THE US NUCLEAR SUBMARINE PROGRAMME
The US nuclear-propulsion programme started just after the war, when a team of officers was sent to the Oak Ridge nuclear research plant, their leader being an obscure electrical specialist who was due to retire shortly: Captain Hyman G. Rickover. More by luck than judgement, the US navy had placed the right man in the right place at the right time: the acerbic and energetic Rickover overcame initial official indifference, and the first two nuclear-powered attack submarines (SSNs),
Nautilus
and
Seawolf
, were launched in 1954 and 1955 respectively. Their overall designs were generally similar, the main difference being that in
Nautilus
the reactor was cooled by pressurized water, while in
Seawolf
the coolant was liquid sodium. The former quickly proved its superiority, and all subsequent US nuclear-propelled submarines have had such a reactor, while
Seawolf
itself was changed to a pressurized-water system in 1959. Despite their prototype status, these first two submarines were used as operational submarines, and they were followed by four smaller boats, the Skate class (2,584 tonnes), which were commissioned in 1957–9 and remained in service until the mid-1980s.
These first six SSNs all had the traditional long, thin hull and twin propellers of the German Type XXI, but in the early 1950s the US navy examined the whole question of submarine shape and manoeuvrability, and tested the conclusions with one of the most influential submarine designs of all time, the
Albacore
. This diesel-electric boat had a ‘teardrop’ hull (i.e. it was shorter and fatter than the traditional design), new types of control, and a single propeller. The shape of the hull not only made the submarine much more manoeuvrable, but also gave a great increase in internal volume, resulting in a much larger battery and thus much greater submerged speed: initially 27 and later a remarkable 33 knots.
The immense success of this experimental design led to a new SSN class with an ‘Albacore’ hull, the Skipjack class, of which six were commissioned between 1959 and 1961. These were, however, quickly followed by the Thresher class, which were larger and had a stronger hull, enabling them to dive to greater depths, and a much improved sonar, mounted in a dome which fully occupied the bows. Eleven Thresher-class SSNs were built, followed by forty-two of the slightly different Sturgeon class, all with a primary ASW mission.
Just as this massive programme was getting under way, however, the US submarine service suffered a major blow with the loss of
Thresher
on 10 April 1963. The submarine was undergoing routine diving tests with 104 crew and
twenty-five
observers aboard when it experienced what it reported as a ‘minor problem’, but shortly afterwards it dived out of control, lost communication with the surface, and imploded as it neared the seabed. This loss led to a total re-examination of the SSN design, resulting in delays in the construction programme, but improvements were made and building restarted.
fn3
The Skipjack-class submarine
Scorpion
was later lost, also with all hands, off the Azores in May 1968. These have, however, been the only losses in the US nuclear-powered-submarine programme.
Finally came the Los Angeles-class SSNs, which were commissioned from 1976 onwards and continued in production throughout the remainder of the Cold War, until the sixty-second was commissioned in 1995. They were designed for three principal missions. The first was anti-submarine warfare, in which these boats would have patrolled off Soviet ports, in choke points and in the Soviet SSBN bastions, with the task of tracking Soviet submarines in peacetime and tension and of sinking them in war. The second role was to serve as part of an aircraft-carrier task group, particularly to detect and attack Soviet cruise-missile-launching submarines. The third role was as covert signals-intelligence (SIGINT) and electronic-intelligence (ELINT) surveillance platforms.
These boats displaced 6,260 tonnes and were equipped, like the previous Permit/Sturgeon class, with a sonar which occupied the entire bows, so that the four launch tubes had to be mounted amidships, firing outwards. The original weapon load was twenty-six torpedoes, but there were various changes. First it was decided to add SubRoc (an anti-submarine missile), then Sub-Harpoon (an anti-ship missile), and finally, from 1983 onwards, Tomahawk land-attack cruise missiles. All these missiles were carried internally, were launched from the torpedo tubes and had to be within the overall total of twenty-six,
fn4
which made the question of weapon mix for each patrol a matter of nice judgement. This problem was, however, later alleviated when it was found possible to locate twelve vertical launch tubes for Tomahawk outside the pressure hull but within the outer casing, which enabled the original torpedo load to be restored.
