Marine: A Guided Tour of a Marine Expeditionary Unit

by Tom Clancy

  While the LCAC has done quite well in its first decade of service, don't think that hauling cargo, vehicles, and Marines is all that the Navy wants to do with it. Concepts to expand the options for LCAC include increased personnel capacity, using a cargo deck passenger module. LCAC is now limited to just 23 passengers in the deckhouse spaces, but the module can carry up to 180 personnel (plus the 23 in the deckhouse) per trip. Configured for medical evacuation, the same module might carry up to 50 litter cases per trip, as well as 23 walking wounded in the deckhouse. This is important to the Marines, given the "golden hour" of combat trauma cases. Survival rates for wounded personnel are directly related to how quickly they reach medical facilities aboard the LHD/LHD or LPD. The Navy has ordered a number of these modules, and they should be coming into the force soon.

  Another use for LCACs is in mine warfare. The Navy has funded demonstrations of LCACs equipped to both lay and sweep underwater mines, as well as a rocket propelled system that throws an explosive mine-clearing charge over a beach landing zone from offshore. There have also been studies of using the LCAC as a gunboat to support landing operations. Though the LCACs are unarmed (mounts for three machine guns are normally not used), there are concepts for mounting 20mm and 25mm cannons. The Marines have demonstrated the ability to fire vehicle mounted weapons such as the LAV's 25mm Bushmaster cannon and the 120mm gun on a M-1A1 tank from landing craft.

  With only ninety-one LCACs either delivered or under contract, it is likely that the Navy and Marines will jealously guard them for their primary mission as ship-to-shore delivery systems. In this role it is not, of course, ideal (like all designs, it is a set of engineering compromises). For one thing, it is more vulnerable than conventional landing craft to enemy fire, but has the speed and maneuverability to avoid many threats. And the LCAC cannot handle extreme seastates as well as a conventional landing craft like the LCU or LCM, but it can land cargo under a wider variety of coastal conditions. Still, don't get the idea that LCACs are not tough. One unit, LCAC-42 (landing craft have only pennant numbers, not names), has survived two major incidents, and is still in service. It hit a protruding coral head sideways during one exercise, and struck a large navigation buoy on another, but got off with only minor damage and is still hauling for the Pacific Fleet. In over ten years of LCAC service, the U.S. Navy has yet to lose even one in operations. Plan on seeing LCACs around for a long time to come. A SLEP (Service Life Extension Program) will extend the planned twenty-year service life of the LCAC fleet to a full thirty years. Next-generation landing craft will be air-cushioned. Scaled-down designs for LCM-SIZED LCACs are being considered as general-purpose deliver platforms for the ARGs of the mid-21st century. Not bad for a giant air hockey puck.

  Landing Craft, Utility (LCU)

  It might surprise you that in an era of satellite navigation and computerized logistics, a large percentage of landing craft used by the Navy and Marines are virtually identical to World War II types. Many such craft will continue to serve well into the 21st century. Currently, the largest of these is the Landing Craft, Utility (LCU). In fact, the LCU is the largest Navy vessel that is not commanded by an officer. The LCU is a ship, with full crew accommodations (galley, berthing, heads, etc.) for its crew often (fourteen in wartime). It has enough range (up to 1,200 nm/2,195 km at economical speeds) to transit the Mediterranean or Baltic Seas in even the worst weather. LCUs are the heavy haulers among landing craft, in the twilight of their years, but still doing a vital job. Let's have a look.

  A Landing Craft, Utility (LCU) of Assault Craft Unit Two (ACU-2) leaves Cadiz Harbor on February 16th, 1996, to mate up with the USS Whidbey Island (LSD-41) for the homeward leg of its Mediterranean 1995/96 cruise. JOHN D. GRESHAM

  Like other conventional landing craft, the LCU design dates back to the 1940s. The idea behind the LCU was simple. Take the largest possible cargo/vehicle load possible, deliver it to and from a hostile shore, and then return to a mother ship-usually one of the first-generation LSDs. The LCU can carry up to 180 tons of vehicles, troops, and cargo at speeds approaching 12 kt/22 kph in virtually any seastate or weather, and deliver them to a "hot" shoreline. It is a big, brutish sort of craft, with none of the LCAC's futuristic look. In fact, the beast looks like it could seriously hurt a bigger vessel by ramming (this is no joke; it probably could!). These classic landing craft, loved by their crews and prized by the ARG and MEU (SOC) commanders, are still finding new ways to serve.

