Cold War Command: The Dramatic Story of a Nuclear Submariner

5 A Very Close Call

In March 1969 Sealion was snorting in deep water to the northwest of Ireland at 10 knots, her maximum snorting speed. She was acting as a sonar target for the first of Great Britain’s Polaris-armed nuclear-powered submarines, the SSBN HMS Resolution, then undergoing her ‘first-of-class’ sonar trials. To avoid any possibility of a collision occurring, the two submarines were separated by depth zones, the Resolution running in the deeper of the two and in a position then unknown to Sealion. At about 0030 Sealion’s first lieutenant was about to hand over the watch to Conley and the weapons engineer. The control room was darkened, illuminated by a few dim red lights.

Suddenly, the after planesman reported that his hydroplanes had jammed to ‘full rise’. He immediately transferred the control of the planes to a separate emergency system and applied ‘full dive’ angle to the hydroplanes which remained indicating ‘full rise’. The submarine, however, adopted a severe down angle and increased depth.

The ‘Stop snorting!’ order was rapped out and the control systems watchkeeper urgently went though the tasks of shutting hull valves, lowering masts and — as part of his standard procedure — flooding the snort induction mast with seawater to avoid it being over-pressured. The forward planesman put full rise on his hydroplanes which limited the down angle to about 25 degrees, but he could not counter the effect of the larger and more effective after planes.

Part of the ‘Stop snorting’ drill on Sealion was to empty two small external compensating tanks using high-pressure air to counter the additional weight of water incurred in flooding the snort mast. Unfortunately, the control systems watchkeeper did this with the tank emptying valves shut and the effect of the high-pressure air caused the reliefs on both tanks to lift with a very loud and explosive report. The reliefs vented through the pressure hull into the control room wing bilges and the pulse of high-pressure air from the port relief forced an alarming jet of bilgewater into the control room. In the darkness and confusion of noise, at first it appeared that an explosion had occurred and the pressure hull had been breached. Spray hit the electrical starter of a pump, causing a second violent blast and a flash. This was followed by a major electrical short-circuit which caused the loss of most of the control room instrument illumination.

The runaway Sealion, with a significant bow-down angle, was going deep at speed. Preoccupied by their fight to regain control of the submarine, the two planesmen had failed to shut off their large shallow-water depth gauges. These registered a maximum of 140ft, which Sealion had long since passed, and now their gauge glasses fractured and more seawater sprayed into the control room.

As Sealion left her safe depth and she entered the depth zone of the Resolution beneath her, Conley manned the underwater telephone and broadcast the alarming report: ‘Going deep! Going deep! Out of control!’ Apart from warning the SSBN of their descent, he was determined that if Resolution was within reception range she would be aware that the Sealion was in trouble. There was, however, no response from Resolution; the Sealion headed for the depths out of control and apparently flooding. Unless the dive angle and speed were reduced Sealion would reach her crush depth within two minutes. Amid the terror induced by this prospect, Conley had the curious thought that it was unfair that this was happening before, and not after, impending visits to Copenhagen, Oslo and Stockholm.

A mid the shouting and confusion the Sealion’s captain had appeared in the control room and ordered the motors to ‘Full astern’. The drag of the reversed propellers gradually slowed the submarine and slowly she levelled out. Much to everyone’s relief, she adopted a bow-up angle and she was again put into ahead propulsion. Unfortunately, Sealion continued to make stern-way and increase her depth. This was because the motor room watchkeepers were having difficulty responding to the ahead order, owing to problems on the main motor control. By torch Conley noted from one of the small deep-depth gauges that at 600ft they were way below the safe depth of 500ft.

In response to the rapidly worsening situation, the commanding officer now ordered ‘Stand by to surface!’ Conley was alarmed to hear the first lieutenant instinctively ordering the manipulating of the main ballast tank vents as part of the normal surfacing procedure. The Sealion was far from being in a normal situation and Conley was fearful that, having opened the vents, they would be prevented from then promptly shutting them, which was vital to enable high-pressure air being put into these tanks to gain positive buoyancy and reach the surface. However, his heart beating and anxious about the state of the vents — were they open or shut? — Conley heard the air rushing into the main ballast tanks. Eventually, after what seemed like a long moment of suspended animation, Sealion began gaining headway as she headed for the surface.

