Submarine: A Guided Tour Inside a Nuclear Warship

The Improved SSN-688 Design

Of all the nuclear submarines designed by the United States, none has been the subject of more political infighting and controversy than the Los Angeles (SSN-688) class. The design has its roots in a series of incidents that occurred in the late 1960s, right at the time the United States was trying to decide just what kind of nuclear attack submarine (SSN) to build to replace the highly successful Sturgeon-class boats. The infighting began with the desire of then-Director of Naval Reactors (DNR) Vice Admiral Hyman G. Rickover to build a high-speed (over 35 knots)[9] submarine capable of directly supporting the fleet of aircraft carriers that represented the backbone of American seapower.

The U.S. Navy organization charged with actually developing the specifications and design for the next generation of SSN, the Naval Sea Systems Command (Navsea), favored a design called Conform that would not be as fast as Rickover's design, but would have the advantage in areas such as habitability and quieting.

In the end, the decisive event that swung the situation in Rickover's favor was something known today as the Enterprise incident, which was a shock to the U.S. Navy and intelligence communities. In early 1969 the carrier USS Enterprise (CVN-65) and her escorts left their base in California for a war cruise to Vietnam. As she left harbor, U.S. national intelligence picked up message traffic indicating that the Soviet Union was going to dispatch a November-class SSN to intercept the carrier and her group. In an attempt to establish once and for all just how capable the first-generation Soviet SSNs were, the top battle group was provided with air cover from ASW aircraft and then told to outrun the November. It did not quite work out though, as the presumably slower Russian boat was able to match speed with the Enterprise. At 30 knots the game was called off. When word reached Washington, D.C., it caused rapid reassessment of just how capable the Russian SSNs really were.

Up until that point, it was assumed that the Novembers were only capable of speeds like those of the Nautilus and the Skates, around 20 knots. Yet here was one doing 50 percent better than that and not even trying! And what did this mean about the newer generation boats, such as the Victor I and II classes? In addition, there were mounting indications that the Soviets were working on a new class of deep-diving (over 2,000 feet/700 meters), extremely high speed (over 40 knots) SSNs.

In fact, the performance of the Novembers was due to the extreme lack of radiation shielding. Much like a hot rod that has been stripped of everything that weighs it down, the Russian boat simply did not have to haul around the reactor shielding that every other civilized nation considered essential to the good health and safety of their sailors. The November's superiority was based on a misinterpretation of the information, but there was no way to know that at the time. And Rickover was not a man to let slip an opportunity that would help justify his point of view. Through his network of Navy and congressional supporters, he pressured the Navy to kill Conform and build a class of his high-speed fleet boats. In the end he won authorization for a twelve-boat class of his fleet submarines, though to help gain critical budget authorization votes in Congress, he broke with the longstanding Navy tradition of naming submarines after sea creatures and instead named them for the home cities of the twelve congressmen who swung their votes in his favor. (Rickover is alleged to have said, "Fish don't vote!")

The first boat of the class, the Los Angeles (SSN-688), was to be the embodiment of his ideas of speed and power, but from the very start, it was a series of compromises. It is said that a camel is a horse designed by a committee, and the Los Angeles was no exception to that rule. The first problem had to do with fitting the massive S6G power plant into a hull with the dimensions needed to achieve the 35-knot speeds specified by Rickover. Quite simply, the reactor was going to come in 600 to 800 tons overweight. This meant that one or more of the key specifications of the boat-torpedo tubes/weapons load, habitability, radiated noise level, speed, sensors, or diving depth-was going to have to be reduced. The compromise was to thin the hull and limit the diving depth of the new boats to about three-fourths that of the Sturgeons and Permits (950 feet/300 meters). In addition there would be some severe compromises in habitability, forcing even more of the crew to hot bunk. As it was, there was very little reserve buoyancy (around 11 percent) and less growth potential than in any other SSN ever designed by the United States.

Once the design of the Los Angeles was finalized, there was the matter of selecting a prime contractor. The Navy chose the Electric Boat Division of General Dynamics Corp., despite their having submitted a bid that, in retrospect, was not capable of recouping even the costs of building the first group of twelve boats. Clearly, Electric Boat was "betting on the come"-that they could recover their lost profits from construction of boats beyond the first twelve units. Unfortunately, they did this at a time of relatively high inflation and recession in the economy, and the terms of the contract began to make it impossible for Electric Boat to break even on the first boats. Then a Navy inspection of welds found that a number of the boats had either faulty or missing welds on critical parts of the pressure hulls. This meant a number of the boats had to be completely rebuilt, further increasing costs to Electric Boat. In the end the U.S. Navy had to bail out Electric Boat and pay the costs of the overruns on the Flight I boats. This bailout caused a massive scandal that wound up costing General Dynamics the sole-source contract for the subs as well as causing the indictment of the Electric Boat yard manager on bribery charges. The Navy got the boats, but at a massive cost to the taxpayers.

On the positive side, what the Navy and taxpayers did get were the fastest, quietest, most capable SSNs ever built. On trials, the new boats proved to be all that had been hoped for them. And in 1976, when the Los Angeles was commissioned and sent on patrol, she clearly marked the beginning of a new era of attack boats. Part of this came from the improved sensor suite. For the first time, an integrated sonar suite was included in the design of the boat from the very start. In addition, she was among the first boats to be able to take advantage of the new family of submarine weapons, the Mk 48 torpedo and the UGM-84 Harpoon antiship missile, that were coming on line at that time. Thus what the United States got with the Flight I Los Angeles- class boats was an extremely capable camel.

This might have been the end of the Los Angeles story except for the sudden chill in the Cold War that occurred in the late 1970s. After the downturn in East-West relations, the Navy got an authorization for additional units of the Los Angeles class. And when Ronald Reagan won the presidency in 1980, the construction of additional submarines as part of the "600-ship Navy" clearly meant more Los Angeles-class boats. In these boats were to go some of the improvements that had been planned for the class early on. Starting with the USS Providence (SSN-719), the type designation changed to Flight II. The Flight II boats had a number of improvements, particularly in the area of weapons stowage. One of the problems with U.S. SSNs had been the limited number of weapons (around twenty-four) that could be carried in their torpedo rooms. And with the addition of Harpoon and the new family of UGM-109 Tomahawk cruise missiles (antiship and land attack versions), it was getting tougher to plan an appropriate weapons load. To get around this, a twelve-tube vertical launch system (VLS) for Tomahawk cruise missiles was added to the forward part of the boat, where room had been left for them in the original design.

Almost two dozen of the Flight II boats were built, and their cruise missile firepower proved quite useful during Operation Desert Storm in 1991. The Flight IIs were also the first major group equipped with the new anechoic/decoupling coating designed to reduce the effectiveness of active sonars, as well as to reduce the noise radiated by the boat. Eventually all of the Los Angeles-class boats would be retrofitted with this coating. Another major improvement was that beginning with the Flight II boats, the S6G reactors were fitted with a new high-output reactor core. This allowed the Flight II boats to maintain their high speed (over 35 knots) despite the additional drag imposted by the new coating.

The final evolution of the Los Angeles-class boats was the version known as the Improved Los Angeles (688I). This version of the basic design would be fitted (in addition to the VLS system from the Flight II boats) with the new BSY-1 combat system. This system, which ties all of the boat's weapons and sensors together, was designed to overcome the problems associated with track and target "hand-off" between the sensor and fire control operators. In addition, the 688I was modified to support under-ice operations. This included strengthening the fairwater so that it could be used as a penetration aid through Arctic ice, as well as moving the forward dive planes from the fairwater to the hull, near the bow. Finally, the basic boat design was enhanced with a number of quieting improvements. It has been openly stated that the 688Is are almost ten times quieter than the basic Flight I boats.

All in all, the 688I is the finest SSN roaming the oceans today. While it does have shortcomings, diving depth and habitability being most notable, it still has the best single mix of mobility, weapons, and sensors ever fitted to a submarine. And while the next generation of SSNs will make up for the shortcomings of the Los Angeles class, it will be at an enormous price. In any case, the U.S. Navy had better get used to them-they have ordered a total of sixty-two boats in the class. And with the retirement of the entire Permit class, as well as planned early decommissioning of most of the Sturgeons, it is entirely likely that the year 2000 will see the U.S. Navy operating fifty to sixty Los Angeles-class boats and probably just two or three Seawolfs.

USS Miami: Our Guided Tour Begins

For our guided tour of a 688I, we will profile the USS Miami (SSN-755), the third U.S. Navy vessel to bear the name. The previous Miamis included a double-ended gunboat that fought during the Civil War, and a Cleveland-class light cruiser during World War II. The cruiser Miami (CL-89) earned six battle stars during her service in the Pacific during World War II, and fought in such actions as the Marianas, Leyte Gulf, Iwo Jima, and Okinawa. The current Miami was built at the Electric Boat Division yard of General Dynamics at Groton. She was launched November 12, 1988, and was commissioned June 30, 1990. She is assigned to SUBDEVRON 12 based at New London. She is some 362 feet long and 33 feet in diameter and has a crew of 13 officers and 120 enlisted men.

Her captain at the time of this writing is Commander Houston K. Jones, USN. He is a graduate of the U.S. Naval Academy (class of 1974), and this is his first afloat command. He is generally considered to be one of the top U.S. skippers in the sub force today, not only by his fellow officers but by the captains of the boats of the Royal Navy and other NATO nations that he has mixed it up with during various exercises. His executive officer is Lieutenant Commander Mark Wootten, USN. He is a graduate of the University of Pennsylvania (class of 1978), and is on the track to obtain a submarine command himself.

Miami is fortunate in that she is the first of the 688Is to be fitted with a complete BSY-1 combat system and all the other goodies planned for the class. The other boats of the group, starting with the USS San Juan (SSN-751), have less capable preproduction versions of the system and thus will have to await refits to move up to the full 688I standard. In addition, Miami is reported to have done 37 knots out on trials with her high-output reactor core. She is a fast, smart-looking boat with an excellent record thus far on exercises and patrols. Let's go aboard and take a look for ourselves.

Hull/Fittings

As you walk across the gangplank onto the boat the first thing that strikes you is the straight and level nature of the hull. Several things account for this. First and foremost is the fact that for most of its length, the Los Angeles-class boat is a perfect 33-foot-diameter tube of steel. This is a function of her high speed requirement. Long, narrow hulls have less drag than the teardrop-shaped hulls that can be seen on earlier U.S. or British boats. And while this does make for a faster boat, it has some adverse effects on handling during operations. In addition, it is easy to tell that Miami is equipped with the Mk 32 VLS system, since it is sitting level in the water. The earlier Flight I boats, because they are not equipped with the VLS, always have a pronounced "nose up" attitude when they ride on the surface.

Another thing that you immediately notice is the long shroud running down the starboard side of the hull. This is the housing for the various parts of the TB-16 passive towed array sonar. Along the shroud runs a track that allows personnel on deck to secure themselves to the hull, if surface operations are required. As you step onto the hull, you immediately notice that it seems to be made up of a series of tiles or bricks. And when you step on them, they seem to "give," much like the padding under a carpet. This is the anechoic/decoupling coating designed to defeat active sonars as well as reduce the noise emitted by the boat's internal machinery. It covers the entire hull except for the hatches, control surfaces, and sonar dome/windows.

Forward toward the bow are the twelve hatches for the VLS missile launch tubes. The outer doors or caps for the four torpedo tubes are located, two to a side, below the waterline. Along the top of the casing, aligned along the center axis of the boat, are three hatches. The one just forward of the fairwater is the weapons loading hatch. Here, using a special set of loading gear, the various weapons fired from the torpedo room are loaded. Two more hatches aft of the fairwater are set aside for the more mundane job of personnel access. Both are equipped to act as airlocks in the event that a rescue submarine needs to lock on, or as a way for swimmers to leave the boat. The aft hatch leads into the machinery spaces aft of the reactor compartment. Entry into this area is strictly controlled. The other hatch, just aft of the fairwater, is the main entry point in the forward part of the boat.