  Like the LCAC, the LCU is a "double-ended" design, with ramps at both ends allowing vehicles to load by driving through one LCU to get to the next one. They are constructed of heavy steel, welded back in the days where the quality control test was a long swing with a sledgehammer! The LCU may be one of the most bullet-resistant craft in the Navy, which explains why they are frequently used as gunboats and escorts for rubber boats and AAV-7s. LCUs were built by many contractors, such as Defoe Shipbuilders of Wisconsin, General Ship & Engine Works of Boston, Gunderson Brothers of Oregon, Moss Point Marine of Mississippi, and Southern Shipbuilders of Louisiana. Their construction was simple, requiring no special skills or equipment. Though the original LCUs date back to 1951, the class currently in service, the LCU- 1610s, were built between 1959 and 1985. During all that time, the design was essentially unchanged, except for one experimental unit constructed of aluminum.

  The LCU is essentially a floating steel box or barge, with a deckhouse to starboard, fore and aft loading ramps, and some side plating to keep passengers in and water out. Powered by four GM/Detroit Diesel engines (each delivering 300 hp), they are some of the most powerful ships per ton of displacement in the Navy. They are even used as tugs when actual tugboats are not available to push barges and lighters around. When you climb up the bow ramp of a LCU, you are immediately struck by how functional everything is. The chief petty officers who run the LCUs do so in a no-nonsense fashion, without pretensions to polishing the brass or keeping the paint clean. But I defy you to find a line out of place, corrosion forming, or a hatch left undogged. This is the Navy of the old chiefs, where you find little of the high technology or political correctness that permeate the big ships of the "real" Navy. Aside from a portable GPS receiver in the pilothouse and a small homegrown cable TV/VCR network down in the crew berthing spaces, everything on the LCUs of the 1990s would be familiar to your grandfather, if he was a sailor in the 1940s. The steel deck has tie-down stanchions to keep heavy gear and cargo from shifting in heavy seas; and since the cargo deck is open to the elements, the crew quickly hands you a life preserver. There is a winch-driven anchor system to drag the LCU off of the beach if the tide goes out while it is beached.

  The 121-by-25 ft/36.9-by-7.6-m cargo deck takes up most of the LCU's 134.75-ft/ 41.1-m length. The cargo deck can handle up to 1,850 ft2/171.9 m of vehicles, troops, and cargo, up to a weight limit of 180 tons! Given that the LCU can deliver this load in almost any seastate, you can see why the Marines like to have LCUs hauling their heavy gear like 70-ton M1A1 Abrams tanks and large palletized-loading-system (PLS) trucks. In a seastate where an LCAC would be unable to haul a single M1A1, an LCU can carry two of the armored monsters, with space and capacity to spare.

  The LCUs' long range means that they can be used as utility transports in closed waters (like the Baltic and Adriatic), returning to base to haul fresh food, spare parts, and that vital commodity, mail. LCU crews take working inshore quite seriously, and frequently mount machine guns, grenade launchers, and other weapons. They have even fired 25mm and 120mm cannons of embarked LAVs and M1A1s, which is awesome firepower. The LCU crews see themselves on the cutting edge of the recently reborn art of riverine warfare, and they practice it often in exercises.

  As noted earlier, LCUs are warships, with their own berthing, galley, and head facilities. The galley, aft of the pilothouse in the starboard deckhouse, can whip up a full meal. In fact, when they are in the well decks of their mother ships, they require only power, water, and sewage hookups (some also ask for access to t
he ship's cable TV system) to live independently from the ship's company. They buy their own food from the mother ship's supply system, and even have their own communications call signs for message traffic from higher commands. The living facilities are located belowdecks, along with the engine rooms (there are two, separated to improve survivability), machine shop, and other necessities. You might call the living conditions spartan, but LCU crews like them just fine. In fact, life in an LCU is reminiscent of life aboard a submarine, with many of the same benefits and drawbacks. As with a submarine, the only private space is the captain's cabin, though the commander of an LCU is only a chief petty officer! Don't say "only" a chief, though, because these men know their stuff! There is a saying in the Navy that if you want someone to think, ask an officer. But if you want it done, ask a chief...nicely!

