Supercarrier

  • Photgraphs by Grant Delin
  • Slabs of steel brought by rail to the Newport News shipyard in Virginia wait to be cut, pressed and curved into the hull of the USS Ford, which is scheduled to launch in 2015. The annotated model (opposite) highlights the carrier"â„¢s most critical new systems.
  • Photgraphs by Grant Delin
  • Using a 23-storey gantry crane, the largest in the Western Hemisphere, workers manoeuvre a structural unit into place. Imahe credit: Grant Delin
Date:31 July 2009 Tags:, , , , , , ,

To design the US Navy’s new Ford-class aircraft carrier, architects rely on virtual reality to shape 54 000 tons of steel into the world’s most powerful warship.

The first pieces of the US Navy’s newest class of aircraft carrier – meant to be the cornerstone of American military sea power over the next hundred years – lie in the open air of a shipyard in Virginia. A misting rain is falling on the jumbled field of steel bulkheads, stacks of pipe and 180-ton sections of hull. It’s as if some gargantuan child broke apart his model ship and scattered the pieces on the ground.

But Northrop Grumman’s staff at the Newport News shipyard know where every part is located – and the exact order in which each piece must be connected. Building an aircraft carrier is like putting together a 3D jigsaw puzzle, for years on end. Engineers have been designing some of the pieces since 2000; the job won’t be finished until 2015. And on a complex project of this scale, there is little margin to correct design mistakes. If not found and fixed, one small flaw can have ramifi cations that cost tens of millions of dollars, months of hot-metal work or even the life of a sailor not yet born. “ ese ships are like entire planned cities,” says Eric Wertheim, editor of  e Naval Institute Guide to Combat Fleets of the World. “It’s like building Disney World.”

For more than six decades, aircraft carriers have been involved in virtually every major American military engagement, from World War II to the current confl icts in Iraq and Afghanistan. But America’s carrier fl eet is getting old. Designs for today’s Nimitz-class ships began in 1964, and although upgraded, the carriers’ steam-powered catapults and cramped quarters belong to another era.

So, for the first time in two generations, the Navy is commissioning a new carrier, named after President Ford, who served with distinction on the carrier Monterey during World War II. Following custom, each subsequent ship constructed to these specs will be named after him: the Ford class of carriers.

Building a supercarrier is a uniquely American enterprise. There are 21 aircraft carriers in service around the globe; 11 belong to the United States. A few other nations – Britain, Spain and India – have plans to build aircraft carriers. But no one else makes them this large or with such advanced capabilities. No one else is about to try.

The last time American engineers designed a carrier from scratch, in the 1960s, they drew the ship in ink and built full-scale wooden models to prove their designs. Then, the constructionyard workers had to figure out how to put the ship together. Things work a little differently in 2009. Now, engineers and foremen can wander around a mock-up of the ship without wearing helmets or boots. All they have to do is slip on chunky black glasses, stare at a screen and step inside the ship’s CAD plan.

Sam Vreeland, the Ford’s jowly, red-cheeked construction director, hands me a pair of the bulky glasses. We’re in a black-walled room inside a nondescript building at the shipyard. On a 2,4 m-tall screen in the centre of the room, engineers from around the country meet – without leaving their offices – to perfect blueprints in virtual-reality simulators. In front of me is a virtual 3D model of every element of the ship’s jet-fuel room, from pumps and pipes to shims and studs securing bulkheads. In the lower decks, engineers have assigned a part number and a supplier to every one of these digital pieces. “We got this technology because we can walk anybody through, including the Navy,” Vreeland says. "They can see it more clearly than with a mock-up.”

Penn State University research associate Vaughn Whisker appears on the screen to my left. Or at least his unshaven, blackclad avatar does. It waves from University Park, Pennsylvania, some 640 km to the northwest, where Whisker is stomping around a 3 m by 3 m room lined with virtual-reality screens. In the digital fuel room, the avatar reaches up for a pipe to make sure it’s in the right place. Then he moves behind a pump to ensure that maintenance workers will be able to fit behind it.

With another mouse click, any designer with access to the CAD file can see the room from the point of view of future crewmen, ensuring that pipes and open hatches don’t impede lines of sight to gauges or alarms, or the hand signals of shipmates at their stations. “We always had to find the engineering balance,” says Lin “Yank” Rutherford, a former rear admiral and the shipyard’s director of platform integration. “But in the past, there was some subjective thinking.”

I reach out with pixellated hands, grab the pump and toss it across the room. Then I spin the lighting fi xtures around and tilt the floor. If the Northrop designers wanted to incorporate my horseplay, they would dump the data into the CAD system and ship it 4 km to the fabrication plant at the other end of the shipyard, where metal is shaped to the exact specifi cations called for by the digital blueprint.