The hull is composed of a series of rings or barrel sections, welded together at the building yard. The 33-foot-diameter hull is itself approximately 3 inches thick and composed of HY-80 high-tensile steel. At each end of the 360-foot-long hull is a hemispheric end cap, which is welded onto the cylinder formed by the barrel sections. The main ballast tanks are at the forward and aft ends of the hull, with the sonar dome mounted forward and the propulsion section and its control surfaces mounted aft. In addition, smaller variable ballast tanks, which are used to maintain the trim of the boat, are located inside the hull.

One final thing that comes to the viewer's eye is the detail work done by the designers to minimize any type of flow noise from the hull. All of the fittings, called capstans, used to secure the boat to the pier forward of the fairwater are mounted along the centerline, so that they are already in disturbed water and will not cause any other noise on their own. No expense is spared to make the hull clean of anything that might disturb the water flow and create noise. Even the huge seven-bladed propeller, made of a special bronze alloy, is specifically designed to prevent and delay the onset of cavitation.

Sail/Fairwater

If we were to move to the top of the fairwater, we could just squeeze into the tiny bridge area. It is extremely cramped and has only the most basic of navigational aids to support getting in and out of harbor. In the past, submarine captains actually used to fight their submarines from this position. But with the advent of nuclear-powered subs, which spend most of their time underwater-Miami is, in fact, more stable and faster submerged than surfaced-this position has become less important.

Just behind the bridge position are the masts containing the various sensors for the boat. These include the attack and search periscopes as well as the ESM, radar, and communications masts. Some of these masts actually penetrate the hull and provide the boat with its eyes and electronic ears to the world topside. In addition, a floating antenna is reeled out from a point on the after part of the fairwater to provide Miami with access to the Very Low Frequency (VLF) and Extremely Low Frequency (ELF) communications channels. It trails out several thousand feet behind the boat once she has dived and stabilized. In the floor of the bridge position is a small hatch leading down some three stories into the control room. As you finally drop into the hull, you are in the port side passageway, just forward of the control room.

Control Room

Walking the few feet aft into the control room you are immediately struck by the fact that the air is clean and fresh and the room is brightly lit. And while the room is full of busy people and packed with gear, it is not really confining. One popular misconception is that if you are claustrophobic, you will not be able to live and work on a submarine-on the contrary, the very fact that over a hundred men are working, eating, and living in this confined metal tube can be reassuring.

In the middle of the control room is a raised platform with the periscopes in the middle of it. The forward part is the watch station for the officer of the deck (OOD). Here he has full view of all of Miami's various status boards ahead of him, access to the periscopes behind, as well as fire control to his right and ship control to his left. These are the weapons control consoles for the BSY-1 combat system, which is the heart of the Miami's fighting power. The ship control area is in the forward corner on the port side.

The navigation and plotting areas are at the rear of the compartment. Down the port side of the control room are the various navigational systems, including the new Nav-star global positioning system (GPS) receiver. It is most noticeable by the gap that it sits in. Where before there was a rack of navigational equipment that took up 4 to 6 cubic feet of volume, the GPS system, which gives a three-dimensional navigational fix accurate to within 9 feet/3 meters, is a wonder taking up only about 60 cubic inches. It derives its accuracy from a series of twenty-four satellites operating in low earth orbit. The readouts show the exact latitude and longitude, as well as a number of different useful functions. So accurate is the GPS system that some U.S. Navy ship captains have been able to make blind approaches to piers in heavy fog using only GPS as a reference. The only limitation to GPS is that the Miami must raise a mast, such as the search periscope, to obtain a. fix. To make up for this, Miami also has a ship's inertial navigational system (SINS) that keeps constant track of the sub's position through an advanced three-dimensional gyroscope system that senses relative motion from a known starting point. Proper use of SINS with periodic GPS updates helps keep the Miami within a few hundred feet of its planned track at all times.

The plotting area, aft of the periscopes, has a pair of automated plotting tables, though most of the movements are plotted by hand. Despite what one might think, most of the plotting of Miami's movements is done manually by a junior officer or enlisted man, on tracing paper over a standard navigational chart. Scattered throughout the passageways are a series of upright steel boxes secured to the bulkheads. They contain several complete sets of charts which cover the entire world, as well as detailed charts for specific areas to which the Miami might be tasked. In addition to the navigational instruments and plots, there are a number of instruments associated with the Miami's ability to work under the Arctic icepack. These include devices to obtain vertical traces of the bottom and ice floes, as well as various instruments to measure temperature and water depth.

The periscopes are mounted side by side, with the Type 2 attack scope to port and the Mk 18 search scope to the starboard. The Type 2 is a basic optical periscope with no advanced optics and only a simple daylight optical capability. The majority of the periscope work is done through the Type 18. It is the most advanced periscope currently fitted to a U.S. sub. In addition to its straight optical capability it has a low-light operating mode, which can be projected onto a number of television monitors around the boat. It is also equipped with a 70mm camera for taking periscope photos, as well as the readouts for the Electronic Support Measures (ESM) receiver mounted on top of the Type 18 mast. It also has an antenna for the GPS receiver mounted on it. This is a truly great scope, capable of almost any activity that might be asked of a periscope. The masts for the two scopes go up through the fairwater; they may be coated with a radar-absorbing material (known as RAM) to keep their radar signature down.

The ship control area, located in the forward portside corner, has three bucket seats-with seat belts-as well as room for another person to stand. Normally it is manned by two enlisted personnel who operate the diving planes and rudder (called the planesman and helmsman), and the diving officer and the chief of the watch controlling the ballast and trim. The planesman and helmsman are faced with aircraft-style control wheels, and sit facing a bank of control readouts and instruments. There is no view of the surrounding sea and even if there were, it would do little good. At depths over a few hundred feet very little light penetrates, and the sea becomes, as Jacques-Yves Cousteau calls it, "a dark and silent world."

Just behind the ship control area stands the diving officer, who is actually ordering the planesman and helmsman what to do and when. To his left is the position where the COB may sit, though others will frequently draw duty there. This is where the controls for the multitude of valves, tanks, and other equipment required to dive and surface the boat are located. Each man controls either the rudder and bow planes, or the horizontal stabilizer. Two-man control has been a hallmark of U.S. design philosophy for generations, and Miami is no different. For every primary system there is a backup, usually with a manual operating mode. Most noticeable of these are a pair of mushroom-shaped handles located at the top of the ballast control panel. These are the manual valves to conduct what is known as an emergency blow. In the event the boat needed to get "on the roof" in a hurry, the person at the ballast control panel would activate these two handles. These valves, which require no power of any kind, send high-pressure air directly from the air banks into the ballast tanks-when that happens, you're headed up fast. Early American SSNs did not have this feature, and this lack was felt to be a contributing cause of the loss of the Thresher in 1963.

Diving the boat is not the crash dive of 1950s submarine movies. In fact, it is a carefully controlled and balanced procedure that resembles a ballet danced by an elephant. First, the captain orders any personnel down from the bridge, and the closing of all hatches. Once that is done, the diving officer looks over the status board to the left of the ship handling stations to verify that all hatches and vents are sealed, and that the air banks have an appropriate reserve of air pressure. This done, the diving officer opens the vents atop each ballast tank to allow a measured amount of water into the tanks. This is just enough to make the boat slightly heavier than the surrounding water (called negatively buoyant). As this is happening, the diving officer orders the planesmen to put 10 to 15 degrees of down angle on the boat, using the bow and stern diving planes. At this stage the boat begins to settle. All told, this process normally can take from five to eight minutes.

Initially the dive will be held up when a depth of 60 feet (periscope depth) has been reached. At this point the depth will be maintained with the dive planes and the forward motion of the boat. During this time the diving officer will have the chief of the watch pump water in and out of the trim tanks to make the boat neutrally buoyant and balanced. In addition, the captain will probably order a series of checks on all of the compartments of the boat for watertight integrity, and do a check to see if any machinery is making abnormal noises, or if any objects are loose or improperly stowed. Next the captain will probably order a series of extreme diving exercises called angles and dangles, which are designed to discover if anything is still improperly stowed. The old hands take a perverse pride in being able to walk and keep a cup of coffee from spilling during high-angle dives. Now the Miami can get down to cruising.

Maneuvering a 6,900-ton submarine is something that is done with subtlety and a minimum of rapid action. A slow and delicate touch on the planes and rudders is required to prevent unwanted noise. If you desire to change speed, you rotate a knob called an Engine Order Telegraph, which sends an instruction back to the engine room to either increase or decrease the power to the propeller shaft. The lack of precision might surprise some people, as there are only Forward and Reverse, with choices for All Stop, One Third, Two Thirds, Full, and Flank. In spite of this, the precision that you can maneuver the boat with is amazing. In fact, the OOD can order the precise number of propeller revolutions or "turns" required to maintain any speed required.

The one problem with driving a 688I is that it tends to be slightly unstable at some depths and speed settings. This is partly a product of the 688I's hull shape, which is optimized for speed, and partly from the forward placement of the fairwater. Normally only light corrections will be necessary to keep tracking but one must be ready for any situation, including combat maneuvers, which can become downright violent.

Running underwater is, if nothing else, probably the smoothest ride that you will ever know. Once the boat is trimmed and level, there is little or no sensation of motion, and you feel as if you're walking through the basement of a building. There is, in fact, a feeling of being on very solid ground. Very reassuring, and very quiet. In fact, quiet is the name of the game in this business. When the sub is running underwater, nobody raises their voice, slams a hatch, or even drops the toilet seat hard. After a time, you become hushed and silent. So much the better.

Surfacing the boat is an exercise in itself, as there is no more vulnerable time for a submarine. Part of this is because a surfacing boat makes lots of noise: the rush of compressed air from the air flasks into the ballast tanks; the noise of the hull expanding from the decreased water pressure, called hull popping. All this noise makes the boat partially deaf and blind, so special precautions are taken. The first thing the diving officer does is to have the planesmen at the ship control stations bring her to periscope depth. At this point the search periscope will be raised to do a visual check for any surface vessels, as well as sonar listening for any surface or subsurface contacts. Once the captain is confident that all is clear topside, he will order the diving officer to blow compressed air from the air flasks into the ballast tanks to give the boat a slightly upward, or positive, buoyancy. Within several minutes the boat will surface, and the captain will establish a bridge watch up on the fairwater.

Once on the surface, you immediately notice the rolling of the boat in the surface swells. It is an ironic truth that the same hull design that provides such a smooth ride in the depths of the ocean rolls rather drunkenly in a mild surface swell. While it is not particularly uncomfortable, when compared to the amazing stability of the boat at depth, the difference seems enormous. While running on the surface, it is essential that the bridge watch maintain a constant lookout for any surface vessels. Since a submarine is as hard to see as it is, submariners are always concerned about being run over by a rogue supertanker or liner, and are cautious to avoid fishing vessels, especially those using drift nets.

Communications/Electronic Warfare Spaces

The communications shack is located forward of the control room along the port side passageway, and is notable for the security warnings posted on the door. It is incredibly vital to the operations of Miami. Packed into that tiny space is all of the radio transmission and cryptographic gear that is required to send and receive messages, ranging from operational combat orders to personal "familygrams."

The radio equipment covers a broad spectrum of frequency ranges from ultra-high frequency (UHF), high frequency (HF), very low frequency (VLF), and extremely low frequency (ELF). In addition, there is equipment designed to allow the Miami to contact communications satellites, as well as underwater telephone equipment commonly known as Gertrude. Most of the radio equipment is tied to sophisticated encryption gear (called crypto) designed to make it impossible for anyone but an American to read the message traffic.

This particular point has not always been so secure, as the discovery of the Walker family spy ring showed in 1985. For over fifteen years, a Navy petty officer, along with his family members and a friend, helped the Soviet Union acquire the keys to the various crypto systems used by the United States. This meant that the Soviets had access to virtually all our major crypto systems from 1969 to 1985, when the ring was finally apprehended. Since that time the National Security Agency, which is charged with the design and security of crypto systems, has apparently rebuilt the U.S. family of encryption systems and allegedly changed the procedures that allowed John Walker and his family to put so much of our national security at risk.

