US Navy used its “last line of defense” against Houthi missile

(CNN) — The destruction of a Houthi missile by a U.S. warship in the Red Sea this week marks the first time the advanced weapons system, known as the Navy’s “last line of defense,” has been used in this conflict.

The Navy destroyer USS Graveley deployed the Phalanx Close-In System (CWIS) on Tuesday night, which US officials said was a cruise missile that came within 1.6 km of the ship, and therefore was somewhat safe from impact. Was seconds away.

The Phalanx automated system has Gatling cannons that can fire up to 4,500 20-millimeter projectiles per minute, hitting projectiles or other targets at extremely close range.

Manufacturer Raytheon states on its website “Last Line of Defense,” “The Phalanx weapon system is a rapid-firing, computer-controlled, radar-guided cannon that can defeat anti-ship missiles and other close-in threats on land and at sea.” Can.” ,

According to analysts, US warships have repelled dozens of past Houthi missile attacks using long-range defense, possibly using standard SM-2, standard SM-6 and evolved Sea Sparrow missiles. These defensive missiles attack their targets at a distance of about 12 km or more.

But this did not happen on Tuesday night for reasons that have not been disclosed.

Tom Caraco, director of the Missile Defense Project at the Center for Strategic and International Studies, said it was “concerning” that the Houthi missile came so close to the US warship.

“If you’re going at a good pace, 1.6km translates into less time,” Caraco said.

Analyst Carl Schuster, a former U.S. Navy captain, said the Houthi missile, traveling at about 600 miles per hour, was probably about 4 seconds away from hitting the U.S. warship when it was destroyed by the rocket’s explosion. Two to three seconds of machine gun fire from Gravely’s Phalanx system.

He said destroying the incoming missile at a distance of 1.6 km would not prevent warships from being hit by debris.

“Missiles do not vaporize when destroyed, but instead leave behind thousands of pieces and fragments of the missile structure,” Schuster said. “The good news is that lighter fragments fall rapidly, but larger fragments can fly up to 500 meters.”

He explained that the closer the missile was to the ship at the time of destruction, the greater the danger to the ship, as large fragments could penetrate unarmored parts of the hull and superstructure from about 200 meters away. Schuster explained.

In the case of a subsonic cruise missile like the Gravelly, “depending on whether the warhead detonates, the size of the debris, the missile’s flight angle and altitude at the time of its destruction, about 2% of the debris could reach the ship,” he said Tuesday. They said.

Up to 70% of the debris from missiles traveling at high speed, such as supersonic cruise missiles or ballistic missiles, will hit a warship after being attacked by the Phalanx, he said.

The Phalanx has limited altitude range, Schuster said, so it may not be able to shoot down even ballistic missiles fired from above a warship.

Even with these caveats, the Phalanx is an important weapon for the Navy.

Since its introduction in 1980, it has been installed on all Navy surface ships, and at least 24 US allies also use it, according to Raytheon, which notes that the land version has also seen combat before. Is.

It remains to be seen whether it will be used in the current hostilities in the Red Sea. But the Iran-backed Houthis have shown no signs of slowing their attacks on commercial shipping and warships in the waters around their base in Yemen, which they say is retaliation against Israel for the war in Gaza.

A day after the Graveley attack, US Central Command reported that another US destroyer, the USS Carney, had shot down anti-ship missiles and drones. And on Thursday, U.S. forces shot down a Houthi drone over the Gulf of Aden and destroyed a surface drone in the Red Sea, he said.

Meanwhile, the Central Command said two ballistic missiles launched from Houthi-controlled areas of Yemen missed targets in the Red Sea.

–CNN’s Oren Lieberman and Natasha Bertrand contributed to this report.