From the late 1940s the United States Navy deployed submarines on intelligence-gathering operations in the seas off the main Soviet Union naval bases in the Barents Sea and in the Western Pacific in the Sea of Okhotsk and off Vladivostok. Submarines operating covertly in the midst of Soviet naval forces provided hard intelligence which could not be gained by satellite surveillance. Furthermore, unaware of the intelligence-gathering submarine’s presence, the Soviets undertook weapon tests which otherwise they would not have carried out in the overt presence of a NATO warship or aircraft. Besides gathering information on Soviet weapons and tactics, an objective of these operations was to provide early warning of a military build-up which could be a precursor to hostilities.
A submarine has several intelligence-gathering techniques at its disposal using visual, electronic and acoustic equipment. The underwater hull survey is a particularly challenging procedure, whereby a submarine takes station right underneath a ‘target’ warship as she makes way through the water, positioned below her keel at a depth where the raised periscopes are about 15ft below the warship’s hull. Moving along the length of the hull, very close visual observation is gained of its features including sonars, propellers and other underwater fittings. This technique can also be employed on ships at anchor, but the anchor cable is an obstruction which clearly has to be avoided. If attempting this on a surfaced submarine there is also the risk of it diving unexpectedly on top of the observing submarine.
During intelligence-gathering missions, some occurring at close range, it was inevitable that collisions happened, particularly between two submarines. These may have amounted to no more than a glancing blow, but severe damage was sometimes inflicted. Despite these high risks, no submarine has been lost in this way, nor is it believed that any fatalities have been incurred. Nevertheless, an unexpected underwater collision is a very alarming experience to those involved.
The Royal Navy started to participate with the United States Navy in the Barents Sea operations in the 1950s and in due course extended their intelligence-gathering to Soviet naval forces in the Baltic and Mediterranean. For diesel boats the long snort passage to the Barents had its own challenges. In the winter months their crews incurred the stress of prolonged periods at periscope depth, conducting surveillance in conditions of near permanent darkness and in often violent seas. The control room watchkeepers worked in a very dark environment, the only illumination being their faintly red-lit systems and equipment dials. To allow their eyes to adjust quickly to varying levels of lighting, off-watch officers endured living in constant red lighting in their wardroom for weeks on end.
Events which occurred during these operations, routine or otherwise, were and still remain very highly classified, tightly controlled and not discussed even within the submarine community. However, inevitable leaks of information occurred from time to time within naval circles, for example the presence of HMS Sealion off Nova Zemlya in the early 1960s to gather information upon Soviet nuclear bomb tests.
In 1968 a Royal Navy SSN was for the first time committed to Barents Sea operations. Unlike their American colleagues, the Royal Navy designated a single specially-equipped submarine for the task, rather than affording a number of submarines the experience. Fitted with specialist listening and observation devices, this practice allowed the nominated British submarine crew to build up expertise in intelligence-gathering in these Arctic waters while minimising the additional costs incurred in the equipment fit.
The first British SSN dispatched on this task was HMS Warspite. In October 1968 she was involved in a collision with a Soviet Echo-class missile submarine. The Russians subsequently reported that their submarine was operating normally when it suddenly began listing to starboard, its hull shaking. The boat was consequently rapidly surfaced, whereupon her commanding officer spotted another submarine’s silhouette through his periscope. With the conning tower hatch jammed, the crew used a sledge-hammer to open it, and it was several minutes before the commander could climb to the bridge, by which time the stranger had disappeared. Back at base, Soviet repair crews discovered a hole in the Echo’s outer casing, described as so large that ‘a truck could easily have driven through it’. On the basis of identifying navigation light remnants and some metal fragments stuck in the wreckage, the Soviets concluded that they had been hit by a foreign submarine. Meanwhile, Warspite limped back to Faslane with a badly damaged fin and the cover story that she had hit an iceberg.
In due course Warspite was replaced by Courageous as the designated and specially-fitted submarine for operations in the Barents Sea. During one patrol, whilst gathering data on an anti-ship missile firing, the latter’s specialist Russian linguists, who were tuned into the radio frequency of an attendant destroyer which had VIPs embarked, reported extreme alarm onboard the destroyer when in error the missile hit it instead of the target barge. After Courageous there has been at least one Swiftsure- or subsequently Trafalgar-class boat designated for Barents Sea intelligence-gathering operations.
Among the nations of the NATO alliance, this elaborate game of cat and mouse was not solely the preserve of the British and Americans. Norway, Germany, the Netherlands and Australia have also conducted submarine intelligence-gathering patrols, demonstrating their own considerable achievements with remarkable resilience and skill.
Apart from the gathering of very valuable and exclusive intelligence, the experience of patrol operations provided NATO nations’ submarine crews with invaluable training, manifesting the West’s will and ability to confront successfully Russian naval forces in war. Indeed, it is remarkable to consider the West’s submarines were the only element of its military forces which during the Cold War operated undetected as close as five yards from the opposition.
By the 1970s the Soviet Navy was much larger, more capable and had truly global reach. Besides maintaining a substantial permanent naval force in the Mediterranean, with normally a large number of naval warships anchored off Libya, the Russians periodically deployed significant numbers of submarines into the Atlantic, demonstrably projecting their own sea power and potentially seeking out NATO SSBNs. Moscow also established a network of intelligence-gathering auxiliaries, known as AGIs, stationed off naval bases of interest. These invariably shadowed Western naval forces when they were undertaking major exercises. Almost permanent residence was taken up off Malin Head, the most northern point of Ireland, by one such auxiliary, its purpose to monitor American submarines proceeding to or from their depot ship in the Holy Loch, and British boats on passage to or from Faslane and the Clyde.
The Russians also embarked upon a very comprehensive oceanographic research programme, gathering extensive hydrographic and ocean features information, constructing and operating a large number of oceanographic research vessels to achieve this. Besides enhancing the ability of their own submarines and ships to exploit the environment to the best strategic and tactical advantage, the programme potentially offered methods of detecting the West’s submarines other than by acoustics, including wake detection or disturbance of the sea’s micro-organic structure. However, achieving successful detections using such methods remained elusive.