Differences in weapon load were, however, only an outward indication of improvements, since the Los Angeles class also improved dramatically internally during its nineteen-year production run. Analogue fire-control and sonar systems gave way to digital systems, new silencing methods were introduced, while from
San Juan
(SSN-751) onwards numerous changes were incorporated, including moving the foreplanes from the sail to the bows (to ease surfacing through ice in the Arctic), as well as a new integrated command system.
Not surprisingly, such highly effective weapons platforms were very expensive. Sample figures for a single Los Angeles-class submarine (in ‘then-year’ dollars) were $225 million in 1976, $326 million in 1979 and $844 million in 1983.
SOVIET NUCLEAR-POWERED ATTACK SUBMARINES
With the commissioning of the first US nuclear-propelled attack submarines in 1955, NATO naturally looked for the arrival of the first Soviet SSN, and the first November-class boat,
Leninsky Komsomol
, duly ran on nuclear power on 4 July 1958, some three years after its US counterpart. Despite having watched so carefully for this event, however, Western intelligence was still taken by surprise when three different types of nuclear-powered submarine all appeared within a year of each other: a ballistic-missile class (Hotel) a cruise-missile class (Echo) and an attack class (November). All were powered by the same propulsion system, consisting of two separate power trains, each with a 70 megawatt reactor and a single turbine set driving a motor-generator; there was also a creep motor on each shaft. This propulsion system was known as the ‘HEN’ power plant in the West (derived from the initials of the NATO reporting names, Hotel–Echo–November). As can be seen from
Appendix 19
, this system was somewhat unreliable in its early days, resulting in numerous accidents and a large number of deaths and injuries to the crews.
Like the early US SSNs, the November class had been designed along the lines of the German Type XXI, with a long, thin, figure-of-eight-section hull and twin propellers, but with the next class, the Victors, Soviet designers changed to a shorter, body-of-revolution design with a single propeller.
fn5
As in most navies, the naval staff was very reluctant for change, and it took some time for the design bureaux to persuade the naval leadership that this was the best way ahead. In the end, forty-nine Victor-class SSNs were built, to three slightly different designs.
fn6
At this point the Soviet navy sought to make a major leap in design practice by replacing the high-grade steel traditionally used in hull construction with titanium, to produce a submarine capable of diving to a depth of 700 m. Designated the Alfa class, this new design also had a very high-powered and highly automated propulsion system, which gave it a very high maximum speed. A submarine of this class created consternation in Western navies when it ran under a NATO task force at a speed in excess of 40 knots and
then
dived deep, indicating a performance which contemporary Western ASW ships, sensors and weapons could not begin to match. The Soviet programme was very expensive, but it also compelled the West to initiate some even more expensive programmes, to deal with it, including faster and more capable surface ASW ships, ASW helicopters, faster submarines, and faster, deeper-diving torpedoes.
The Soviet navy next developed two new designs in parallel – a practice already observed in ICBM development, where a radical design was backed up by a second which was more conventional and less risky technically. In this case the more advanced design was the Sierra class, which had a titanium hull, and was both fast (35 knots) and deep-diving (700 m or more). It was also the quietest Soviet SSN yet produced, but it was also extremely expensive, and the programme was cancelled after four had been completed. The parallel design was the Akula, which had a steel hull and was considerably cheaper; sixteen were produced before production ceased after the end of the Cold War.
THE UK
As in the USA, early British design work on nuclear power plants for submarines started during the Second World War, but it was given a low priority and eventually the British purchased US propulsion technology, resulting in
Dreadnought
, which was commissioned in 1963. This was followed by five of the slightly larger Valiant class, commissioned between 1966 and 1971. One of these,
Conqueror
, established a record as the first (and so far the only) nuclear-powered submarine to have sunk an enemy ship in battle, when it dispatched the Argentine cruiser
General Belgrano
on 2 May 1982, during the Falklands War (although it had to use two Mark VIII torpedoes of Second World War vintage to do it). Subsequently, a very small number of British SSNs patrolled off the Argentine coast and not only were able to confine the Argentine navy within its national territorial waters, but also were able to give early warning of Argentine strike aircraft taking off from shore airfields and starting offensive missions towards the Falkland Islands.
