Part 6 (1/2)
NNS nevertheless remains the only American s.h.i.+pyard capable of building nuclear-powered surface wars.h.i.+ps. If future carriers or any of their escorts are to be nuclear-powered, then NNS will build them. Since at least one more Nimitz Nimitz-cla.s.s carrier is planned (the as-yet-unnamed CVN-77), the yard will stay fat in flattop construction for another decade. Meanwhile, Congress has guaranteed NNS a share of the NSSN production with Electric Boat, allowing the company to utilize its investment in submarine construction facilities built for the Seawolf Seawolf program years ago. There has also been a steady flow of Navy and commercial refit and modernization work, and this is proving to be highly lucrative. In fact, NNS is preparing for one of the biggest refits ever, when USS program years ago. There has also been a steady flow of Navy and commercial refit and modernization work, and this is proving to be highly lucrative. In fact, NNS is preparing for one of the biggest refits ever, when USS Nimitz Nimitz (CVN-68) comes back into the yard for its first nuclear refueling. (CVN-68) comes back into the yard for its first nuclear refueling.
Building the Boat Before we actually go on board a Nimitz- Nimitz-cla.s.s carrier, let's take a look at how the s.h.i.+p is built. A Nimitz- Nimitz-cla.s.s CVN is among the largest man-made moving structures. And with a price tag around $4.2 billion, it is also among the most expensive. Only the biggest commercial supertankers are larger. Such vessels are mostly hollow s.p.a.ce, and they aren't built to take anything like the punishment a wars.h.i.+p must be able to absorb. On top of that, carriers must hold six thousand personnel and operate over ninety aircraft. And finally, no supertanker has a power plant of such impressive capability as the nuclear power plants on Nimitz- Nimitz-cla.s.s-or one that requires such obsessive care. Every component of the nuclear power plant comes under the meticulous scrutiny of the Office of Naval Reactors. Very early in the history of U.S. Navy nuclear propulsion, it was realized that the first nuclear accident would mean the end of the program. Therefore, rigid inspection standards and elaborate safeguards were applied to every step of design, construction, and testing. For example, every welded pipe joint (there are thousands of them!) is X-rayed, to ensure that it has no flaws, cracks, or voids.
Strange as it may sound, building a 95,000-ton aircraft carrier is a precision operation, which requires immensely detailed planning. For example, the maximum draft of a s.h.i.+p being built at NNS is limited both by the size of Dry Dock 12 and by local tidal conditions. Even at an unusually high tide, Dry Dock 12 can be flooded only to a depth of about thirty-three feet/ten meters, meaning that construction of a carrier can be taken only so far before it must emerge out of the dock into the James River. Once that's done, the hull is moored to a dock on the eastern end of the yard for final construction and outfitting. Because of the quick-moving tidal conditions near the mouth of the Chesapeake Bay, the launching is normally timed to the minute, and there are never more than a few inches to spare.
A Nimitz- Nimitz-cla.s.s CVN gets its start in Was.h.i.+ngton, D.C., about a decade before its launching, when admirals at the headquarters of the Naval Sea Systems Command (NAVSEA, formerly known as the Bureau of s.h.i.+ps, the agency that manages s.h.i.+p construction) fix the retirement date of an aging carrier. This determines the time line for budgeting a new flattop. The time line, almost a decade long, starts at the point when money begins to be committed to the building of the new s.h.i.+p. Soon after that, contracts are signed for ”long-lead items”-those components that can take years to order, design, manufacture, and deliver. These include nuclear reactors, turbines, shafts, elevators, and other key items that must be installed early in the construction of the s.h.i.+p.
