The Silent Deep

by James Jinks

  OPERATION ‘AGILE EAGLE’

  A few months later, HMS Sovereign, under the command of Commander Richard Farnfield, surpassed the Batfish’s record by conducting what remains perhaps the longest trail of a Soviet submarine during the Cold War. In September 1978, Sovereign was ordered to track down what was then known as the ‘Eastern Atlantic Victor’, with a secondary aim of locating any Type II or Type III Soviet nuclear submarines in the Eastern Atlantic. Departing on 24 September with two other SSNs, one British and one American, Sovereign’s command team had little experience of trailing using the new towed array and forty-six hours was allocated to practise trailing techniques. The exercise, codenamed ‘Agile Budgie’, was disappointing. Sovereign only achieved six hours of tracking before it came to an end on 28 September.168 The next day, Sovereign began Operation ‘Agile Eagle’ and arrived at her designated patrol area, over 28,800 square miles of ocean, 200 miles southwest of Rockall. For the next five days, Sovereign and the two other SSNs searched the Eastern Atlantic for the Victor, but they found nothing. On 4 October, the other Royal Navy SSN, operating in a nearby area, concluded its patrol and Sovereign was allocated an additional 24,000 square miles to the east. The same day, SOSUS updates indicated that a homeward bound ‘Yankee’ class SSBN was closing from the southwest. Sovereign manoeuvred in to establish contact, but again failed to intercept the Soviet submarine.

  Two days later, on 6 October, a further intelligence report indicated that a ‘Delta’ class SSBN was operating 190 miles to the west of Sovereign’s position. At 2330 that evening Sovereign located the ‘Delta’ and spent three days slowly closing the range. However, just as she approached within forty miles of the ‘Delta’ the complex computer equipment that interpreted the data from the towed array crashed and it took thirteen hours for Sovereign’s crew to get the system working again. During those critical hours, without information from the towed array, Farnfield was forced to switch to Sovereign’s far less capable hull-mounted sonar. Sovereign was unable to regain contact. On 10 October, a UK Maritime Patrol Aircraft indicated that the Delta was continuing along a southwesterly course at a steady speed of 7 knots, and a few hours later a US Navy P3 Orion Maritime Patrol Aircraft reported a firm contact 290 miles to the east. Farnfield ordered an intercept course and Sovereign sprinted 320 miles at an average speed of over 25 knots to re-establish contact with the Delta at 0845 on 11 October, at a range of 63 miles. SSIXS had dramatically improved the way intelligence was communicated to Sovereign. SOSUS information, as well as real-time intelligence, could now be transmitted in time for it to be useful during operations. According to Roger Lane-Nott:

  In 1976 when I was in fleet headquarters running special submarine operations, we reckoned real time was twenty minutes. That was the time in which you got a piece of intelligence, whether it came from an aircraft or some other form of surveillance, and you were able to turn that around and relay it to our submarines. Remember, we were transmitting on teletypes on very-low-frequency radio to submarines at that time. Assuming they were at periscope depth or had a wire out to receive it, twenty minutes was a pretty amazing timescale to get a piece of information that the submarine could use when they were chasing another submarine.169

  Farnfield was able to inform headquarters that he was trailing the Delta at 1529 on 11 October and an acknowledgement was received on VLF some forty minutes later, ‘a very impressive example of the effectiveness of the SSIXS Communications system,’ he wrote.170

  Sovereign settled in to the trail of the Delta some 650 miles off Cape Finisterre. It continued southwards until 16 October, when it altered course to the southwest, and then again southwards. On the morning of 20 October, Farnfield broke off the trail temporarily and ordered Sovereign to periscope depth in order to transmit and receive signals. At 1043, after Sovereign had dived back down to continue the trail, the Delta unexpectedly began to clear its stern arcs, by conducting a routine manoeuvre practised by all nuclear-submarine commanders in order to ensure that they were not being followed by another submarine. In Royal Navy submarines, the Type 2001 sonar only provided main sonar coverage about 120 degrees either side of the submarine’s bow. This meant that 120 degrees through the stern and 60 degrees on either side were not effectively covered by broadband sonar. In order to check these blind spots submarines would slow down and clear stern arcs at infrequent intervals. In the Royal Navy this manoeuvre was carried out in two ways. The first was to swing 70 degrees one way, sweep the arc for contacts before swinging 140 degrees the other way, clearing that arc before resuming course. This was often used when the submarine was on a fast passage and did not want to lose speed. The second method involved slowing down and swinging 140 degrees either to port or to starboard, clearing both stern arcs before resuming the original course.