After their slow start, and despite the smallness of their SSN fleet, the British introduced some innovative design features, including the pump-jet propulsor and anechoic (sound-proofing) tiles, and claimed that their SSNs were the quietest in any navy. Six Swiftsure-class SSNs were commissioned between 1973 and 1981, followed by seven of the improved Trafalgar class between 1983 and 1991.
The tasks of British SSNs included countering Soviet SSBNs in their bastions, operations in choke points (e.g. the Greenland–Iceland–UK gap)
and
ensuring the safe departure and return of British SSBNs from their base in the Clyde.
FRANCE
Although the first French SSN programme was started in 1964, it was then postponed so that all efforts could be devoted into getting SSBNs into service; only when that had been achieved did France turn to developing SSNs. The four Rubis-class boats were commissioned between 1983 and 1988; displacing 2,670 tonnes, these were the smallest operational SSNs to enter service in any navy, and were also reputed to be the noisiest.
CANADA
The only other Cold War country to give serious consideration to SSNs was Canada, which in the 1980s needed to replace three British Oberon-class diesel-electric submarines which had been purchased in 1965–8. What started out as a fairly simple and modest project rapidly turned into a large, sophisticated and extremely expensive undertaking, principally because the Canadians wished to establish proper control over their northern waters. The eventual requirement was for twelve SSNs, and not surprisingly France and the UK fought tooth and nail for the order. The project eventually came to naught, but only after much money had been spent without a single piece of hardware to show for it.
fn1
The snorkel tube was actually invented by the Dutch navy in the 1930s, to enable submarines in East Indies waters to recharge their batteries without exposing themselves to the tropical heat.
fn2
The Soviet navy carried out experiments in the late 1930s with the
Kreislauf
air-independent propulsion system, which used liquid oxygen as the source of oxygen for submerged propulsion. It was later used in a class of post-war submarines.
fn3
With the loss of the original name-ship, the class was then officially redesignated the Permit class.
fn4
There was also a sub-limit of eight on Tomahawks.
fn5
A body of revolution is one which is symmetrical about its main axis – e.g. an Indian club or a baseball bat.
fn6
Specifications of Soviet SSNs are given in
Appendix 20
.
18
Diesel-Electric Submarines
DIESEL-ELECTRIC SUBMARINES, WHICH
were also known as ‘conventional’ submarines, played a significant role in the Cold War from the very start. When NATO became operational in the early 1950s the Soviet surface fleet was generally considered to be of minor importance, since it had achieved little of strategic significance during the Second World War and by the late 1940s most of its ships were obsolescent, if not obsolete. The Soviets were outnumbered in every category, and had no ships at all to match the West’s aircraft carriers and amphibious shipping. There was, however, one area in which they were believed to pose a significant threat: that of attack by diesel-electric submarines on Allied sea lines of communication across the Atlantic. With the memories of the German U-boat attacks in the north Atlantic still fresh, this perceived Soviet threat became one of the driving influences in NATO fleet development and deployment throughout the Cold War.
Fortunately for the Allies, the revolutionary new German submarines, the ocean-going Type XXI and the coastal Type XXIII, were only just entering service as the war ended, but there was no doubt as to their excellence. Both were real submarines, whose natural habitat was below the surface and which surfaced only when forced to do so. Compared with its predecessors, the Type XXI had a stronger and much more streamlined hull, a larger battery and new control systems which enabled it to fight underwater, and its snorkel tube enabled it to recharge its batteries while remaining submerged. Its underwater speed of 17 knots made it faster than most contemporary ASW ships, especially when there was bad weather on the surface. The Type XXIII was a smaller, coastal equivalent; it too was fast and capable, although its value was limited by its ability to carry only two torpedoes.