Budgeting must also take into account changes and new items that go into each new carrier, for each has literally thousands of changes and improvements over earlier s.h.i.+ps of the cla.s.s. To lower the drag of the hull, the most recent Nimitz- Nimitz-cla.s.s carriers have bulbous bow extensions below the waterline. Lowering the hull drag extends the life of the reactor cores and allows power to be diverted from propulsion to the ”hotel” systems like air-conditioning and freshwater production. Most design changes are not so significant, and usually involve nothing more than a material or component change, like a new kind of steam valve, electrical switch, or hydraulic pump. Even so, every change involves written change orders, as well as stacks of engineering drawings. Back in the 1960's and 1970's, a small army of draftsmen, engineers, and accountants was required to produce the mountain of paper doc.u.menting the changes on a new carrier. Today, a much smaller force manages a computerized drawing and change-management system custom-programmed for NNS. In fact, in the interest of efficiency and compet.i.tiveness, the entire NNS operation has become heavily computerized.
A prime example of computerization is the ordering-and-materials-control system. NNS cannot afford a huge inventory of steel plate and other materials sitting around rusting in the humid Tidewater climate. There is only limited s.p.a.ce for storage and construction, and every bit must stay busy for NNS to turn a profit. To minimize this potential waste, NNS has installed a computerized ”just-in-time” ordering-and-materials-control system. The many components and raw materials (steel plate, coatings, etc.) that go into a Nimitz Nimitz-cla.s.s carrier arrive exactly when they are needed. No earlier, and no later. In this way NNS's investment capital is not needlessly tied up, and the final cost to taxpayers is reduced by millions of dollars. The NNS work-force has also become more efficient, since fewer items need to be stored, protected, hauled from place to place, and inventoried.
The actual start of construction begins some months prior to the official date of the ceremonial keel-laying. At that time, the Dry Dock 12 cofferdam is placed so that about 1,100 feet/335.3 meters of room are opened at the rear of the dock. This leaves 900 feet/274.3 meters at the river-gate end of the dock for construction of tankers or other projects. NNS workers then begin to lay out the wooden and concrete structural blocks that the carrier will be built upon. Building a s.h.i.+p that displaces over 95,000 tons/86,100 metric tons on wood and concrete blocks may sound like building a skysc.r.a.per on a foundation of paper, but NNS uses lots lots of these blocks to spread the load around. This very old technique is also used when s.h.i.+ps are brought into dry dock for deep maintenance. Some things just work, and cannot be improved upon. of these blocks to spread the load around. This very old technique is also used when s.h.i.+ps are brought into dry dock for deep maintenance. Some things just work, and cannot be improved upon.
The close tolerances in the construction of a Nimitz Nimitz-cla.s.s carrier demand absolute precision from the start. Exact placement of the first keel blocks is critical, as they represent the three-dimensional ”zero” points upon which everything else is built. This preliminary work goes on for four to six months, until the keel-laying ceremony draws near. At the same time, some initial a.s.semblies are welded together and stored on the floor of the dry dock, since storage s.p.a.ce in the main construction yard is tight. At the ceremonial laying of the keel on a Nimitz- Nimitz-cla.s.s vessel, the guests include the Secretary of the Navy, the Chief of Naval Operations, and hundreds of other dignitaries. By tradition, the s.h.i.+p's ”sponsor” (a sort of nautical G.o.dmother) is appointed-usually the wife of a high-ranking Administration official or politician whose favor is being sought by the Navy. Then a ceremonial weld is made in the first ”keel” member (a steel box girder built up along the centerline of the lowest part of the hull), and the carrier's construction is officially under way.
Now a thirty-three-month countdown clock starts. From this day forward to the launch date, the construction process is a race to determine the milestone bonuses and resulting profits for NNS stockholders. Meanwhile, Navy officials plan dates for commissioning and first deployments, select the ”plankowner” officers and crew who will first man the new carrier, and a.s.semble the ”pre-commissioning unit” (PCU). These are the sailors who will report on board the s.h.i.+p while it is still under construction, in order to learn every detail of maintenance and operation.
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Automated flame-cutting of steel plates at NNS.
JOHN D. GRESHAM.
