world's most accurate medium-caliber combat system, The

Sea Power, Nov 2002 by Keeter, Hunter

Mk46 Weapon Station Makes the Grade With Marine Corps

The General Dynamics-built Mk46 weapon station-now in development for installation on Advanced Amphibious Assault Vehicles (AAAVs) and San Antonio-class (LPD 17) landing platform dock ships-has done well in recent tests and is now attracting interest from U.S. allies overseas, according to program officials.

The weapon station, designed to accommodate the Mk44 30mm/40mm gun built by ATK Ordnance and Gun Systems, is being developed in two variants: Mod 0 for installation on the AAAV and other vehicles that can maneuver both in the littorals and on land; and Mod 1 for installation on amphibious ships and other surface combatants. The two variants are largely common in design.

Field-testing of the Mk46 on an AAAV PDR (program definition and risk reduction) vehicle prototype was carried out earlier this year (15-31 May) at Aberdeen Proving Ground (Md.). According to the government report on the system's performance, the Mk46 weapon satisfactorily demonstrated its accuracy and lethality against small targets at both 1,500 meters and 2,000 meters. "I am supremely confident that ... (it) will continue to be demonstrated as the most accurate medium-caliber combat system in the world," Lt. Col. Darrin Johnson, the Marine Corps' Mk46 program manager, told Sea Power.

The Mk46 design has now been largely stabilized, Johnson said, and ongoing technology development efforts-including refinement of the electro-optical targeting system-are fine-tuning the system for various applications. Johnson's confidence in the Mk46 is shared by other government officials-and at General Dynamics, which hopes to offer the weapon station to a large market of other potential customers, both in the United States and overseas. The Mk44 gun (developed by Boeing before that firm sold its gun business to ATK last year) is used by, among others, the Finnish, Norwegian, and Swiss armies.

The Mk46 system, already selected by the U.S. Navy for installation on the LPD 17 amphibious ships being built by Northrop Grumman Ship Systems, could attract additional customers, including the U.S. Coast Guard and the burgeoning coastal forces of Japan and South Korea. The U.S. Coast Guard awarded its Deepwater modernization contract last year to a team led by Northrop Grumman and Lockheed Martin. The contract calls for the development and construction of a large number of new cutters, many of which could be armed with weapon stations such as the Mk46.

The Japanese and South Korean navies also are interested in the Mk46 system. South Korea's Marine Corps now uses the same United Defense AAV7A1 amphibious assault vehicle fielded by the U.S. Marine Corps, and undoubtedly would welcome the opportunity both to upgrade to the AAAV and to procure an advanced weapon system common to both land vehicles and amphibious ships.

The Japanese are acquiring Aegis AAW (anti-air warfare) combat systems for their own Aegis ships, and are monitoring the U.S. Navy's plans to evaluate the Mk46 for installation on its Arleigh Burke-class Aegis guided-missile destroyers (DDGs). The U.S. Navy's Aegis DDGs currently are armed with United Defense's five-inch guns and Raytheon's 20mm close-in weapon systems.

Last year, General Dynamics-which also serves as prime contractor for the AAAV-offered the Mk46 to Britain for the Royal Navy's Type 41 ships, but the weapon system was not selected for consideration, primarily because of what were described as "contracting issues." The firm also has met with Spanish shipbuilder Bazan about installing the Mk46 on Spanish Navy ships.

The U.S. Army is another potential domestic customer. Johnson said that the Army's Close Combat Armament Center has recommended that the Mk44 30mm gun be considered for use in Block 1 of the Army's Future Combat System (FCS) medium-caliber variant. Boeing and the Science Applications International Corporation are the Army's lead systems integrators for the FCS, which is envisioned as a family of deployable combat vehicles tailored to meet the service's requirements for a "transformed" land combat force.

A Marine Corps threat assessment study has determined that 30mm rounds would have the lethality needed to defeat current threats. However, the Mk46 system and its Mk44 gun are designed to be easily upgraded, as technology advances, to 40mm and "Supershot" ammunition. The 40mm upgrade for the Mk44 would require a change of barrel and modifying sections of the weapon's ammunition feed mechanism.

The 30mm ammunition used by the Mk44 is the same ammunition, Johnson noted, bought in large quantities by the Air Force for the GAU-8 cannon mounted on the Air Force's A-10 Thunderbolt It attack aircraft, and therefore could be acquired inexpensively for training purposes by the Marine Corps and Army.

Several types of advanced ammunition-including Supershot, armor-piercing sabot rounds, and anti-personnel air-bursting rounds-are being developed for the 40mm application.

The Mod 1 shipboard variant of the Mk46-being developed for delivery to the Navy as CFE (contractor-furnished equipment) for the LPD 17s-also is moving along on schedule, General Dynamics said. According to Ronald Cole, GD's Mk46 program manager, the technology challenges associated with LPD 17 installation are not as great as those involved in the development of a stabilized system for use with the AAAV, particularly with regard to the Mk46 fire control system.