Submarine: A Guided Tour Inside a Nuclear Warship

^{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.

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.'

^{One of the bathythermograph probes that can be launched by the 3-inch signal /decoy ejector of the USS Miami. JOHN D. GRESHAM}