Back at Dry Dock 12, the thirty-three-month construction moves forward rapidly. The secret to staying on schedule is ”modular construction,” a technique originally pioneered by Litton-Ingalls s.h.i.+pbuilding in Mississippi. Rather than constructing a s.h.i.+p like a building, from the bottom up, the s.h.i.+p's designers break the design down into a series of modules. Each module is completed alongside the construction dock, with piping, fixtures, and heavy equipment already installed. Then it is lifted into place and ”stacked” with other modules to form the hull. When that is done, the modules are ”joined” (welded together). Pipes, ducts, and electric wiring bundles are connected into a mostly finished configuration, and the s.h.i.+p is ”floated” out of the dock (or launched), with final work done alongside a ”fitting-out” dock elsewhere in the yard. This mode of construction has many advantages. For one thing, the s.h.i.+p can be launched at a more advanced stage of construction than used to be the custom, which reduces costs considerably. Work that takes an hour to do in an NNS workshop usually takes three hours out in the yard, or eight hours in the s.h.i.+p once it is floating in the water. So anything that can be built in the shops or installed in the yard before it is a.s.sembled reduces costs; it is money in the bank.
Though modular military s.h.i.+pbuilding was pioneered by Litton-Ingalls, the scale at NNS is far greater. At NNS, they call this the ”Superlift” concept. By way of comparison, Litton's largest module weighs around 500 tons/ 453.6 metric tons, while NNS utilizes modules up to 900 tons/816.6 metric tons lugged in place by the huge bridge crane. NNS can build a Nimitz- Nimitz-cla.s.s carrier with about a hundred ”Superlift” modules. Two dozen ”Superlifts” make up a Nimitz- Nimitz-cla.s.s carrier's flight deck, while the bow bulb and island structure are individual Superlifts.
A Superlift starts as a small mountain of steel plates, brought by rail and truck to NNS. Flame-cut to exact tolerances in the shops just south of Dry Dock 12, the plates are tack welded together by spot welds, then permanently joined by robotic welders along a pair of side-by-side production lines. These are then linked into the structural a.s.semblies that form each Superlift. Once the basic structure is completed, cranes move it to the large a.s.sembly area next to Dry Dock 12. Then NNS yard workers crawl over and inside it to ”stuff” electrical, steam, fuel, sewage, and other lines, fittings, and gear into place. Sometimes Superlifts are turned upside down, to make ”stuffing” easier. When a Superlift is ready for joining, the nine-hundred-ton bridge crane is moved into position overhead, the lift cables are fastened, and the a.s.sembly in Dry Dock 12 made ready. Despite a Superlift's gigantic size and weight, this is a precision operation, with tolerances frequently dictated by the relative temperatures of the s.h.i.+p a.s.sembly and the Superlift. Depending on temperature, the metal structure of a Superlift can easily expand or contract over an inch during a given day on the Tidewater.
Around the a.s.sembly yard, several dozen Superlifts are in various stages of preparation at any given time. Some interior and exterior painting is done on Superlifts, to make this nasty and environmentally sensitive job a little safer. Because power, water, and air-conditioning can be installed in a Superlift while it is being a.s.sembled, the construction process is considerably facilitated. This is particularly helpful in the hot, muggy summers and cold, wet winters of the Tidewater region. There is a particular order to how Superlifts are stacked. The initial Superlifts-including the double bottom, reactors, steam power plants, ammunition magazines, and heavy machinery-are laid around the keel structure. In general, these items (making up the bottom of the middle third of the carrier) are the heaviest and most deeply buried components, and cannot be accessed or installed easily later on. They take some four months to a.s.semble.
