will be on both types of Littoral
Combat Ships (LCSs), the Coast
Guard’s new National Security
Cutters and the new DDG 1000s. It
also is used by many allied navies.
The rapid firing Mk110 can handle a variety of intelligent munitions,
which can be remotely programmed
to detonate at a predetermined
point, creating a deadly spray of pellets that makes it effective against
maneuvering boats or missiles.
BAE said it will provide a digital
fire-control system for LCS that
allows the Mk110 to accurately fire
automatic salvos of the Mk295
ammunition at 220 rounds per
minute and a range of up to nine
The Mk295 programmable, prefragmented and
proximity-fused ammunition makes the gun effective
against aerial, surface or ground threats.
Another popular gun is the Mk38 chain gun, a 25mm
multipurpose defensive weapon that is on all the DDG
51s, most of the U.S. amphibious ships, the coastal
patrol ships, the two command ships, the Coast Guard’s
Hamilton-class cutters and many of its patrol craft.
The Navy is fielding the Mod II model of the Mk38,
which will be retrofitted on nearly every ship that has
the older gun.
The new gun, produced by BAE with Israel’s Rafael
Armament Development Authority, is remotely controlled from the combat information center inside the
ship, while the Mod I is manually operated by a gunner
exposed to the weather and enemy fire.
Probably the most prevalent naval gun system is the
Mk15 Close-In Weapon System made by Raytheon.
Called the Phalanx, or just CIWS, the Mk15 combines
the M61 Vulcan six-barrel 20mm cannon, with a firing
rate of up to 4,500 rounds per minute, a dual search-and-track radar and remote fire-control systems to provide quick-reaction defense within 4,000 yards.
The compact CIWS unit was developed as a last-ditch defense against sea-skimming missiles. But it has
been improved with the Block 1B upgrade that
Raytheon says also makes it an effective defense against
attack helicopters and high-speed surface threats.
One or more CIWS systems are installed on nearly
every U.S. surface combatant, aircraft carrier and
amphibious ship, and on the ships of 22 allied navies.
The Navy also is making some effort to respond to a
long-standing Marine Corps complaint about the lack
of high-volume, precision naval gun fire support for its
forces if they are more than a few miles inland.
Small craft suspected to be from the Islamic Republic of Iran Revolutionary
Guard Navy maneuver aggressively in close proximity of the U.S. Navy cruiser
USS Port Royal Jan. 6, 2008, in the Persian Gulf. In response to threats such
as wave-skimming anti-ship missiles, explosives-loaded terrorist boats or
swarming fast-attack craft, the defense industry is producing a range of
improved guns and munitions for U.S. and allied navies that provide greater
close-in defense capability.
The Mk45 comes in two models. The original, the
Mod 2 5-inch 54-caliber gun, has an effective range of
about 15 nautical miles. Two Mk2s were on all the
Ticonderoga-class cruisers and one was on each
Arleigh Burke destroyer, up to DDG 81.
To provide longer range, BAE now makes the Mk4
5-inch 62-caliber gun, which has a longer and stronger
barrel and can take higher chamber pressure. The Mk4
gun is on all of the Burkes from DDG 81 on, and will
replace the Mk2s on all the cruisers and older destroyers
as they go through modernization/service life extension.
The Mod 4 was designed to shoot rocket-boosted,
extended-range guided munitions, with a goal of at
least 41 nautical miles. But two attempts to produce
those rounds failed.
The Navy has improved the versatility and effectiveness of the 5-inch guns by acquiring two new rounds —
the Mk179 HE-ET and Mk182 KE-ET. Both use an
Army-developed electronic fuse to provide a timed airburst capability that can be more effective against smaller, moving targets than the point-detonation projectile.
NAVSEA also is working to improve the Multi-Function Fuze for the 5-inch rounds, to reduce the sea
clutter effect on the proximity detonator.
One of the most widely used naval guns is the Mk75,
produced by Italian firm Oto Melara. The 76mm gun is
on the U.S. Perry-class frigates, the Hamilton- and
Famous-class Coast Guard cutters and more than 1,000
other vessels in 53 navies around the world.
The Mk75’s high rate of fire and variety of munitions
make it an effective short- and midrange defense
against fast-attack craft, and for anti-air and anti-missile
Another widely used gun is the 57mm Mk110, developed by Sweden’s Bofors and now produced by BAE. It