"Hands to Action Stations" Royal Navy 1983 Covert Submarine Operations Off Argentina...

 

It was 0830 local time on Friday 11 March 1983. Off the coast of Argentina, south of the Valdes peninsula the Argentine A69 patrol frigate GUERRICO was proceeding south at 17kts on a covert patrol, all her radars powered down, and operating under ‘EMCON silent’ procedure. Unknown to her ships company though, the GUERRICO was being stalked by the Royal Navy submarine HMS OSIRIS, closed up at action stations and tracking the warships every move as she conducted secret intelligence gathering patrols off the Argentine coast…

In the aftermath of the Falklands War in 1982 the Royal Navy established an ongoing commitment to deploy submarines to the region to monitor Argentinean military activity, gather intelligence and provide a credible military deterrent to any renewed aggression. The war itself had proven the value of submarine operations, with both nuclear and conventional submarines deployed in roles ranging from special forces support, covert reconnaissance and intelligence gathering of Argentine airfields and more conventional anti-shipping, for example the sinking of Belgrano and the near attack on the carrier 25 De Mayo. The war was a textbook example of how the superbly trained Royal Navy submarine force could have a strategic effect on the conduct of operations.

They Come Unseen (Crown Copyright)

Popular imagination has the narrative is that after being defeated, Argentine forces left the islands and returned home, a broken military unable to pose a threat or conduct military operations again. In fact, reviewing documents from the post war period, its clear that the threat was assessed to be significantly higher than we now popularly realise. To meet these concerns, the Royal Navy was tasked to continue to be ready for war against Argentina, long after the conflict had ended.

After the end of the war most of the RN task force rapidly returned home, but the decision was taken to keep an SSN on station to provide support to the Commander British Forces Falkland Islands (CBFFI) as necessary. This was deemed adequate at first, but intelligence reports indicated a possible change in threat. Accordingly, on 24  January 1983 Michael Heseltine MP, the newly appointed Secretary of State for Defence:

“agreed that the SSK HMS OSIRIS should be temporarily deployed to the South Atlantic to augment the SSN already on station. This was in a response to a request from CBFFI, in the light of intelligence assessments of a heightened Argentine threat, it was felt to be important to boost our submarine surveillance capability in the area.

SofS informed the Prime Minister of this on 26 January, indicating the position would be kept under review, with the aim of reverting to the agreed force level as soon as circumstances permitted, given the strain on SSK resources”.

The ‘O’ Boats were arguably the finest conventional design ever used by the RN and a hugely important asset for submarine operations. In UK service for over 30 years, they deployed globally carrying out a diverse range of missions from conventional submarine patrolling to special forces work (such as in the Gulf War) or intelligence gathering operations (such as OP SCOOP involving covert photography of Soviet warships in the Med in the late 1960s). It’s a measure of how capable the boats were that they were active participants in both the Falkland’s and Gulf wars, far from home water.  HMS OSIRIS was an OBERON class submarine, commissioned into the Royal Navy in 1964, and serving until 1989. During the 1982 conflict she was deployed in the minelaying role and presumably certain other tasks too. Given the task at hand, namely to monitor and build an intelligence picture of the likely threat posed by the Argentine Navy in the early months of 1983, HMS OSIRIS was the perfect platform for the mission.

HMS OSIRIS

Sailing from the UK, OSIRIS was tasked to conducted dived surveillance operations off the coast of the coast of Argentina, arriving in theatre on 27 February 1983. Her mission was to patrol international waters from 12 - 40 miles off the coast of Argentina, trying to build an understanding of normal pattern of life and collect intelligence on any military platforms in the area. According to her patrol report, the official requirement was to:

“proceed directly to an area adjacent to the Bahia Balance – Mar De Plata coastline to carry out surveillance of shipping routes, monitor air traffic of the regional military airports and gather intelligence on the Argentinean 209 SSK class based in Mar De Plata”

OSIRIS initially spent 10 days operating off the Mar Del Plata, a major base for the Argentine Navy, and home to their submarine force and major surface combatants. Her patrol report notes that:

“these operations were carried out at periscope depth in shallow water between 15 and 40 miles off the Argentine coast. The seas were generally calm, and heavy bioluminescence, clear water and a sandy bottom added to the operating hazards”

In other words, while OSIRIS was a stealthy platform, she was operating in conditions where an alert enemy would potentially detect her, and leave her with very few places to hide.  

