Operating the world’s largest cruise ship means a lot of moving parts.

Below the guest decks on Royal Caribbean International’s new Harmony of the Seas — away from the eyes of the regular cruisegoer — crew members move in an almost nonstop bustle of activity through the busiest corridor, or main artery, of the ship.

They call it “I-95.”

Here, you’ll find them shuffling along the main thoroughfare to and from daily duties, some pushing food and beverage carts, others moving pallets of provisions and supplies, or carrying items for recycling or the trash compactor.

For just one weeklong cruise, Harmony carries thousands of pounds of food and hundreds of different beverages, including 40 brands of beer, 340 brands of wine, more than 40 kinds of fruits and 80 different vegetables. There are thousands of rolls of toilet tissue, paper hand towels and new lightbulbs, and gallons of hand sanitizer to stock.

That’s just a snapshot of what it takes behind the scenes, with 2,100 crew members performing the critical work that results in smooth sailing aboard Harmony of the Seas, which now departs from Port Everglades.

“A ship like this is all about the crew and bringing (all that it offers) together, and it’s not only about the crew that guests see,” said Mark Tamis, senior vice president of hotel operations for Royal Caribbean.

It’s a mammoth undertaking to cater to the up to 6,780 passengers that can be accommodated on the Harmony. The $1.5 billion floating resort features 22 food outlets.

Harmony goes through 20,000 pounds of baking potatoes, 12,600 pounds of flour, 15,000 pounds of beef and 9,700 pounds of chicken for a week’s worth of meals. After all, there are 80,000 plated meals to serve daily.

“We’re one of the largest food operations in the world,” said David Reihana, traveling corporate chef for the line’s parent company, Royal Caribbean Cruises Ltd.

Out of 1,056 culinary team members on the ship, there are 532 in its restaurants and 184 in beverage service, as well as 200 cooks.

The ship’s pastry kitchen on Deck 3 operates around the clock in two shifts to churn out desserts, cookies, cakes and other sweets, Reihana said. Meanwhile, the bakery on Deck 4 makes muffins, breads and other baked items for the ship’s food outlets.

On any given seven-day Harmony cruise, there’s a selection of more than 40 types of breads and 100 pastries for guests to choose from, according to Royal Caribbean.

“Everything we make on-board — every dessert, every pastry — is made fresh,” Reihana said.

At the American Icon Grill main restaurant on Deck 3, during dinner service, a synchronized meal prep gets underway immediately after the waiters’ orders are in.

“We have only 30 minutes to do all the main courses,” said Reihana. “At 7 p.m., it looks crazy (in the kitchen), but it’s actually organized-crazy, and it’s a nice flow.”

In the cockpit bridge, the work of steering the ship takes place.

From here, Capt. Gus Andersson and his navigational crew go about sailing a vessel that weighs 226,963 gross registered tons and measures 1,188 feet long and about 216 feet wide. The 18-deck Harmony was built from more than 500,000 individual parts and is nearly four football fields long.

Despite its mega size, the big ship’s no slouch.

“We have one of the fastest modern cruise ships here,” said Andersson, of Sweden, who has previously captained other Royal Caribbean ships including Anthem of the Seas, Quantum of the Seas and Enchantment of the Seas.

Harmony’s average cruising speed is 22 knots, or about 25 mph, but the ship did go over 25 knots, or 28 mph, during sea trials before it officially launched earlier this year, Andersson said.

Not unlike the cockpit of an airplane (only much bigger), Harmony’s cockpit bridge is an intricate network of computerized screens with radars that detect weather conditions and maritime traffic nearby. The bridge also has a closed-circuit TV system that monitors other areas of the ship.

From the bridge, there’s a vantage view of the surrounding waters and you can also see the ship’s helipad, typically used to drop off people rescued at sea or to evacuate people for medical treatment on land.

As the third ship in Royal Caribbean’s Oasis-class of vessels, Harmony is more energy-efficient than its sister ships, Allure of the Seas and Oasis of the Seas, which launched in late 2010 and 2009, respectively.

Energy-efficient equipment can be found across the ship’s engines, lighting, elevators, kitchen galleys and other operational areas, said Richard Pruitt, vice president of safety and environmental stewardship for Royal Caribbean Cruises.

“It’s over 200 individual initiatives that have gotten (Harmony) to be approximately 20 percent more energy-efficient per person, per day than even the Allure that came out six years before,” Pruitt said.

And in the end, crews have to prepare to do it all over again.

Perhaps the most important crew orchestration is getting Harmony ready for its next cruise within about 10 to 12 hours of returning to port from its last seven-night cruise.

That’s like restocking a small city with food and supplies. Not to mention all the passenger luggage to unload for departing guests, and the 2,747 staterooms to set up for a new batch of passengers to enjoy.

“Every time we come into our home port here in Fort Lauderdale, it takes about 30, 18-wheeler trucks that come into the port and replenish (the ship),” Tamis said.

“And that logistical equation that happens every single week is one of the most amazing things because the guests never see it.”