Written by Michael W. Robbins (popsci.com)

	Lord Nelson's H.M.S. Victory in J.M.W. Turner's Battle of Trafalgar. Bottom: The fully loaded U.S.S. Harry S. Truman. National Maritime Museum, London; courtesy Ed Katz (bottom)

Going into battle, the captain notes from the bridge that the crosswind has picked up, and he has a word with his officer of the deck. The OOD issues an order to the young helmsman. The helmsman turns the wood-spoked wheel to the right, and the boatswain picks up his silver whistle and alerts the crew. A seaman plots the change of course on a large paper chart with a straightedge and pencil, noting the time. Below, in sight of the captain, hundreds of crewmembers ready the ship's weapons for a fight.

Ah, the ritual and romance of the fighting ship in the Age of Sail, when the 100-gun man-of-war, one of the most complex machines ever devised, roamed the oceans of the world. It's the romance that turned Patrick O'Brian's 20 Aubrey/Maturin novels into modern classics of nautical fiction and, Hollywood hopes, will make this month's Master and Commander, starring Russell Crowe, into a blockbuster. But the scene described above is actually standard operating procedure on the bridge of Nimitz-class U.S. Navy supercarriers today, carriers such as the recently commissioned U.S.S. Ronald Reagan, the Harry S. Truman and the Abraham Lincoln. Silver whistles, pencil and charts, the spoked wheel -- all are used in today's Navy, although, of course, a carrier also relies on instant messaging via encrypted satellite signals and, instead of powder-fired cannon shot, launches cruise missiles and smart-bomb-equipped F/A-18 Hornets.

For all the enormous and obvious changes in ship design, materials, propulsion systems, weaponry, controls, navigation, communications and the like, the fundamental purpose of big warships has not changed much in the 200 years since Lord Nelson commanded the H.M.S. Victory, the Nimitz of its day: "forward presence" during peacetime -- in the form of awesome machines whose mere appearance signals the will of empire -- and overwhelming firepower during war. (The ship in the Crowe movie is a smaller, faster brig, but itself a marvel of compact complexity.)

At sea level, the fundamentals also endure. "Wind hasn't changed. Waves haven't changed. The weather hasn't changed," says Capt. James "Hubs" Hubbard, who until last year was the U.S.S. Harry S. Truman's "air boss," the officer in charge of flight operations. Hubbard made the remark during a training cruise off the Virginia Capes before the ship's deployment for duties in the months before the Iraq war. "We still have to take all those things into account during an operation. For instance, we won't launch our F-14s in a crosswind greater than 7 knots."


STRATEGY AND FIGHTING
Nelson would have marveled at the military possibilities represented by carrier technology -- cannons that fly, my Lord! -- but he would probably have regretted a key difference between his ship and ours. The supercarrier, too valuable to risk losing, and able to hurl its ordnance beyond the horizon, is made to stand away from battle, sometimes hundreds of miles away. Nelson took the British Empire's technology right into the thick of things. Engagement was often a ship-versus-ship slugfest. A big naval encounter involved what was called a "line of battle": a fleet of 30 or more ships lined up bow to stern so they could concentrate their firepower in thunderous cannonball broadsides at an enemy fleet -- preferably from ranges of 240 yards or less. The intent of these barrages of flying iron was to hole an enemy hull and sink the ship while sending showers of deadly wood splinters into the crew, or at least do enough damage to immobilize a ship for boarding, hand-to-hand fighting and capture.

	Prior to the July 12 commissioning of the U.S.S. Ronald Reagan, the newest Nimitz-class carrier, sailors steady an F-14D Tomcat as it's hoisted up to the deck. Courtesy Rusty Black/Navy Newsstand

Today, the primary modern fighting maneuver of the carrier is to position itself for the launch and recovery of its F-14s and F/A-18s. "The ultimate thing we do," says the Truman's Capt. Michael Groothousen, "is put fused bombs on the target." The dangerous, skilled, clockwork duty of hundreds of sailors is the maintenance, arming, launch and capture of the carrier's aircraft, a ferocious, beehive form of warfare in which the fighting is the one thing not directly seen except by a handful of pilots sent out to engage the enemy with their smart bombs and other devastating ordnance.

The actual maneuvering of the ship, pointing it into prevailing winds, may sound relatively simple, but there are complicating factors. U.S. carriers operate as the centerpiece of a complex battle group that typically includes Aegis guided-missile cruisers and destroyers, conventional destroyers, a guided-missile frigate and attack submarines -- "our ring of steel," Groothousen calls it -- plus a support vessel that carries ammunition, fuel and supplies. All these must be able to stay near the carrier, without interference or collision. Sea space may be limited, if there are islands or shoals in the way. Winds may shift, and currents and tides may impede the ship. A carrier may steam upwind launching its heavily armed jets, then turn and go downwind, then turn again upwind to receive its returning aircraft, which may be low on fuel and need to land promptly.

