“We overestimated our intelligence.” At the start of any campaign it is a military cliche that an honest commander will have to admit that be was inadequately informed about the enemy. The latest to join this distinguished company is Admiral (William J.) Crowe (Jr.), Chairman of the U.S. Joint Chiefs of Staff, who made his confession last September when talking about the damage to merchant shipping caused by Iranian mines laid from an assortment of transport vessels, and by small arms carried in the first patrol launches of the Revolutionary Guard. It isn’t easy for those educated in the atmosphere of superpower confrontation between ships and submarines of unimaginable firepower to take seriously either horned mines that look as though they had escaped from an exhibition of WWII memorabilia or men in open boats with hand-held rocket launchers. We can be sure that the admiral’s advisers knew about the mines and the small craft, but in the deluge of information available they failed to isolate what proved to be the most important elements at the start of the u.s. Navy’s involvement, and my guess is that the mining expert was unable to make himself beard above the roar of SILKWORMS, EXOCETS, and midget submarines.
The same problem of too much information, too many choices, confronts almost every aspect of naval affairs, starting with equipment procurement and selection of weapon systems and moving on through command and control and tactical data handling. To find a path through this jungle you need experts, which means people with previous experience of all aspects of the particular problem which you are trying to resolve. And yet so much second-hand information is available that men of intelligence and goodwill who have no knowledge of the sea still feel competent to make judgements and choices, buoyed up by the sheer volume of indiscriminate or “selective” evidence with which they can be presented by the products of modern information technology. The trouble is, of course, that many of the experts are also people with a vested interest in the preservation of the status quo plus a little bit better and a little bit more, so providing a readily available rationale for those who wish to undermine or supplant their judgements in the competitive struggle for budget priorities. But whereas there may be justification for turning to independent advice to balance special pleading, in the end it is essential to trust the judgement of those who have first-hand knowledge of the environment, regardless of suspicions about their motives. This seems to me particularly important in maritime affairs where the scale of events is so easily distorted by focusing on small-scale maps. To a generation brought up with the daily images of satellite weather photography allied to the certainty of being able to fly anywhere in the world in a few hours, the whole maritime scene is as though viewed through the wrong end of a telescope. The sea is still as vast as it was in the days of Raleigh and Columbus because ships still move at a speed which both of those two global explorers would have no difficulty in recognizing. If you leave Portsmouth harbour (the English one that is) and take the second turning on the right as depicted on the TV weather map you finish up in the Norwegian Sea; in reality you would be up the creek in Southampton Water less than 20 miles from your point of departure. Perhaps to the professional sailor one of the few satisfying aspects of the Gulf war has been the education of at least a section of the western media into the difficulties of identifying radar contacts in what is by oceanic standards a tiny area of sea. Naval spokesmen don’t always help themselves in explaining their time and space problems by talking about barriers and choke points. Bottling up the Irish sea to prevent submarine egress seems a comparatively simple business as an abstract idea. At the northern end there are just less than 15 miles between Scotland’s Mull of Kintyre and Northern Ireland’s Rathlin Island, and yet such are the sonar conditions in that stretch of water that detecting a submarine by the most modern of active or passive acoustic devices generated difficulties which by comparison make even the identification of the Pasdaran launch in the Gulf a relatively easy task. Much of the ill-informed comment on the vulnerability of ships to shore-based air attack could be countered by releasing a statistical analysis of the efforts needed by planners to ensure that contact of any kind is made between ships and aircraft during exercises even quite close to the airbase concerned; and a warship’s ability to launch “for exercise” surface-to-surface missiles against lighthouses or other non-offending bits of a coastline, to say nothing of friendly and neutral shipping, is remarkable even when not subjected to the stress and fog of war.
There is both above and on the surface of the sea today a hopeless imbalance between the range to which weapons will go and the firing platform’s ability to be certain of its target, hence the pressures for better third-party targeting, improved IFF identification equipment (well, almost anything would be an improvement), more computer-based automation (as though this will somehow alleviate the situation), and greater communications compatibility between ships of different countries who may find themselves being greater danger to each other than to the enemy. In an extreme case, an exchange between two detached task group units might go like this: “Request send your helicopter to identify the radar contact bearing due north range 30 miles from me.” “On my plot the contact 30 miles to the north of you is me and my helicopter is at this moment refuelling on your flight deck.” The possibility exists that in war this exchange might have been preceded by a missile fired in panic. Such difficulties ought to be containable by improved data-link capability which, with the need to control active electronic emissions, becomes more and more important, but air and surface-plot compilation is subject to a range of human frail-ties even in an environment free of electronic countermeasures. If the theorists are correct, in the future the task unit commander described earlier could ask the all-seeing satellite to identify his unresolved contact, which is an application of what is described as “real-time targeting by satellite.” Such a thing is possible now under trial conditions in carefully chosen scenarios and within a benign electronic environment; but applied to the sandstorms of the Gulf, the darkness of northern Norway, the gale-lashed Atlantic, or major shipping routes anywhere in the world, satellite targeting on demand is an arm-chair fantasy believed in only by those who do not know the sea or who have been so long away from it that they have forgotten the reality. Straying into unknown territory myself, I would venture that leakproof ballistic missile defences come into much the same category of self-interested science fiction. But, if by virtue of the size of the ocean and the largest identification problem, and not least because of its own passive and active defences, the modern well-run task force or air defence ship is not as vulnerable to hostile long-range air attack as its detractors would like to believe, there is lurking in the depths a far greater problem, and that of course is the nuclear-powered attack submarine (SSN).
