A Change of Life
A Change of Life
It always starts the same way. Sometimes it is expected. Sometimes there is no warning at all. Even though we are not at war, we always perform this ritual the same way, just for the practice. And for a very important consistency.
The loudspeaker on the bridge, which has been quiet for minutes or hours, suddenly comes alive with a voice that I recognize, saying, "Bridge, this is the navigator. I relieve you of the deck and the conn. Submerge the ship."
We almost never use the word "ship", but this particular ritual is too critical for any casual phrasing.
Four seconds have elapsed.
In response to that order from the Lieutenant Commander in the conning tower below me, I whirl to the fixed microphone mounted on the bridge, push the button, and reply, "Submerge the ship, aye. Right full rudder! Steady course zero six zero!."
The acknowledgement is directed at the Navigator. The last two commands are directed at the helmsman who is also in the conning tower. I had been constantly aware of the direction in which the seas were running all during my hours on the bridge, and I did not need to think about which way to turn, or about what specific heading would point us directly into the big swells. This is critical. The seas had not changed much over the past couple of hours, a slight veer to the right, from a more northeasterly direction earlier, and now northeast by east.
The total elapsed time at this point is eight seconds.
The two Seamen who are standing watch as lookouts had started moving as soon as they heard the tone of voice over the loudspeaker. They are scrambling to grab their binoculars and jackets and to get below decks. My next action is unnecessary, but always part of the ritual. At the top of my voice I yell, "Clear the bridge! Clear the bridge!"
The new Officer of the Deck (Submerged) turns to the helmsman and orders, "All ahead full!" The helmsman is busy turning the helm, and signaling on both motor order telegraphs back to the main propulsion cubicle, telling them to rack up full power on the main motors.
Ten seconds have elapsed.
My hand is already on the knob for the klaxon, and I sound it twice. From far down below, barely audible, I hear the ah-OOOO-gah, ah-OOOO-gah that is causing a dozen specialists to spring into action.
Twelve seconds have elapsed.
The sound of the klaxon is the first warning to the rest of the crew that we are diving. At least a dozen of them must immediately drop what they are doing and carry out their own, individual critical actions to allow us to survive the dive.
The Chief Hospital Corpsman who is serving as Chief of the Watch in the Control Room immediately begins moving levers to open some valves and to shut other valves using the power of the 600 pounds per square inch working pressure in the main hydraulic system. The chief's movements are as those of a church organist playing the standard refrains in a weekly service. He has done it all hundreds of times before, in practice and for real. But this is different from playing the organ. If the chief gets it wrong, we could all die.
The First Class Engineman who is the Throttleman of the Watch in the Forward Engine Room jumps to turn off the fuel valves to both engines, and to port compressed air to the appropriate cylinder ports, to force the engines to stop turning right away, instead of letting them die naturally. With his other hand he moves the hydraulic levers to shut the outboard exhaust valves and the inboard air intake valves for each of the engines. He begins cranking the inboard exhaust valves shut by hand, watching the indicator panel as he does so. When the four red lights all turn green, he knows that his engine room, at least, is now watertight. The very young sailor who is serving as his Oiler runs around opening and shutting fuel valves, turning off the generator field windings, draining critical engine components, and cleaning up after the exercise. The tiny engine room has suddenly gone quiet, except for the momentary clanging of the big steel valves going shut. After the roar of the two engines, the effect is disorienting.
The Second Class Engineman who is the throttleman in the After Engine Room, and his oiler, perform exactly the same motions, as if they were dancers on the other side of the same stage during a performance.
The First Class Electrician's Mate who is the Senior Controllerman of the Watch in the main propulsion cubicle turns the knob to acknowledge the order for full speed. He grabs the big rheostat handle on the port main motor, and he turns it to the minimum setting. He immediately does the same to the rheostats for the two port generators. He flips the huge lever that controls the power source for the port main motor, moving it from the "Generator" position to the "Off" position, and then to the "Battery" position. He verifies the position of the motor field rheostat at the minimum setting, then he presses the "Stop and Think Latch", and he moves another big lever into the position in which the port main motors are connected in series across the huge battery. He monitors the ammeter, watching for the initial surge of direct current to peak at about 5,000 amps. As the current begins to drop off in reaction the the back EMF from the motor, he moves the lever into its final position, which removes the huge ballast resistor from the motor circuit. The ammeter needle again indicates a big surge of current, which again drops off. The controllerman turns the motor rheostat to obtain the maximum power available from parallel batteries and series motors.
