Measuring 610 feet from bow to stern and looking like something from a sci-fi movie, the USS Zumwalt is far from invisible.

Nor is it inexpensive.

Yet the $3.3 billion destroyer that will be christened Saturday at Bath Iron Works is, according to naval analyst Eric Wertheim, representative of “the future of the Navy” – a “stealth” warship designed to support land attacks and built to adapt to an ever-changing military environment.

“It is a very advanced and very technologically sophisticated ship,” said Wertheim, author of the “Naval Institute Guide to Combat Fleets of the World.”

“You can’t argue that this is an evolutionary ship,” he said. “It is a step more. And you could argue that is why we don’t need as many of these.”

The Zumwalt-class DDG-1000 ship is the largest destroyer ever built for the Navy, at 15,000 tons based on the weight of the water it displaces. The more traditional destroyers built at BIW are about 500 feet long and have a displacement weight of 8,300 tons.

The Zumwalt also can reach speeds as fast as 30 knots and operate in shallower waters than the reigning destroyer class, the DDG-51, Arleigh Burkes, which also are built at BIW.

The Navy has been planning the new ship for two decades. BIW, which has more than 5,000 employees, began construction five years ago.

Secretary of the Navy Ray Mabus, elected officials from Maine and an estimated 4,000 to 5,000 other people are expected to attend Saturday’s christening of the USS Zumwalt, which is named for the late Chief of Naval Operations Adm. Elmo R. “Bud” Zumwalt Jr. The ceremony will be open to the public.

The ship is the first of three Zumwalt-class destroyers to be built by BIW. That is down from the more than 30 that were envisioned well over a decade ago, a shift that reflects the high cost of the high-tech ship and changes to the Navy’s anticipated needs.

But Saturday’s christening will mark a milestone for BIW – one of Maine’s largest private employers – and for the Navy, which is marking its first new destroyer class in more than two decades. The last christening of a Navy ship at BIW was in May 2011.

“For a lot of people at BIW, it feels good to have a Navy ship pier-side again,” said BIW spokesman Matt Wickenheiser.

The christening was originally scheduled for Oct. 19, but the Navy postponed it because much of the federal government was shut down during the budget stalemate in Washington. The vessel was launched anyway without a public ceremony and placed at the shipyard’s docks so that crews could test equipment, including the ship’s massive engines.

LOADED WITH HIGH-TECH SYSTEMS

The DDG-1000 is different, inside and out, from an Arleigh Burke-class DDG-51. The Zumwalt is designed to fight in open water or support battles on land by getting closer to shore.

While Arleigh Burke destroyers have all of the features one would expect in a destroyer – such as the crowning “super structure” – Zumwalt destroyers are all smooth surfaces and vertical lines designed to evade detection.

The 900-ton deckhouse is entirely enclosed atop an angular ship designed to sit low in the water. The antennas, dishes and other pieces of the ship’s communication and surveillance systems also are tucked away, as are the “small boats,” used to ferry special operations forces to shore.

The result is a “stealth destroyer” expected to show up on radar looking more like a small fishing boat than a 600-foot warship. According to Navy officials, the Zumwalt has a radar cross-section that is one-fiftieth that of an Arleigh Burke destroyer.

Wertheim said the DDG-1000 also has a lower profile on underwater sonar and infrared systems.

“That doesn’t mean you can’t find it,” he said. “It just means it is harder to detect, and that allows it to get closer to its target.”

The Zumwalt is also the first destroyer to have a single gas-turbine powerhouse for the entire ship, capable of producing 78 megawatts – enough electricity to power 78 million 100-watt light bulbs. That powerhouse can provide enough juice to handle the ship’s propulsion, weaponry and other electricity needs, with room to spare.

“It gives the ship the ability to be flexible to future power needs,” said Capt. James Downey, the DDG-1000 program manager with Naval Sea Systems Command.

One of those uses could be an electromagnetic “rail gun,” which uses electricity instead of gunpowder or chemical propellants to shoot a projectile over long distances at seven times the speed of sound. Although electricity-intensive, the rail guns now under development by the Navy would use relatively cheap projectiles rather than, say, a Tomahawk missile that costs $1 million.

The Zumwalt will have the missile systems featured on all guided-missile destroyers. It will also have two high-volume, 155 mm “advanced gun systems” capable of shooting GPS-guided ammunition at targets more than 60 miles away.

SHIP TO BE A DESIGN TEST CASE

The Zumwalt is designed to operate with a crew of 158, including personnel for several on-board helicopters. That is about half the crew size for Arleigh Burke destroyers, a reduction made possible by automation and a “total ship computing” network.

Of course, such technology comes at a price: now estimated at $3.3 billion for the first ship with 90 percent of construction complete, Downey said. By comparison, the newest Arleigh Burke destroyers are expected to cost about $1.5 billion each.

The cost of the next two Zumwalt-class destroyers is expected to be lower, but the high price is one key reason why Navy officials balked at the initial plans for a fleet of Zumwalts.

Downey said officials have also determined in recent years that, based on the current global military environment, the Navy wants to strengthen its ballistic-missile defense systems. The Arleigh Burke destroyers are geared to address those threats, so the Navy opted not to propose additional changes to the Zumwalt destroyers.

“The plan is to build the three ships, make them war-ready upon delivery and then get them out to the Pacific,” Downey said. “And then the Navy will decide whether they meet the requirements and whether more are needed or not.”

Wertheim, with the nonprofit U.S. Naval Institute, regards the Zumwalt as a sort of technology test case that will enable the Navy to see what works and what doesn’t for future designs.

“These are platforms that allow us to push the envelope, and of course you don’t need as many of them to do that,” Wertheim said.

BIW spokesman Wickenheiser said the USS Zumwalt is expected to begin at-sea trials in May 2015.

Kevin Miller can be contacted at 317-6256 or at:

kmiller@pressherald.com