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.
A Los Angeles-class nuclear submarine breaks the surface during an emergency blow drill. ELECTRIC BOAT DIV., GENERAL DYNAMICS CORP.
The ballast control panel governs the ballast and trim tanks, which allow the boat to surface, dive, and remain neutrally buoyant. JOHN D. GRESHAM
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.
An operator’s view of the ballast control panel on board the USS Miami. In the upper left are the emergency blow handles designed to surface the boat in an emergency. JOHN D. GRESHAM
Some of the instruments that would be seen by the helmsman and planesman while “driving” the USS Miami: (left to right) dive/bank angle, heading, and depth to keel. JOHN D. GRESHAM
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.
Ship control console, USS Miami. The plane/rudder control wheel is seen to the left, with the automatic depth control and engine room telegraph (speed control) to the lower right. JOHN D. GRESHAM
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.”
LEFT: One of the bathythermograph probes that can be launched by the 3-inch signal /decoy ejector of the USS Miami. JOHN D. GRESHAM
RIGHT: Notional view of a BSY-1 fire control console analyzing the velocity of sound in the water at various depths. The data is generated through launching of a bathythermograph from the 3-inch ejector tube. JACK RYAN ENTERPRISES, LTD.
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. M
ore 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.
The placement of the Miami’s forward sonar arrays. JACK RYAN ENTERPRISES, LTD.
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.
Mounting of the Miami’s towed sonar arrays. JACK RYAN ENTERPRISES, LTD.
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.
Sonar room, USS Miami. JACK RYAN ENTERPRISES, LTD.
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
Notional view of a BSY-1 sonar display. The white line at the left indicates a contact. JACK RYAN ENTERPRISES, LTD.
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 sou
nd 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.