According to the patrol report, navigation was conducted by using sextants and star navigation (the DECCA navigation device was not used after Ascension Island). Of particular note was the comment that:

“Visual fixes were obtained off Mar Del Plata and between Cabo Rama and Punta Castre. Shore lights and looms from navigational devices were seen at ranges of up to 39 miles. Various buildings in Mar Del Plata were visible at 19 miles during daylight”.

Lets pause for a moment to reflect on the breathtaking audacity here of the Royal Navy. Just 6 months after its victory over the Argentine Navy, British submariners were conducting covert intelligence patrols in international waters, using the land features of the coast of Argentina for navigation purposes. The idea that on a clear day, the Royal Navy was observing the premier Argentine naval base through a periscope from less than 20 miles away,  covertly collecting intelligence from shore and without anyone knowing they were there, is a great reminder of what Royal Navy submarines can do when required. They excel at going to far off places, acquiring great holiday photos and returning without anyone knowing they were ever there…

HMS VALIANT

For most of this patrol period relatively little of note occurred, although the report comments on the sheer scale of merchant traffic off the Mar Del Plata. However, two incidents occurred of particular interest. The first was that at roughly 1115 in the morning, while around 50 miles east of Mar Del Plata OSIRIS had a sonar contact at 43,000 yards range to her south. Covertly moving closer into position, she was able to visually identify the contact as the Argentine navy icebreaker ALMIRANTE IRIZAR.  The IRIZAR entered service in 1975 and participated in the war, and remains in service to this day.

In 1982 though, she was covertly tracked by HMS OSIRIS, which closed to a range of roughly 7000 yards and “a good sonar recording was made” of her two shafts and four bladed propellors turning 158 times per minute. The ship showed no sign or awareness that she was actively being stalked by a Royal Navy submarine, and carried on track to the north at a speed of 12kts, blissfully unaware that she had presented the perfect firing solution to a covertly deployed SSK which had monitored her until she was over 50,000 yards away.

The second incident occurred a couple of days later when HMS OSIRIS was at periscope depth on a course of 240 conducting a coastal sweep off the Argentine coastline. Her Type 2007 sonar picked up a contact at roughly 20,000 yards, and the periscope search spotted a single mast providing visual contact. Closer tracking revealed itself at roughly 8,000 yards to be a warship, and at 5000 yards, was confirmed to be an A69 corvette. At this stage:

“the submarine went deep to 120 feet… a good sonar recording was made with OSIRIS presenting a stern aspect to the target”.

The patrol report notes that the OSIRIS stayed deep until the target warship was some 5000yards distant, at which point she began covertly identifying the vessel. The report noted that from an intelligence perspective, good recordings were made of her propulsion system (“2 shafts, 4 blades, revolutions 174, diesel and blade flutter audible”), while it was also noted that the vessel had no pennant number visible making confirmation of the specific vessel harder. Contact was lost at 10,000 yards.  The report noted that from an intelligence perspective:

“Initial classification by attacker was of a one shaft four blade merchant vessel. Average detection of such contacts has been at 35-40k yards. The A69 is obviously a quiet vessel with initial detection at only 20k yards.

No intelligence on warship movement was available, however target later identified as GUERCIO, the target of Lieutenant Mills blowpipe missile (sic) at South Georgia…

OSIRIS was not detected… This Argentinean warship was conducting a covert transit to the south in the direction of Puerto Deseado. She was at high speed operating no radar and sonar silent EMCON policy”.

The CO’s daily patrol write up perhaps understates the sense of challenge that this encounter had though. In it he noted that the ship had gone to Action Stations and that:

“late detection at a range of 17.5k yards and first classification at 8k yards gave me little opportunity to manoeuvre. A rather exciting 40 minutes in contact”…

It is quite astonishing to consider that barely months after the war, one of the primary combatants in that conflict, which took a bloody nose during the Royal Marines heroic defence of South Georgia (when she was hit by hundreds of rounds of fire and an 84mm Carl Gustav anti-tank missile) was once again being stalked by the Royal Navy…  Incredibly GUERRICO remains in reserve to this day, although at almost 50 years old, her military value is now likely to be negligible at best.

