Marine: A Guided Tour of a Marine Expeditionary Unit by Tom Clancy
In addition, the Marines will soon deploy a mobile survey system based around a GPS receiver to assist expeditionary units in emplacing artillery sites and other position-critical units. Designed and produced by Trimble Navigation, 40 of these systems have already been bought, with an additional 203 planned for future buys. Trimble is also supplying the Marines with a new generation of super-rugged, P(Y)-code GPS units for use by reconnaissance forces. Called the Miniature Underwater GPS Receiver (MUGR), it is about the size of a Walkman radio. MUGR is fully waterproof, and can actually operate underwater! By using a floating antenna attached by a wire tether, the MUGR allows a reconnaissance force to survey a beach or harbor covertly. These systems represent only the tip of the GPS iceberg. In the near future, expect to see the "Fritz" Kevlar helmets of American troops sporting flat satellite antennas with the ability to send and receive signals.
Communications
By the fall of 1996, the Marines will finally begin their long-awaited move to the Army's Single Channel Ground and Airborne Radio System (SINCGARS). SINCGARS utilizes "frequency hopping" to make its signals difficult to intercept or jam. The 2nd MEF will get the entire suite of SINCGARS radio systems for aircraft, vehicles, and personnel in FY-1996 and FY-97. SINCGARS will be taken to the field by 26th MEU (SOC) during their 1996/97 Mediterranean cruise. The current SINCGARS variants are shown in the table below:
Marines deploy a number of satellite communications systems, ranging from large fixed systems for command posts to backpack models for on-the-scene commanders. The key to military satellite communications is access to the proper frequency channels, which are usually overbooked and the subject of intense competition by users, all of whom need to communicate right now. The Department of Defense maintains a number of satellite communications systems to support military operations. But the high tempo of U.S. military deployments has saturated existing military systems. Every communications satellite has a number of transponders, which provide television or radio channels. Each transponder is assigned according to priorities determined by theater commanders, or even by the Joint Staff at the Pentagon. There are simply not enough to go around. As a result, the Defense Department is also a major customer for commercial satellite communications air time from commercial suppliers like INMARSAT and Hughes. The Marines have equipment that operates on most standard satellite frequencies, though the most common is the man-portable UHF TACSAT system. This version, known as the PRC-117D, is carried by a communications specialist, with a backpack battery and transceiver and an attached antenna. Able to transmit voice or data, it works well in the field, though it is a battery hog.
While the Marine Corps has a robust and effective communication architecture today, things are going to be changing fast. Already on the horizon are direct-broadcast /receive commercial satellite phone systems, and military communicators are drooling to get some. Global handheld satellite phones will create a telecommunications revolution that makes current-generation cellular phones look like soup cans connected by a string. For example, Texas Instruments has already developed a two-way satellite antenna that is just a flat square a few inches/centimeters on each side. Requiring only minuscule power to operate, it can be fitted to the roof of an HMMWV, or possibly even the top of a Kevlar "Fritz" helmet. The dream of tying every Marine into a global communications net is now within sight.
Food and Water
Marines might be able to hold a position without fuel and with just the ammunition they are carrying, but without food or water, they will have to surrender or die within a few days. Water is usually no problem; Marines have a ready supply of pure water from the ships that bring them ashore. The Corps has also made a significant investment in portable reverse-osmosis water-purification systems that can be delivered via transport aircraft or prepositioned ships. As a result, other services and coalition allies frequently depend upon Marine units to supply their water needs until follow-on logistics forces arrive.