  Soviet submariners practised another method, the so-called ‘Crazy Ivan’, which involved reversing course, swinging around 180 degrees and hurtling back down their original path at full speed while searching for any trailing submarines using active sonar. This was exciting and testing for the trailing submarine, and Command teams had to take swift action in order to avoid a close-quarters scenario, counter-detection or, even worse, a collision.171 As the Soviet Delta cleared stern arcs and proceeded to head back down its previous course, it passed approximately 800 yards down Sovereign’s starboard side. Despite the extremely close range, Sovereign remained undetected. There was a complete lack of subsequent evasion or reaction by the Delta and it quickly resumed course. This was not unusual. The Royal Navy enjoyed such superior sonar advantage over Soviet submarines that throughout the 1970s its own boats were often able to conduct their patrols without being counter-detected. The counter-detection capability of the ‘Victor’ class on a Royal Navy ‘Valiant’ class was estimated as a factor of 0.5 or less.172 Given the improved silencing techniques used in the ‘Swiftsure’ class, Sovereign most likely enjoyed a far superior capability over the Delta.

  By 25 October, the Delta was some 400 miles west of the Cape Verde Islands, which lay 350 miles off the coast of West Africa. Back in the United Kingdom, news of the trail was circulating throughout Northwood. Both the Commander-in-Chief Fleet and Flag Officer Submarines informed Sovereign via personal signals that the patrol, which had been due to end on 3 November, was being extended by forty-two days, and would probably end no later than 15 December. ‘This was because of the exceptional interest being shown on both sides of the Atlantic in the Delta’s unusual deployment,’ wrote Farnfield. After the initial shock had worn off, Sovereign’s crew reacted in a relatively philosophical manner. Everyone on board was inconvenienced in one way or another; one crew member was due to be married in November and four ratings had paid for their Christmas holiday in Miami. Food rationing was introduced, which resulted in a bread and soup lunch, no choice for dinner, and progressively lighter breakfasts. The Chefs carefully designed the menu around remaining stocks, calorific values and presentation. Milk, sugar and coffee were steadily reduced and canteen stores soon ran out, with matches and toothpaste the two most needed items.

  The patrol was now so important that Sovereign was assigned a new patrol area, the entire Atlantic south of 10°N. But just as she was settling into the trail, events took a turn for the worse. On 26 October, Sovereign’s unreliable communications mast became defective. With no second mast with a UHF capability, Farnfield was forced to reverse Sovereign, open the range up to 40 miles and surface to repair the mast. After seventy-five minutes on the surface, the defect was remedied and communications were re-established. Sovereign dived and sprinted to restore contact with the Delta, which had once again altered course. When contact was made again, the Delta was conducting what Sovereign’s crew assumed was a bottom contour survey of the seabed over an area within a radius of 10 miles. This was valuable intelligence, as it appeared the Delta was carrying out a survey so that the position could be used as an SSBN reference point for bottom contour navigation. This proved to be the southernmost point
of the patrol, as the Delta soon turned 180 degrees and headed north.

  By 2 November, Sovereign had continuously (with one short interruption) trailed the Delta for twenty-two days. She remained in contact for another ten, after which the patrol entered its most difficult period as acoustic conditions deteriorated when a Force 6–7 gale chopped up the seas. On 16 November, Sovereign unintentionally passed between 3000 and 4000 yards from the Delta. As conditions continued to deteriorate, contact with the Delta was lost at 1323 on 20 November. Sovereign then spent the next three days searching, without success, attempting to determine the Soviet submarine’s likely route. It looked as if the Delta would cross the George Bligh Bank, around 100 miles northwest of Rockall, but after searching for twenty-two hours Sovereign’s crew concluded that the Delta had chosen a different track. By reviewing all the available intelligence, as well as the alternative routes available, Farnfield concluded that the Delta would probably keep to the west of the Iceland–Faroes Gap. Sovereign moved seventy miles southeast of Iceland and waited.

