural heritage legislation as a designated war grave. The 44 dead are commemorated by the San Juan Memorial at Mar del Plata (dedicated 2018); by the San Juan Memorial at Buenos Aires (dedicated 2019); and by the annual 15 November Memorial Service conducted at the Argentine Navy Memorial, Buenos Aires.