At twenty-two months to launch, everything aft to the fantail and up to the main/hangar deck is in place. Many of the living and habitation s.p.a.ces are also included in this phase, as well as the majority of the carrier's protection systems (double bottoms, heavy plating, and voids-hollow s.p.a.ces like fuel tanks, etc.). Now the a.s.sembly is beginning to look like a s.h.i.+p. At eighteen months to launch, the hangar deck is taking shape, along with the great overhanging ”sponson” structures that extend out to port and starboard. a.s.sembly of the bow is beginning. The flag (admiral's staff) and air wing s.p.a.ces are fitted out, as well the offices for the various s.h.i.+p's departments. By fourteen months to launch, the hangar deck, sponson, and bow structures are in place, and the first parts of the flight deck are filling in amids.h.i.+ps. After four more months, the hangar and flight decks are almost finished. Meanwhile, the lower bow has been completed, as well as the entire fantail structure. At two months before launch, the entire island structure-an eight-story building-is lifted onto the deck of the s.h.i.+p. This final Superlift represents the completion of major construction.
While the NNS yard workers seal up the hull and make it watertight, the managers and planners get ready for the actual launching of the s.h.i.+p. The launching ceremony is similar in many ways to the keel-laying just over two-and-a-half years earlier. Again, the Secretary of the Navy and the Chief of Naval Operations are present, as is the carrier's sponsor. She gets to break the traditional bottle of champagne over the new carrier's bow. A hint, though: Scratch the bottle first with a diamond-tipped scribe to ensure a clean break. Long-winded speeches, prayers, and benedictions complete the launching ritual. Then things get deadly serious and precise.
Since Dry Dock 12 is not deep enough to float off a finished Nimitz- Nimitz-cla.s.s carrier, as soon as the hull structure is complete, it must be quickly floated out of the dock. Then the uncompleted carrier can be moved to a deeper part of the James River channel, where it can be moored to a fitting-out wharf for completion. The depth of the dock and the tidal conditions of the Tidewater region allow very little margin for error-meaning that the launching of a carrier is synchronized with the highest tide in a given month, to provide maximum clearance over the end of the dry-dock gate.
Before this can begin, any other s.h.i.+ps in Dry Dock 12 are floated out and the movable cofferdam is removed. Then the dock is carefully flooded, with hundreds of NNS and Navy personnel monitoring tidal conditions and the watertight integrity of the carrier. When the dock is fully flooded and the s.h.i.+p has lifted off the keel blocks, the gate is opened. Now things happen fast. As a small tugboat pulls the carrier out of the dry dock, other tugboats wait just outside in the river to take control of the ma.s.sive hulk. When the carrier is finally clear of the gate and safely into the deep channel of the river, it is turned and towed downstream to the fitting-out wharf on the southern end of the NNS property. Here it will be moored until it is turned over to the Navy, approximately two years later.
While it is an impressive sight sitting at the fitting-out dock, the ma.s.s of metal floating there is hardly a s.h.i.+p of war. It is still, in naval terminology, just a ”hulk.” Making it into a habitable vessel is the job of almost 2,600 NNS yard workers-everything from nuclear-reactor engineers to diesel-engine mechanics, computer specialists to roughneck welders. Building a modern wars.h.i.+p takes almost every technology and tradecraft known. Imagine a skysc.r.a.per with offices, restaurants, workshops, stores, and apartments that can steam at more than thirty knots, with a four-and-a-half-acre airfield on the roof. That is a fair description of a Nimitz- Nimitz-cla.s.s aircraft carrier.