  Sovereign had now been on patrol for over two months. To pass the time the various available distractions became very well tried, including quizzes, card games, domino competitions, films and reading, although Farnfield complained that Sovereign’s ‘library was substantially comprised of paperbacks which were rarely man enough to endure the re-reading incurred’ and he later urged that it was ‘imperative to put the procurement of a ship’s library onto a firmer basis’.173 Sovereign had also developed a number of defects, the most serious of which concerned atmosphere control. High freon levels had started to build inside the submarine and by 26 November there was insufficient nitrogen pressure to start up Sovereign’s second electrolyser after it had been stopped to repair a defect (the other had been defective early in the patrol). For three days Farnfield was forced to bring Sovereign to the surface for forty minutes and ventilate to keep the amount of oxygen at a reasonable level.

  After she had waited patiently for twenty-two hours, the gamble paid off. At 1103 on 24 November Sovereign regained contact with the Delta and after careful manoeuvring resumed the trail, following the Soviet submarine from 15–20 miles away right into the Arctic Circle, observing it alter course to the northeast and remaining in contact as it loitered in the Barents Sea. In order to avoid ventilating while trailing near Russian waters, Sovereign’s crew started to burn the hundred emergency oxygen candles carried on board. As the Delta crossed longitude 25°E in the Barents Sea, Sovereign broke off the trail after receiving orders from the UK and withdrew to the southwest. She continued through the Shetland–Faroes Gap to the west of the UK and surfaced in the southwest approaches on the evening of 5 December. A day later, at 0930 on 6 December, she berthed alongside at Devonport, concluding what Farnfield described as ‘a most challenging, testing, wearying and successful operation’.174

  From initial detection on 6 October until the trail was broken on 1 December – a period of eight weeks – HMS Sovereign travelled 10,724 miles and remained in contact with the Delta for a total of forty-nine days, forty of which were spent continuously in the trail. The Royal Navy now held the record for the longest trail of a Soviet submarine. ‘It was hard work,’ wrote Farnfield, ‘and for all the Forward Watchkeepers who were keeping watches one in two for over seventy days it was physically and mentally tiring, particularly for the Officers and Ratings most closely involved in the trail.’175 The Patrol was also important for Northwood. ‘This proved once and for all that [CTF] 311 was totally capable and set up ready to do this and could support any type of operation,’ recalled Lane-Nott, ‘the fact that we had the communications there and the intelligence and weather people upstairs and 345 down the road, we had the ability to share all the information, that was very important.’176

  It was now clear that a Royal Navy SSN, fitted with the new towed array and narrowband frequency analysis equipment, was capable of maintaining a trail on a quiet Soviet nuclear submarine for a sustained period of time. ‘The passive sonar towed array … may well be the most important single development in ASW sensors since 1945,’ commented Rear Admiral Hill in a 1984 assessment of ASW.177 Sovereign obtained valuable electronic and acoustic intelligence, particularly about how a Soviet commander operated a ‘Delta’ class SSBN while it was on patrol. Perhaps most importantly, the Royal Navy and the US Navy had now obtained a detailed track of a patrolling Soviet ‘Delta’ class. They knew the speed and depth at which it operated, where and when it adjusted course (by 40 degrees every 24–36 hours using a long-leg zig-zag), when the Soviet commander carried out a check of his stern arcs (at least every four hours, sometimes as often as every two hours), and when the submarine came up to periscope depth (between three and six times daily), as well as the various navigational methods employed (bottom contours for navigation). These patrol observations were not treated in isolation. They were fed into an overall picture that the West was building about Soviet naval movements and tactics and in particular about Soviet SSBN operations.