Engineers are using other sophisticated software to synch the ship’s design with its future operation. On the flight deck, for example, shipbuilders test the way aircraft are brought to the deck and readied for launch. The Ford is utilising a new, NASCARlike pitstop approach. On Nimitz-class carriers, aircraft are dragged all over the flight deck for fuel refills, weapon reloads and maintenance checks. On the Ford, workers will handle all those jobs in a single spot. The Navy hopes these measures will increase sorties from the ship by 25 per cent – up to 270 per day.

Everything on the Ford is subject to simulation testing, from the views of the flight deck from the bridge to damage control in the engine rooms. According to manager of engineering David Rockey, there are even messing models. “Th at’s where we see how long it takes crew members to get a hot lunch and come back (to their stations),” Rockey says. “It’s like SimCity for carriers.” But this game has a serious purpose: “Before we cut steel and pay the bill, we want to see what we’re going to get for our efforts.”

Eventually, this pixellated world meets the real one. Vreeland and I walk into the fabrication plant to see the raw metal, brought in by the trainload, formed into parts of the hull. It’s a cavernous, clanging, hissing 3 200 m² shop with dross, sparks and metal scraps all around. Everyone calls out, “Hey, Sam-may!” as we walk by; Vreeland, a Virginia native, has been at the yard since 1972, working his way up from apprentice on Los Angeles-class subs to become the Ford’s head of construction in 2000.

One worker, dressed in plaid, looks into a computer screen that displays data from a CAD file. The software guides a cutting machine’s jet of plasma gas over a long, low tub. The water below gurgles and flashes purple before draining to reveal a steel plate. There’s a big, bevelled oval cut in the centre and lots of smaller holes for pipes and wiring. It’s the virtual carrier, starting to come to life.

We exit the plant and step into a company van. Vreeland drives along the waterfront, zipping over worn rails and past low-slung brick buildings and corrugated factories. On the ground are two 180-ton pieces of the hull, curved on one side, flat and toothy on the other. Put them together, and they become a superlift – a piece of the carrier that is ready to be fi t into the puzzle. The shipyard needs to assemble 162 superlifts to create the hull. And just about the only machine on the planet than can handle these massive parts is the powder-blue, 23-storey gantry crane under which we’re driving. Riding on rails eight football fi elds long, the rectangular crane uses three hooks, each capable of lifting more than 270 tons, to pick up ship parts. But even that 800- ton capacity – the largest in the Western Hemisphere – wasn’t big enough for the Ford. So Northrop upgraded the crane’s maximum haul to 950 tons.

The shipyard is obsessed with the timelines of any big-dollar project, and the Ford is easily the biggest. The first Ford-class carrier will cost R114 billion, including R40 billion for research and development; Navy offi cials say the price will drop to around R50 billion per ship with subsequent builds. Delays – and so far the Ford programme has suff ered two years’ worth of them – can mean losing skilled workers and support from Congress or the Pentagon.

As the largest items in the Pentagon’s shipbuilding budget, new carriers are tempting targets for cutbacks. Some defence analysts are already wondering why the US needs a 90 000-ton monster carrier when that country’s most prominent current enemies are terrorists, small guerrilla bands and pirates in skiff's.

Another controversy surrounding the Ford programme is whether this is the right time for a new design. “Do we know enough about future threats?” Wertheim asks. “By 2060, are we even going to have manned fighters? We’re really at a crossroads.” Although Wertheim thinks the new carrier programme could have waited 10 years to get a better idea of the future needs of the ship, he notes that the construction is progressing well. “So far, so good,” he says. “But on these huge programmes, it’s inevitable that they have hang-ups. When that happens, you can’t see it as a failure for the whole programme.” When the Ford is completed, it won’t look much diff erent from carriers built for the Cold War. However, there will be striking changes inside.

The Ford is the first to greatly reduce aircraft carriers’ reliance on steam. Nearly everything done on the Nimitz class – heating cabins, drying laundry, propelling the ship, making potable water, launching jets – is done with steam power generated by a nuclear reactor. All that steam means gangs of sailors to operate valves, read gauges and fix machines when they invariably wear down or spring a leak. On the Ford, many of those systems will be electric.

The most novel use of electricity occurs on the flight deck. Steam-powered catapults currently do not provide heavier aircraft with enough acceleration to take off , so the carrier cranks up the knots to increase wind speed over the deck. On Ford-class vessels, four linear motors will create magnetic waves that propel the catapult, with each jet getting a customised shove into the sky. Planes will land as they do now, by hooking onto arresting cables, but the system that slows their speed will be electromechanical rather than just hydraulic.