During a visit to NNS in the fall of 1997, I spent some time aboard the USS Harry S. Truman Harry S. Truman (CVN-75) while she was about nine months from commissioning and delivery. I'd like to share with you some of my experiences there. My first stop, after NNS and Navy officials led me aboard, was the ma.s.sive hangar deck. At 684 feet/208.5 meters long, 108 feet/33 meters wide, and 25 feet/7.6 meters tall, it is designed to provide a dry, safe place to store and maintain the aircraft of the embarked wing. As we walked forward, I pa.s.sed several large access holes that led into the two nuclear reactor compartments below. These would be b.u.t.toned up shortly, my guides told me. The nuclear fuel packages would then be installed, followed by testing and certification of the twin A4W reactor plants. All around the hangar deck, workers were busy welding and installing pieces of equipment. (CVN-75) while she was about nine months from commissioning and delivery. I'd like to share with you some of my experiences there. My first stop, after NNS and Navy officials led me aboard, was the ma.s.sive hangar deck. At 684 feet/208.5 meters long, 108 feet/33 meters wide, and 25 feet/7.6 meters tall, it is designed to provide a dry, safe place to store and maintain the aircraft of the embarked wing. As we walked forward, I pa.s.sed several large access holes that led into the two nuclear reactor compartments below. These would be b.u.t.toned up shortly, my guides told me. The nuclear fuel packages would then be installed, followed by testing and certification of the twin A4W reactor plants. All around the hangar deck, workers were busy welding and installing pieces of equipment.
Catapult-testing deadweights aboard the Harry Truman Harry Truman (CVN-75). (CVN-75).
JOHN D. GRESHAM.
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The hulk of the USS Harry S. Truman Harry S. Truman (CVN-75) at the NNS fitting-out wharf in the fall of 1997. By mid-1998, the (CVN-75) at the NNS fitting-out wharf in the fall of 1997. By mid-1998, the Truman Truman was conducting sea trials off the Atlantic Coast. was conducting sea trials off the Atlantic Coast.
JOHN D. GRESHAM.
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After climbing several ladders, we emerged on the flight deck, where hundreds more NNS workers were hustling about at their tasks, and then moved forward to the catapults, which were in the process of testing and certification. They are installed in pairs on the bow and the deck angle port-side, and each of the four 302-foot/92.1-meter-long C13 Mod. 1 catapults is capable of launching an aircraft every few minutes (the cycle time depends largely on the skill of the deck crew). Each catapult is powered by a pair of steam cylinders, which are built into the flight deck, and normally use high-pressure saturated steam from the reactor plant; but since the reactors were not yet powered up, Truman Truman drew her power, water, and steam from plants dockside. drew her power, water, and steam from plants dockside.
Testing such powerful machines is a dramatic procedure. Scattered around the deck were a number of orange-painted, water-filled, wheeled trolleys called deadweights. Each deadweight simulates a fully loaded aircraft, with attachment points that allow it to be hitched to the shuttle of a catapult. After the bow has been pointed into the James River channel, and the Coast Guard and local boaters have been suitably warned, each catapult fires the entire range of deadweights. The tests are noisy and the sight of the weights flying hundreds of yards/meters into the channel is bizarre. Nevertheless, this is a highly effective way to prove that the machinery is ready. After leaving the catapults, we headed aft to inspect the catapult control station between Catapults 1 and 2.35 Set on a hydraulically raised platform under an armored steel door, the control station is a pod where the catapult officer-or ”shooter”-can control the catapults in safety and comfort. Another identical station is located on the port side, controlling Catapults 3 and 4. Set on a hydraulically raised platform under an armored steel door, the control station is a pod where the catapult officer-or ”shooter”-can control the catapults in safety and comfort. Another identical station is located on the port side, controlling Catapults 3 and 4.
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The island structure of the Harry S. Truman Harry S. Truman (CVN-75) being finished at NNS. (CVN-75) being finished at NNS.
JOHN D. GRESHAM.
