British submarines "spied on" Northern Ireland

HMS Cachalot 

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Flowing from yesterday’s article here is a rare case of country carrying out operational submarine surveillance of its own territory.

The account below was published at Spanish language website https://www.elsnorkel.com/ on May 10, 2020 at the link https://www.elsnorkel.com/2020/05/operaciones-especiales-submarinos-britanicos-conflicto-Irlanda.html

It was written in Spanish by  Law Professor Mariano Sciaroni [his details are below the article] from Argentina and translated into English at Submarine Matters. Pete has added a large number of links with additional explanation.in square [brackets]. 

“Special Operations British submarines in the Northern Ireland conflict.”

“In the early days of 1975, an order from the Clyde [Submarine] Naval Base (Flag Officer in Scotland and Northern Ireland - FOSNI in charge of operations) arrived at HMS Cachalot (a Porpoise class diesel-electric) submarine, to bring on board special forces for a mission. The code name for the Operation was Awless.”

The conflict in Northern Ireland [known as “The Troubles” for public relations reasons and to avoid  the "war" exclusion that would have rendered Northern Irish property insurance policies valueless!] was in full swing in the mid-1970s. It must be remembered that the warring factions were the unionists (mostly Protestants), who wanted to remain tied to the United Kingdom and, on the other hand, the republicans (Catholics), who were a minority in the population and advocated an independent Northern Ireland. and/or uniting it with the Republic of Ireland.

In 1969 the British Army had intervened (within the framework of Operation Banner), which was initially received as a guarantor of peace against the various armed arms of the opposing communities. However, the deaths of unarmed civilians by 1 PARA (1st Battalion, Parachute Regiment) on “Bloody Sunday” (January 30, 1972) had led to a rejection by the Republican population of what was quickly considered a [British Army] force of occupation and [which “backed’ the Protestant unionist cause]. This led to increased Catholic support for the Provisional Irish Republican Army (PIRA).

In a complex conflict, Operation Granada (a code name for patrols of Royal Navy and Royal Marine elements in support of army units) began to gain its own momentum. Their presence in the vicinity of the Northern Irish coast had a dissuasive purpose in general, but also a concrete utility, which was to prevent weapons, ammunition and explosives from reaching the [Protestant and Catholic paramilitary] combatants by sea.

British submarines were no strangers to that operation.

HMS Cachalot (SSK), Operation Awless, Jan 1975

“In the early days of 1975, an order from the Clyde [Submarine] Naval Base (Flag Officer in Scotland and Northern Ireland - FOSNI in charge of operations) arrived at HMS Cachalot a Porpoise class diesel-electric submarine (SSK), to bring on board Special Boat Service (SBS)
commandos for a mission. The code name for the Operation was Awless.”

Intelligence had been received information that the PIRA was planning to land weapons on the coast in the near future, with indications of the possible areas where this would occur.

The orders received implied that the HMS Cachalot had to set sail with 6^th Squadron Special Boat Service (SBS) commandos, who would disembark from January 11, 1975 near Torr Head in three small canoes (or kayaks) and would be recovered on the January 16, 1975 in the vicinity from Garron Point. The submarine was to remain in the vicinity until the SBS commandos returned. The operation was extremely secretive (this was emphasized at all times) but, as the PIRA was deemed to lack the ability to intercept electronic emissions, the discreet use of the submarine's radar was authorized.

A Sea King helicopter section of the 819 Naval Air Squadron would be on alert for any problems that might occur during the operation.

Once ashore, the commandos were to analyse possible enemy landing zones in the area (Group X, four men), as well as establish an observation post (Group Y, with the two remaining men).

HMS Cachalot finally set sail from its usual base in Faslane, Scotland, without further complications and, after a short navigation, arrived at the area of operations at night on January 11, 1975. There, at a distance, HMS Cachalot made a first distant reconnaissance of the landing area (on the surface and without navigation lights), with the SBS commandos observing the coast with their [then rare] night vision goggles and, just later, a periscope reconnaissance was carried out at a very short distance (less than a mile from the coast).

However, the bad weather and a rough sea complicated the kayak launching phase (which was carried out with HMS Cachalot on the surface), making it clear that the launches needeed to be made at two different points off the coast.

While the Group Y kayak was able to be launched in marginal conditions and HMS Cachalot headed for its next launch point, the first of the Group X kayaks rolled over. The mission having to be temporarily aborted until the kayak and the men were recovered. The weather was so bad that it was only possible to disembark the members of Group X on January 14, 1975 at 23.54 hours (London time). HMS Cachalot withdrew from the shore, remaining submerged.

