GUNS OF THE USS VICKSBURG

By Robert G. Segel

At the personal invitation of Captain Charles “Chip” Swicker, Commanding Officer of the USS Vicksburg, Small Arms Review was invited to spend twenty-four hours aboard the Vicksburg to learn of her mission and observe live fire training exercises by her crew of all crew served and individual weapons aboard excluding missiles and torpedoes.

On November 4, 2006, the SAR Expeditionary Force, consisting of Dan Shea, Robert Segel, Greg Welteroth and Capt. Earle Yerger (USN Ret.) traveled to Jacksonville, Florida and spent the night in a motel just outside Naval Station Mayport in preparation for boarding on November 5. We arrived at the Harbor Services tug dock at NS Mayport at 0800 the following morning and boarded tug C-Tractor 13 to ferry us out to the Vicksburg that was inbound to pick us up. The weather that morning was not perfect with grey skies, 35 knot winds and seas running with six to eight foot swells but the conditions improved as the day went on.

All aspects of the ship were shown to us as we toured the various compartments that included the bridge, the CCS (Central Control Station), main engine room, the VLS (Vertical Launch System) bay, the Mk 46 torpedo magazine and launch bay, the projectile and powder magazine and hydraulic lifts that serve the Mk 45 deck guns and the nerve center of ship’s sensors and weapons systems – the CIC, (Combat Information Center).

The well-prepared and delicious lunch, dinner and breakfast was served in the Ward Room, which doubles as a conference and meeting room. The sleeping quarters in Officer’s Country were spacious and comfortable.

The USS Vicksburg (CG 69) is the 23rd Ticonderoga class AEGIS guided missile cruiser and the 4th ship of the Navy to bear the name of the Mississippi city located along the bluffs of the Mississippi River at the mouth of the Yazoo River. Her keel was laid May 30, 1990, launched September 7, 1991 and commissioned November 14, 1992. Built by Ingalls Shipbuilding, Pascagoula, Mississippi, she is powered by four General Electric LM 2500 gas turbine engines, with two propellers with five blades on each, and has a speed of 30+ knots. She is 567 feet in length, has a beam of 55 feet and a draft of 34 feet. With a full load, her displacement is approximately 9,500 tons. Her crew consists of 31 Officers, 25 Chief Petty Officers and approximately 290 enlisted personnel.

The Vicksburg has a flight deck and hangar to accommodate two SH-60B Seahawk (LAMPS Mk 3) helicopters. The Seahawk is a twin-engine helicopter used for antisubmarine warfare by deploying sonobouys and Mk 46 torpedoes, search and rescue, drug interdiction, cargo lift, special operations support, and surface warfare using Hellfire AGM 114B antisurface missiles. Additionally, each Seahawk can carry a door-mounted GAU- 16 .50 caliber machine gun. They are also equipped with FLIR (Forward Looking Infrared) systems, and have OTHT (Over The Horizon Targeting) capabilities that extend the range of the ship’s own sensors.

Ship’s armament consists of the 122 individual missile cells of the Mk 41 VLS (Vertical Launch System), capable of launching SM-2 Standard missiles, Tomahawk land-attack missiles and VLA (Vertical Launch Anti-Submarine Rockets) equipped with a Mk 46 torpedo. Other systems include Harpoon anti-ship missiles, two triple Mk 32 torpedo tubes launching Mk 46 torpedoes, two Mk 45 5- inch 54 caliber lightweight guns, two Mk 15 Mod 1 “Phalanx” CIWS (Close In Weapons System) Gatling guns that provide a terminal defense against incoming aircraft or missile threats, two Mk 38 25mm “Bushmaster” electrically driven “chain gun” automatic cannons, two Mk 95 twin-mounted Browning M2HB .50 caliber machine guns, three singlemounted M2HB guns, and two 7.62mm Mk 44/GAU-17 miniguns.