The most interesting of these systems are the ELF and VLF systems, which are mainly used as command and control systems for submarines. Their special property is that the signals from ELF and VLF systems can penetrate the water to be picked up by the antenna trailed from the port side of the fairwater. More often than not, because of their relatively low rate of transmission (ELF works at about one letter character every fifteen to thirty seconds; VLF is fast enough for teletype communications), they are used to cue submerged submarines to come to periscope depth, and poke one of their communications masts up to get a signal from a satellite or UHF channel.

It is standard on submarines to minimize any actual transmission from their radio systems. Always looming over the submarine force are the memories of what the Allied ASW forces were able to do to the U-boats in World War II, because of their knowledge of the German Enigma cipher system. The penetrations of U.S. systems by the Walker spy ring have only reinforced the belief that transmitting with a radio is an invitation to a funeral. Thus it is only occasionally when they are close to a potential enemy that they will send messages. To a submariner, only silence is a friend. Any noise, acoustic or electronic, is an enemy.

Another method of communicating with the outside world is for the boat to eject a SLOT (Submarine-Launched One-Way Transmitter) buoy from its forward 3-inch signal ejector launcher. Located in a small compartment forward that doubles as the ship's pharmacy, it resembles a tiny torpedo tube. The first step is to record a message, such as a contact report, on the buoy's recorder. The buoy is then fired into the water, where it waits a period of time, say thirty minutes to a couple of hours, then sends out a high-speed burst transmission that can be picked up on a special satellite communications channel.

In addition to launching SLOT buoys, the 3-inch ejector can be used to launch bathythermographs to monitor thermal layers in the water, as well as several types of decoys such as noisemakers and bubble generators. A second 3-inch ejector is aft in the engineering spaces, and both units can be controlled and fired from a panel in the control room.

Keeping track of the electronic noises an SSN encounters is the job of Miami's Electronic Support Measures (ESM) suite. Technically the suite is made up of a radar and electronic signal receiver known as WLR-8 (V). This is used to monitor the radar and radio emissions in operational areas. In addition, the Miami is equipped with a BPS-15 surface search radar to assist in ship handling and navigation. All these systems have their antennas mounted on retractable masts, which can be raised while the boat is at periscope depth.

AN/BSY-1 Combat System

At the very heart of the Miami's combat power is the new BSY-1 (pronounced "busy one") submarine combat system. All the sensor, fire control, and weapons systems of the Flight I and II Los Angeles-class boats, as well as a few new items, are tied together into a single system controlled by a battery of UYK-series computers running almost 1.1 million lines of Ada (the defense department's systems programming language) computer code. Developed by IBM, with Hughes, Raytheon, and Rockwell as subcontractors, BSY-1 represents the first use of what is known as distributed processor architecture. All of it is tied together by a data highway known as a data bus, which is becoming something of a standard on weapons systems such as the F-18 Hornet fighter/ bomber and the Patriot surface-to-missile system.

This means that instead of having one large computer running all the sensor and combat functions, a central computer hands out processing assignments to other computers running code designed to handle a specific job like acoustic processing or cruise missile mission planning. In this way the distributed system actually runs faster than a larger single computer would. It also makes the BSY-1 system easier to upgrade and better able to operate in a degraded or damaged condition.

Other than the racks of UYK-7, UYK-43, and UYK-44 computers buried in the computer compartments, the most visible signs of the BSY-1 system are the consoles in the sonar room, forward of the control room, along the starboard passageway. Here four manned sonar consoles provide the Miami with her ears to the underwater world. Into these consoles the BSY-1 system feeds information from the various sonar systems. The Miami's main sonar system, almost identical to the BQQ-5D system on earlier Los Angeles-class boats, is actually a collection of many different sonar systems, including:* The spherical sonar array, located in the bow. The large sphere (15-foot diameter) has both active (echo ranging) and passive (listening) modes, and is currently one of the most powerful active sonars (over 75,000 watts of radiated power) afloat anywhere in the world.* The conformal array is a low-frequency passive sonar array mounted around the bow.* The high-frequency array is an upgrade to the spherical array, allowing it to generate the advanced waveforms that make the active modes of the BSY-1 so effective. It also incorporates an under-ice and mine detection capability from an array in the fairwater.* The TB-16D is the basic towed array, which is fed from the tubular shroud on the starboard side of the hull. It is a passive system, designed to provide medium-range detection of low-frequency noise. It is fed from a large reel in the forward part of the boat and played out from a tube in the starboard horizontal stabilizer. It has a 2,600-foot cable that is 3.5 inches/89mm thick, with the receiving hydrophones in a 240-foot-long array at the end of the cable.* The TB-23 is the new passive "thin line" towed array associated with the BSY-1 system. Its smaller diameter (1.1 inches/28mm) means that the hydrophone array can be longer (approximately 960 feet), and it can be farther away from the noise of the towing submarine. The TB-23 is specifically designed to detect very low frequency noise at very long ranges. It is stowed on a reel in the aft and fed from a receiver in the port horizontal stabilizer.* The WLR-9 is the acoustic intercept receiver designed to alert the crew that an active sonar is being used, such as large active sonar arrays or sonar on incoming weapons.

Associated with all these systems is a series of signal processors and other equipment, which translate the sounds emitted and collected by the various sonar systems into the data displayed on the sonar consoles. The four BSY-1 sonar consoles are usually configured to have three of them looking at particular elements of the BQQ-5D sonar sensors while the fourth is used by the sonar watch supervisor. There also is a sonar spectrum analyzer available at a workstation in the forward end of the compartment. Each console has a pair of multifunction displays, which can be configured quickly by the operator for the particular sensor and mode of interest. For example, one sonar technician might be looking at the broadband noise being collected from one of the towed arrays. Another might be watching for broadband contacts on the spherical array.

What the sonar technician actually sees is a rather odd-looking display called a waterfall. It looks like a green television screen full of snow or "noise." The top of the display shows the bearing of a particular noise source or frequency being detected. The vertical scale shows that noise or frequency over time. The sonar technician is looking for something that stands out from the random pattern of background noise being displayed. Usually the sound contact appears as a solid line on the display screen. And this is where the hunt begins.

The technician reports the contact to the sonar watch supervisor and begins the process of classification and identification. The supervisor alerts the officer of the deck that a new sonar contact, called "Sierra Ten," for example (contacts are numbered progressively), has been detected and that the sonar team is working it. The conventions for naming contacts are:* Sierra-a sonar contact* Victor-a visual contact* Romeo-a radar contact* Mike-a contact combining one or more signals from different sensors

What is important now is patience and concentration. And much like my character Jonesy, these technicians pursue just as much an art as a science. As soon as the first sound line has established that a contact exists, the other technicians assist in the classification. Despite all that has been written before, there is no automatic classification mode in the boat's computers-one of the Miami sonar technicians has proudly said, "We still do it ourselves."

Sometimes a frequency line is known to be unique to a particular power plant of a particular ship or submarine class. Other times, the effort to classify the target may require the technician to listen through headphones to try and make out what the signal on a particular bearing is. They can listen to tonal signals to determine whether the source is a surface ship or submarine. Each of the different sonars in the BSY-1 suite has its optimum frequency band, and if another sensor might be better at getting data on a particular signal, the technician is fully empowered to ask the officer of the deck to alter course to bring that sensor to bear. During this time the sonar watch team are the eyes and ears of the boat, and every other man aboard knows that his safety may depend on just how good the operators in the sonar room really are. There are set procedures to help guide the sonar technicians, but in the end it comes down to the individual skills of the technicians doing what must be a mind-bending job.

The sonar supervisor reports the best estimate of what and where the source is, and whether it could be a threat or not, to the officer of the deck (OOD). The OOD stations the fire control team to begin the localization/tracking process. This is a dual process utilizing both the manual plotting table as well as one of the fire control consoles. On Miami this process is different from the older Los Angeles-class boats in that all the information is passed automatically between the sonar room and the fire control console via the BSY-1 system network. At this point the tracking team begins the process known as Target Motion Analysis (TMA). Besides identifying the contact, the TMA provides the fire control team with a usable fire control solution, target course and speed, and a reliable range.

This takes time-sometimes, a lot. While you are trying to get all the information necessary to possibly shoot at a target, you must yourself remain undetected. Much of the data for the TMA process comes from the bearing rate, which is how fast the bearing of a target is changing, and monitoring the Doppler, which reveals whether a target is coming nearer or moving away; this is called the range rate. While the BSY-1 is helping the fire control team do its job, the manual plot team, assisted by a specially programmed Hewlett Packard 9020 desktop computer, is also working on its own TMA/range analysis. This little desktop computer has a program library that helps the manual plot team with the more intensive calculations and generates what can only be called instant ranges to the target. All the while the manual and automatic tracking solutions are checked, and data is crossfed between them. During the TMA process the boat would probably maneuver in a zigzag pattern to help the sonar crew establish better range and bearing rates for the TMA plots.

Some nations have chosen to eliminate the dual TMA process and depend only on an automatic system. But this can lead to ranging errors in critical situations, so the U.S. Navy continues to use manual plots and automatic systems just to be sure. Recently Miami ran an exercise against a diesel boat belonging to one of our NATO allies. Apparently, because Miami had a small acoustic fault (called a sound short), the opposing sub thought the boat was much closer than it actually was: the automatic fire control system calculated the range to Miami at around 6,000 yards when, in fact, it was over 40,000 yards. And when the diesel boat fired at what it thought was a nearby U.S. boat, all it did was expose itself to attack by the Miami. Needless to say, Commander Jones made his "opponent" pay dearly for his error.

The TMA process is continued until the commanding officer believes the tracking party has a good enough picture of the situation at hand. Every contact has to have a reliable TMA solution and must be currently tracked. Here lies the real value of the BSY-1 system. For while the earlier Los Angeles-class boats could keep track of only a few targets at one time, the BSY-1 can handle many more. And once the system has a good track running, it has a great ability to hold and maintain the quality of the tracks.

Eventually the target track(s) will be good enough to fire on, if that is the desired intention, and the time has come to set up a weapon for firing. The fire control technician begins the process by inputting the necessary presets into the chosen weapon. If it is a Mark 48, Harpoon, or Tomahawk antiship missile (TASM), this can be accomplished entirely at the BSY-1 console. Should a Tomahawk land attack missile (TLAM) need to be programmed, this is accomplished at the adjoining Command and Control System (CCS-2) console. For now, though, we will concentrate on the weapons programmed on the BSY-1 console.

If, for example, the desire is to launch an antiship missile, the technician must have a decent estimate of target course, speed, and range. It is also critical to know whether there is any neutral shipping traffic in the area. The technician programs in the route to the target, as well as any waypoints necessary to route the missile around neutral shipping traffic that might be in the way. In addition, the technician programs a search pattern for the seeker head of the missile to lock in. This mission plan can be loaded into any number of missiles, which are then fired from the weapons control console located to the right of the fire control consoles.

The process for firing torpedoes is somewhat more dynamic than that for missiles. First the fire control technician develops a fire control solution through a process called "stacking the dots." The screen where this is accomplished displays the target bearing versus time, similar to that back in the sonar room. On this display the target bearing is shown over a period of time as a series of dots. The technician fine-tunes the solution by adjusting the estimates of the target's range, course, and speed until the display shows a straight column of dots stacked on the display. After several minutes of work and possibly a couple of maneuvers to verify the accuracy of the solution, it is now time to shoot.

Despite what some computer games would have you believe, there are no joysticks for the fire control technicians to "fly" the torpedo onto the target. Instead, the technician changes the weapon presets on a screen that looks like a shopping list of parameters such as the seeker activation point (called "enable run"), search depth, and which seeker head mode the weapon is to be fired in. Also, the BSY-1 has several different operating modes, including a "snapshot" mode for fast-moving tactical situations that require the Miami to react quickly. Let's assume that the fire control technician has been ordered to set up a pair of Mk 48 ADCAP torpedoes for a shot at a submarine. He selects the desired target track and allows the BSY-1 to input the weapon presets to the list.