There is probably more nonsense talked and written, at every level of classification from Top Secret to the washington Post, about anti-submarine warfare than any other military subject. The major navies are under few illusions about the power or the nuclear submarine, but a profitable anti-submarine industry has developed which is dedicated to understating their decisive potential as ship killers and trying to convince itself that as a threat the SSN is containable. In spite of the millions or dollars spent on acoustic equipment improvements in the last 20 years, it is no secret that passive sonar detection ranges which were always unreliable are now decreasing as well, and the laws of physics combined with the structure and contents or the oceans have got active sonar developments in a vise-like and short-range grip. Very low frequency transmitters have some potential but mobility and fire control complexities are always going to limit practical application. Non-acoustic devices are equally flush with development funds and even less productive in achieving anything like a guaranteed area search capability. Meanwhile, the weapon delivery potential or these underwater cruisers continues on a steadily rising curve of improved performance in payload, range, and lethality. As they dive deeper and go raster and the hulls get stronger, the difficulties or a successful counter attack are further compounded. So far, only one SSN has fired a shot in anger and the sinking or the GENERAL BELGRANO effectively excluded a navy with relatively unsophisticated anti-submarine capabilities from the remainder of the Falklands War. But supposing the Argentines had had three or four SSNs, would Britain with all its anti-submarine expertise have sent the task force in the first place? And supposing Iran had a couple of modern SSNs out there in the Indian Ocean, would the U.S. battleships have been so readily deployed? And if you can convince yourself that the answer to those two questions is still “yes,n how about taking a carrier attack group into the Norwegian Sea in the face or 90 or so Soviet nuclear attack submarines?
NATO navies subscribe to the principle of layered defence against air attack. The first layer is to attack the air base, which like every-thing else that is static is genuinely vulnerable; there are no certainties in weapon systems’ effectiveness, but now that the earth’s surface has been mapped from space with such accuracy, and firing platforms know precisely where they are themselves, the one really easy target is the one whose geographical coordinates can be punched into the computer and no allowance needs to be made for movement during weapon time of flight. That is real vulnerability because all the difficult fire control solution problems — search, detection, classification, localization, target motion analysis — don’t exist. The fixed target survives only if its defences are better than the attacker’s weapons or it can quickly be repaired after the attack. So, having had a go at the air base, the second line of defence against air attack is to use shore-based interceptor aircraft on those rare occasions when geography is in your favour and the aircraft can be spared from other tasks. Much more cost-effective in this role are carrier-based fixed-wing aircraft because the mobile airfield can be positioned to allow maximum effective use of precious flight time, control is exercised at the scene of action, and response is immediate and not dependent upon uncertain long lines of communication. The third line of defence is the area surface-to-air missile fired by the specialized air defence ship and further augmented by the close-in hard-kill weapons such as SEASPARROW and VULCAN PHALANX which are now fitted in most warships of corvette size and above. Finally, there is the whole armoury of so-called soft-kill systems — including deception devices, decoys, and jammers – – which force the attacking aircraft and its “intelligent” weapon to make instant judgements if the weapon is to find the intended target, always supposing the aircraft has first arrived in the right area. In summary, the maritime air-defence business requires coordination, alertness in short bursts, and fast reactions.
By contrast, the anti-submarine battle is conducted at a slower and more deliberate tempo. Unlike the aircraft, the submarine is independent ot its base for weeks at a time and the use of depot and support ships adds further mobility. So, although the shore base is still an attractive and easy target, a preemptive surprise attack would be necessary to catch the submarines alongside. In transit, the nuclear submarine is more at risk than at any other time because much of the detectable radiated noise is augmented by speed, and at the same time the submarine’s own sensors are dulled by flow noise. Nonetheless the ocean is vast, there is no underwater sensor remotely equivalent to radar, and the submarine wishing to avoid detection can make the complex environmental water structure work to its advantage. Then once on patrol the nuclear submarine can use its mobility and endurance to search, detect, shadow, and attack at a time and a place largely of its choosing against a defence less alerted than will normally be the case with air attack.