The Third Class Electrician's Mate who is the Junior Controllerman of the Watch mirrors the Senior Controllerman's every move, adjusting the starboard generators and motors to provide a symmetry of power to keep us under control. Their feet do not move, but their hands and eyes execute the same motions in mirror image. It is like synchronized swimming, with a difference.
The Second Class Commissaryman who is preparing the evening meal drops his ladle and lunges out of the galley. He monitors the function of the main induction valve, which is located in the overhead of the crew's mess. This valve is the normal source of air for the boat when it is on the surface. If the powered, hydraulic mechanism fails, the cook will manually shut the main induction valve. It is important that the cook be muscular so that he can do this quickly, if need be.
The noise on the bridge changes abruptly, as all four locomotive diesel engines stop within three seconds of each other. and the noise is replaced with the sound of large, hydraulically operated valves slamming shut or open. The air from the main ballast tanks rushes loudly out of the valves at the tops of each tank, to be replaced by the sea water surging through the huge openings at the bottom of the tanks.
The two lookouts with all of their gear are gone now, and I am going down the first ladder as close as possible behind them, the last person to go below. The ladder is vertical, and there is a smooth stainless steel pipe alongside the ladder, so I don't need to use the rungs. I jump, clamping my calves on the outside of the ladder to get a little friction, grabbing the vertical poles with my hands for a little more friction and control.
A left turn puts me at another ladder, which I descend the same way. I’m still not safely inside the submarine yet. The ocean is rushing up at me.
Eighteen seconds have elapsed since that loudspeaker on the bridge startled me out of my reverie.
At the foot of this ladder I sidestep to the left and climb through the water-tight hatch that will be my access to safety. It takes an extra second to maneuver through the hatch, and I actually need to step on one rung of the ladder for control, then I drop to the deck of the conning tower just as I had dropped to the two decks above it.
Twenty-two seconds have elapsed.
In the corner by this last ladder is the overqualified Seaman who is acting as Quartermaster of the Watch. He is standing there, waiting for his part in the ritual. I reach up for the heavy cable lanyard that I use to pull the upper hatch shut. It is a very heavy hatch, on a very strong spring, and it takes a good eighty-pound pull to swing it shut. With the adrenalin flowing, eighty pounds of pull is easy. But there isn’t room in the conning tower for me to throw my weight around to get the necessary leverage, and everybody is trying to stay out of my way. Everyone except for the quartermaster, that is. He has the riskiest job of the exercise. In order to pull the hatch shut, I must put one or two feet up on the ladder that I just skipped down. If I miss, I will kick the quartermaster in the gut, or worse. And he has to keep his hands up. He can’t lower them to protect himself.
I get the hatch lowered into position, and the quartermaster dogs it shut, turning the handle through nine revolutions. He yells at me, "Hatch secure!"
A total of twenty-six seconds have elapsed.
I turn my back without acknowledging the quartermaster, step off the platform under the upper hatch, sidestep between the helmsman and the lower hatch, and drop down the last ladder, using one rung on this one, also. This last move puts me at the diving stand, the position in the Control Room where I stand behind the planesmen, the same two sailors who had been lookouts less than a half a minute ago. They are already busy turning on the diving planes, checking them out, and verifying the normal and backup indicating systems for the planes. But I ignore them for a moment. The first thing that I do is to look at the indicator panel above the hydraulic manifold. I check to see that all hull openings are shut, and important other valves are open. Each such critical opening has a pair of indicator lights. As I turn to look, I see the last of the indicators change from red to green. The Chief Hospital Corpsman who is serving as Chief of the Watch yells at me, "Green board!" At that moment, the cook pokes his head into the Control Room and yells, "Main induction shut and locked!" I turn my face toward the hatch that leads up into the conning tower, and I yell at the navigator, who is now the Officer of the Deck, Submerged, "Green board! Main induction shut and locked!"
In 1934 a submarine was lost, with most of the crew, because of a failure of the main induction valve, which is 36 inches in diameter. In 1972, we are still reporting on the status of the main induction valve with every dive, aboard every submarine.
Twenty-nine seconds have elapsed.
The Second Class Torpedoman's Mate in the Forward Torpedo Room is monitoring the bow planes rigging mechanism, verifying that the important diving planes are moving properly from their retracted, stowed position for surface running, to their fully extended position for submerged operation. He watches the actual mechanism, the shafts and positioners, not some remote indicator. When the planes are fully extended, he monitors the bow planes tilting motor to ensure that it starts properly.
The Third Class Torpedoman's Mate who is standing watch in the After Torpedo Room verifies the proper start of the stern planes tilting motor.
I bark an order to the planesmen, my voice no longer a full yell, but still plenty loud enough, "Full dive, both planes!"