At any time, he can override or alter the presets to suit the tactical situation. For example, the ADCAP has modes to avoid making circular runs and attacking the firing sub accidentally, as well as the ability to preset a three-dimensional search zone for the weapons to search in, but not go outside. Once the weapons have been loaded with the required data, they can be fired by the weapons officer at the order of the captain. With the weapons now in the water, a junior officer calls up the weapons display on his console and monitors the torpedoes' status.

One of the nice features of the BSY-1/ADCAP combination is that the technician can "swim" the torpedoes out onto the target and use the seeker heads as offboard sensors to fine-tune the firing solution. This is made possible by the data link wire that the weapons trail out behind them, which is connected to the torpedo tubes of the Miami. This means that if the technician sees the target move out of the selected area, or do something tactically different from what he thought it would do, he can quickly change the necessary presets right from his weapon control menu.

When the ADCAPs finally acquire the target, the process becomes completely automatic, with the operator's help required only if a torpedo malfunctions. The logic in the guidance systems of the ADCAPs is very good, though if anything goes wrong the fire control technicians are always ready to step in on their own. Assuming that the weapons do their job, the final run to the target will be like watching a train wreck. When they hit, the sonar technician must assess the damage that has been inflicted. There may be breaking-up noises or the distinctive crunch of an imploding pressure hull. In any case, the tracking teams are now ready to start again, a never-ending task while on patrol.

One thing we haven't mentioned yet is just why the Miami has an active sonar mode when so many great things can be accomplished just by listening passively. For almost thirty years, going active with a sonar has meant giving up the tactical advantage. The simple truth is that while using an active sonar does alert a potential enemy to your presence, it does have some significant advantages. The latest nuclear boats produced by the former Soviet Union/Commonwealth of Independent States are almost as good acoustically as a Flight 1 Los Angeles. This means that finding them passively is going to be extremely difficult. And the current generation of diesel boats, when running on their batteries, are just a little worse, being very quiet targets to any passive sonar system in existence. Using an active sonar can overcome some of these problems at relatively short ranges, and has tactical benefits in some situations, especially in verifying ranges before shooting. Unfortunately, an active sonar can be heard at least five times farther than the sonar can detect a target.

The active sonar mode of the sphere sonar is incredibly powerful and can cause steam bubbles to form on the outer surfaces of the sonar dome. The spherical array does give accurate ranges and bearings, providing excellent fire control solutions in the process. In addition, it has the ability to form its sound signals into beams that are focused instead of just radiating in all directions. This means that only the target boat will know it is being "pinged," and other boats in the area will not. In the sort of close-range "knife fights" that may develop between the quieter boats inhabiting the oceans today, going active may just be a good thing to do.

This is a rough picture of how the BSY-1 system and her operators work together. Many other elements go into the process, but I hope this has given you a feel for how the operators would use BSY-1 to fight the boat. If you think it seems like a huge game of blindman's buff, you are right on target, for it is said that in the land of the blind, the one-eyed man is king. In the dark realm of the world's oceans, the Miami with its BSY-1 combat system is the king with the biggest eye.

Torpedo Room

When you wander down a couple of flights of stairs and move forward, you eventually wind up in the torpedo room. Here you are struck by the feeling of being in the very bowels of the Miami. Three sets of two-high racks allow for the stowage of twenty-two weapons, and four more are kept in the tubes. Usually, however, one or two of the rack spaces or tubes are left empty, to facilitate movement of the weapons and allow maintenance. Between the center and side racks are sets of loading and ramming gear. Go forward down the aisles between the racks and you will find the torpedo tubes. These have an internal diameter of 21 inches/533mm and are angled approximately 7 to 8 degrees off the boat's centerline, so that when weapons are launched, they clear the bow with its big active sonar dome. One unique design aspect is the ability to move any weapon from any position in the racks to a torpedo tube or any other position on the racks. While the geometry of such a move is somewhat complicated, the actual movement of the weapons resembles a child's puzzle in which eight pieces are moved through nine spaces to form a picture.

Loading the weapons into the boat itself is a rather involved process, though one that the Miami's designers actually thought out pretty well. Just forward of the fairwater is the weapons loading hatch; through here the weapons are brought on board. The first step in the process is to open this hatch and unstow the loading gear, which is cleverly composed of sections of the flooring structure from the second and third decks of the boat. The second-deck flooring becomes a loading rack that is hoisted up on deck to receive the weapons from the loading crane alongside. A section of the third deck serves as the transit rack, which spans the gap left by taking up the floor structure. Thus while loading is taking place, a gap like a canyon runs down the middle of the boat to the torpedo room.

The actual weapons-loading process is quite rapid once the gear is assembled. The weapon is swung over on a crane from the dock or tender and gently lowered into the loading rack. Once it is aligned, the loading rack is rotated up about 45 degrees, and the weapon is winched down on a chain-powered hoist. When the weapon has completed its nearly 50-foot journey, the transit rack is swung back to the horizontal, and the weapon is laid into the waiting skids on the torpedo room racks. At this point it is secured to the skids and moved over so that another weapon can be loaded. In all, the boat can be completely loaded, including setting up and striking the loading gear, within twelve hours, all with minimum support from a tender or dock crew. Afterwards, when the deck structures have been put back in place, you would never know this is the path the weapons take to the torpedo room.

Loading a torpedo, while straightforward, is anything but simple. The first step is to move a weapon from the storage rack onto one of the loading trays. This requires a bit of brute force (Mk 48s weigh about 3,400 lb/1,545 kg) as well as some precision; even in this day and age, human brawn is still useful. Once the weapon is loaded onto the tray, the inner door (called the breech door) to the chosen torpedo tube is opened and a quick inspection is conducted. If another weapon has just been fired, the crew may need to remove a wire dispenser and/or some guidance wire (if it is a Mark 48 torpedo), or to check for wear on the tube. This little process, known as diving the tube, is a job best handled by those with narrow shoulders and long arms.

Once this is done, the loading ram carefully moves the weapon into the tube. At this point one of the torpedoman mates (TMs) connects the data transmission link, called an "A" cable, from the back of the weapon (all U.S. submarine-launched weapons are equipped with such connections), attaches the guidance wire (if it is a Mk 48), and seals the breech door. Once the hatch is closed, the technicians check to make sure all the connections and seals are properly set, then hang on the tube a small sign: WARSHOT LOADED. One of the nice features on the 688I/BSY-1 boats is that once a tube is loaded, it automatically can tell what kind of weapon is loaded. On several control panels and status boards around the boat, the change in the tube's status to Loaded and what it is loaded with are noted and marked.

Once a decision to launch a weapon has been made (this always requires a look at the mission orders and the standing rules of engagement), then the technicians at the BSY-1 firing control panels up in the control room power on the weapon to warm it up. Then the fire control technician assigned to control the weapon loads targeting and other data into the weapon's memory system. In the case of an Mk 48, this includes speed settings and seeker head mode. For a guided missile like a Tomahawk, it involves loading a complete mission flight profile. Once this is done, the weapon is ready to be fired.

The process of firing a weapon from a torpedo tube is probably one of the most well tested procedures on the entire boat; it dates back many decades. With the weapon warm and ready to fire, the order is given, "Make the tube ready in all respects!" This is not done lightly, for this is the first of a number of actions that radiates a great deal of noise into the surrounding water. Once the tube is flooded, the outer door or cap is opened, and the tube is ready to launch the weapon. The commanding officer gives the command, "Firing point procedures," when the other necessary steps (such as sealing the breech door) have already been completed.

At this point the captain issues the firing command, "Match bearings and shoot!" When the order to fire is given, the weapons officer at the BSY-1 launch control panel presses the firing button, and the firing sequence begins. The firing command directs high-pressure air from the air banks onto a piston. The air forces the piston to move along the piston shaft, forcing water out of another tube and through a slide valve in the rear of the torpedo tube, thereby forming a water ram that ejects the weapon out into the sea at something like four to six times the force of gravity.

What happens next depends on which weapon has been fired. If it is a guided missile, then the outer door can be closed, and the tube is drained and made ready for reloading. If the weapon is a Mark 48, then the decision will probably be made to leave the outer door open. This is because the Mark 48 trails a guidance wire behind it, which allows the boat to guide the torpedo as it runs up to ten miles from the launching point. At any time, though, the wire can be cut. If the sub is traveling too fast, or makes too sharp a turn, then the water flow may break the wire. In any case, until the need for the guidance wire is gone, the tube must stay in use.

Vertical Launch System (VLS)

One of the weaknesses of all U.S. attack submarines since the Permit-class boats hit the water has been the shortage of space for torpedo tubes and weapons stowage. For over thirty years, U.S. attack boats have always had four 21-inch/533mm torpedo tubes to deliver their weapons, and about twenty-two stowage positions to hold them inside the boat. This was not much of a problem so long as all that the boats had to fire were heavy torpedoes and the occasional SUBROC. But beginning in the late 1970s with the introduction of the UGM-84 Harpoon antishipping missile, and the early 1980s with the UGM-109 Tomahawk missile series, this began to pose a real problem for submarine planners and skippers.

For example, say a U.S. sub skipper wants to shoot Harpoon missiles at a surface warship. Submariners traditionally prefer to keep at least one torpedo in a tube as a just-in-case weapon, much as a police officer keeps a hideout weapon in an ankle holster. This means the maximum salvo size that can be fired at the target ship is three Harpoons. This might be fine, but against a target like a Kirov-class battle cruiser with all its antimissile systems, those three missiles will be soaked up like water into a sponge; the weapons will be wasted, and the target will be alerted to the presence of the sub. What clearly is needed is a way to stow more weapons on the boat and fire more of them at one time.

The designers of the Los Angeles-class boats anticipated this, because both the designs for Harpoon and Tomahawk were known at that time. Space was left in the forward ballast tank for twelve Vertical Launch System (VLS) tubes, each capable of storing and launching a Tomahawk cruise missile. In addition, space for the associated control and hydraulic systems necessary to operate the VLS system was left in a compartment forward of the torpedo room. Thus it was possible for a Los Angeles-class boat to carry and launch twelve additional cruise missiles without affecting the weapons stowed and fired out of the boat's torpedo room. This meant an increase of 50 percent in weapons stowage and a 400 percent increase in ready firepower (when firing cruise missiles) over a non-VLS sub.

This change was not made immediately, however. Even though all the Los Angeles-class boats were capable of being fitted with the VLS system, the first boat to be so equipped was the USS Providence (SSN-719). And, because of budget constraints, it is quite unlikely that any of the earlier Flight I boats will ever be retrofitted with VLS missile tubes. Nevertheless, by the time the class is finished building, some thirty-one Flight II and 688I boats will have the system, providing room for some 372 Tomahawk missiles in the fleet. And that is a lot of firepower. By the way, it is easy to make out which boats have the VLS and which don't by whether they are level in the water (VLS equipped) or nose up (non-VLS Flight I).

The way the VLS system works is quite simple. The missile canisters are loaded vertically from a crane. Each canister contains a complete all-up Tomahawk round, ready to fire. At the top of each canister is a thin membrane of clear plastic, which keeps the missile dry and safe. This is how it stays until the time to fire. The boat comes to launch depth, usually about 60 feet, and reduces speed, say 3 to 5 knots, perhaps raising a communications mast to get additional targeting or a navigational fix from the GPS satellite constellation. Once the flight instructions have been programmed into the desired missile(s), the launch system automatically begins the firing sequence.

The system opens the missile launch tube hatch hydraulically and an explosive charge propels the missile up through the plastic membrane and into the water. After the missile travels up about 25 feet the booster rocket fires, thrusting the Tomahawk out of the water. At this point the missile tilts over, drops the burned-out booster motor, lights the turbojet engine, and heads for its preprogrammed target. Meanwhile the launch tube fills with water (helping to compensate for the lost weight of the missile), and the hydraulic hatch is closed.

The VLS system is causing a revolution in design of new weapons for submarines. It has radically increased both the firepower and stowed weapons load for the U.S. submarine force-all at no increase in the size or displacement of the basic Los Angeles design.