5″/54 Mk 45

Vicksburg proceeded to the east from Mayport into the Atlantic to a designated live-fire practice area where the first live fire exercise was with the two (fore and aft mounted) 5″/54 Mk 45 Light Weight Gun Mounts (LWGM). The Mk 45 LWGM is the Navy’s primary surface combatant gun and Naval Surface Fire Support (NSFS) weapon. It provides surface combatants accurate gunfire against fast, highly maneuverable surface targets, air threats and shore targets during amphibious operations. It is fully automated, with an unmanned mount and a gun crew of six Sailors. The gun weighs 21.7 tons, fires a five-inch caliber projectile weighing approximately 70 pounds out to a range of 13 miles. It can fire 16-20 rounds per minute. Muzzle velocity is 2,650 feet per second (fps) with a full charge and 1,500 fps with a reduced charge for defilade fire or illumination rounds. Each mount has its own projectile and powder magazine located directly beneath each gun holding 500-600 projectiles and powder charges. A vertical drum holding 20 projectiles provides ready firepower, after which the gun crew pulls the appropriate designated projectile and powder charge from their respective magazines and loads the gun via a hydraulic elevator system providing an uninterrupted flow of ammunition to the gun. The mount traversing movement can travel 170 degrees either side of centerline at a rate of 30 degrees per second. Elevation movement totals 80 degrees from -15 to +65 degrees with a movement rate of 20 degrees per second.

Ammunition used for the exercise was ten rounds for each gun mount using BL&P (Blind Loaded and Plugged) blue practice rounds and ten FSC (Full Service Charge) powder charges. Aiming point was set at 4,000 yards. Action was for each mount to fire one round to warm the barrel, four rounds spotting in accordance with Maintenance Required Card U25, and then fire the remaining five rounds rapid and continuous.

CIWS (Phalanx) Mk 15 Mod 1

The next weapon exercise employed the CIWS (Close In Weapon System – commonly called the “sea-whiz”) Mk 15 Mod 1 “Phalanx.” The ship has two CIWS systems mounted; one each on the port and starboard side.

The CIWS is a fast-reaction, rapid-fire 20mm gun system that provides terminal defense against incoming air targets, whether they be anti-ship cruise missiles or aircraft, at short range. It operates independently from other onboard systemsand will automatically engage missiles or aircraft that have penetrated other fleet defenses. As a unitized system, it automatically performs search, detecting, tracking, threat evaluation, firing and kill assessments of targets. The fire control system consists of two parts: a search radar for surveillance and detection of hostile targets and a track radar for aiming the gun. It thus tracks both the incoming target and the stream of outgoing projectiles that enable it to correct its aim to hit fast moving targets.

The gun subsystem uses an M-61A1 Gatling gun consisting of six barrels and fires a 20mm APDS (Armor Piercing Discarding Sabot) subcaliber projectile using a heavy metal tungsten 15mm penetrator surrounded by a plastic sabot and a lightweight metal pusher. The M-61A1 gun fires at a rate of 4,500 rounds per minute with a magazine capacity of 1,550 rounds. The gun drive is pneumatic and the mount drive is electric. 500 rounds were allocated for each CIWS during the training exercise.

Mk 38 25mm Machine Gun System

The Vicksburg is also equipped with two electrically driven Mk 38 25mm automatic cannon, commonly called the “chain gun,” mounted one on the starboard side and one on the port side of the aft missile deck. This weapon system provides ships with a defensive and offensive capability for engagement of a variety of surface targets. It is designed to provide close range defense against patrol boats, floating mines and small craft. It also can be used for targets ashore including enemy personnel, lightly armored vehicles and other terrorist threats.

The Mk 38 Machine Gun System consists of the gun and the Mk 88 gun mount. The Mk 38 is an externally powered, single-barrel weapon that can be fired in semiautomatic or full automatic mode. Its cyclic rate of fire is 175 rounds per minute. The gun does not depend on gases for operation but instead uses an electric motor to drive all the moving parts that includes feeding, loading, firing, extraction and ejection. The gun has an effective range of 1,000 yards and a maximum range of 6,500 yards. The Mk 38 gun weighs 240 pounds and the Mk 88 mount weighs 1,250 pounds.

This crew served weapon is fired by one man and supported by two others. The Mk 38 is unstabilized and all traverse and elevation adjustments are done manually by the gun operator. The gun can be elevated 55 degrees and depressed -20 degrees. Since the maximum elevation of the Mk 38 is 55 degrees, it has limited anti-airwarfare capabilities and is primarily used against surface or shore targets. 110 rounds were allocated for each gun for the exercise.