Food is a different matter. The Corps is a virtual hostage to the meal systems produced by the U.S. Army; it must order food items from the Army logistics system. Options are limited. To begin with, there are Meals Ready to Eat (MREs), heavy, bland, but nourishing rations. Since Desert Storm, MREs have actually gotten heavier, for the Army has chosen to pack more stuff into the brown plastic packages, rather than make what was already inside more appetizing. The result is that field troops tend to throw much of the MRE away, and thus fail to take in the nutrients and calories they need. Though MRE manufacturers like Star Foods already have better products on hand, the Army is not willing to buy them at this time. It is working to issue better MREs, though, and expects to field several new kinds in FY-2000. Because MREs are so unappetizing, American peacekeepers in Bosnia have been using their own money to buy nutritional snacks or freeze-dried camping food; and if they're lucky, they can get some French or British rations. The French version of the MRE, for example, contains fresh bread and pate!
The Marine food service system falls into three levels. The first or "A"-type rations are boxes with three trays of prepackaged food (meats, vegetables, and starches), which are heated in tray boilers and served cafeteria-style to troops. The "B"-type rations are actual meals that are cooked in field kitchens made from locally purchased ingredients as well as dehydrated/freeze-dried ingredients shipped from the U.S. Finally, there are the field rations, normally composed of MREs. I say normally, because when troops enter cold-weather and high-altitude areas, they begin to burn calories at an incredible rate. While a typical Marine might burn about three thousand calories per day under normal environmental conditions, cold weather can double this rate. Since Marines routinely throw out much of the stuff inside the four MREs issued each day, something else is clearly required for cold-weather operations. That is the cold-weather ration. Produced by Oregon Freeze Dry, Inc. (they also produce Mountain House brand camping food) and packaged by Right Away Foods, these rations take up only half as much space and volume as a comparable diet of MREs, and deliver more calories. The ration itself is composed mainly of freeze-dried foods which are contained in a sealed plastic bag. These only require rehydration to make them ready to eat. Given a supply of snow for melting and a heat source, the cold-weather ration can provide an excellent source of hot food for field units. As an added benefit, it is very high in calories (about three thousand per issued ration), and quite light in weight. Compared to MREs, cold-weather rations are quite tasty, and this means that the troops eat everything in the packs issued each day.
A cold-weather ration, with its contents displayed on the right. This is a two meal, freeze-dried ration, containing a breakfast and lunch. It includes oatmeal, soup, granola, crackers, cocoa, coffee, candy, and a powdered drink. The breakfast rations are designed to provide maximum sugar/carbohydrate content on cold mornings.
JOHN D. GRESHAM
As the Marine Corps moves towards the 21st century, it is looking forward to the new varieties of MREs due to be fielded by the Army. But don't be surprised if the USMC finally begins to produce rations to its own design and specification. The Commandant's Battle Lab at Quantico, Virginia, is studying the problem from a purely "Marine" point of view, and may yet produce field rations with an "expeditionary" flavor.
Fire Support
Marine units are primarily infantry-based formations, which depend upon the fire of supporting units to achieve their objectives. Supporting fire must be both accurate and lethal to allow lightly laden Marines to stand up to everything they might have to face, from irregular forces (as encountered in Somalia and Liberia) to conventional military units like those in the Persian Gulf. Without firepower, Marines have to trade their lives to take objectives; and the American people simply will not accept excessive casualties. Thus, Marines have a great professional interest in fire support. Almost every Marine can read a map, use a radio, and call in fire from ships, aircraft, or artillery. A single rifle platoon might receive air support from AV-8B Harrier IIs or AH-1W Super
A Marine mans an M2 Browning .50-caliber machine gun mounted on an HMMWV.
OFFICIAL U.S. MARINE CORPS PHOTO
Browning M2.50-Caliber Machine Gun
To listen to an old Marine "Gunny," you would think it was the most beautiful of women. The M2 .50-caliber machine gun is a favorite heavy weapon of Marines and ground troops everywhere. This heavy machine gun provides a base of fire for the rifle platoon and company. It forces the enemy to keep his head down and confronts him with a threat he must neutralize. While he is trying to knock out the damned machine gun, Marines can maneuver onto his flanks or close with his position. A heavy machine gun can shred dry-wall or wooden buildings, or unarmored vehicles. At short ranges and favorable angles it can even penetrate the side or rear plating of armored vehicles. This makes it a very dangerous piece of equipment to have in your pocket.