Living Spaces

On the Miami's second level is the bulk of the living space aboard the boat. If you stand aft near the forward escape trunk, then you walk forward, you will find the largest open area on the boat, the enlisted mess area. This place is a combination of cafeteria, schoolroom, movie theater, game room, and almost anything else that involves gathering the boat's enlisted population together. Here are six tables with bench seats on both sides so that something like forty-eight sailors at a time, about half the Miami's population, can sit down at once. Along the starboard bulkhead are such cherished pieces of equipment as the soda machines (no longer do they serve the hated "Yogi" cola), milk dispenser, soft ice cream machine, and that most cherished of Navy wardroom icons, the bug juice dispenser. By the way, well-informed palates suggest that the red flavor is best, but stay away from the orange! Strangely, it also makes an excellent scouring powder for cleaning floors and heads (all that acid in it, they tell me). Back near the escape trunk is the ship's laundry. About the size of a phone booth, it handles the laundry for the entire boat, with a washer and dryer that would seem small in most apartments.

Adjacent to the enlisted mess area is the galley. Inside a room about the size of an apartment kitchen, the meals (four per day) are prepared for over 130 officers and men. It's amazing that so much can be done in such a small space. There are all the usual institutional kitchen fixtures (electric mixer, oven, grill, and stewing pots), as well as a pair of refrigerated spaces for food storage. Usually one of these is set up as a deep freeze, the other as a fresh food refrigerator, though for longer patrols fresh food is avoided, and only frozen and dry stores are carried. It is a matter of record that the single most limiting factor to SSN operations is the quantity of food and other consumables. Before a long deployment, virtually every spare nook and cranny is packed with stores-food, soap, paper for the copy machines, dry stores, and, of course, most vital of commodities on board a sub, coffee.

Moving forward on the port side passageway, you encounter the berthing spaces for the enlisted personnel. I should say here that if you have a touch of claustrophobia, this is where it will manifest itself. The three-tall bunks are roughly 6 feet long, 3 feet wide, and 2 feet tall: about the size of a coffin. Each bunk has a comfortable foam rubber mattress with bedding, a light for reading, a blower for fresh air, and a curtain for privacy. All your personal gear goes into lockers on the walls, or the 6-inch-deep trays under the bunks. For the enlisted personnel, this is the total extent of their privacy. This is even further limited, as about 40 percent of the enlisted population has to share, or "hot bunk," their sleeping accommodations. This is because the 688I design just did not have enough room to provide a bunk for each enlisted man. This means that groups of three enlisted men have to share two bunks, with the sleep periods (they sleep in six-hour shifts) rigidly scheduled in advance.

On the starboard side of the boat are the berthing and mess spaces for the senior enlisted personnel, generously known as the "goat locker." Here there is a small seating area about the size of a corner booth at a restaurant, which serves as eating area, office, and conference room for the chief petty officers. Heading aft from here is another aisle of three-high bunks, though these are reserved for each man.

For the officers there is a separate wardroom for eating, studying, and doing paperwork. It is a nicely appointed area with its own pantry for coffee and snacks around the clock. In the middle of the space is a single table that serves as dining table, desk, and conference table. Unlike the commander of almost any other ship in the Navy, the commanding officer does not have a separate pantry to take his meals. He sits with his officers at every meal, giving it the feeling of a family gathering. The submarine service has always been more informal than the surface forces, and this is part of the esprit that makes the "bubbleheads" different from the rest. Commander Jones runs a "loose" wardroom where kidding and friendly ribbing is always welcome. He makes no secret of his love of good seafood, and is a big fan of ice cream. In fact, he is fond of saying that other than having the only private stateroom on the boat, his only command privilege on the Miami is choosing the flavor of ice cream for the machine in the galley. He chooses a rather diplomatic French vanilla flavor.

As for the commander's cabin, it is hardly the stuff you might find on the Queen Elizabeth II. Located just forward of the enlisted mess, on the second level, it is roughly 10 feet long by 8 feet wide. It is dominated by a combination desk/closet unit in the after portion of the cabin. Against the outside bulkhead is a pair of seats with a small table between them; this unit folds down into the bunk. Commander Jones is proud of saying that it's the best bunk on the boat, and certainly it is the only one that does not have another bunk above and/or below it! On the door to his cabin are three notices. One reads KNOCK AND ENTER and another is, THINK QUIET! IT'S OUR BUSINESS… IT COULD BE OUR LIVES. The final one is a copy of Rudyard Kipling's famous poem, "If," not a bad philosophy to advertise if you are in charge of 132 lives and $800 million of the taxpayers' money.

The commander's desk contains a variety of different manuals, a safe for classified documents, and various communications devices to keep him in touch with the rest of the boat. One of the newest pieces of equipment to be added is known as a multifunction display, mounted adjacent to his bunk. This marvelous device, which is tied into the BSY-1 combat system, is a red gas-plasma display showing data on position, course, speed, heading, and depth, as well as modes to show the current tactical situation around the boat. The advantage to Commander Jones is that he can wake for a moment in the middle of the night, reach over and check the boat's status, then roll over and go back to sleep-all without having to ruin his night vision by turning on a light or having to pick up a phone and talk to the OOD. He figures that not having to wake up fully several times is worth several hours' more sleep. And that can be life and death for the boat in a combat situation. A total of eight of these devices are located around the boat in such places as the control room and sonar room.

The Engine-The Reactor/Maneuvering Spaces

If you wander aft from the enlisted mess, past the forward escape trunk and down half a deck, you find the great divide on the Miami. This is the entrance to the tunnel aft to the propulsion spaces containing the S6G nuclear reactor (built by General Electric) and the main engineering spaces. It is marked by a number of different warning signs from the DNR, ranging from information on possible radiation hazards, to security notices about just who on the boat is allowed aft of this point. It should be noted that no member of the media, including myself, has ever actually seen an actual nuclear submarine reactor compartment or her engineering spaces. Nevertheless there are a number of things that we do know about these areas, and I will try to share them with you.

The first thing to understand about the nuclear reactor on a submarine is that it has only one real purpose, to generate heat to boil water into saturated steam. Other than that, all of the other parts of a nuclear submarine propulsion system are similar to any other type of steam-powered turbine plant. Its advantage over an oil-fired steam plant is the amount of energy concentrated in the nuclear fuel in the reactor core, as well as the complete lack of any need for air. On a weight and volume basis, nuclear fuel, such as enriched uranium, has several million times the amount of stored heat of a comparable amount of fuel oil. This concentration of energy is what makes all the dangers of handling nuclear fuel worth the trouble. In addition, because of the efficiency of the nuclear "fire," it is possible to build boiler plants that are considerably smaller than comparable oil-fired plants.

The process of nuclear fission is essentially quite simple. Imagine a floor covered with mousetraps. Each mousetrap has, mounted on the striker arm, two Ping-Pong balls. If we imagine a uranium atom as a mousetrap, it is holding on to a pair of attached particles called neutrons much like the Ping-Pong balls. Now if you drop another Ping-Pong ball onto one of the traps and trip it, two balls will fly into the air. This represents what happens when a neutron enters the uranium atom and strikes the nucleus: the atom splits and releases the two neutrons, releasing energy as heat. And when those two fall onto two more traps, these will trip and each throw two more Ping-Pong balls skyward. This will continue to double and double again until all the traps fire off their balls in one final fusillade. This same principle, whereby neutrons strike more and more atoms until all of them finally split, is called an uncontrolled or supercritical fission reaction. And this is what happens when an atomic bomb detonates.

But we don't desire an explosion, we want a slower reaction like a fire in a boiler. Imagine that in our room of mousetraps and Ping-Pong balls, we hang some monkeys from the ceiling. And we train them to grab one out of every two Ping-Pong balls when a trap goes off. This would allow the series of tripping traps to go on for a much longer time. And this is exactly what happens in a nuclear reactor. Instead of monkeys, a reactor uses what are called control rods (made of a neutron-absorbing material like cadmium or hafnium) set to absorb exactly the right amount of neutrons to bring the reaction into controlled or critical fission. This reaction still generates a great deal of heat, which is used to boil water into saturated steam to power the sub's turbines. In this way the same nuclear fuel that can cause a nuclear explosion in an instant can be used to power a ship for a period of years. And because of design procedures that have been tested over a period of decades, the fuel in the reactor cannot explode or even come close to doing so. The DNR takes great pride in the safety record of the boats with U.S.-designed reactor plants, which is perfect.

Most of the heat in the reactor is collected into what is known as the primary coolant loop. This is a series of pipes passing an extremely pure water-based coolant through the core of the reactor. This heat is passed through a heat exchanger to what is called the secondary loop. This is where the water for the steam turbine is actually boiled. Now, the steam created here is not the stuff you get from the tea kettle on your stove. This steam, which is under high pressure, is heated to literally hundreds of degrees and contains a great deal of motive energy. And this is the stuff that turns the turbine blades of the main engines, which feed into the reduction gears, which turn the propeller shaft and the propeller. Quite simple, really!

There are a few small problems with this system, though, and we need to discuss them. The obvious one is the question of how to protect the men aboard from the harmful effects of the reactor's radiation. As we mentioned before, the early Soviet nuclear boats scrimped on shielding and became cancer incubators for the naval hospitals of that now-defunct nation. The answer, in a word, is shielding. The entire structure surrounding the reactor compartment is layered with a variety of different shielding materials.

Between the reactor compartment and the forward part of the boat is a huge tank of diesel fuel, which powers the big Fairbanks-Morse auxiliary engine in the machinery compartment. As it turns out, that fuel is extremely efficient at modulating or absorbing the various subatomic particles that could damage human tissues. In addition, the entire reactor is contained inside a reactor vessel that looks like an oversized cold capsule on end. Surrounding this vessel, as well as inside of it, is a system of layered shielding. While the materials actually used are classified, it is easy to deduce that lead (an excellent gamma ray absorber) and chemically treated plastics (based on fossil fuels) are probably used extensively.

In addition to its extensive shielding, the entire reactor plant has been overengineered. Since its earliest beginnings, the DNR has insisted that naval reactors be built with extremely high safety margins. While DNR will not comment, for example, upon just how much pressure all of the reactor plumbing can take, it is generally acknowledged that the entire reactor plant has been built several hundred percent more robustly than is required (400 percent to 600 percent has been mentioned). In addition, every system has at least one backup and usually an extra manual backup on top of that. The legacy of the Thresher loss is this fanatical obsession with safety.

Another area of extreme secrecy is the exact configuration and design of the reactor core itself. In fact, other than the technology used to reduce radiated noise, nothing on the Miami is as sensitive as the power plant core. This probably consists of a series of uranium fuel elements formed into plates to allow maximum heat transfer to the primary coolant loop. The fuel elements are probably mounted parallel to each other in a fuel assembly mounted atop a support structure in the base of the reactor vessel. The fuel used is highly enriched Uranium-235, probably 90 percent pure U-235 or better. For those who might wonder, the fuel used in commercial nuclear power generation plants runs about 2 percent to 5 percent pure, and the material used in nuclear weapons is about 98 percent pure. In between each fuel element is room for a control rod (also in the form of a plate and made of a neutron modulator), to control the rate of nuclear fission. Each rod is designed to drop automatically into place between two fuel elements in the event of a reactor problem, thus quenching the nuclear reaction. In addition, a procedure called scram allows the crew or the automated monitoring systems to shut down the reactor immediately, and restart it later if conditions allow.

Around the core circulates the coolant of the primary loop, which feeds the heated coolant into a steam generator. The steam generator directs its steam into a secondary cooling loop, which feeds a pair of high-pressure turbines in the machinery spaces, where the steam is condensed back into water and fed back into the steam generator. The turbines feed into a massive set of gears known as reduction gears, which turn the main propeller shaft. In addition, some of the steam is used to turn several smaller turbines that provide electrical power to the boat and its various pieces of machinery.

It may come as a surprise that other than the transit tunnel aft to the main machinery space, the reactor is not manned. The DNR limits the time a man can stay in proximity to the reactor, even how long he might stay in the transit tunnel. The actual control area for the reactor plant and the turbines, called Maneuvering, is located aft in the engine room. While it has never been shown to the press, it probably follows the convention of commercial power plants, with the controls laid out over a block diagram of the reactor/turbine system. This panel is manned at all times, even when the boat is in port and the reactor is shut down (noncritical).