ARA GUERRICO

The rest of the patrol passed without notable incident, and on 7 March OSIRIS was tasked with ‘Coastal Surveillance Operations’: “Tasked with HMS VALIANT to carry out a daylight coastal surveillance sweep from Mar Del Plata to Cabo Blanco”. The report is very light on details as to what OSIRIS did during this period, beyond a side comment noting that:

“while on patrol off Trelew a Skyhawk and later an S2E Tracker were detected”

One can only imagine the response had the Argentine Naval Aviation force which operated the Tracker for ASW purposes if they realised that they had overflown a pair of British nuclear and conventional attack submarines lurking just off their coastline conducting covert intelligence gathering missions and were being actively tracked by the Royal Navy.

The rest of the patrol appears to have passed with little incident (at least from the publicly available files) and the intention was to bring the OSIRIS home once intelligence indicated that the threat had changed. There was clear disappointment that they were unable to complete their primary mission of tracking the Type 209 SSK:

“in the event both 209s remained alongside and only after HMS OSIRIS was proceeding south in the next phase of the patrol and was some 250 miles from Mar Del Plata did SALTAS put to sea. The lack of opportunity to locate and monitor the 209 on this occasion may be compensated for in the next patrol when HMS OSIRIS returns to the area with a Towed Array”.

This of itself is a fascinating snippet into UK intelligence capabilities in Argentina in 1983 – given that no submarines were on task off the main naval base, it implies that other forms of collection (perhaps satellite based imagery intelligence) or other feeds were available to provide timely updates on the movements of the Argentine Navy in this period. It’s a good reminder to those who worry about the risks of a ‘sneak attack’ on the Falklands today that the UK clearly has exceptionally good intelligence capabilities in place to monitor Argentine military movements, which have been covertly observing the Argentine armed forces for decades and which would give significant advance notice of any new threats emerging.

The plan originally was to withdraw OSIRIS from theatre quickly, although in Whitehall there was some debate about this. In a submission to Secretary of State for Defence it was noted that although deployed as a contingency against increased threat:

“ there has, in the event, been no noticeable increase in the Argentinean threat…

SofS may also like to know that the anniversary of the sinking of the GENERAL BELGRANO (2 May) coincides with the next SSN HANDOVER (from HMS VALIANT to HMS COURAGEOUS). CBFFI will therefore have two SSNs in the area over this period”.

Originally it was intended to release OSIRIS and send her home, working on the assumption that if the threat did change, then two SSNs would provide a reasonable level of defence. However, by April 1983 things were changing, and there were growing concerns about the risks to the Islands again. In a memo to ACDS Commitments, it was argued that:

“The strain on submarine resources in meeting our other operational commitments and tasks argues strongly for returning HMS OSIRIS as soon as the operational situation permits.

However, I understand that some major Argentine naval activity is in prospect. While there are no indications that this has aggressive intent, for intelligence gathering reasons alone, it would seem sensible to retain the SSK on station while the activity continues”.

What we can deduce from these files is that in the early 1980s post war period then, the Royal Navy was maintaining a very significant and capable submarine presence off the coast of Argentina at all times. This was used to carry out surveillance patrols, build an understanding of electronic intelligence, monitor shipping routes and deploy into Argentine naval exercise areas to actively sit in, and observe their naval exercises. Its probably fair to say that for much of the early 1980s, most major Argentine Navy exercises almost certainly had Royal Navy observers covertly present under the sea, watching, recording and listening.

Patrol Chart

We know that HMS OSIRIS returned to the Falklands on patrol, as did other O Boats, and it seems likely that this commitment was maintained for many years. Documents also indicate that it was policy that an RN SSN was based in the region for “50% of the year”. By 1991 the agreed force level in the South Atlantic was intended to be a destroyer/frigate, an OPV and an SSN for 6 months of the year, and one permanently at 14 days notice to sail as well as appropriate support services. This included routine deployments of the Fleet Repair Ship RFA DILIGENCE to support the forward based SSN as required. There is no mention made of an SSK being required for this role. The task for the SSN included:

“Submarine orders should include an appropriate level of overt operations during these patrols to demonstrate commitment and deterrence”.

