USS Miami (SSN-755) JACK RYAN ENTERPRISES, LTD.
USS Miami, external layout. JACK RYAN ENTERPRISES, LTD.
Logo of USS Miami. JACK RYAN ENTERPRISES, LTD.
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.
RIGHT: The executive officer of USS Miami, Lieutenant Commander Mark Wooten, USN. OFFICIAL U.S. NAVY PHOTO
LEFT: The commanding officer of USS Miami (SSN-755), Commander Houston K. Jones, USN. OFFICIAL U.S. NAVY PHOTO
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.
USS Miami, external layout top view. JACK RYAN ENTERPRISES, LTD.
The twelve hydraulically operated doors of the Miami’s vertical launch system for Tomahawk cruise missiles. Note the pressure caps to protect the missiles. JOHN D. GRESHAM
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.
The coating of decoupling tiles on the hull of the USS Groton (SSN-694). The individual tiles are glued to the hull to form a carpet of rubber around it. Note the safety track on the TB-16 shroud, which crew members on deck hook onto. JOHN D. GRESHAM
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.
Los Angeles-class submarine on the surface. ELECTRIC BOAT DIV., GENERAL DYNAMICS CORP.
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.
The Mk 18 search periscope in the control room of the USS Miami. JOHN D. GRESHAM
Control room, USS Miami. JACK RYAN ENTERPRISES, LTD.
The Miami’s mission status board, located in the control room. This board is to be filled in and maintained by the officer of the watch. JACK RYAN ENTERPRISES, LTD.
The automatic plot readout in the control room, USS Miami. JOHN D. GRESHAM
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.
Plotting table used aboard a Los Angeles-class submarine. Each boat has two of these tables in the control room. JOHN D. GRESHAM
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.
Periscopes in the control room, USS Miami. JOHN D. GRESHAM
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.”
LEFT: A sa
ilor operating the dive planes. To his right is the steering control station. JOHN D. GRESHAM
RIGHT: Ship control station of a Los Angeles-class submarine. The control wheels govern steering and diving. The center console telegraph orders the speed of the boat. JOHN D. GRESHAM
The helmsman, planesman, and diving officer man the ship control station of the USS Miami. JOHN D. GRESHAM
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.