The dominating feature of the machinery space is the deck, or more correctly, the mounting for all of the machinery. While it may seem solid enough, it is in fact a large platform or "raft," which is suspended on mounts on the inside of the hull. The mounts use at least one, probably two, sets of noise isolation mounts. These are like oversized shock absorbers designed to reduce the vibrations of the larger pieces of engine room machinery. The purpose of a raft is to take the noisiest things on the boat and isolate them from the hull, which radiates noise like a speaker into the water.

Mounted on the raft are the two main engines, the boat's electrical turbine generators, and the supporting pumps and equipment associated with moving the boat. Proceeding aft, you see the main propeller shaft leading back to the main packing seals in the stern. In addition there are a number of workbenches, as well as a limited machine shop capable of supporting many small-scale repairs. The size of the main gear, called a bull gear, would preclude repair, but virtually every other contingency in the space could be handled by the engineering team. These crew members, by the way, are recognizable by the different types of radiation monitoring devices they wear. Unlike the film badges worn by those who live and work forward of the reactor, these personnel wear a small dosimeter (which looks like a tiny flashlight), so that any dosage of radiation they receive can be assessed immediately.

To get the power plant started, the engineering officer of the watch orders the personnel at the reactor control panel to retract the control rods to a known position. This allows the core to heat up, causing the coolant to generate steam in the steam generator. From here the turbines are set turning, and so too the reduction gear train. There is a popular notion that the speed of the boat is increased by just retracting the control rods farther from the reactor core. This, in fact, is exactly the converse of what actually happens; the rods are simply retracted to a fixed point and held there. The engineers' main goal is to bring the reactor into equilibrium so that the basic amount of heat going into the primary coolant loop is constant. One can then control the speed of the boat by simply tapping more steam from the steam generator, thereby increasing the steam supply to the turbines. This results in cooling the primary coolant loop more, thus increasing the efficiency of the nuclear reaction, feeding more heat to the steam generator, and increasing the speed of the boat.

Conversely, stemming the flow of steam to the turbines not only slows down the spinning of the turbines, it also takes less heat from the primary coolant loop, and rapidly drops the efficiency of the nuclear reaction, "cooling" it down.

Life Support and Backup Systems

The auxiliary machinery space down on the third level aft of the torpedo room is arguably the most important compartment on Miami. Here is located all of the life support equipment, as well as the auxiliary power source. As you enter the space and head down the starboard aisle, you are given a quick introduction to "Clyde," the big auxiliary diesel engine. This is an old favorite of the chiefs onboard, because it is a direct link with the old World War II fleet boats. Built by Fairbanks-Morse, the design dates back to the 1930s and is a scaled-down version of the model used to power all of our submarines during the war. It is reliable and the crew loves it, therefore the name Clyde, as in, "… right turn, Clyde!"

While some folks might wonder why such a dinosaur would be on one of the most advanced submarines, remember that not everything always works properly, including nuclear reactors. For example, what would happen if Miami was at sea and needed to scram the reactor plant? Restarting a reactor takes a lot of power, and while there is a large bank of batteries underneath the torpedo room, it might not prove adequate to completely restart a cold S6G plant. Thus the Fairbanks-Morse engine can provide, through a generator turned by the diesel, enough continuous power to get the tea kettle running again. It has other uses, too. In the event of a reactor casualty, the diesel provides the means for getting home. In that event, the captain orders the engineers aft to lower a small electric outboard motor, which is recessed in the lower hull aft, into the water to provide motive power to get home or to get help.

The diesel engine also has a role in firefighting onboard that might surprise some folks. In the event of a fire, one of the first things the captain might do (assuming this is not in a combat situation) is to surface and start up the diesel. This is because the diesel draws its air from within the boat, and thus it would suck up any air being polluted by the fire. Opening just the fairwater hatches from the control room will completely change the air in the boat in a matter of minutes.

This space is also where the air is made or, more properly, maintained. Several different pieces of equipment in the auxiliary machinery space help to provide the clean, fresh air that can be found onboard. First are the carbon dioxide (CO) scrubbers. CO is the gas given off by humans when they breathe and is dangerous when the concentration gets too high. The Miami utilizes a chemical scrubber to remove it from the air. The chemical absorbs CO when it is cool and releases it when it is warmed. In addition, CO and H "burners" remove the carbon monoxide and hydrogen gas generated by equipment as well as by cigarette smoking, which is allowed onboard. Finally, filters and dehumidifiers clean the air and help keep it "friendly" not only for the crew but also for the many pieces of equipment-especially electronic-on the Miami. In case a fire or some other emergency contaminates the onboard air, a force-fed air supply called the Emergency Air Breathing (EAB) system has attachment points throughout the boat, allowing crewmen with breathing masks to plug in to it and continue their duties.

Other life support equipment includes a device that takes water and electrically "cracks" it into its base elements of hydrogen and oxygen. The oxygen is retained in tanks and released into the boat's atmosphere automatically by the environmental control system, and the hydrogen is vented off the ship from a small port in the aft edge of the fairwater. There is a fresh-water distillation plant that produces something over 10,000 gallons/38,000 liters of fresh water a day. Most of the water is used for drinking, cleaning, cooking, and personal hygiene. Very little water is usually required for the power plant (for charging the cooling loops and steam generators), but the reserve tanks are usually maintained near full "just in case." It should be said that the obsession with water conservation is mostly for contingency purposes. Most COs like to have full tanks of water before they enter a tactical situation, just in case they need to shut down the distillation plant to keep noise down. And from what I hear, some boats just choose to run the distillation plant full-time and let the crew have as much shower time as they want, particularly during runs home. On a normal day aboard Miami, the majority of the water produced would go to crew habitability.

Weapons-Torpedoes, Missiles, and Mines

While submarines are useful for covert actions like intelligence gathering and landing special operations forces, it is the threat of what they can do with their weapons that can cause so much fear and respect in an adversary. Ever since Sergeant Ezra Lee tried to sink HMS Eagle in Boston harbor back in 1776, just the potential threat of harm from a submarine has been enough to make an enemy stop and consider whether he should move his ships against you. Today the weapons can hit a wider variety of targets, and they have become even more deadly.

Torpedoes

The torpedo is the traditional weapon of the submarine, and the torpedoes that equip the U.S. SSNs today are truly awesome. For some years now, the U.S. standard torpedo has been the Mark (Mk) 48. This weapon, which first appeared in 1971, has gone through a series of different upgrades, culminating in the Modification (Mod) 4 version, which appeared in 1985. This version, designed as an intermediate upgrade to the next major version, allows for the greater speeds and deeper diving depths of the newer Soviet subs that were appearing at the time. As this book is written, about half the torpedoes being loaded aboard U.S. subs are Mk 48 Mod 4s.

A recent addition is known as the Mk 48 Advanced Capability (ADCAP) torpedo. Manufactured by Hughes, the ADCAP takes the basic Mk 48 package and adds the following new features:* A bigger fuel tank that provides for a 50 percent increase in range (about 50,000 yards), and a speed of 60+ knots.* A new data send/receive module, which packs 10 miles of guidance wire into the aft end of the torpedo and 10 more miles into the dispenser in the tube. This allows the submarine to clear the launch point and still guide the weapon.* A new combination seeker head/computer that uses electronically steered sonar beams to guide the weapon to the target. Earlier versions of the Mk 48 (like the Mod 4) used to have to "snake" about their course to search effectively for a target. The head allows the torpedo to see almost all the 180-degree hemisphere ahead of the weapon. The computer controlling the whole system is designed to make the ADCAP the world's "smartest" torpedo.

With ADCAP, the submarine force arguably has the finest torpedo in the world. Not only is it fast, deep diving, and maneuverable, but it has a big warhead (650 lb/295 kg of PBXN-103 explosive) with an active electromagnetic fuse that allows the weapon to be detonated precisely where it will do the most damage. And it has more "brains" than any other torpedo, with an amazing ability to outsmart countermeasures and jamming, as well as the capability to feed seeker-head data back to the BSY-1 system on Miami. This allows the fire control technicians to use the ADCAP as an offboard sensor. With such capabilities as these, it's no wonder that the crew of Miami calls the ADCAPs in her racks "wish me dead" torpedoes.

Missiles

Strange as it may sound, the nuclear submarines of the U.S. Navy operated for over twenty years without a dedicated weapon for attacking surface ships. Part of the reason was the ASW focus of the SSN force during the 1960s and 1970s. Also, for much of that time their primary targets, the surface ships of the USSR, had no long-range weapons that could attack a sub while it was submerged. But with Soviet deployment of their first sea-based ASW helicopters and the ship-launched SS-N-14 Silex ASW missile, there was a clear need for a weapon that would allow a boat to stand off farther than the ten to fifteen miles a torpedo shot would allow. It had to be launched from a torpedo tube and carried as an all-up or "wooden" round, requiring no maintenance and a minimum of support.

The weapon that was produced was the McDonnell Douglas A/R/UGM-84 Harpoon. This missile, which can be launched by ships, subs, and aircraft, was originally developed to allow patrol aircraft to shoot at Russian cruise missile subs on the surface. First deployed in 1977, it is approximately 17 feet/5.2 meters long, weighs about 1,650 lb/750 kg, and carries a 488-lb/222-kg high-explosive warhead. It utilizes a radar seeker that looks for surface targets and then initiates an attack "endgame" on the target. Packaged inside a buoyant, torpedo-shaped launch capsule, it is fired from one of the normal torpedo tubes and rises to the surface. When it reaches the surface, the nose of the capsule is ejected, and the missile is launched into the air by a small rocket booster. Once airborne, the booster is dropped, an engine inlet cover is ejected, and the small turbojet engine is ignited. The missile then descends to about 100 feet above the surface, and transits to the area of the target ship at a speed of about 550 knots.

The Harpoon can be launched in a variety of modes. These include what is known as Bearing Only Launch (BOL), in which only the bearing to the target is known. There is also a series known as Range and Bearing Launch (RBL) modes, which require both range and bearing. Depending on the range to the target and the amount of neutral shipping in the area, the seeker can be set to RBL–L (Large) for open ocean situations, or RBL-S (Small) for tight, short-range situations. If necessary, several doglegs or waypoints can be programmed into the Harpoon's Midcourse Guidance Unit (MGU), which utilizes a small strapdown inertial guidance system to keep the missile on course. For submarines, there is even a self-defense option that allows the defending SSN to shoot the Harpoon "over the shoulder" into a charging surface ship.

Once the missile gets to the target area, the seeker is switched on and begins to search an area shaped much like a piece of pie. If the seeker radar locates a suitable target, the onboard computer does a quick test to make sure it is a valid target (not a wave or a whale), and begins the endgame. The missile descends to an altitude between 5 and 20 feet (depending on the height of the waves) and heads for the target. At the discretion of the Miami's fire control technicians, the missile can be programmed to run straight into the side of the target ship (just a few feet above the waterline), or an optional "pop-up" maneuver can be selected to make the missile plunge deep into the middle of the ship.

In any case, the exploding warhead will tear much of the guts out of any ship up to cruiser size. In addition, any of the jet fuel not used by the missile's turbojet will add to the destruction aboard the target vessel. It is a little-known fact that the warhead of the Exocet missile that sank HMS Sheffield in 1982 failed to detonate, but the residual rocket fuel in the missile's motor caused enough of a fire to eventually sink the ship.

The latest version of Harpoon aboard the Miami is the UGM-84D, which uses a denser fuel mixture to give it more range (reportedly around 150 NM/250 km). All in all, with some eighteen different countries using it, Harpoon is one of the most successful missile programs ever run by the U.S. Navy.

After the ADCAP, no weapon has done more to make the Miami deadly and effective than the UGM-109 Tomahawk cruise missile. Tomahawk is an outgrowth of a loophole that was discovered after the signing of the SALT I arms limitation treaty in 1972. While the exact origin of the cruise missile program is debated, it is generally assumed that Henry Kissinger, then the National Security Advisor, asked the Department of Defense (DoD) to look for classes of nuclear weapons that had not been considered during the SALT I negotiations. After some study, the DoD systems analysts came to the startling conclusion that air-breathing cruise missiles, basically cheap pilotless aircraft with nuclear warheads, would make an excellent weapon to circumvent the terms of the SALT I agreement. They could be launched from ground vehicles, aircraft, ships, and submarines, would be extremely accurate, and would be quite difficult to detect and intercept.