  For all of their age, the LCUs are a pleasure to ride. One of the joys of preparing this book was a late summer ride out to the USS Wasp (LHD-1) on the bridge (above the pilothouse) of an LCU. Stable as a rock as we headed into the huge well deck, we could not help feeling that we had rediscovered something wonderful about the world. The LCUs ride well, even in a heavy or following sea, and can handle almost any climate from the heat and dust of North Africa to the ice and cold of Norway. They also fit well aboard amphibious ships, as the following chart shows:Amphibious Ship LCU Capacity

  As you can see, amphibious ships trade about two LCACs for each LCU. Given the LCU's compatibility with older ships like the LHAs and LSD-36s (for which they were designed), it's a shell game to mix and match ships and landing craft to obtain the ideal combination of landing craft for a particular mission. For example, when Captain C.C. Buchanan (Commander of Amphibious Squadron Four, PHIBRON-4) was configuring his force for the 1995/96 cruise of PHIBRON- 4 and its embarked Marine unit, the 26th MEU (SOC), he decided on the following mix. Aboard USS Wasp (LHD-1, his flagship), he embarked three LCACs from ACU-4 at Little Creek, Virginia. He then ordered up one LCU each for USS Whidbey Island (LSD-41) and USS Shreveport (LPD-12) from ACU-2 (the Atlantic Fleet LCU unit: ACU-1 services the Pacific Fleet), also at Little Creek. This mix made optimum use of available well deck space, and provided maximum lift capacity for the coming Mediterranean cruise. It was a prudent decision. Sailors and Marines are conservative, and they believe in the reliability of the big steel LCUs. In fact, the LCUs are scheduled to get the fancy new AN/KSQ-1 Amphibious Assault Direction System, which says something about their longevity in the eyes of Naval planners. "Rusty but trusty," the LCUs fill a vital role in the amphibious Navy.

  Landing Craft, Medium (LCM)

  The last landing craft we will look at is by far the eldest: the venerable Landing Craft Medium, Mark 8. The LCM-8 is the last direct link with the kind of landing craft you see in old war movies storming the beaches of Normandy or Iwo Jima. The basic design of this long-serving utility craft dates back to a British vessel of the early 1940s. Back then, the requirement was to haul a thirty-ton tank or equivalent load from an offshore transport. Other than increasing the payload capacity to accommodate a modern main battle tank, not much has changed.

  The basic LCM-8 is a metal box, with a retractable bow ramp and a pair of 165 hp marine diesels. Most of the LCM-8s are made of high-tensile steel, though some units were welded aluminum to reduce weight for stowage aboard LKA-113-class assault cargo ships. Aft is a small pilothouse. And that is about it. There are armament or berthing facilities for the crew of five (they live aboard their mother ship). The cargo area is open to the elements. The LCM-8 can make about 10 kt/18 kph for a range of about 190 nm/347 km with a sixty ton cargo load or perhaps 125 Marines. An LCM-8 can carry every piece of ground equipment in a MAGTF, except the M1A1 Abrams tank. The LCM-8s roll a fair amount, and can ride decidedly rough in heavy seas. Nevertheless, they are quite seaworthy, despite the pounding that they deliver to their passengers and cargo.

  Currently, though the capability does still exist, an ARG carrying an MEU (SOC) would almost never carry LCM-8s. Where you find the LCM-8 is in the three maritime preposition squadrons. There they function as cargo carriers for vehicles and equipment. They act as tugs for barges, and transport personnel between ships. Many allied forces, including Britain's Royal Navy, use the LCM, and will continue to for some time. After a half century of service, however, the LCM's retirement from the U.S. Navy is finally at hand. Within the next ten to fifteen years, the last LCMs will leave U.S. service, becoming a fond memory to the sailors that crewed them. They have served in wars from the Pacific to the South Atlantic, with distinction.

  What will replace them? By about 2010, the Navy will need a landing craft with a cargo capacity in the thirty-five-to-fifty-ton range. A logical successor might be a downsized LCAC. In addition to carrying cargo, a gunboat version able to escort LCACs or AAAVs would be very useful. The problem, of course, is money. There simply is no budget for anything but paper studies, and no program office has been chartered to solve the problem. Given the fiscal limitations of the next decade or so, you might see LCMs serving well into the first quarter of the 21st century. They are simple. They work. That alone may keep them around for some time to come.

