natsouth (natsouth) wrote,

Deep-sea investigation and recovery operations - the ARA San Juan

Updated 9 December 2017

End of year update:

Pretty amazing legacy of the intense search, don’t think I’ve seen anything like it in my professional career. I hope that some of #ARASanJuan families are able to see this. I think we take it for granted the exhaustive work that has taken place here. Of course, to note that these are the AIS tracks of ships involved. There were other ships who weren’t on AIS, such as some of the participating Argentine Navy ships- (ARA La Argentina, ARA Robinson, ARA Sarandí, ARA Puerto Argentino at times...).

All of the seagoing US Navy teams and the WHOI research ship RV ‘Atlantis’ have terminated their search in the last week of December.

BZ to all of the multi national ship crews and aircrews!

The last search teams and ships are the:
- Russian Navy ‘Yantar’
- The Argentine Navy ARA ‘Sarandí’ and the ARA ‘Islas Malvinas’ with Russian Navy ROV teams onboard.

1 month of searching for the ARA San Juan: 15 December update.

Deep-sea investigation and potential recovery operations



Once the Argentine submarine, ARA San Juan, is located by the specialist ships and equipments, then robotics systems such as ROVs, will be used to investigate more closely the submarine.

The steps in locating a sunken ship:

  1. bathymetric profiling with multibeam echosounder of the seabed;

  2. by detailed profiling multi-beam sonar array (either an UAV or on a ‘sledge’).  The images obtained are digitally processed & analysed for subsequent verification;

  3. by sending down an ROV for visual inspection of the object.

Source: BAS

The seabed profile of the search is complex: from a fairly flat continental shelf that drops down, with numerous ravines.

Hence you might just appreciate the complexity of the operations for locating the ARA San Juan.

Here’s a screen shot from when the Chilean Navy ‘Cabo de Hornos’ was participating in the search:

After location, then it is the turn of the tethered Remotely-operated Vehicles, (ROVs), to get a visual close-up of the submarine’s condition. The ROVs mentioned in the ARA San Juan operation, include the Russian Navy operated Saab Pantera-Plus (depth rating of 1000m) and the US Navy operated Phoenix, (BM2 Sibitzky with a depth rating of 600m), and US CURV-21 (depth rating 6000m onboard RV Atlantis).

The situation as of 9 December

The seabed search continues - Ships with ROV and UAV sonar equipment

RV 'Atlantis', (WHOI)
- has onboard an ROV,  a US Navy CURV 21 ROV (6000m depth rating), especially flown in by air from US.

ARA "Puerto Argentino"
- with US Navy URC equipment onboard
(UAV sonar -Iver 580 UUV with 100m depth rating -withdrawn from operations 2 Dec ?) 1 December - announcement that US NAVY UAV UUV equipment from 'Skandi Patagonia' will be transferred to ARA "Puerto Argentino" (To be confirmed).

ARA "Robinson"
- with Russian Navy ROV equipment onboard
Tethered ROV (300m depth rating?)

ARA "Islas Malvinas"
-with Russian Navy ROV equipment, Pantera -Plus tethered ROV (1000m depth rating)
with deep-sea ROV and 2 submersibles onboard

Ships with multi-beam/ side scan sonar + magnetometer participating in initial search;

Dr. Victor Angelescu (Argentina) — Fisheries oceanopgrahic research vessel
RV Atlantis (USA) Woods Hole Oceanographic Institution
ARA Austral — (Argentina) Naval research vessel, (EM 122 Kongsberg multibeam)
Cabo del Hornos (Chile) — Naval research vessel (EM 122 Kongsberg)
ARA Puerto Deseado (Argentina) — Naval research vessel
ARA Puerto Argentina —  temporarily outfitted with US Navy sonar equipment
HMS Protector (UK)  Naval research vessel

Yantar (Russia) see below section for more details.

The situation as of 1 December: End of Rescue Phase

The US Navy Undersea Rescue Command press release outlines the equipment sent to Argentina:


List of ships with rescue chambers, PRM,

The 'Skandi Patagonia' (OSV chartered for search ops) - US Navy URC
Norwegian-flagged offshore support ship (OSV)

  • the Submarine Rescue Chamber (SRC)

(Withdrawn from operations 1 December 2017)

The "Sophie Siem" (OSV chartered for search ops) - US Navy URC

  • The Pressurized Rescue Module (PRM), was loaded onto the  ‘Sophie Siem’, after an amazingly fast but extensive outfitting of the ship, to be able to accommodate the equipment and A-frame (for launching & recovering the PRM). The PRM has a depth rating of 600m.

(Withdrawn from operations 1 December 2017)

Brazilian Navy Submarine Rescue ship, the NSS "Felinto Perry" also has a SRC, (a diving bell), and a ROV, (600m depth rating). Arrived in Argentine 29 November.

