The most likely threat to a carrier is a submarine armed with antiship cruise missiles (SSMs). Though unlikely to cause fatal damage to a supercarrier, a few well-placed SSMs can force her to leave the scene of action for repairs. The range of modern cruise missiles (up to 300 miles) makes the task of protecting the carrier far more complex than it was only two decades ago. Another problem is the decreasing number of ASW escorts available to the commanders of CVBGs. In just the last couple of years the U.S. Navy has retired dozens of cruisers, destroyers, and frigates. Since the submarine remains the primary threat, another submarine must be one of the protectors.
The most formidable dedicated cruise-missile submarine (SSGN) is the Russian Oscar class (nicknamed “Mongo” by some NATO submariners because of its awesome size). The Oscar-class SSGN is, in some ways, the Russians’ first modern submarine. It is large and relatively quiet (much like a Sierra-class SSN) and is equipped to stream a large towed-array sonar. This boat, designed specifically to be a carrier hunter, is equipped with twenty-four SS-N-19 Shipwreck SSMs as well as a full array of torpedoes. It is the single most powerful attack submarine in the world, and thus must be hunted by the best boats we have, the 688Is.
Currently each CVBG usually has a pair of SSNs assigned to provide long-range ASW protection. Unlike the surface escorts, which have to stay within a few dozen miles of each other, the subs may be hundreds of miles from the main group. They will likely operate in clearly defined ASW kill zones, into which only they are allowed to operate and shoot. This is designed to minimize the chances of a “blue-on-blue” ASW encounter.
Oscar-class guided missile submarine. OFFICIAL U.S. NAVY PHOTO
Hunting SSGNs is a most interesting game, different from other ASW tasks. Unlike SSBNs, which run silent and deep, the CVBG relies on mobility for its defense. And when the carrier moves swiftly, so must the hunting SSGN. Speed reveals any submarine’s vulnerability. Speed creates noise and degrades sensor performance. The SSNs tasked to defend the carrier know both where and how fast the battle group is going, and can position themselves in ambush for whatever missile-carrying hunter may be listening. In addition, the American force may have the edge of a Surveillance Towed Array System (Surtass) ship supporting the CVBG. Using an advanced towed array, the Surtass ships are like mobile SOSUS listening posts, and the data collected can be forwarded to the CVBG commander and the hunting SSNs.
The pattern of this hunt will be sprint-and-drift. The hunters on both sides alternately race forward, then slow down to listen. As in all undersea encounters, the side that can hear first and farthest away has the biggest advantage. Knowing where and when an SSGN would have to approach, the U.S. sub has the ability to stay quiet and wait for the Oscar to come to it. Because of its need to obtain targeting data from the Russian RORSAT, the Oscar has to come shallow periodically to raise its satellite data link masts. This causes hull popping and mast flow noises. Thus it is entirely likely that the 688I can be guided by targeting updates via the ELF/VLF radio circuits to a point where it will be able to obtain a direct path passive sonar contact to the Oscar. This will probably occur at a distance of 10,000 to 16,000 yards.
As in the hunt for the Typhoon, the 688I must go to an extremely quiet operating routine, to remain undetected by the towed array of the Oscar. But unlike the hunt for the boomer, here time is of the essence. Potentially, the Oscar can fire its missiles once it is within range of the CVBG. This means it must be eliminated quickly and effectively. The U.S. skipper is likely to try maneuvering to a position behind the Oscar, so that any torpedo hit will strike near the propeller shafts. This is likely to pop the shaft seals, flooding the engine room of the Russian boat and hopefully sinking it. All the while the fire control technicians operating the BSY-1 system will be “polishing the cannonball” on the firing solution to the Oscar. At 6,000 to 8,000 yards, assuming the Oscar has not yet heard them, the U.S. skipper may launch a pair of wire-guided Mk 48 ADCAPs. These are fired initially in the slow-speed setting, using the wires to guide the weapons and provide data back to the U.S. boats. The fire control technicians may even try to “swim” the weapons under a thermal layer to mask their noise signature from the sensors of the Oscar.