The "50 cal" first entered service with the U.S. Army in 1919, too late for service in World War I. During the Second World War it was standard armament on American fighter and bomber aircraft, and was widely employed as an anti-aircraft weapon on every kind of ship and ground vehicle. The M2 is an automatic recoil-operated, air-cooled machine gun that weighs 84 1b/38 kg. Recoil-operated means that it uses an ingenious arrangement of levers, cams, and springs to capture part of the recoil energy to extract and eject the spent cartridge case, feed the next round, load it, and fire it. This cycle repeats as long as the gunner holds down the V-shaped trigger located between two hand grips at the rear of the gun. Release the trigger and a latch secures the mechanism in the "open bolt" position, ready to fire again.
The .50-cal can be found in the turret of the AAV-7/LVTP-7 amphibious tractor, on the simple pintle mount on the HMMWV, and on the high-tech coaxial mount on the Avenger air-defense vehicle. The weapons platoon of a Marine rifle company fires it from a hefty 44-1b/20-kg tripod. It takes at least two Marines to carry the weapon, plus men to carry cans of ammunition. The ammunition is assembled into belts with reusable spring clips called "disintegrating links," which are stripped off by the gun's feeder mechanism. The rate of fire is 550 rounds per minute, and gunners are trained to fire short bursts to conserve ammunition. The theoretical maximum range is 4.22 mi/6.8 km, and the M2 has even been used for "indirect fire" at high angles of elevation to create a "fire-beaten zone" on the other side of a hill. In typical battlefield conditions the practical range is about 1.1 mi/1.8 km. The legendary lethality of the M2 derives from the heavy charge of propellant in the cartridge and the superb ballistic shape of the projectile, which has a distinctive "boat tail." There are several ammunition types. These include target-practice (TP), armor-piercing solid-shot, armor-piercing incendiary (API), and high-explosive (HE).
An HMMWV on patrol with an Mkl9 40mm grenade launcher mounted on top. This weapon can fire all of the same rounds as the M203 grenade launcher.
OFFICIAL U.S. MARINE CORPS PHOTO
Over the years, many firms have produced the M2 on license from the holders of John M. Browning's original patent. The current contractor producing the M2 for the U.S. Department of Defense is Saco Defense, Inc., and the FY-1994 unit cost was $8,118.00. Its unique combination of range, lethality, durability, and simplicity guarantees that the M2 will soldier on well into the next century. In fact, the last Marine M2 gunner has probably not yet been born.
Mk 19 40mm Machine Gun, Mod 3
Back in the 1960s, deep in the swamps of the Mekong Delta where a well-concealed and heavily armed Viet Cong ambush might lurk around the next bend in the river, crews of U.S. Navy patrol craft discovered that .50-cal machine gun fire was often insufficient to break up an attack. They needed a weapon that could spew out a stream of explosive grenades to suppress enemy forces. To meet this need, the Navy developed the Mk 19, officially classed as a "machine gun," but actually an automatic grenade launcher. The Mk 19 had a long and troubled development cycle, earning the nickname "Dover Dog," after the Delaware arsenal where it was designed. After a series of modifications, it has proven itself in service with the Army, Navy, and Marine Corps. The Mk 19 is an extremely simple weapon using the "blowback" principle. The barrel and receiver assembly recoil against a heavy spring, and as they rebound, the next round is loaded and fired. The weapon fires the same family of 40mm grenades as the M203 launcher attached to the M 16 rifle.
An M 19 towed howitzer assigned to BLT 2/6, buttoned up and ready for deployment.
