Tuesday, September 6, 2016

Damned If You Do, Damned If You Don't-II

Elmo Zumwalt, who probably, should he be still alive today, would hate to see what kind of ships' class was named after him, had some ideas about naval warfare which certainly did not and do not fit US Navy's preferences of, as either Hyman Rickover or Arleigh Burke (do not remember from the top of my head) stated, "the US Navy got used to traveling the first class". The "first class", of course, being large and expensive, or rather very expensive, combatants. There always existed this contradiction between Arleigh Burke's "we need numbers" and this very "traveling the first class". Indeed, it is very difficult to have both and especially so when the foundation of contemporary operational culture of US Navy is classic Nimitz, and upcoming Ford-classes CVNs who pack an immense punch against inferior nation and her fleet but also are immensely, in fact--outrageously, expensive. They are not only expensive in themselves, let alone with organic air wing on and under their decks, but they require a constant escort of several other very expensive and sophisticated AEGIS ships equipped with the  SPY-1D,  and its further modifications, radar. Of course, the issue of ASW of Carrier Battle Group follows not far behind. This is an antithesis to a US Navy's contemporary slogan of Distributed Lethality.  

Enter Elmo Zumwalt and his tenure as CNO (Chief Of Naval Operations) in early 1970s. As one of the truly great US Navy's historians, George Baer, wrote: "The colossal expense of each heavy nuclear-powered carrier (1.44 billion in 1977) and many years it would take to replace one if it was sunk, had become reasons for being more cautious about using such carriers on the offense. To be sure, carriers retained a much debated value as politically unencumbered strike bases, but their use increasingly depended on existing Sea Control and on the ability to defend them. Further more, Zumwalt's thinking went, the technologically complicated carrier (and the similarly sophisticated and expensive nuclear submarine) required Navy personnel to go early into intensive specialization. Officers and sailors were thus forced to adopt a narrow, operational focus to form "unions", particularist and exclusive communities within the Navy that closed minds and limited vision". ("One Hundred Years Of Sea Power, The US Navy 1890-1990". George W. Baer, pages 402-403). Needless to say, US naval aviators "union" is immensely powerful and influential. Yet, it is one of the major obstacles to US Navy's achieving even a slight departure from its manifest carrier-centrism towards true Distributed Lethality. 

Zumwalt understood this problem in late 1960s. As much as some still thought (and some still do) about naval warfare in WW II carrier paradigm, facing technological reality was inevitable: once the ranges of the anti-shipping missiles reached the vicinity of deck aviation's ranges, the game was up. Russians, initially, called their first crude Anti-Shipping Missiles (ASMs) an airplane-shell (samolet-snaryad), which pretty much summed it up. Initially crude and short-range, those ASMs still represented the threat to US Navy's assets which it never encountered before. Those assets could be hit from relatively afar not by real aircraft and required a very different approach to the defense of US Navy's most prized possessions--aircraft carriers. Here is a dilemma which US Navy faced: in good old times of naval gunnery (with the exception of tragic HMS Hood and Russian humiliation at Tsushimathe exchange between two adversaries was pretty straight-forward--they pummeled each-other with relatively inexpensive (when compared to the cost of some battleship or cruiser) shells until one of them was either sunk or quit but it was quite often after dealing a lot of damage to the victor. So, all in all, the side that lost could at least claim a good fight, granted that often victors, indeed, did require either serious repairs or, altogether, a withdrawal from the operation for a very long periods of time. ASMs changed all that on 21 October 1967 Then, of course, came Operation Trident with same good ol' P-15 Termites (NATO Styx) ASMs doing the trick on Pakistan's Navy ships and HQ in Karachi. The whole notion that several small 183-ton displacement ships carrying ASMs could wreck the havoc on the enemy came as a surprise to US Navy. Yet, US Navy still decided to stick to its carrier-centric template. USSR, on the other hand, continued to develop a whole line of ASMs, ranging from cumbersome P-6/P-35 (NATO Shaddock) to, later, first ever submarine launched ASMs P-70 Ametyst, later substituted with more advanced P-120 Malakhit (NATO SS-N-9 Siren). Here was a serious change in the paradigm. Consider this: the older, however powerful,  Shaddocks carried a ton of explosives to a distance of 450 km but they had one huge drawback since required Echo-class (Project 675) SSGNs to surface and remain surfaced for a significant periods of time to provide guidance to ASMs until they could be guided by TU-95RTz hanging near US Navy's CBGs. The chances of Echoes to survive this ordeal were, frankly, very modest. Once surfaced they could be relatively easy to detect, both visually and by radar, and to launch US Navy's first Harpoons, which, at that time were carried by P-3 Orion patrol (ASW) aircraft. Actually, this is how AGM-84 (also RGM and UGM) Harpoon came into existence, not least through efforts of Admiral Zumwalt, who headed  at that time the division of System Analysis. Here is what Zumwalt had to say:

As you can see, "carrier union" at that time was so confident (arrogant?) in the power of its wings that it didn't pay too much attention to some funny weapon such as ASM. Well, the reality, however, was not that bright. Here was a weapon which for a tiny fraction of cost of its carrier could badly damage or eliminate altogether US Navy's most prized and most expensive possession--an aircraft carrier. Here is a simple math: 

 The case of Echoes SSGNs

As was already stated, after the launch Echoes remained a sitting ducks for approximately half-an-hour, providing guidance to their missiles. Obviously the time varied with the distance of salvo or how close (or far) was one of the TU-95RTz. And here we can do some pretty simple modelling for, let's say, the range of salvo by Shaddocks of about 300 kilometers. This is by no means to make actual calculations but to merely give a very simplified impression of what went into considerations at the dawn of serious ASMs. The truth was that with Echoes the task of defending a CBG was a twofold:

a) to conduct a real ASW search of the area where submerged Echo or multiple Echoes could be;
b) to shoot down incoming Shaddocks and to detect and destroy surfaced Echo(es) in order to prevent either a second salvo of 4 Shaddocks or prevent a first 4 missile salvo altogether.   

If to consider the range of salvo to be 300 kilometers and to mentally freeze sailing CBG we get the circle with the radius of r=300 kilometers. Let's use good ole area of the circle formula and calculate what area should CBG's escorts and aviation cover (conduct search) to detect Echos

Not a small task, if to consider that this search area is about half the size of France. For now we we'll omit all those Detection Probabilities and Operational Sweeps but we, certainly, can easily calculate the time it is required for a single aircraft with, say, MAD (Magnetic Anomaly Detector) which is a corroborative but extremely important search sensor for submerged subs. To properly detect a sub, a patrol aircraft with MAD has to be pretty low (hundreds of meters) and with the range of MAD, say, R=2 kilometers we can easily calculate Sweep Width (W), which is:

                      W=2R=2 x 2 = 4 kilometers

Now it is time to calculate Sweep Rate (R) which is R=WV, where V is a speed of a patrol aircraft. Let's say that this aircraft has a speed near surface V=250 kilometers per hour. It will be a bumpy ride, but then again--patrol aviation lacks this glamour of fighter jets, yet it is this aviation which often carries out the most important mission.  So, the Sweep Rate (R) for this patrol aircraft will be: 

             R=WV= 4 x 240 = 960 square kilometers per hour

Here, using the formula of the time for search per specific area, we get:   

294 hours--not a pretty picture, to put it mildly, but, of course, in real life the issue is addressed by the increase of the number of patrol aircraft operating both from carrier and from nearest bases, organic to CBG attack subs also conduct their own sweeps, as well as the surface ships, thus increasing Sweep Rate dramatically. But this is as far as the submerged Echoes go. Once on the surface to launch this ever important Sweep Width (W), grows tremendously for patrol aviation since it can detect Echoes by visual and radar means. Radar changes equation and here we are talking Sweep Widths jumping into many tens of kilometers. Consider the range of patrol aircraft radar when detecting a surfaced Echo at the range of 50 kilometers, suddenly the equation changes for R, since on higher elevations patrol aircraft fly faster, say 400 kilometers per hour, and see much further:

    R=WV= 100 x 400 = 40,000 square kilometers per hour 

This is a totally different game. But it also shows what a dramatic, revolutionary really, change came about when first Ametysts, and, later, P-120 Malakhits started to be launched by new Project 670 (Charlie-class) SSGNs from the submerged position--this changed the game completely, but especially so when P-700 Granit (SS-N-21 Shipwreck) came online in early 1980s. Their operational range was 600+ kilometers and that made a Search Area a whopping 1,130,400 square kilometers. Even for mighty US Navy's CBGs of 1980s this was not an easy task, to put it mildly. But that is what makes Zumwalt such a remarkable naval thinker, he foresaw the coming of missile paradigm in 1960s and he knew, that the real fight for Sea Control, especially closer to the Soviet Navy's bases was impossible within old WWII carrier paradigm. Elmo Zumwalt was not "distastefully arrogant"....  

For those who want to get acquainted in general with some ASW and Search Theory issues, a superb presentation of a renown Professor Alan Washburn of Operations Research Department of US Naval Postgraduate School can be of help  

To be continued....

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