And what about the effectiveness or ASW in depth? Can the same attrition factors be expected as in layered air defence? The trouble is that all anti-submarine search systems depend on the vagaries of sound propagation in a noisy and unreliable medium. In the early days both passive and active sonars relied upon noise or echo returns being above ambient or background sea levels. The first breakthrough was the application of correlation techniques which enabled selected broad-band frequency noise to be recognized even though it was below ambient levels. The principle was the same as that of the human ear being able to detect someone speaking its owner’s name below the noise level or a crowded room. Then came narrow-band frequency analysis which allowed specially tuned receivers to pick out, focus, and magnify individual or discrete sounds which at the bottom end of the frequency spectrum travel greater distances through water the lower you descend the frequency ladder. By good fortune such noises were common to the propulsion and auxiliary machinery of the early classes of nuclear submarines, as they are to surface ships, but because the submarine operated alone, and often in deep-water channels, conditions were better for the propagation of noise than in the surface layer or duct. That was the good news; the bad news was that reception was unreliable, being affected by such things as depth of water, temperature, salinity, surface weather, the target submarine’s aspect and depth, the amount of machinery it was running, and in addition there had to be an open or clear acoustic path between target and sonar receiver, a path which could be interrupted by circumstance, for instance shallow water or a noisy ship in the vicinity, or by countermeasure devices. Whether the passive sonar receiver is installed in another submarine or towed behind a surface ship or monitored from an aircraft or from shore, all these difficulties apply and even when a detection is achieved it provides only a single line of bearing, and the lower the frequency, broadly speaking, the less accurate that bearing will be, hence the need for long hydrophone arrays.
The really bad news is that all the detect-able noises can be virtually eliminated by better design and operating techniques, so closing the so-called passive sonar window, and at the same time jamming and deception devices are being developed to disrupt further this already fragile acoustic environment. There is still some potential gain to be made in improving sensitivity circuits and computerized target recognition equipment and it seems probable that this may buy a bit more time. Also, because the technology has been operating in conditions which need human skills of a high order, it takes years to build up operator expertise and adequate training facilties. To expect to be able to buy a towed sonar array and go out and detect so-called “noisy” nuclear submarines is to misunderstand the nature of the problem. The state of the art amongst those navies with experience of low-frequency passive sonar equipment is that spectacular ranges can be demonstrated as having been achieved on carefully selected occasions, but even then detection, when it happens, is often not continuous and may not always lead to attack criteria being accomplished; as the primary method of anti-nuclear-submarine warfare the passive sonar has never been reliable, its capabilities are frequently and wilfully exaggerated, and tor all the efforts or modern technology the situation is now steadily deteriorating.
So, of the two primary threats to surface shipping, multiple air attacks can be contained if the defence is adequately equipped and well organized, and in the worst case of multiple raids has carrier-borne fighter aircraft and an action data automation system approaching the capacity of the AEGIS system. It also helps the defence if the airbase can be disrupted, an option not exercised in the last major campaign at sea in the South Atlantic in 1982. There can be no such confidence in the outcome of the underwater battle, where the nuclear submarine’s mobility and stealth give it such a decisive advantage over surface forces. Of the other elements of the maritime battle none has the same obvious potential for major impact as air defence and anti-nuclear submarine warfare, but all of them could be decisive in some circumstances. Mines have had much publicity recently both in the Gulf and in the Red Sea and can cause great inconvenience and much loss of shipping. But, as with the diesel-powered submarine, which is a formidable type of advanced mobile intelligent floating mine, there is a requirement for cooperation by the target in that it must first go where the minefield has been placed so making the mine a weapon primarily of defence and attrition rather than one of offence and initiative. Land attack cruise missiles and dedicated amphibious ships are key elements or the “ships against the land” strategy which forms part or the armoury of any well-balanced modern fleet, as is the whole range of logistic support vessels. It is reach, the ability to operate other than in coastal sea denial, that separates the major navies from the others. In spite of the complications generated by maritime strategists, and the proliferation or scenario-based operational concepts which provide harmless employment for naval staffs all over the world, seapower in the late 1980s remains fundamentally about the protection or disruption of economic and supply shipping, whether as an end in itself or as an adjunct to the land battle. This makes it peculiarly idiosyncratic to individual nations since not all will suffer evenly if shipping is disrupted. It also means that those dependent upon the sea cannot give up the unequal struggle just because defence of shipping has become more difficult and expensive.
[THE SUBMARINE REVIEW is privileged to digest portions of “The Foreward to Jane’s Fighting Ships” 1988-89, by special permission of the editor, CAPT Richard Sharpe.]