M60 Machine Gun

The Vicksburg has four M60 machine guns used primarily by the VBSS (Visit, Board, Search & Seizure) teams aboard their 22 foot grey RHIBs (Rigid Hull Inflatable Boat). The M60 is an air cooled, belt fed, gas-operated 7.62mm machine gun. Two 100-round battle packs were used firing from the flight deck.

Browning .50 Caliber M2HB Machine Gun

There are seven M2HB .50 caliber Browning machine guns aboard the Vicksburg, four of which are on twin mounts at all times on the port and starboard sides of the ship. The twin fiftiesare crew served and can be fired singly or together. Used for protection against small boats, they provide a rapid response to any close-in threat. A total of 1,400 rounds were used for this training exercise.

Mk 44 GAU-17 Minigun

New to the Vicksburg are two Mk 44 GAU-17 7.62mm miniguns. Mounted on each side of the bridge on the extended bridgewings, they provide particularly lethal close-in defense against small boat attacks and other high speed inbound surface contacts. The Mk 44 GAU-17 is electrically driven with a 24 volt battery and drives six rotating barrels firing at 3,000 rounds per minute. The gun is equipped with a top rail for mounting an AN/PVS- 20 night vision device or a SureFire Hellfighter light.

Captain Swicker intends to enclose the entire exposed bridgewing with NIJ Level III ballistic fiberglass panels that will, in effect, turn the area into an armored guntub capable of withstanding 7.62x39mm AK fire, providing a degree of protection for his Sailors in an otherwise very exposed position in a close-in fight. Both guns were demonstrated in day and night operations with a total of 9,000 rounds being expended.

Personal Protection Equipment

Vicksburg’s crew served weapons are manned by the ship’s Small Craft Action Team (SCAT). These specially-trained Sailors are required to wear comprehensive PPE (Personal Protection Equipment) whenever they man or train with their weapons. This includes Kevlar helmets, MOBI (Man Overboard Indicators), flash gear (face protection and gauntlets), gas mask, body armor, battle dress and ballistic eye protection. The team t-shirts they wear under their body armor read, “If Everything Around You is Exploding…It’s Probably Us!”

VBSS

The VBSS (Visit, Board, Search & Seizure) boarding teams consist of approximately 18 Sailors. The number of personnel that actually go on vessels being boarded and searched depends on the ship’s size and threat intelligence. Equipment used includes two 22-foot RHIBs (Rigid Hull Inflatable Boat) with M60s mounted for protection. VBSS personnel are equipped with Mk 18 Mod 0 5.56mm Close-Quarter Battle (CQB) carbines, an M16 variant custom made for VBSS teams and Navy SEALs by the Navy’s armorers at Crane, Indiana. These weapons are outfitted with AimPoint red dot sights, SureFire lights, and vertical foregrips. Secondary weapons are M9 Beretta semiautomatic pistols and Mossberg 12-ga. pump-action shotguns. Team members wear London Bridge buoyant VBSS vests with NIJ Level III ballistic protection. Other gear includes climbing and rappelling equipment and cutting torches.

Live fire drills were conducted with the Mk 18s and M9s from the flight deck.

Small Arms

The USS Vicksburg has an interesting array of small arms aboard in the ship’s armory. These include:

• M79 40mm grenade launchers with HE rounds
• M14 rifles
• M9 pistols
• Four M60 machine guns
• Seven .50 Cal. M2HBs
• Two Mk19 40mm grenade launchers with HE rounds
• Five M16A1 rifles
• One M203 40mm grenade launcher
• Eight Mossberg 12-ga. shotguns

It is interesting to note that on the bridge there is a gun rack that contains three M14 rifles – always at the ready.

The USS Vicksburg is currently homeported at Naval Station Mayport, Florida and is preparing to deploy to a war zone in the summer of 2007. She is a fast, maneuverable, potent fighting ship, capable of both long distance and short range offensive and defensive combat. As Captain Swicker is quick to point out, though the ship has many capabilities, it is her highly trained crew that makes those capabilities a lethal reality.

Small Arms Review is extremely grateful to Captain Swicker – Commanding Officer, LT Kevin Hoffman – Combat Systems Officer, LT Ken Athans – Weapons Officer, LT John Nelson – Systems Test Officer, Master Chief Joe Hawkins, and the entire crew of the USS Vicksburg for their outstanding hospitality and patience during our 24-hour visit in answering all our questions and taking the time to take us through every compartment of the ship and explain its function.