Inevitably though, the Oscar hears the two Mk 48s and begins to react. It counterfires torpedoes down the bearing of the attacking Mk 48s, forcing the 688I skipper to cut the guidance wires and run for cover. Its distance lead over the Russian fish, as well as efficient maneuvering of decoys, should allow the American boat to survive. The same may not be true of the Oscar. The captain of the Russian boat tries the same evasion tactics as his American opponent, but they are probably not as effective.
As in the Typhoon example, at least one and possibly both ADCAPs are likely to hit their target. And if the desired shaft hits have occurred, then the Oscar is dead in the water. Even if only a single hit has been made, the 688I has accomplished its mission. The Oscar is badly hurt, and likely suffering from severe shock damage. It may even have to surface. In any case, it will be making horrendous amounts of flow noise and mechanical transients. The U.S. skipper may reattack and finish off the Oscar, or he may also call the carrier to give it the coordinates of the damaged missile boat. Within a very short time the carrier group could have a flock of S-3B Viking ASW aircraft and SH-60 ASW helos over the damaged Russian boat to finish it off. Much like a wounded bear being stung to death by a swarm of bees, it would die. And the American boat can now head out on another mission.
Mission #2—Antisurface Warfare
The nineteenth-century Frenchman Jeune Ecole first codified the idea that a navy isn’t the real target of maritime warfare—the real target is what navies were designed to safeguard, merchant shipping. The sea is, before all things, a highway over which nations trade. And navies were invented to protect that, first from pirates who were little more than thieves at sea, and then from foreign navies whose thievery was on a somewhat grander scale. One might say that the real role for the submarine grew from this doctrine. The first submarines were too slow to be really effective at hunting other warships but quite fast enough to seek out and kill the slower and more fragile merchant tubs that carried the things nations need: food, raw materials, manufactured goods. Since the global economy has made all countries into island nations surrounded by water, the vulnerability of international maritime trade is made greater still by the fewer, slower, larger, and massively expensive merchant vessels of today. The environmental consequences from even minor damage to a single large crude oil carrier represent yet another way in which the world as a whole can be at risk. Navies exist to protect the trade and the traders, and a threat to either is a threat to both.
Tactical Example—Holding a Choke Point (Interdiction of a Surface Action Group)
The simplest example of a choke point is a highway intersection, a relatively small area through which people from distant places must pass on their separate journeys. Just as the intersection is a convenience for merchants who build shopping centers and people who establish maritime trading centers, so it creates highly rewarding hunting grounds. In World War II, the first Japanese task group to be detected was preparing for the invasion of the Kra Peninsula and the subsequent descent on Singapore, which guards the Strait of Malacca. England spent a great deal of its history seizing and building upon such places as these, even before Alfred Thayer Mahan published his thoughts on their importance. The Falkland Islands became British property because they are conveniently close to the Straits of Magellan. Ascension Island is in the middle of the Atlantic Narrows. Malta lies close to the Straits of Sicily. Gibraltar sits on the entrance to the Mediterranean. Such was the vision of the English in the days of sail.
Ships move faster now, but the choke points remain. In these places that people must pass through, arrival time and engagement range are predictable quantities.
A lucky submarine will hug a shallow bottom. Shallow water, not uncommon in straits, generally makes life easier for a submarine, though S
SNs usually like at least 600 feet/200 meters of water to operate. Given time, the submarine will sniff around, learning currents and environmental factors. The mouth of the Mediterranean is known for the treacherous mixture of warm currents and cold, making for confused sonar conditions. In other places such conditions might mitigate against a sub, but long-range detection is of less importance when you are already astride the place where others must pass.
The other side knows this, too, of course. The mere possibility that someone might be there to threaten your battle group or your crude carrier forces you to take this threat seriously. Willie Sutton robbed banks because, he said, “That’s where the money is.” Choke points are where the targets are. You can bank on it.
Let us consider the most famous submarine action in recent history: the sinking of the Argentine cruiser General Belgrano during the 1982 Falklands War. Before the British task force entered hostile waters the Royal Navy deployed a trio of nuclear submarines along the most likely approach routes to the islands. Because of his limited air power and surface-to-surface missile capabilities, Admiral “Sandy” Woodward was counting on this trio of boats to be the flank guards against any type of counterattack by the Argentine Navy. As it turned out, they were the only units of the Royal Navy to engage the major surface units of Argentina during the war.