Simultaneously, the navigator yells down through the hatch at me, "Make your depth six two feet!"
The planesmen respond, quietly and simultaneously, "Full dive, on the bow planes, aye" and, "Full dive on the stern planes, aye."
I reply to the conning tower, "Six two feet, aye!" as the communications tumble all over each other.
I place my hand on the shoulder of the bow planesman, as I look over his shoulder, and I say, "Make your depth six two feet." I don't wait for his reply when, without moving, I place my other hand on the shoulder of the stern planesman, and I say, "Seven degree down angle." Each of them replies formally.
Thirty-two seconds have elapsed.
We are below the surface completely now. The main motors are pushing us ahead with full power, drawing huge current from our 250-Volt battery. For the next few seconds I am in full control of the boat. The Officer of the Deck (Submerged), above me in the conning tower, is just waiting. This is a dangerous time.
When a submarine dives, its stability changes completely. Its metacentric height flip-flops. That is the most classic measure of a ship's stability, one which the naval architects spend most of their time designing around. So long as any ship remains on the surface, even a submarine, the metacentric height remains consistent. When we are submerged, that same measure is consistent, though inverted. During the process of diving, it disappears. The only thing keeping us upright is inertia. In theory, a wave could turn us upside down, and we would sink with all hands. This is the reason that I ordered that the bow be turned into the seas just as the dive was beginning. It could be crucial to our survival that we not have any waves or seas from that side as we pass through this point of no stability.
As diving officer, I have the information and control to drive us through these dangerous five seconds. The effort has my full attention.
This boat stabilizes as the last of the air leaves the main ballast tanks. Our keel reaches forty feet, and we are clearly descending. There is one sturdy tank full of water that is used to make us heavier than the amount of the ocean that we displace when we are fully below the surface. That "Negative Tank" gives us the impetus to actually submerge instead of lolling about just an inch below the surface. We no longer need this negative buoyancy. So I yell over my left shoulder, "Blow Negative to my mark."
The Machinist Mate First Class who is now standing watch at the air manifold replies, "Blow negative to the mark, aye," simultaneously opening the valve for the compressed air. A very loud noise of air rushing through the pipes dominates the control room. The Chief of the Watch monitors the gage on the Negative Tank, and signals with his hand when the tank is dry. I relay the hand signal to the air manifold operator, who shuts the valve. In the quiet that follows, I immediately give him the verbal order to do what he has just done, to "Secure the air to negative."
Thirty-nine seconds have elapsed.
The motors are still draining the precious battery, and I turn full attention to analyzing the response of the boat in the vertical plane. The gross indications are that things are under control. I yell up through the hatch at the Seaman who is serving as helmsman, "All ahead two-thirds." I am still in control of the boat's speed, and everything else. My regime will end quite soon, but right now my power is absolute.
The helmsman acknowledges my order, and I analyze the behavior of the boat with only 40% of the speed as with full power. This gives only 16% of the same effectiveness to the diving planes, so problems with buoyancy quickly begin to show up. We are arriving at our ordered depth, so the bow planesman announces to me, "Six two feet, sir." I tell the stern planesman, "One degree down angle." I call out to the Fireman who is operating the trim manifold, "Flood auxiliary from sea, one thousand pounds."
Forty-eight seconds have elapsed.
The trim manifold operator, who aspires to become a Machinist's Mate, opens a water valve, and sea water rushes into a specific variable ballast tank, to make us heavier. As the ship gets heavier, I can tell that the planesmen are getting better control over our depth and deck angle. Their actions are achieving better precision because our buoyancy, both overall and fore-and-aft, is setting up properly.
I yell up at the helmsman in the conning tower, "All ahead one-third." This is a significant order. With this action, I give away all of my power. This last order is a formal statement to the Officer of the Deck, Submerged, that I have achieved full control of the submarine, and that I am ceding to him the authority over our speed. If he chooses to give me less than three knots of speed with which to control our 2,400 tons as we move through the water, then that is now his prerogative and my problem.
As I finish with this last, the trim manifold operator notifies me that he has completed flooding 1,000 pounds of sea water into the auxiliary tank, as I had ordered. I focus more now on fine-tuning our buoyancy for stability.
Fifty-five seconds have elapsed.
The watchstanders in the control room begin to settle into their watch routines. I am still wearing the binoculars that I had been using to scan the horizon less than a minute earlier. There is a modest activity in straightening out these incidental details of the dive.
The Interior Communications Electrician Second Class, who is on duty as the messenger of the watch, asks me, "What do you want in your coffee, sir?"
Sixty seconds have elapsed.