  ASSESSMENTS OF THE SOVIET NAVY

  By the late 1970s, that intelligence picture had allowed the West to assess the strengths and weaknesses of the Soviet submarine fleet as a whole. Despite its weight in numbers there were many differences between the Soviet and Western philosophies and approaches. In October 1978, the MOD’s Sea/Air Warfare Committee conducted an audit. The Soviets’ strengths were:

  a. Command and Control. The Soviet Navy has developed a centralised command and control system, with secure and rapid communications, enabling close control to be exercised over submarines at short notice …

  b. Satellite Targeting. Soviet reconnaissance satellites, using radar, EW and photography, make it progressively more difficult to conceal the presence of multi ship formations at sea. They still have a major data handling and collation problem to solve, but if they can do this they will have a command and control system offering a much increased ability to direct their submarines. It is now a realistic Soviet aim to develop real time satellite targeting for their SSBN/SSG missiles.

  c. Speed. Soviet design has put a premium on speed. With the top speed of the VICTOR at 32 knots and the YANKEE/DELTA at 27 knots most Soviet nuclear submarines have a speed advantage over their Western opponents.

  d. Resistance to attack. Soviet submarines are designed with double hulls. Together with their thick deep diving pressure hulls, this considerably reduces their vulnerability to impact and proximity explosions.

  e. Anechoic coatings. Most Soviet submarines are fitted with either an 8cm or 10cm anechoic coating which may in some conditions reduce the homing range of active torpedoes by up to 40% and the detection ranges of active sonar by up to 30%.

  f. Anti Ship weapons. Soviet submarines have effective and reliable anti ship missiles and torpedoes with large warheads.

  g. Minelaying. All Soviet submarines have the capability to lay mines.178

  Despite these apparent strengths, Soviet submarines had a number of weaknesses that could be exploited by Western submarines:

  a. Noise. Soviet radiated noise levels are generally higher than for corresponding Western nuclear SMs. They are estimated to be some 10 years behind the SWIFTSURE Class in noise reduction, which makes them considerably more vulnerable to detection by passive systems.

  b. Sonar. Sonar and noise reduction are closely linked, giving Soviet submarine passive sonar a low level of performance. Analysis of encounters between UK and Soviet submarines indicates a sonar range advantage of 2 or 3 to 1 to the UK.

  c. Navigation. It is believed that the Soviet SINS needs frequent independent navigation checks; that the Soviet SATNAV system is inferior to the US system; and that Soviet submarines rely heavily on bottom contour navigation which necessitates the use of echo sounders liable to detection.

  d. Communications. Although the Soviet command and control is generally a strong point, Soviet submarines do not appear to use floating wire aerials and are only just beginning to use communication buoys. This eq
uipment deficiency constrains the submarines to frequent periods at periscope depth. Furthermore the rigidity of the Command and Control system, particularly its probable requirement for exchange of communications during tactical missile firing, may offer detection possibilities. Soviet information transfer systems have, of course, the same inherent vulnerability to jamming as similar Allied systems.

  e. Training. 60–70% of Northern Fleet submarine ratings are conscripts serving only 3 years. It must be a problem of some magnitude to produce and sustain the high operating standards needed in nuclear submarines; and this tends to be borne out by the simple nature of many exercises carried out with the minimum of freeplay.

  f. Experience and Tactical Proficiency. Some Soviet SMs have recently demonstrated an improvement in tactical expertise, but with only 15% of any class on patrol at one time and few major Fleet exercises, general operational competence is not high by Western standards.179

  The overall intelligence picture also led to some troubling conclusions. Throughout the 1970s, the US and UK developed just one type of nuclear submarine each: the ‘Los Angeles’ class and the ‘Swiftsure’ class. In the same period, the Soviets deployed eight different classes, many of which departed from mainstream design. One of the most advanced was the Project 705, later designated the ‘Alfa’ class, whose appearance puzzled Western intelligence agencies. In the UK, the JIC was certainly aware of the existence of what a 1972 assessment of the Soviet Navy described as the ‘A’ class SSN and that it had been delivered to the Northern Fleet. But the 1972 assessment stated that the ‘Alfa’ had ‘not yet been evaluated’ and that it was ‘expected to have a performance better in some aspects, than the V’.180 The United States mounted a considerable intelligence effort against the submarine. Many analysts refused to believe that the Soviets had departed from a basic philosophy that underpinned Soviet submarine development, one based on steady evolutionary advances in design and steadily improving tried technologies. The West believed that when it came to submarine design, the Russian’s adhered to a basic philosophy: ‘to build and create things good enough to do what they were meant to do was considered wise; to make them better than necessary was a waste of energy and precious resources’.181 Indeed, an old Russian proverb, Better is the enemy of good enough, was apparently inscribed on a plaque on the desk of the chief architect of the Soviet Navy, Admiral of the Fleet Sergey Gorshkov.