As she approached the surface, the torpedo officer was assigned the duty of surfacing officer of the watch. Unfortunately, in the absence of the large-scale shallow-water depth gauges, it was difficult to judge when the boat had breached the surface. In consequence, the upper hatch was ordered opened while Sealion was still ascending. Fighting to open a hatch still under pressure, the torpedo officer was deluged by a torrent of water as, a moment or two later, Sealion surfaced and he got the hatch open with water still in the conning tower. A few moments later the officers of Sealion not immediately occupied assembled in the wardroom and, most unusually at sea, each had a glass of Scotch.

It was afterwards discovered that the incident had been caused by the failure of the after planes indication system, a defect compounded by the fact that there was only a single indicator in the control room. A further shortcoming was the limitation of Sealion’s deep-depth gauges which registered a maximum 750ft, well short of the 900ft-plus crush depth of the submarine’s hull. Moreover, the small-scale calibration of these gauges made it difficult to determine quickly whether the submarine was increasing or decreasing depth, a situation exacerbated by the emergency. If, like the Affray, the Sealion had been lost, it would have been very difficult to establish the cause, giving rise to numerous improbable conspiracy theories, such as Sealion having collided with a Soviet submarine spying on Resolution.

In fact, Resolution had not been in close proximity and failed to hear Conley’s underwater telephone transmissions. As for Sealion, she carried out repairs on the surface and after a few hours dived and continued with the trial. There was no subsequent inquiry.

Some time afterwards, Conley learned that on the night that Sealion made her uncontrolled dive, his grandmother had a premonition that he had drowned at sea. The following day she sent a telegram to this effect to an aunt of his who lived in South Africa. Although the incident shook up the Sealion’s crew, there had been no panic. At the time, as a twenty-two-year-old bachelor, Conley himself was not personally worried by what had happened, considering it ‘all part of the deal’. On reflection, however, he considered it a sufficiently exceptional incident which had come close to losing the submarine. HMS Sealion could easily have been the fifth Western submarine to be lost between 1968 and 1970.

The Scandinavian visits, over which Conley had inconsequentially agonised in his extreme moment, were to be Sealion’s swansong before paying off into refit at Rosyth. As he had anticipated, they were thoroughly enjoyable, with the crew extremely well looked after by very hospitable locals. For Conley, calling at Stockholm marked a professional high-point in his career thus far, because the mandatory embarkation of a local pilot was frustrated by a strike. Conley therefore personally undertook the long and tortuous pilotage through the skerries of the outer archipelago, a passage in excess of forty miles.

Undertaken in calm conditions, in brilliant, early morning sunshine and passing close to the immaculate lawns of cottages where Swedes were enjoying their breakfasts, it was one of those wonderfully memorable occasions when a salary appeared to be an unnecessary bonus. On arriving alongside in Stockholm, the crew were saddened to hear that the Swedish host submarine had suffered a battery explosion involving fatalities and therefore would not be partaking in the social programme arranged for them.

When Sealion arrived at Rosyth for a long refit in July 1969 her ship’s company was dispersed. Conley was part of this exodus. By the time he left Sealion he had served in submarines for just over eighteen months. His experiences in Odin and Sealion had been sufficiently varied to encourage a feeling of being a seasoned campaigner and to recognize that he had found his métier in life. It was not without some excitement that he learned that his next appointment was to the eight-year-old Oberon, then completing her extensive modernisation at HM Dockyard, Portsmouth. Destined to be a unit of the Seventh Submarine Division, Oberon was under orders to proceed to Singapore and he would, at last, be exchanging the inclement weather of the Western Approaches for the tropical climes of the South China Sea.