Ships have to talk to each other, and that is far easier now than in Nelson's time. "One of the great difficulties of operating a man-of-war in the Age of Sail was just communicating," says John Hattendorf, a professor of maritime history at the Naval War College in Newport, Rhode Island, "both between ships and onboard a ship. For routine commands, like changing sails -- which involved a great many men -- the boatswain piped a set of precise orders. And the captain might use a megaphone." But imagine the situation in combat, as the cannons roared, firing raggedly after the first united salvo, with the wind and sea sometimes roaring too, and the smoke -- especially on the gun decks -- making it nearly impossible to see. "Once in battle," Hattendorf says, "they might signal from ship to ship with flags that had a particular meaning, like ?Enemy fleet in sight' or ?Engage closely.' And sometimes at night they used lanterns, though night battles were rare. Occasionally, the fleet would have a frigate stand away from the line, and avoid the smoke, to relay signals to the fleet." Onboard ship, during a battle, the captain used runners -- often boys known as "powder monkeys" -- to communicate with, say, gun crews.

Today, boatswains still use their pipes -- sounding over a ship-wide PA system -- to alert the carrier crew to a major announcement, but a PA system does not suffice for most of the onboard communicating. There's a "ship's telegraph" between the bridge and the engineers. Between ships in the battle group and up and down the chain of command, from the admiral in charge of a battle group through the commander of the Naval Air Force Atlantic Fleet and all the way up to the Pentagon and the White House, communications are encrypted. "We actually do the bulk of our communicating by e-mail," says Lt. Comdr. Brenda Malone of the Truman. "For unclassified stuff, we use Microsoft Outlook. Of course, there are also secure networks that use other programs. And between ships we do some video teleconferencing, both secure and unclassified. Our telephoning is done via special secure satellites."

The launch of the Reagan this year represented, the Navy says, the most significant technological leap forward for the Nimitz-class carriers since the Nimitz itself, with much more emphasis on the digital display and distribution of information. Digital instruments in the bridge produce a more intuitive "glass bridge" modeled after the so-called glass cockpits in modern aircraft, and there are touchscreens instead of old-style gauges and dials. Communication data flows through a fiberoptic system.

Yet there is one place on a carrier where the roar and near chaos of a man- of-war persists: the flight deck during battle. Military jets are unmuffled and often operate on the deck at full throttle, producing a thunder above which no shout can be heard. Pilots and flight deck crew, including the catapult crew -- the "shooters" -- communicate via hand signals. A missed signal ("jet blast reflector up," "turn right," "fold wings," "go") can kill, just as miscommunication between crewmembers manning a recoiling cannon could dispatch a Royal Navy seaman in the blink of an eye.

	In the following passage from Master and Commander,* Jack Aubrey's little 14-gun sloop, the Sophie, goes into full-broadside battle with the Spanish xebec-frigate Cacafuego. The Sophie is smaller than the ship used in the Russell Crowe film (Crowe as Aubrey seen above, bellowing), and a pipsqueak beside a mighty first-class three-decker. But the vivid elements of close battle are similar. "And all this time the Spaniards fired on and on, irregularly, spasmodically, but never stopping. The Sophie's maintop had been hit again and again, and now it was coming to pieces -- great lumps of timber falling down on deck, stanchions, hammocks. Her foresail yard was held only by its chains. Rigging hung in every direction and the sails had innumerable holes: burning wad was flying aboard all the time and the unengaged starboard crews were running to and fro with their fire-buckets. Yet within its confusion the Sophie's deck showed a beautiful pattern of movement -- the powder passing up from the magazine and the shot, the gun-crews with their steady heave-crash-heave, a wounded man, a dead man carrying below, his place instantly taken without a word, every man intent, threading the dense smoke -- no collisions, no jostling, almost no orders at all." * Pages 330 and 331, WW Norton paperback edition of Master and Commander, by Patrick O'Brian.

CAPTAIN AND CREW
A man-of-war captain in the late 18th and early 19th centuries had to know all about the actions and interactions of the ocean and the weather -- indeed, everything that could help or hinder the progress of his ship, moment by moment, season by season, anywhere in the world (a British squadron under Lord Nelson shadowed a hostile French fleet in 1805 from the Mediterranean across the Atlantic to the West Indies and back, navigating as usual with a chart, a lead line, sextant, chronometer, compass). Quick, accurate mathematical calculation was critical, Hattendorf says, and "the captain's mind was his computer." Because ships moved at the mercy of the wind, a fickle power source at best, the captain needed a deep understanding of how each one of some three dozen sails, from the flying jib to the mizzen topgallant sail, could affect movement -- and how long it would take the topmen to scramble high into the rigging to reef a sail. Today, a Nimitz-class carrier's power source is remarkably reliable: Two nuclear reactors, whose operation a captain spends many months at the Navy's Nuclear Power School studying, are equipped to produce 20 years' worth of electricity. In addition to possessing sailing and navigation chops, every carrier's commanding officer is required to be an accomplished aviator. Captain Groothousen, for example, who got his wings in 1976, first flew A-7E Corsairs aboard America and Independence, then flew F/A-18 Hornets, became a Hornet instructor pilot, and finally commanded a Hornet squadron before assuming command of his first ship, the U.S.S. Shreveport, an amphibious-assault transport.

