To the Submarine Service these new boats restored morale and offered something in the way of parity with the surface Fleet which in recent years had benefited from the introduction of several new classes of destroyer and frigate fitted with modern sensors and weapons. This question of morale was of considerable importance in view of Wilson’s major shift in government policy. To undertake the stewardship of the nuclear deterrent required an elite force, not a run-down arm of a shrinking Navy which had found it difficult to adapt to its peacetime roles and was regarded with low esteem by some in the surface Navy.
The rundown from the high-stress pitch of the war to peacetime conditions had had a profound effect upon morale which reached a nadir when HM Submarine Affray was lost in the English Channel in April 1951. Although at the time this had been attributed to the failure of her snort gear, the cause of her loss, be it human error or material failure, has never been established. Bad enough as this was, the Affray’s loss was made far worse because she had on board an entire class of officers under training and these circumstances were held to be a contributing factor towards a culture of hard drinking within some elements of the corps of submarine officers.
Ten or more years later there remained a small but significant number of commanding officers who, having started their careers in this low period, drank excessively when in harbour. These men failed to exhibit those professional standards expected of naval officers, let alone submarine captains, and were regarded askance by their subordinates. Thus when Conley’s group of officers under training were dispersed from Dolphin and posted to their submarines, they were to discover that the best commanding officers had been selected for the new nuclear boats. In a number of cases, those who remained in diesel boats were in the last phases of their careers and although many of these men commanded a perverse respect on account of long service and experience, several were inadequate for the task, and had very limited tactical or war-fighting ability.
As for those commanding officers selected for the nuclear programme in command or at executive officer (second in command) level, many were to find their new charges very challenging. Contending with the much more complex task of being in command of a nuclear submarine required of them qualities which a fair proportion lacked; consequently, they found it difficult both to delegate responsibility and to exploit the full capabilities of their new, and much more capable, charges.
In 1967 the Flag Officer Submarines (FOSM) was Rear Admiral Ian McGeoch, who as a wartime submarine commander had lost one eye when HM Submarine Splendid was sunk in the Mediterranean. Many other senior officers had very accomplished war records, such as McGeoch’s successor, Rear Admiral John Roxburgh, who had commanded his first submarine at the age of twenty-two. Such men exuded an undoubted aura of experience and professionalism, but there was a world of difference in offensive submarine operations in the Second World War, which was a young man’s type of war where a touch of the bravado in the character was an essential for success, and the qualities necessary to command a nuclear submarine in the Cold War. The new Submarine Service was moving away from being a peripheral, semi-piratical organisation, regarded by the rest of the Fleet with a mixture of envy and affectionate scorn for its raffish disregard for the full panoply of naval protocols. The new, nuclear-powered Submarine Service was taking over the mantle of the nation’s sure bulwark. Its ships’ companies might cling to the anachronism of calling their submarines ‘boats’, but these were Great Britain’s new capital ships.
Conley’s training class consisted of twenty officers, including two Australians. Of the British officers on the course, four, including Conley, would eventually command submarines. Over time the others would leave the Submarine Service or the Navy either from choice, for reasons of health, such as degradation of eyesight, or unsuitability.
From the outset, these men were instructed in the detailed principles of how a submarine works by being able to vary its displacement. With her machinery, crew accommodation, power plant and weaponry contained in a central pressure hull, varying her displacement requires the filling and emptying of ballast tanks external to the pressure hull. On the surface its ballast tanks are kept full of air, providing positive buoyancy; to submerge, vents are opened, air escapes and is displaced by water. The vessel’s displacement increases and she slips below the surface in what amounts to a controlled sinking. In addition to the main ballast tanks, there are also several variable seawater-filled compensation tanks inside the pressure hull which enable the submerged boat to be maintained precisely in a state of neutral buoyancy. In normal conditions this means she is trimmed horizontally fore and aft, providing a level platform for her crew. The content of these supplementary tanks is carefully adjusted prior to diving to ensure, as far as possible, that the submarine is neutrally buoyant: too little weight of water in these tanks will make it difficult for the submarine to submerge; and too much will result in loss of depth control when submerging. In the case of a conventionally powered submarine, prior to diving her diesel engines are shut down and her propulsion shifts to her battery-powered electric motor.
Once underwater, depth is changed by applying a bow up or down angle to the boat through the use of hydroplanes, one set fitted forward in the bows, the second set aft and close to the rudder. Older boats controlled both these hydroplanes and the rudder using separate handlebar levers, but modern submarines use a single or twin joystick. This arrangement is not dissimilar to an aircraft’s controlling joystick. As a submarine goes deeper her hull compresses quite significantly, decreasing its displacement and making it vital that ballast water be pumped out in compensation for the increased negative buoyancy. To surface, high-pressure air retained in immensely strong compressed-air cylinders is blown into the ballast tanks where it expands, ejecting the ballast water, positive buoyancy being regained and the boat rising.
All combat submarines operate in a relatively shallow stratum below the surface of the sea, those of Western navies up to maximum safe depths of less than 1,500ft (455m) although some of their Soviet counterparts could operate significantly deeper down to greater than 3,000ft.
Some of the Royal Navy’s older post-war boats were restricted to a safe depth of little more than 350ft, not much of a margin greater than the length of the hull. If a submarine goes below its safe depth through flooding, total loss of power or a high-speed uncontrolled dive, the boat risks crushing by the immense pressure of the sea with the loss of all on board. This point of no return is known as her ‘crush depth’ and is normally a factor of between one and a half to twice her safe depth. High speed can involve steep boat angles in excess of 30 degrees in both axes and, accordingly, nuclear submarine crews are taught ship control in three-dimensional trainers very much akin to those used for aircrews. Should a nuclear submarine be proceeding at depth and high speed when a catastrophic failure of her hydroplanes occurs, if these happen to be in the full-dive position, the crew must react very fast indeed to avoid the boat exceeding her crush depth.
For most of the Second World War, all submarines of all the belligerent powers had one thing in common: they were designed to operate on the surface the majority of the time. The low available speed underwater when under electric power deprived them of most of their tactical advantages beyond the obvious one of being out of sight. For this reason, German U-boat operations against Atlantic convoys commonly occurred in darkness and were often made by limiting the dived period during an approach to a convoy to ducking under the sonar search area of the leading escorts. Once inside the screen they could surface and attack several targets as the cumbersome merchantmen steamed past in their columns, before submerging under the tail of the convoy where the sea was churned by the passing wakes, further confusing the sonar operators of the rear escorts. To counter this, the escorts preferred to prosecute a U-boat well beyond the immediate vicinity of the convoy. In response, towards the end of the conflict the Germans came up with the expedient of operating at periscope depth under diesel power, drawing air into the U-boat using a raised intake, a pipe they called the ‘schnorkel’, anglicised to ‘snorkel’ or later, when adopted by the Royal Navy, ‘snort’.