Next we walked over to the island structure, where our guides showed us how the many systems on the flag and navigation bridges, the primary flight control, and the meteorology office were installed. Although the basic Nimitz Nimitz design is over thirty years old, the many changes bringing it into the 21st century are quite visible. Up on the design is over thirty years old, the many changes bringing it into the 21st century are quite visible. Up on the Truman's Truman's navigation bridge, for example, are many of the ”Smart s.h.i.+p” systems (mentioned in the second chapter) that make it possible for three people to steer the s.h.i.+p from auto-matedcontrol stations (before, almost two dozen people were required to do the same job). Similar systems will be scattered throughout the navigation bridge, for example, are many of the ”Smart s.h.i.+p” systems (mentioned in the second chapter) that make it possible for three people to steer the s.h.i.+p from auto-matedcontrol stations (before, almost two dozen people were required to do the same job). Similar systems will be scattered throughout the Truman, Truman, and will be tested when she goes to sea in 1998. and will be tested when she goes to sea in 1998.
The cluttered flight deck of the Harry S. Truman Harry S. Truman (CVN-75) while being fitted out at NNS. (CVN-75) while being fitted out at NNS.
JOHN D. GRESHAM.
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As we moved farther aft, we pa.s.sed by the kinds of tool sheds and other temporary storage buildings that you find at any construction site. Then we dropped down a ladder back to the hangar deck and down another into the bowels of the s.h.i.+p. At this point, the primary work on Truman Truman involved preparing some eight hundred (out of a total 2,700) compartments for turnover to the Navy. Those compartments contain crew berthing, medical facilities, galley and mess areas, office s.p.a.ces, the s.h.i.+p's store, the post office, and storage rooms. Everything needed to finish these s.p.a.ces must be carried up and down ladders and through narrow pa.s.sageways by hand. Sprained knees and ankles are the price paid to haul paint cans, power cables, and tools into the s.h.i.+p. involved preparing some eight hundred (out of a total 2,700) compartments for turnover to the Navy. Those compartments contain crew berthing, medical facilities, galley and mess areas, office s.p.a.ces, the s.h.i.+p's store, the post office, and storage rooms. Everything needed to finish these s.p.a.ces must be carried up and down ladders and through narrow pa.s.sageways by hand. Sprained knees and ankles are the price paid to haul paint cans, power cables, and tools into the s.h.i.+p.
Shortly after this job was completed, just after New Year's of 1998, the first of the Navy's crew of ”plankowners” arrived. Several of the s.h.i.+p's s.p.a.ces that had already been turned over proved to be spotless when we visited them; and the quality and workmans.h.i.+p are very impressive. In particular, the communications s.p.a.ces, which were just being brought to life by a Navy crew, had the look and smell of a new automobile. As the final stop on my visit, I was allowed to visit the magazines and the pump room in the very bottom of the s.h.i.+p.
It was close to quitting time when we made our way back to the hangar deck, aft to the fantail, and down the access ramps to the dock. As we sat waiting for our tired leg muscles to loosen, the s.h.i.+ft alarm went off, and we watched 2,600 NNS workers come off s.h.i.+ft and head for home-an impressive sight. As they pa.s.sed by us on the dock, I was reminded of the builders of the Egyptian pharaoh's pyramids. Both groups labored to build a wonder of the world. Unlike the pharaoh's slaves who hauled and stacked the stones in the desert, these people have chosen have chosen to labor at their ”wonder of the world.” They to labor at their ”wonder of the world.” They want want these jobs, take pride in what they do, and make good livings. For those who think that Americans don't build anything worthwhile these days, I say go down to NNS and watch these great men and women build metal mountains that float, move, and fly airplanes off the top. It truly is the ”NNS” miracle. these jobs, take pride in what they do, and make good livings. For those who think that Americans don't build anything worthwhile these days, I say go down to NNS and watch these great men and women build metal mountains that float, move, and fly airplanes off the top. It truly is the ”NNS” miracle.
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The ”NNS Miracle”: Some of the 2,600 Newport News s.h.i.+pbuilding workers leave the Harry S. Truman Harry S. Truman (CVN-75) at the end of an afternoon s.h.i.+ft. (CVN-75) at the end of an afternoon s.h.i.+ft.
JOHN D. GRESHAM.