As a result of these studies, a joint project office to develop cruise missile components was started by the U.S. Navy and U.S. Air Force. While both services wound up choosing different models of missile (the Air Force selected a model built by Boeing), most of the components such as engines, warheads, and guidance systems were of a common design. The winner of the Navy competition was the B/UGM-109 model developed by General Dynamics. McDonnell Douglas is the second-source contractor for the missile, called Tomahawk.

The basic nuclear land attack version of Tomahawk, known as B/UGM-109A (also called TLAM-N), is launched into the air by a small rocket booster. Once airborne, a miniature jet engine about the size of a basketball ignites to power the missile at about 500 knots. It flies low to the surface (whether over the open ocean or land), held there by a guidance unit (MGU) being fed by a radar altimeter. The missile is kept on course by the MGU utilizing an inexpensive strapdown inertial guidance system. Once over dry land, the MGU is updated with position data from a system known as Terrain Contour Matching (Tercom), which matches the terrain under the missile with a three-dimensional database in the memory of the MGU. By using periodic Tercom updates, a TLAM-N is normally able to place its 200-kiloton W-80 nuclear warhead between the uprights of a football goal-post after a 1,300-mile flight.

While the nuclear-armed version of Tomahawk was being developed, it occurred to a number of people that perhaps the Tomahawk could be used to carry other things, and thus was born the whole family of conventionally armed Tomahawks in service now. The first of these was the B/UGM-109B Tomahawk Anti-Ship Missile (TASM), which replaced the TLAM-N MGU with a modified radar seeker and MGU from the A/R/UGM-84 Harpoon antiship missile. In addition, the W-80 nuclear warhead was replaced with a 1,000-lb/455-kg high-explosive warhead.

The idea was to provide units of the U.S. Navy with a really long-range (250 NM/410 km) antiship missile. One problem that had to be overcome was the fact that a TASM flying out to hit a target ship at maximum range would have to fly almost thirty minutes to get to the target area. During this time, a fast warship might travel as far as fifteen to twenty miles, so a special series of search patterns was added to the TASM launch and control software. These search patterns comprise a series of "expanding boxes" designed to allow the TASM to fully search the uncertainty zone or the possible target area. In addition, TASM has a passive ESM system called PI/DF (Passive Identification /Passive Direction Finding), which is designed to direct TASM onto larger enemy warships, probably through detection of their large air-search radars.

Following the TASM into service was the largest subfamily of the R/BGM-109 program, the Tomahawk Land Attack Missile-Conventional (TLAM-C) series. This particular series takes the basic guidance system of the TLAM-N, adds the high-explosive warhead of the TASM, and a new terminal guidance system called Digital Scene Matching (DSMAC). It has a range of roughly 700 NM/1,150 km, and uses the same basic Tercom system to get into the vicinity of the target. DSMAC is an electro-optical system that matches the image from a small television camera in the nose of the TLAM-C to one stored in system memory. This system can even be used at night, with a strobe light on the target during the final approach. Called the B/UGM-109C, it became the first of the Tomahawk series to be used in combat, during Operation Desert Storm.

Several derivatives of the basic TLAM-C include the B/UGM- 109D, which replaced the basic high-explosive warhead with a dispenser for 166 BLU-97/B combined effects (fragmentation and blast) submunitions. Called TLAM-D, these Tomahawks are particularly effective against vehicles, personnel, soft targets, and exposed aircraft. A further variant of the TLAM-D, which is armed with antirunway cratering submunitions, is known as the B/UGM-109F. The newest version of Tomahawk, called Block III, incorporates a number of new features such as its own Navstar GPS receiver, a new penetration warhead, an improved engine, and more fuel to bring its range to over 1,000 NM/1,640 km. It should be operational in 1994.

All the various types of Tomahawks can be loaded and fired from any 21-inch/533mm torpedo tube or VLS tube on the Miami. Besides twelve missiles in the VLS tubes, additional Tomahawk rounds, as required by a particular mission, can be stored in the torpedo room. This makes Tomahawk the most flexible strike system ever deployed by the U.S. Navy. It also opens a new dimension for the U.S. SSN force, since now they can join the surface and air forces in striking "over the beach" at significant targets.

The following might be a typical mission load-out for the Miami. When preparing to leave for a cruise to the Mediterranean, she might carry a full load of Tomahawks, which would include twelve VLS tubes full of TLAM-C/D variants, with several more in the torpedo room racks. In addition, she would carry a mixed load of Mk 48 Mod 4s and ADCAPs, as well as several Harpoon Block ID antiship missiles. There would be no TLAM-Ns, as all of these have been withdrawn from U.S. ships, aircraft, and submarines following President Bush's order in the fall of 1991. Nevertheless, though it is the policy of the U.S. Navy not to deploy nuclear weapons, and they normally refuse to discuss it, the capability does still exist. Also, there would be no TASMs aboard, as the submarine community seems to feel that the Harpoon Block ID is more than adequate to the antishipping task, and the TASMs are hard to get long-range targeting for, on a submarine.

The biggest single bottleneck to effectively utilizing the growing force of TLAM-C/D cruise missiles in the inventory is the preparation of suitable mission plans. Each mission plan has to be developed from a Tercom data base that the Defense Mapping Agency (DMA) has assembled over a period of fifteen years. The data is made into mission plans at one of the Theater Mission Planning Centers (TMPC) located at various places around the world. Here the Tercom data bases are merged with terminal target photos (for the DSMAC cameras), to produce mission plans that can be stored on disk packs on the sub, or downloaded to the sub via a satellite link.

Once the Miami has a particular mission plan aboard, the basic plan can be modified on the BSY-1 Command and Control System (CCS Tac Mk 2) console in the control room. Located adjacent to the BSY-1 fire control consoles, this console can be used to plan and control missions for all the variants of Harpoon and Tomahawk. Should Miami not have a plan available in her onboard library, she can use the CCS-2 to develop her own plans. And with the coming deployment of the Block III version of TLAM-C, the requirement for access to a complete Tercom library for mission planning will be reduced.

To launch a Tomahawk or Harpoon, the boat has to slow to about 3 to 5 knots and come to periscope depth. The CCS-2 (or BSY-1 in the case of Harpoon or TASM) console operator powers up and loads a mission plan into a missile loaded in either a torpedo or VLS launch tube. This can be done for as many or as few missiles as the situation requires. Once this is done, the weapons officer inserts a launch key (a holdover from the old TLAM-N days) and presses the firing button. If the weapon is a Tomahawk, it is ejected from the tube (the version fired from torpedo tubes is carried in a tube liner), fires its booster rocket, and away it goes. If it is a Harpoon, the weapon in its buoyant capsule is ejected from the tube and heads for the surface. When it gets there, the booster rocket fires, and it heads for the designated target.

The one problem with all these missiles is that they make the firing submarine extremely vulnerable to detection by aircraft or surface ships, and the amount of noise made by a missile being fired underwater is simply amazing. So it is essential that if the Miami is ever tasked with firing a weapon, as the USS Pittsburgh (SSN-720) and USS Louisville (SSN-724) did during Desert Storm (they fired a total of fourteen TLAM-Cs and TLAM-Ds), she will have to be sure she is clear of any threat during the launch cycle.

Mines

Probably the least appreciated weapons that can be carried by a 688I are mines. These "weapons that wait" are perhaps the most cost effective weapons ever derived for naval warfare. Though most of the mining done by the United States since the end of World War II has been done by aircraft, there may be situations where the stealth and precision of a submarine may be preferred for delivery of these dangerous "eggs."

The first of these is the Mark (Mk) 57 moored mine. It is a derivative of the air-dropped Mk 56 and can be moored in several hundred feet of water. It has a variety of different sensor and triggering systems, including acoustic and magnetic influence fuses. They can be programmed for activation delay or programmed to activate only for certain types and numbers of ships.

Another type is the Mk 67 mobile mine. These are obsolete Mk 37 torpedoes that have been rebuilt into mines that lie on the bottom and wait for a target to drive over them. A submarine might fire them up into a shallow channel, to a distance of 5 to 7 miles. Like the Mk 57, this mine has a variety of different fusing options.

But the crown jewel of the U.S. mine arsenal has to be the Mk 6 °Captor mine. This is an encapsulated Mark 46 torpedo, programmed to wait for enemy submarines; when one is detected the torpedo swims clear and attacks the sub. As an added benefit they can be programmed to listen for a certain type of submarine, like a Kilo or Akula. During the Cold War, it was planned to seed Captors along all the transit routes used by the submarines of the Soviet Union. Now they can be used against any of the growing number of countries that have chosen to buy and use diesel submarines in their navies.

One of the nice things about mines is that they take up only about half as much space as the other types of weapons a sub might carry. Thus a 688I could carry as many as forty mines and still have a couple of ADCAPs for self-protection. The deployment of the mines is no different from loading and firing a torpedo (the BSY-1 has a mine launch mode), though the position of the mine has to be plotted absolutely accurately, so that it can be swept later. Fortunately the advent of GPS has made this task a bit easier, though efficient use of the SINS system is also required.

All in all, these weapons make for a very dangerous quiver of arrows for the submarine force.

Escape Trunks/Swimmer Delivery

Wandering aft about 25 feet from the enlisted mess puts you underneath the forward escape trunk. This is a two-man air-lock used for a variety of purposes, though primarily as the main entry point to the forward part of the boat. It is composed of a pressure vessel about 8 feet tall and 5 feet in diameter. At both the top and bottom is a hatch capable of standing as much pressure as the actual hull of the boat. Most often personnel and supplies are loaded through this trunk. There is also another trunk farther back over the aft machinery spaces.

In the event of an emergency the escape trunk comes into its own. If the boat is on the bottom and stable, the normal procedure is to wait for one of the deep-submergence rescue vehicles (DSRV) to be transported to the rescue site. The DSRV then comes down and docks to the collar over one of the escape trunks. It blows out the water from its own docking collar, now held in place by the pressure of the surrounding water. The crew of the DSRV open their own bottom hatch and enter the downed boat through the trunk. Now the crew of the downed sub can come aboard, albeit only about two dozen at a time. This means that if a Los Angeles boat were to go down intact with all her crew alive, it would take something like six trips to get them all off.

If the boat is flooding and the crew must get off immediately, the escape trunk takes on a more vital role, allowing the crew to escape from the boat under their own power. This is done using a Steinke hood, a combination life jacket and breathing apparatus that fits over the head of a sailor. Two at a time the men enter the escape trunk wearing their Steinke hoods. They close the bottom hatch and huddle under an air bubble flange installed in the trunk for such operations. The sailors then charge their Steinke hood air reservoirs from an air port in the side of the trunk, and open a flood valve to fill the trunk with water. While they sit under the air bubble flange, the upper hatch opens. If they are the first ones to escape from the sub, they will have the additional job of pushing a life raft out of the hatch; this floats to the surface and provides some shelter for the men when they get there. Then, one at a time, they duck under the flange and float up through the hatch.

At 400 feet (the maximum depth that the hood can be used), the men will have something like a minute to flood the trunk and get out. Any longer, and they risk getting "the bends" (small bubbles of nitrogen gas that form in the blood) as they rise to the surface. After they have exited, the controller in the area below the trunk closes the hatch via his control panel and begins to drain the trunk for the next pair of escapees. Meanwhile the two sailors literally rocket up to the surface. This would be extremely dangerous (the decreasing water pressure makes them vulnerable to a variety of air embolisms if they hold their breath), but with their heads in the air bubbles of their Steinke hoods, the men are able to breathe normally throughout the ascent to the surface. Once on the surface, they try to inflate the raft and stay together.

One of the other primary uses for the escape trunk, this one far less ominous, is as an airlock for divers and special operations teams. One of the little-known facts about U.S. submarines is that they have, at all times, a small team of divers (usually three to five rated divers) aboard to support the operations of the sub. The diving equipment and other gear is stored in the compartment forward of the torpedo room, near the VLS support equipment room. The divers' jobs include everything from clearing fouled propellers and running gear, to running security checks on the boat before she leaves harbor. In fact, when the Miami is in a foreign port she is not allowed to leave the harbor unless she has at least three divers aboard to assist in examining the hull before she gets underway.