But in the late 1980s things became more challenging. The Royal Navy SSN force was paralysed by the discovery of reactor faults, known as the ‘trouser legs’ issue, that reduced the forces seagoing availability while serious risks in the reactors were addressed. This issue, coming at the tail end of the Cold War saw many older SSN’s paid off ahead of time, and others kept in port while their reactors were repaired. Although mostly forgotten today, at the time this issue effectively destroyed the ability of the RN to get nuclear submarines to sea for a long period of time, and only the most high priority operations (e.g support to CASD) were approved due to the risks identified in sending the SSN force to sea.

The end of the Cold War meant a sudden and significant culling of defence spending, seeing the reduction in size of force numbers, particularly submarines as the old OBERON class paid off and the UPHOLDER replacements capped at four boats (not the 12 previously planned).  The impact on the Falklands was significant, it meant that by 1991 the RN was struggling to justify getting submarine coverage in the region, which by 1991 had reduced to 42% of the time (assessed as being in each financial, not calendar year). In a memo to MINAF, it was noted:

“Because of the reduction in SSN availability due to the continuing trouser legs problem and the early rundown of Submarine numbers under Options (for Change), there are increasingly serious difficulties in meeting the 42% commitment. In short given the size of the future SSK fleet, it will no longer be feasible to plan on deploying SSKs to the South Atlantic after the end of this year. To meet the requirement with SSNs would account for a disproportionate amount of all SSN availability; there would be serious impact on operational effectiveness, training (including a further setback to Trident requirements), NATO and national exercises and commitments”.

It was clear that by the early 1990s, the days of the RN maintaining a submarine on station most of the time had come to an end. It was also clear that the military situation really did not necessitate it, with plans put forward in the early 1990s to remove the escort ship for 6 months of the year, essentially only being in theatre during the main Argentine Navy exercise season. Additionally, SSN deployments were becoming more challenging due to the need to maintain RFA DILIGENCE as the ‘Z Berth’ vessel able to support the deployment, given the many different demands on her time by other submarine deployments elsewhere.

ASTUTE Class Successor (MOD Crown Copyright)

The agreement was therefore reached that the military value of the submarine presence was incredibly low. It seems that alternative sources of intelligence collection were available, reducing the need for coastal surveillance patrols, and that the main purpose of the SSN was not of itself to carry out intelligence work, but rather to serve as a visible deterrent to Argentina, which would not know when the submarines were in the area. This led to the conclusion that from the early 1990s it would be possible to reduce submarine coverage to between 15-25% of the year, albeit with regularly planned sighting opportunities.  The final word on the (publicly available) nature of the subject comes from a SECRET memo which states that:

“While the amount of time on station will no longer be specified in advance, I intend to ensure that an adequate level of presence is maintained. There will be at least one patrol in Falklands waters each year, and an appropriate number of sighting opportunities will be presented to ensure our deterrent posture”

This highlights the interesting challenge of submarine operations – they are incredibly valuable assets and very powerful means of shaping behaviour, but paradoxically once you know and understand your theatre of operations, and once the threat level is sufficiently low, their military value on that task becomes questionable. If your capability relies on its overtly being ‘detected’ to send a message, that in turn raises questions about whether a submarine is the best asset needed in theatre or not.

It is many years since a British SSN publicly visited the Falkland Islands. Thankfully the vastly reduced threat level and change in relations means that the need for a large military presence has long diminished. The threat is minimal and the value of an SSN deployment here, versus elsewhere is relatively low – as the Russian bear begins to growl again, the Royal Navy force of ASTUTE class SSN’s are needed in colder northern waters, and not the South Atlantic. But the fact that the RN has spent many years operating off the Argentinean coastline, and has long experience of working near their ports suggests that were intelligence to indicate a threat looming, then an SSN could deploy on station if required to carry out deterrence patrols again. It may be many years since attack periscopes broke the surface of the waters off the Mar Del Plata, and used coastal features for navigation purposes, or stalked Argentine warships in their exercise areas, but unless you have the ability to find and track SSNs, you can never be certain that when you put to sea, someone else may be watching…