  The Maritime Prepositioning Force (MPF)

  During the past two or three decades, the U.S. has managed to abandon or get thrown out of most overseas bases for its forward deployed forces. It was our own fault really. Sometimes we backed the wrong dictators (Marcos in the Philippines or Noriega in Panama). Sometimes we just got our butts kicked out, as happened in France, Vietnam, and Libya. And sometimes nature takes a hand, as when the volcano Mount Pinatabo erupted, wrecking Clark Field and hastening our exit from the Philippines. As a result, the U.S. Navy is currently limited to a handful of overseas bases, usually on old colonial possessions or territories of our best allies. These include Guam, Diego Garcia, the Azores, and Okinawa. Unfortunately, such bases are separated by thousands of miles/kilometers from the continental U.S. and from the most likely potential flash points.

  This caused serious difficulties in the late 1970s when the U.S. had virtually no bases in Southwest Asia to confront the Islamic revolution in Iran or the Soviet invasion of Afghanistan. The only U.S. base in the Indian Ocean, Diego Garcia (leased from Great Britain), is almost 2,000 nm/3,700 km from the Straits of Hormuz, at the head of the Persian Gulf. This situation was compounded by drastic cuts in the Navy's budget, slashing the power-projection capability it had possessed just five years earlier at the end of the Vietnam War. The drawdown of U.S. military by the Carter Administration probably encouraged the actions of the Soviets and Iranians in 1979. Then-Secretary of Defense Harold Brown authorized a study in 1979 to find ways to reverse the downward slide of forward-based U.S. forces around the world. Several alternatives were considered, including:* Construct a vast new fleet of amphibious ships, roughly doubling Navy lift capacity.

  * Build additional strategic airlift aircraft (C-5s, C-141s, etc.) to rush units of regiment and brigade size to crisis areas.

  * Find new ways to forward base units and equipment for rapid deployment to a crisis.

  The third alternative won out: prepositioning stocks of military equipment close to potential trouble spots, allowing troops to fly in and form up their units on the spot. Called Prepositioning Of Materiel Configured in Unit Sets (POMCUS), it was a key element of NATO strategy during the Cold War. It was much cheaper than maintaining full-time units on the inter-German border, and allowed ground forces to be based mainly in the continental U.S., saving vast sums of money. The Marines already had prepositioned stocks in Norway, stored in large caves in the Oslo area. POMCUS sites are also used in Korea to deter aggression by a belligerent neighbor. The problem in Southwest Asia in 1979 was that the U.S. had no allies willing to allow basing of equipment on their territory. Some way had to be found to base enough equipment for a Marine brigade (about 18,500 personnel) without upsetting the neighbors.

  The answer was a pair of commercial shipping technologies that came of age in the 1970s. T
he first, containerized cargo handling, allowed long-term packing and storage of equipment and supplies, with computerized tracking to provide rapid access to the contents of any particular container. The other technology was the Roll-On, Roll-Off (Ro-Ro) ship, which allowed vehicles to drive on or off a ship without special handling equipment or personnel. All that was required was a jetty or wharf where the ship could drop its ramp. The vehicles did the rest themselves. Ro-Ro ships were fairly common by the late 1970s, and it was quite possible to package a complete Marine brigade on a group of such ships. You could have ships sit in an island lagoon or just steam offshore from the crisis area. All they would need was a port facility to off-load, and an airfield to fly in personnel and aircraft. The ships would carry enough supplies (water, fuel, food, ammunition, etc.) to support a Marine brigade long enough for follow-on forces and supplies to arrive from the United States.

  By 1980, an interim force of seven leased merchant Ro-Ro ships (enough for a reduced 11,000-man Marine brigade) was stationed at Diego Garcia in the Indian Ocean. This was only a temporary stopgap, so in 1981, the Maritime Prepositioning Force (MPF) was established as a permanent unit. MPF leased thirteen converted Ro-Ro ships, forming three Maritime Preposition Squadrons (MPSRONs). Each MPSRON can equip, supply, and support an 18,500-man brigade-sized MAGTF for up to thirty days. With three such units on permanent station, at least one would be within seven days steaming from anywhere in the world they might be needed. As history turned out, this has been the case.