(Withdrawn from operations 2 December 2017)

Most equipment dedicated to rescuing the crew of a stricken submarine is limited to an average of depth of around 650m or so, because this is the average limit of the fatal  crush (collapse) depth of a submarine.

Infographic showing use of PRM and ROV for sbmarine rescue operations.  Source: La Provincia

Before 1st December

The 'Skandi Patagonia' (OSV chartered for search ops) - US Navy URC
Norwegian-flagged offshore support ship (OSV)

  • the Submarine Rescue Chamber (SRC)

  • a Bluefin Underwater Automous Vehicle (UAV) sonar - (1500m depth rating).

  • Additionally there are also 3 deep-sea ROVs onboard, (one with 9000m rating — unconfirmed)

The "Sophie Siem" (OSV chartered for search ops) - US Navy URC.

  • UAV sonar ?  (Iver 580 UUV?) 100m depth rating

(Both withdrawn from operations 1 December 2017) - It is possible that some sonar equipment has been transferred to the RV 'Atlantis'

NB: None of these ROV have any rescue capabilities, only limited underwater search and reconnaissance and maybe a small robotic arm for sampling or tool manipulation.

Source: Wikipedia SIDE SCAN SONAR

Ships with multi-beam/ side scan sonar participating in search; (27 Nov).

 This is an unprecedented international effort of great magnitude for a loss submarine:

Dr. Victor Angelescu (Argentina) — Fisheries oceanopgrahic research vessel

RV Atlantis (USA) Woods Hole Oceanographic Institution

ARA Austral — (Argentina) Naval research vessel

Cabo del Hornos (Chile) — Naval research vessel

ARA Puerto Deseado (Argentina) — Naval research vessel

ARA Puerto Argentina —  temporarily outfitted with US Navy sonar equipment

Skandi Patagonia (Norway) OSV — temporarily  outfitted with US Navy equipment (Withdrawn 30 Nov)

HMS Protector (UK)  Polar patrol & oceanographic vessel (Withdrawn 4th Dec?) TBA

NSS Almirante Maximiano (Brasil) Polar oceanographic vessel (Withdrawn 28 Nov)

Side scan images have appeared on the 1 Dec press briefing given by the Argentine Navy.  The images are of 2 vessels, one a Chinese fishing boat sunk in 2000, the other unknown & uncharted of another fishing boat (?)


The Russian Navy operated ROV is onboard the ARA 'Islas Malvinas" and can go down to 1000m deep.

Source: El Clarin

DEEP-SEA CAPABILTIES - The Russian Navy 'Yantar'

The Russian Navy,’Yantar’, is an 'oceanographic research' ship , which was recently off Angola. It was tasked with participating in the search operation area and has yet to arrive.  Additionally, the Russian navy sent by air, a specialist team, belonging to the Russian Navy's 328th expedition search and rescue unit, as well as another ROV, the Pantera Plus, (1000m depth rating),  which presumably will be loaded onboard the ARA 'Islas Malvinas’ later in the week.

The Russian Navy’s rescue and search capabilities are outlined:  (TASS 23 Nov 17)

Onboard the ‘Yantar’, are 2 submersibles, capable of going down to 6000m.  These are more likely to be used to take samples, to take images and carry out on-site investigation of the submarine in-situ.  It is not a SRC or a PRM and does not have a rescue capability. The submersibles are reportedly the project 16810 Rus-class submersible[4] and the project 16811 Konsul-class submersible.

Both min-subs are equipped with two heavy-duty robotic arms, capable of handling up to 200 kg loads, and are able to carry and control ROVs. They have an operational endurance of around10–12 hours.

Deep-Sea Recovery Operations —  3 examples involving submarines.

One successful recovery of a submarine is the Peruvian 'El Pacocha' in 1989, following a fatal collision and sinking the year before.

Any potential deep-sea recovery effort at is going to be extremely challenging.  Only one submarine, the Soviet nuclear submarine ‘K-129’ had been partly raised from 4.8km depth, that was part of a 6-year long top secret CIA operation codenamed ‘Project Azorian’ in 1974.

Then there is the salvage of the ‘Kursk’ submarine in 2001, where it was raised from a depth of just over 100m.  A giant Dutch operated barge with 26 cranes was used to lift it from the seabed.  This was in much shallower waters then where the San Juan has disappeared, yet very costly.

The salvage operation was done with a extremely heavy lift salvage barge and using teams of divers to assist.

One has to look at deep-sea commercial salvage operations to see the complexity and difficulty of even raising small loads, such as recovery of silver from the SS 'City of Cairo', torpedoed in 1942 in the Atlantic.

Tags: #arasanjuan, ara san juan, azorian, dsrv, kursk, mini sub, rov, russian navy, salvage, submarine rescue, us navy, want

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