The other type of diver-related operation that is conducted through the escape trunk is submerged "lock-out" of special operations teams, such as the U.S. Navy's elite SEAL teams. These kinds of operations are really not the forte of the 688I and will, until they are retired, be predominately the job of modified Sturgeon-class boats like the Parche (SSN-683). Part of the problem is that the Los Angeles-class boats are optimized for speed and are not properly equipped to conduct this kind of mission effectively. Also, the already cramped accommodations of the 688I make it necessary to set up temporary sleeping quarters for the team, perhaps on bunks down in the torpedo room.

In the unusual case of a special operations mission, the boat nears the target of the team and hovers over the seabed. The team then enter the trunk two at a time under the air bubble flange, and follow the same procedure as escaping sailors except with their diving gear. Retrieval is exactly the reverse, with the team reentering the trunk two at a time, closing the hatch, draining the trunk, and exiting through the bottom hatch back into the boat.

The Sounds of Silence — Acoustic Isolation

Silence. That is what has made American boats better than their opponents for over thirty years. It is their armor and their cloak all wrapped up into one vital quality. Nevertheless it comes at a high price and is called a fragile technology-fragile because it is based upon well-understood principles of physics, and because it can be compromised so easily. In terms of military technology, it is one of the crown jewels, in the same category as the ability to build stealth aircraft and nuclear weapons. So effective has this silencing effort been that the latest U.S. SSNs and SSBNs are so quiet, they can effectively disappear in the ocean's background noise.

To make a quiet submarine, the naval architects must take a holistic attitude to the design of the boat and every piece of equipment that goes into it. The key is mounting each piece of equipment that moves or makes noise on something that damps out the vibrations. The transmission of these vibrations-things like the spinning of a pump or the hum of a generator-sends noise out into the hull, where it is radiated into the water. In addition, the rubber decoupling tiles coating the hull help keep noise inside the hull from being transmitted out into the water.

The mounts on the main machinery raft take care of the biggest source of radiated noise. The rest of it is probably taken care of by secondary mounts underneath each piece of equipment (pumps, turbines, etc.), designed to attenuate the specific type of noise generated by that particular piece of equipment. In addition, each piece of machinery is probably designed to be as smooth running and noiseless as America's best mechanical and electrical engineers can make it. For example, the seawater circulation pumps, which are arguably the most noisy devices on the boat, transmit almost no noise in the 688I-class boats. Supporting this is a noise-monitoring system with sensors throughout the boat designed to tell if any piece of equipment or gear is loose or malfunctioning. An added benefit of this system is that it probably is capable of predicting when and how a piece of machinery is going to fail by its acoustic signature (such as the sound of bearings wearing out).

The various techniques used to decrease the radiated noise of American submarines constitute the single most classified aspect of the Miami and her sisters. The above description is only the most cursory discussion possible of this incredible technology. In fact, the only real way to describe the magnitude of the achievement is to say that the S6G reactor generates something like 35,000 shaft horsepower[10], yet with all this power the total noise radiated by the Miami is probably something less than the energy given off by a 20-watt lightbulb. It is for this reason that submariners sometimes refer to their Air Force cousins flying the F-117A stealth fighter as "the junior stealth service."

Life Aboard

So, you ask, what is it like to live aboard a submarine like Miami? Well, imagine a combination of living in an oversized motor home and summer camp, and this is a lot of what life in the 33-foot pressure hull is like. Not much room, very little noise, very little news from home, and virtually no privacy. Against these "downs" are the esprit de corps of the submarine force, and the knowledge that being a submariner truly makes a man the best of the best in the U.S. Navy.

If you were to go out on a cruise on Miami, the very first thing you probably would notice is that you seem to be bumping into everything and everyone on the boat. This is not unusual for someone new on a sub, and after just a few hours you begin to "think small and thin" so that you can smoothly move around your fellow submariners.

The next thing that comes to your attention will probably be the rather odd working schedule, a watch program that has a crewman working six hours "on" and twelve hours "off." While he is "on," a sailor is standing watch; while "off," he is eating and sleeping, doing maintenance on equipment and systems, and studying for qualification. This creates the unusual standard of a Miami "day" being eighteen hours rather than twenty-four. Unfortunately the entire boat takes on this schedule, which tends to lead rapidly to crew members' suffering from sleep deprivation. While in theory a crew member is allowed eight hours of "off" time in a given twenty-four-hour period, this rarely works out into long periods for sleeping. Very quickly one loses all sense of time on the surface and back home, and the sleep that one does get tends to be "on the fly."

As for sleeping itself, this is a relatively comfortable thing to do on Miami. With the exception of Commander Jones's stateroom, the bunks for all the officers and men are about the same size, with similar appointments. And while a berthing space is about the same size as a big coffin, once you learn to think small, the space seems quite roomy. With fresh air blowing on your face and a nice foam mattress, falling asleep is really not much of a problem.

What is a problem is the "hot bunking" required for a large portion of the enlisted personnel on the Miami. This tends to dominate the schedules of the junior enlisted crew members, with a rigidly set schedule for many of the berthing spaces. If "special" or extra personnel have to be aboard, the crew will lay out extra bunks in the torpedo room over the weapons stowage racks. These are actually quite comfortable, with good headroom, though some folks find the idea of sleeping in a room with literally tons of explosive and fuel rather discomforting. Another problem is the lack of personal stowage space. For those with their own bunks there is a 6-inch-deep stowage pan under each mattress, as well as some locker space. For those having to "hot bunk," three men have to share the space normally allotted to two.

Dining aboard Miami is truly a pleasure, as the Navy goes all out to give the men the best chow the taxpayers' money can buy. In fact, because of the limited room for exercise, many of the men actually tend to gain weight on cruise. The food itself is simple but wholesome, with fresh fruit and vegetables becoming the most prized items after a few weeks. The Navy has done some rather clever things to extend the storage life of much of the fresh food aboard. For example, eggs are specially treated with a wax coating to extend their shelf life.

The cooks and their helpers (everyone does an occasional stint of mess duty) work hard to vary the menu and make meals interesting, using a galley about the size of an apartment kitchen. Certainly the culinary highlight of a cruise is the traditional halfway meal of "surf and turf" (steak and crab legs). Unfortunately, by the last few weeks of the cruise every man aboard will be sick of three-bean salad, and dreaming about fresh veggies almost as much as he does about his family.

Those dreams of home and family are always at the center of the submariners' thoughts, though there is very little the Navy can do to give them the kind of communications home that sailors aboard a carrier or frigate might have. The stealth of the modern SSN means that the crew of the Miami is almost never allowed to send personal messages home, and news from home is heavily limited and censored. Word from home is limited to a series (about one a week while on patrol) of forty-word messages called "Familygrams." Each Familygram is carefully crafted by a wife, parent, or loved one to give the crewman at sea an idea of what is happening at home. An example of a notional Familygram is seen below:

Once the Familygram has been placed into a drop box at the boat's home base of Groton, Connecticut, it is reviewed by personnel at the submarine group for any security problems or personal bad news. Occasionally the message will be returned for an edit or suggested change. As a general rule, no "Dear John" letters or bad news (death, illness, etc.) will be transmitted to the boat.

In addition, when the ship's office on Miami receives the Familygram, the personnel will also look over the messages and forward any that look like problems to the captain or executive officer for disposition. The Navy is quite conscious of the sacrifices of those who choose to love and live with submariners, and tries to close ranks whenever there is trouble. As it is, the majority of submariners I have met treasure the Familygrams they have received over the years on cruise. In these notes are news of babies on the way and babies born, birthdays and first words. For the men aboard Miami and all U.S. submarines, the Familygram with its "ILY" (I Love You) greeting is the only news they want to hear. It is their sole lifeline to home and "the world."

One of the ways the Navy helps the crew keep their minds off their homes and loved ones is to work them very hard. Every day the officers and men stand watches, maintain equipment, and study. This studying, known as qualifying, takes up almost all the "free" time of a submarine sailor. Since the days of World War II, when the sub force had to expand rapidly, the Navy has always pushed its submariners to gain knowledge and move up in the ranks. There is a ship's library, and video movies on the closed-circuit system, but these tend to be left alone in deference to a sailor's or officer's qualification book. In the enlisted mess, there is frequently a class running in what is known as "the school of the boat." During a visit to Miami the chiefs were running an orientation program on the boat's reactor plant-all of this while stores were being packed away and lunch being served.

Another function is the ritual of drills. One of the best ways to keep the skills of the crew honed and their minds sharp is to run daily drills simulating responses to various emergency and combat situations. These may range from fire drills (which are run every day or so) to simulated reactor restarts, to chemical spills ("Otto Fuel spill in the torpedo room" is a favorite!), and tracking drills. The drills are an excellent way to keep the crew from getting bored, and the words "Drill Period" on the boat's plan of the day are both hated and cherished by the crew for the difficult tasks this brings, and the confidence it builds.

The fire drills are quite interesting to watch. Without the facilities and equipment back home at Street Hall in Groton, the chiefs on the Miami are hard pressed to simulate the effects of such emergencies. For example, say there is a fire in one of the machinery spaces. The XO and his fire response team move to the compartment where the exercise is being conducted, with all the equipment they would use if the emergency was real. There the fire team find the drill supervision team equipped with gray tablecloths (to simulate smoke), and they must perform to the ship's accepted standards.

Other normal day-to-day functions take on some interesting bents on the Miami. Just aft of the drink machines is the ship's laundry, which hardly seems worthy of the title. At about the size of a phone booth, it has a tiny washer and dryer that would hardly be satisfactory in an apartment unit. Here it serves the needs of over 130 officers and men.

Even taking the garbage out has its exotic aspects. Just forward of the enlisted mess on the starboard side is the compartment containing the Trash Disposal Unit (TDU). The compartment contains the TDU (which looks like a small torpedo tube going through the floor), a garbage compactor, a large sheet metal roller, and the supplies necessary to dispose of the garbage produced by 132 men for several months.

How this is done is actually quite fascinating. The first step is to roll a "garbage can" out of pierced sheet metal. This can is placed in the trash compactor and filled with garbage. Usually the Miami generates two to three cans a day. When the time comes to dispose of them, each can has a couple of lead weights added to it and is sealed. Then the sonar crew does a complete check of the area to make sure nothing is around that might hear the operation. Because of the noise the cans make as they rattle down the TDU ejector tube, it is normal policy to store full cans if the boat is in a tactical situation requiring extreme stealth. In this case, the cans are stored in one of the refrigerated spaces to keep the smell down. When it's time to eject the cans, the cover to the TDU is opened, and a circular cake of ice is placed inside to protect the ball valve at the bottom. The can is placed on top of the ice, the TDU cover is closed, and the can is ejected much like a torpedo.

The daily life on board the Miami is filled with many of the kinds of things that go on anywhere that many men are packed together to do a very tough job. The boat becomes a place of quiet, with words whispered and steps taken lightly. And on those occasions when a difficult mission or operation comes along, the boat continues the same kind of routine, only more so. Anything that makes noise, even routine maintenance, is deferred to keep the noise down.

And how do we reward such devotion? By saying "Well done," and giving them more of the same to do. The life of a submariner is one of a private and personal pride, the kind that comes from being part of an elite club that you cannot buy or beg your way into, and you have to perform "above and beyond" just to stay in.

And then there is the ultimate reward of returning these men to their families and homes. It is said that when a boat is going back to base, the engineers in the machinery spaces have a special setting for "going home." If you have ever seen the incredible spectacle of a warship returning its men to the land, you know why. Every wife and girl-friend has her best on for her man, many with new babies and older children under their arms. If you ever want to know why they do it, look at the loved ones they leave behind in the knowledge that their sacrifices protect those they love most.

America can take pride in the sacrifices of these men and their loved ones over the last forty-five years of SSN operations. Pride for a job well done. Pride in what they are. And pride in what they will do in the future.