In the last few days of April 1982 the Argentinean surface fleet was split into three task groups. Their plan appears to have been based on a three-pronged pincers movement against the British task force from the north, south, and west. The northern group was composed of their aircraft carrier Veinticinco de Mayo (Twenty-fifth of May) with a small air wing of A-4 Skyhawk attack aircraft, and several guided missile destroyers carrying Exocet SSMs. The western group was composed of several Exocet-armed frigates. The southern group was potentially the most dangerous force of all, composed of the cruiser General Belgrano (the former USS Phoenix) armed with 6-inch guns, Exocet SSMs, and Seacat SAMs, accompanied by two Exocet-armed destroyers of World War II vintage.
It is likely that national intelligence sources of the United Kingdom and their allies noticed the planned movement even before the ships raised anchor and left their harbors. And once they had sortied, it must have been fairly straightforward for the Royal Navy operations center (known as HMS Warrior) at Northwood, England, to feed the updates to the subs via their satellite communications. The three British boats were placed along the three surface groups’ lines of advance, and were left in waiting while the British naval and civilian leaders decided whether to shoot.
Mark-8 torpedoes are loaded aboard a Royal Navy submarine. U.K. MINISTRY OF DEFENCE
The key question here was whether or not the Argentine forces would attempt to penetrate the 200-mile-radius total exclusion zone (TEZ) from Port Stanley in the Falklands. Clearly if they tried to penetrate it, there would be no question but to attack with the nuclear boats. But the ships did not come on directly and seemed to rally just outside the zone, though quite close enough to dash in at a moment’s notice. The northern group was trying to find some wind to launch her strike of A-4s at the British task group, though (amazingly for the weather in the South Atlantic) it was calm and windless.
The choke point in that area was, ironically, not a strait but the extremely shallow water. The Argentinean southern group was operating over a shallow rise in the ocean called the Burdwood Bank, which made difficult operating conditions for HMS Conqueror (S-48), the southern boat in the British barrier. This hydrographic choke point was a major problem for the British SSN, and became a factor in the decision coming from 10 Downing Street. Already the Conqueror and another boat were tracking their assigned target groups, and a decision was needed from on high.
TA periscope shot of a Royal Navy frigate on the receiving end of a Perisher student’s three-torpedo practice spread during an approach. A spread of Mark-8 torpedoes just like this sank the Argentine cruiser General Belgrano. U.K. MINISTRY OF DEFENCE
Late on May 2, 1982, the message was sent from Northwood authorizing the sinking of the Belgrano, and any of her escorts that attempted to intervene. Even though it was still some distance outside the TEZ, the Conqueror was the first to strike. Her captain, Commander Christopher Wreford-Brown, set up a classic Perisher approach on the General Belgrano. Loaded in his five torpedo tubes were three World War II-vintage Mark 8 torpedoes and a pair of Tigerfish Mod 1s. The plan was to use the Mk 8s first because of their larger warheads (800 lb/363 kg versus 200 lb/91 kg for the Tigerfish), and save the Tigerfish for a second shot if required. If the Mk 8s worked on the first try, the Tigerfish would be available for a shot or two at the escorting destroyers if necessary.
In the plotting area of Conqueror, Lieutenant John T. Powis, the boat’s navigator, carefully plotted the intercept from ranges and bearings called by the commander on the periscope, and inputs from the sound room. It was a totally normal approach, which later would be judged considerably easier than most of the approaches made during a Perisher course. Wreford-Brown maneuvered the Conqueror just 1,200 yards off the projected track of the General Belgrano and patiently waited. The Argentine ships continued blindly along their track, completely oblivious of the coming danger. And then it was time.