JOHN D. GRESHAM
By itself the weapon weighs 72.5 lb/33 kg. It was designed to use the same tripod as the M2 .50-cal. machine gun, but is also found in the turret of the AAV-7/LVTP-7 amphibious tractor. The cyclic rate of fire is from 325 to 375 rounds per minute, but the practical rate of fire is about 40 rounds per minute in short bursts. To achieve the maximum range of 2.2 km/1.37 mi, you have to elevate the weapon to loft the grenades and forget about real accuracy. Practical range for flat-trajectory fire is about 1,500 m/4920 ft. There are several types of ammunition, assembled into disintegrating link belts and transported in metal canisters. The HEDP (high-explosive, dual-purpose) grenade will pierce 2 in./51mm of armor, and spray metal fragments that can kill within 5 m/ 16.4 ft and wound within 15 m/49.2 ft. Other types of ammunition include incendiary, smoke, and tear gas rounds. The Mk 19 is usually found in the weapons platoon of a rifle company and the weapons company of a rifle battalion. One Marine can load and fire the weapon, but it requires a team of three to four to carry it, along with a supply of grenades. It is manufactured by Saco Defense, and the 1994 unit cost was $13,758.00.
Mortars
Mortars are the company or battalion commander's own personal artillery. The mortar is a portable, cheap, and simple weapon: just a metal tube with a bipod elevating bracket and a heavy base plate. You assemble the weapon, aim the mortar at the target, and drop the mortar round down the barrel. The round strikes a firing pin at the bottom of the tube, and off it goes. Limitations of the mortar are its relatively short range and inaccuracy. But this old weapon is now gaining new respect, thanks to the development of precision guided ammunition.
Marines employ two different kinds of mortars. The M224, used in the heavy weapons platoon of the rifle company, is a 60mm weapon weighing only 46.5 lb/21 kg. Maximum range is 2.2 mi/3.5 km. A good crew can sustain a rate of fire of around twenty rounds per minute. The other model, the M252, is used in the heavy weapons company of the infantry battalion. An 81mm weapon, it is based on a 1970s British design, weighs 89 lb/40 kg, and has a maximum range of 3.5 mi/5.6 km. The sustained rate of fire is sixteen rounds per minute. There is a wide variety of ammunition types in each caliber, including high-explosive, smoke, and incendiary rounds. High-explosive rounds can be fitted either with an impact fuse or a proximity fuse that detonates at a preset altitude, showering the target with fragments.
M198 155mm Towed Howitzer
This big gun is one of the more controversial weapons in the Marine arsenal. While it is the Marines' primary field artillery piece, the Corps leadership feels that the M 198 is simply too big and too heavy. Also, it takes up too much space on amphibious lift ships, and in firing position it is too vulnerable, especially when a quantity of ammunition is stacked near the gun. In addition, the M198 has a high center of gravity, which makes it prone to tipping over and being difficult to handle. On the other hand, it uses standard, widely available 155mm ammunition with terrific lethality. Weighing 15,758 1b/7,154 kg, it requires a heavy (5-ton) truck to tow it, along with its eleven-man crew and a supply of ammunition. It can be lifted as a sling load by the CH-53E helicopter. The M198 can hurl a projectile up
Mk 45 5-in./54 Naval Gun Mount
With the retirement of the Iowa-class (BB-61) battleships, the Navy's gunfire support capability is reduced to one or two of these rifled 5-in./ 127mm weapons on each major surface combatant (cruiser, destroyer, and a few amphibious ships). Built by United Defense's Great Northern Division, the Mk 45 5-in./54 turret has a high degree of automation, sustaining a rate of seventeen rounds per minute. The turret normally operates unmanned, with the six-man Navy crew working below decks. The Mk 45 can throw a 70-1b/31.75-kg projectile to a maximum range of 14 mi/23.6 km, though extended-range ammunition is under development. The main ammunition types are high-explosive and incendiary (white phosphorus). A ship generally carries several hundred rounds per gun in its magazines, and major task forces are accompanied by ammunition ships, which can rapidly replenish the supply, using a UH-46 helicopter.