When the initial crew cadre came aboard Truman in early 1998, they began to help the NNS yard workers bring the s.h.i.+p's various systems to life. This process (ongoing until the s.h.i.+p is handed over to the Navy) is designed to make her ready for her ”final exams,” when the carrier will become truly seaworthy, with her reactors powered up and most of her ”plankowner” crew aboard. Combat systems tests occur when the s.h.i.+p is about 98% complete, with evaluations of the radar and radio electronics, defensive weapons, and all the vast network of internal communications and alarms. After these tests, it is time for sea trials off the Virginia capes, including speed runs to evaluate the power plant. After these trials are completed, the Navy conducts one last series of inspections prior to the most important ceremony of the entire building process (at least for NNS). This is the signing of the Federal Form DD-250, which indicates that the Navy has taken possession of the vessel and NNS can now be paid!
The next six to eight months are filled with training and readiness exercises, including the traditional ”shakedown” cruise. Following this is a short period of yard maintenance (known as ”Post Shakedown Availability”) to fix any problems that have cropped up. The new carrier will then spend much of her time over at the Norfolk Naval Station, moored to one of the long carrier docks, where she will get ready for commissioning. At the commissioning ceremony, the high officials, the dignitaries, and the s.h.i.+p's sponsor once again gather. Again there are speeches and presentations. And almost a decade after the decision was made to build this mighty wars.h.i.+p, a signal is given, the commissioning pennant is raised, the crew rushes aboard to man the sides, and she is finally a wars.h.i.+p in the U.S. Navy.
The Nimitz Nimitz Cla.s.s: A Guided Tour Cla.s.s: A Guided Tour Let's now take a short walking tour of a Nimitz- Nimitz-cla.s.s carrier. We'll start the way most guests come aboard, at the officers' accommodation brow on the starboard side just under the island. One of the first things you notice is the thickness of the hull, which is composed of high-strength steel several inches thick. It is that thick to protect against battle damage and fires. The same material makes up the flight and hangar decks, providing them with a similar resistance to damage and fires. Everywhere, there are redundant water and firefighting mains, with damage control stations in every pa.s.sageway. The Navy is deadly serious about firefighting, and there even is a water deluge system, which can flood the deck, or wash it down in the event of a nuclear or chemical attack.
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A front cutaway view of an improved Nimitz Nimitz-cla.s.s (CVN-68) nuclear-powered aircraft carrier.
JACK RYAN ENTERPRISES, LTD., BY LAURA DENINNO.
Past the entryway hatch, you take the first of many tall steps over structural members the crew calls ”knee knockers.” Though they are a constant nuisance to movement throughout the s.h.i.+p, these steel thresholds provide structural strength to the entire vessel. A Nimitz Nimitz has miles of virtually indistinguishable pa.s.sageways. And there are dozens of places in them where just standing around watching can be hazardous-due to noise, fumes, moving machinery, or simply wet, slippery decks. These pa.s.sageways are considerably narrower than those in other combat vessels, particularly amphibious s.h.i.+ps which have room for combat-loaded Marines to move around. Despite their huge size, carriers are volume-limited, and s.p.a.ce for people to live, work, and walk takes away capacity for fuel, bombs, and fighting power. So getting around with any sort of load can be a genuine ch.o.r.e. You often see ”bucket brigades” of sailors moving loads of food and other supplies from one place to another. has miles of virtually indistinguishable pa.s.sageways. And there are dozens of places in them where just standing around watching can be hazardous-due to noise, fumes, moving machinery, or simply wet, slippery decks. These pa.s.sageways are considerably narrower than those in other combat vessels, particularly amphibious s.h.i.+ps which have room for combat-loaded Marines to move around. Despite their huge size, carriers are volume-limited, and s.p.a.ce for people to live, work, and walk takes away capacity for fuel, bombs, and fighting power. So getting around with any sort of load can be a genuine ch.o.r.e. You often see ”bucket brigades” of sailors moving loads of food and other supplies from one place to another.