These novel designs come with risks. According to the US Government Accountability Offi ce, developing the launch system’s generator has led to a 15-month delay. Th e Navy hopes these developmental risks will be rewarded with long-term savings, especially from the decrease in manpower. On old carriers, it takes gangs of men to move food, laundry, spare parts and ordnance. On the Ford, forklifts, not sailors, will haul supplies. Programme managers say the Ford will require 700 fewer people than a current carrier, saving as much as R40 billion over the life of the ship. Protecting those sailors is another concern: the US Navy has gone to great lengths to ensure its carriers can take a hit. For 25 days in 2005, engineers with Naval Sea Systems Command conducted classifi ed explosions on the USS America, a Kitty Hawk–class carrier that served in Vietnam and the Persian Gulf. The ship eventually flooded and sank in the largest damage-control experiment ever conducted. Th e Navy says results of that test have been incorporated into the design of the Ford.

Later this year, the megacrane will lower the first superlift piece into the dry dock where the Ford will be assembled. Navy brass, politicians and company officials will gather around the massive section of the hull and make speeches; bands will play martial songs. Th en more curved side shells will be outfitted with pipes, lights and as many fi xtures as possible before being lowered into the dry dock.

One superlift at a time, the USS Ford will slowly take on the aspect of a ship. When the carrier’s structure is complete from hull to island, the dry dock will be flooded with water from the James River. Tugs will tow the massive, empty vessel to another part of the shipyard for years of wiring and systems integration, freeing up the dock for the construction of the next Ford-class vessel. The process will continue until 2058 or until funding ends. Every day between now and then, at 12.30 pm, a shrill whistle at the shipyard will blow twice. Workers across Newport News – some wearing coveralls and hard hats, others in virtual-reality goggles and slacks – know it means their lunch break is over. They will head back to their respective corners of the shipyard and get back to work.

Carrier-killer defence
Will America’s enemies be able to sink the Navy’s next-generation aircraft carriers? The answer is debatable, but it’s inarguable that potentially hostile nations are developing – and exporting – weapons for the task. And tactics are evolving: think-tank researchers and military intelligence professionals follow Chinese military journals for the latest theories on stopping US aircraft carriers. The Navy then incorporates new defences to thwart these emerging threats

Threats

Decoy: The first step in killing a carrier is to confuse the escorts that protect it. The cheapest way to do this – decoys. Covert teams in fishing trawlers, for example, can drop buoys that are programmed to emit delayed radio signals to misdirect a carrier group’s defensive ships and aircraft.

Anti-radar drone: Unmanned aircraft can blind a carrier’s escort ships. The Harpy, a drone that Israel sold to China in 2004, circles an area, seeking radar signatures, which it then targets with a kamikaze attack. Without radar, escorts can’t find and shoot down anti-ship missiles

Diesel submarine: These quiet, lethal menaces can evade detection, especially in shallow water, and fire Sizzler missiles (a Nato designation) that skim the waves at supersonic speeds. Iran operates Russian-made diesel subs; Pakistan has purchased French-made Scorpions. China is the biggest enthusiast: it built 14 diesel subs in 2006 alone.

Su-30 Flanker: Russian-made aircraft have long been designed to attack carrier groups. The Su-30 can fire barrages of missiles to overwhelm an aircraft carrier’s defences. In 2011, the Russians plan to export an upgraded version called the Super Flanker

Anti-ship ballistic missile: By 2015, Chinese mediumrange ASBMs may target carriers. Over-the-horizon radar could identify ships by bouncing signals off the ionosphere or by propagating signals over the ocean surface. Dong Feng 21 missiles are designed to use onboard radar to find carriers and close in at a high Mach speed.

Defence

E-2C Hawkeye: To defeat decoys, carrier-launched surveillance airplanes with high-power radar can confi rm the presence of approaching enemy ships and aircraft. As they gather fresh data from the air, Hawkeyes also direct warplanes and surface ships.

Arleigh Burke destroyer: Engineers are upgrading destroyer sensors to spot multiple threats, including small ones such as drones. A phased-array radar, which can track 100 targets at once, operates in the S-Band frequency range, allowing optimal performance in any weather conditions. The objective: find and destroy drones before they can strike.

SH-60 Seahawk: Helicopters deploy sensors called sonobuoys to detect acoustic, sonar, thermal or magnetic signatures of submerged submarines. Instead of dipping a sonobuoy into the water, expendable modern versions are dropped from helicopters such as the Seahawk. Remotely operated boats are also used to drag arrays in search of enemy subs.

F-35C Lightning II: When it comes to defending the airspace around a carrier, the F-35C is expected to carry the load for the US Navy. The stealth aircraft is made to kill foes before being seen. However, it is not an agile, cannonequipped dogfi ghter like the F-18A Super Hornet, which it will replace in 2015.

Aegis cruiser: Ship-based ballistic-missile defences have come a long way. Some Ticonderoga-class Aegis cruisers carry SM-2s that can shoot down inbound warheads in the final stages of flight. New SM-3s engage targets even earlier – in their mid-course stage.

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