Just before 1600 hours on May 2, 1982, the only combat torpedo shots ever fired by a nuclear submarine were launched from Conqueror . The three Mk 8s were angled in a way designed to ensure that at least two of them would hit the General Belgrano. And that is exactly what happened. The first Mk 8 hit forward near the bow, tearing it from the ship. The second one struck in the engineering spaces, causing a complete loss of power and massive flooding. The General Belgrano immediately took on a heavy list to port, and within minutes it was sinking. Her captain had no choice but to abandon ship and have his crew take to the life rafts. (Ironically, the exact same type of hits in the same places had sunk her sister ship, the USS Helena, during the Battle of Kula Gulf in 1943.) Some 400 of the Belgrano’s crew of over 1,000 perished in the sinking and while waiting to be rescued.
In addition to the two hits on the cruiser, the third Mk 8 appears to have hit one of the escorting destroyers, though it failed to detonate. Unfortunately for the crew of the General Belgrano, the escorting destroyers did not even know what had happened until they looked and noticed that the cruiser was no longer in formation. It would be almost forty-eight hours until all the survivors of the sunken cruiser were finally rescued.
HMS Conqueror returns home after sinking the Argentine cruiser General Belgrano during the 1982 Falklands War. Note the “Jolly Roger” flag hanging from the mast. U.K. MINISTRY OF DEFENCE
A local resident of the Falkland Islands personally greets and thanks the crew of a Royal Navy submarine following the 1982 war. U.K. MINISTRY OF DEFENCE
Aboard the Conqueror, there was the satisfaction of hearing the sounds of two solid hits and the breaking-up noises from the cruiser. In addition, the sub reported the dropping of a few depth charges, though this has never been confirmed by the Argentines. Since the escorting destroyers had just continued blindly on, there had been no opportunity to immediately follow up the first attack. And when they moved away from the TEZ, it is likely that the prevailing rules of engagement prevented further action. The Conqueror continued on station, as assigned.
As for the Argentine Navy, the effects were rapid and enormous. One story, told at the bars where submarine officers go after hours, says that as soon as the carrier group to the north of the Falklands got word on the sinking, they immediately reversed course and headed back to port. The story goes on to say that apparently this spoiled the opportunity of another Royal Navy submarine commander, who allegedly was watching the oncoming carrier group through his periscope. Royal Navy gossip has it that he watched the carrier and her escorts turn for home less than thirty minutes before he himself would have gotten in his shots at the Veinticinco de Mayo. The Argentine surface forces never again ventured out of port during the war, and the British had, in essence, reduced
the conflict to a set-piece battle against the air and land forces of Argentina. All for the expenditure of three World War II-vintage torpedoes, perhaps the most cost-effective naval victory in history.
Tactical Example—Maritime Interdiction (Attack of a Convoy/Amphibious Group)
This is a high-risk situation for everyone. A convoy by definition is a large group of valuable ships protected by a force of warships. If your enemy has a convoy, he is transporting something important to his war effort, something that you don’t want to let arrive. An amphibious warfare group is a little different; in this case the cargo is the most precious of all for the enemy and the most dangerous of all for you: fully equipped combat troops who have a job to do. You’ve got to try to stop the enemy in either case, while he must guard a moving asset. In fact, that asset will be moving as rapidly as possible to minimize the risk—the faster they move, the less time you have to attack. But unlike a carrier group, in which every ship has the ability to defend itself, most of the flock in a convoy is relatively helpless. For the amphibious group, there is one other difficulty. While a convoy probably wants to go from one friendly port to another, the amphibs by definition are heading into harm’s way—they want to go where you and your allies live. That means the submarines will have to hunt their enemy on the enemy’s ground.
Let’s suppose that the government of the Ukraine has decided to support some of their former allies in the Balkans, the Serbians perhaps, with an amphibious expedition from the Black Sea to the Adriatic. It might be composed of some six to eight ex-Soviet Ropucha- or Polnocny-class landing ships with a regiment of landing troops aboard. The landing ships probably have an escort of four to six frigates (like Krivaks or Grishas) and/or corvettes (like Pauks or Tarantuls), though nothing like the kind of escort that the old Soviet Navy used to be able to put together. In any case, this is the very kind of intervention that the UN is desperately trying to avoid in a festering part of the world. While NATO air and surface forces could certainly deal with such a group, it would be messy. And there would be repercussions: further confrontations between east and west might develop. Or, someone could just deal with it. Someone who has something that can just make things disappear.