As to the crew, a 100-gunner of the Royal Navy carried about 820 men, comprising experienced officers and veteran seamen -- some of them "impressed," essentially kidnapped -- as well as "landsmen," landlubbers who didn't know a tiller from a touchhole, and about 150 fighting marines. A Nimitz-class carrier operates with a crew of more than 3,200 trained and specialized young men and women, enlisted and officers. An eight-squadron air wing adds another 2,500 people. "Young" is a key word here: The average age of a carrier crewmember is under 20. During routine operations, these sailors work relentlessly, 14 to 16 hours a day; in combat, far more. The nation's most impressive symbols of military power are run by thousands of sleep-deprived, highly disciplined sailors, many of them teenagers.


THE WEAPONS
Ships of the line, from 100-gunners, known as First Rates, to 78-gun Third Rates, carried a roster of cannon ranging from 32-pounders down to 12-pounders (named for the weight of the ball fired by black powder). With a range of over a mile, these were massive weapons, but they were not very accurate, hence the need for broadsides. "The guns couldn't really move from side to side," says Hattendorf. And they could only be elevated about 10 degrees and only by moving a wooden wedge called a quoin under the breech. "So moving the guns meant moving the ship. Aiming was essentially steering." In addition to the plain cast-iron ball, the cannon sometimes fired grape shot (a container of small balls for antipersonnel use at close range) and chain or bar shot (two balls linked by a short chain or a pair of sliding bars that would whirl in flight, the better to tear up the enemy's sails and rigging). Whatever the ammunition, even a superbly drilled gun crew could manage a rate of fire of only one round every 2 minutes. Marines, fighting from the deck or in the rigging, also hurled grenades, fired muskets, and employed pikes and cutlasses.

The array of offensive weapons on a Nimitz-class carrier reads like a list of all the varieties of hellfire. The F-14 Tomcats are armed with up to 13,000 pounds of AIM-54 Phoenix missiles, AIM-7 Sparrow missiles, AIM-9 Side-winder missiles, "air-to-ground ordnance" (bombs) and a M61A1/A2 Vulcan 20-mm cannon. The F/A-18 Hornets can carry most of the above, along with AIM-120 AMRAAM, Harpoon, Harm, SLAM, SLAM-ER and Walleye missiles, plus general-purpose bombs, mines and rockets. Antisubmarine and other offensive missions are carried

out by S-3B Vikings, which can unleash AGM-84 Harpoon, AGM-65 Maverick and AGM-84 SLAM missiles, plus torpedoes, mines, rockets and bombs. The SH-60 Seahawk helicopters can carry three Mark 46 or Mark 50 torpedoes, or AGM-119 Penguin or AGM-114 Hellfire missiles. And all this firepower can get off the boat in a real hurry: When the flight deck is in full "cyclic" mode, it launches a combat aircraft every 20 seconds. The key to this speed is the muscle of four C-13 Mod 2 steam-powered catapults, which, with 450 pounds per square inch of steam pressure, can help accelerate a fully loaded fighter to 165 mph in 3 seconds.

This much Navy treasure needs protecting. Apart from its own air wing and its escort ships, a Nimitz-class carrier's defensive weapons include three NATO Sea Sparrow short-range surface-to-air missile launchers; four six-barrel 20-mm rapid-fire Phalanx Close-In Weapons

	On the U.S.S. Harry S. Truman in the Mediterranean, ordnance crew, preparing for morning flight operations, transfer laser-guided GBU bombs from the hold to an aircraft-weapons elevator. Dustin Gates/Navy Newsstand

Systems (CIWS) mounts, with Gatling guns; and something called the "32" electronic warfare system that includes among its assets a wide-band radar warning receiver to pick up early indications of an attack and a wide-band radar jammer.

For all that, nothing as big as an aircraft carrier is invulnerable, and the attack on the U.S.S. Cole in October 2000 in Yemen revealed that ships, like buildings, can take a direct hit from terrorists. Carriers now enforce more assiduously an air-and-sea "bubble," or perimeter within which no craft can approach without challenge. "One of the tough decisions I make is when you have an in-bound and we don't have a good ID on him," says Groothousen. "Let's say I have a small boat heading right for us -- we've warned him over the radio, we've told him, ?Turn away,' and he refuses to turn away. I'm probably going to have to tell someone to engage him, at least shoot across the bow once or twice. And if he doesn't turn away, take him out. And it's the same thing with airplanes in the Persian Gulf."

In battle, though, U.S. carriers are almost invulnerable today -- at least while the enemy is as underequipped as Saddam Hussein or the Taliban. It is as if Nelson had sailed into Trafalgar against rowboats rather than the 33 ships and 2,600-plus guns of the French and Spanish fleets. For the 21st-century American carrier, there probably will be no Trafalgar-like test. The job is to sit back and hurl the flying cannons beyond the horizon.


Michael W. Robbins, a freelance writer, has been published in Mother Jones and the Washington Post Magazine.