The recovery phase, which had been postponed to the early hours of the January 17, 1975, was not easy either. HMS Kirkliston a Royal Navy Ton class minesweeper almost collided with HMS Cachalot when he at periscope depth. HMS Kirkliston was not alerted to the presence of HMS Cachalot or the SBS, and (such was the secrecy) that the sub and SBS were not authorized to contact HMS Kirkliston. Problems from the SBS on the ground led to only two kayaks showing up to be picked up by HMS Cachalot. Meanwhile the remaining members of the SBS patrol were exfiltrated by ground means (ie. they hitched a ride with a surprised civilian who drove by in a vehicle! :).

Despite all these problems (including that one of the SBS had to be hospitalized with “Trench foot”), HMS Cachalot’s commander considered the mission "very successful".

The Submarine Force Commander (FOSM) had the same opinion, but he also indicated that many of the dangers faced could be avoided in the future by having his submarines with an image intensifier in the periscope (such as it was being developed for the Swiftsure-class nuclear attack submarines (SSNs)) and thus be able to carry out shoreline reconnaissance at night.

The Force Commander's appreciation was quickly received and the Oberon-class submarine (successor to the Porpoise class) HMS Osiris was entrusted to conduct a patrol with an image intensifier in late July 1975.

HMS Osiris (SSK) Operation Artelot, July 1975

The January 1975 Operation had been codenamed Awless, but the Commander-in-Chief of the Fleet quickly asked for a name change for post January operations to Operation Artelot, to avoid confusion.

However, Operation Artelot was doomed from the start. The radio equipment on the HMS Osiris and the communications plan were deficient, without a direct channel of communication with military or police forces that could immediately exploit the intelligence the submarine obtained.

HMS Osiris arrived at the area of operations on July 24, 1975 and began to carry out reconnaissance and surveillance of the coast, using the two periscopes (observation and attack) at night and sporadically using the [thinner, therefore harder to see by arms smugglers] attack periscope during daylight hours. The [relatively new, therefore problem prone] night vision equipment was deficient, only being able to detect a darkened target within 1,000 yards. In all cases, the MAE [surveillance?] equipment was also exposed, as well as [any weapons smuggler] HF and VHF communications monitored.

It is worth adding that HMS Osiris withdrew from the coast in the afternoons on the July 25 and 26, 1975 to recharge batteries using its snorkel.

The only suspicious contact occurred at 21.00 (9pm London time) on July 27, when two small motor boats were detected in the vicinity of Red Bay and, although at first they were taken to be fishermen, a second glance found that they had no fishing equipment. Also, a small white light came from the shore, appearing to be a signal to the two motor boats.

But the boats were already long gone when a message from HMS Osiris was received by military and police forces informing them of this rare situation. HMS Kirkliston was sent to investigate, but it was too late.

However, being a moderately successful operational concept, the mission was repeated between November 16 and 18, 1975, using the submarine HMS Opossum [another Oberon class sub]. But HMS Opossum had the same problems with communications as its twin HMS Osiris.

[Despite clearly little progress...] By the end of 1975 (which had turned into a particularly bloody year in the Northern Ireland conflict), the Flag Officer Submarines (FOSM) Force Command considered such patrols to be an "appropriate use of resources", recommending to the commander in command of the fleet to continue with them, even to the detriment of other scheduled operations.

HMS Cachalot returns, Operation Aver, Jan 1976

HMS Cachalot was then appointed again for a new covert surveillance patrol to prevent arms and explosives trafficking in the conflict zone. As an improvement on the two previous operations, emphasis was placed on the security and speed of communications with the various ground units. This was achieved by mounting a radiotelephone on the submarine.

In this way, Operation Aver started January 1976. HMS Cachalot did not have important contacts, despite the fact that it monitored several merchant ships and the fishing fleet that operated in the vicinity of its designated area. HMS Cachalot had the support of the Ton-class minesweeper HMS Bildeston. 

The communications did not fail, and the reports of those involved mention the improvement in the command and control of operations, as well as that the coordination worked perfectly. FOSNI considered that Operation Aver "successfully tested the changes recently introduced for the command and control of submarines used in support of Operation Grenada." Submarine missions in support of Operation Grenada continued until the late 1970s and possibly later.

An interesting use of submarines for coastal surveillance, in the context of a low intensity conflict.

A lesson for the present and future.

Mariano Sciaroni is a lawyer, has a Master's in Strategy and Geopolitics and a postgraduate course in Contemporary Military History from the Argentine Army's Superior War College. He is also a member of the Argentine Institute of Military History. He is professor of procedural law at the Faculty of Law of the Argentine Catholic University and Reserve Lieutenant of the Argentine Army. He has published two books and dozens of articles on military history, published in Argentina, the United States, the United Kingdom, Germany, and Russia. [and, of course, is a Contributor to elSnorkel . com]

More Mariano Sciaroni Articles here.   Email: marcantilan (a) yahoo.com.ar 

A short account of HMS Cachalot, the SBS and Troubles surveillance is here.