Beyond The Horizon AUTHOR LCDR. Glen F. Erickson, USN CSC 1989 SUBJECT AREA - General Executive Summary Title. Beyond the Horizon Thesis. The LCAC will preserve the significant military capability of Amphibious assaults but not without its shortcomings. Issue. Since World War II, the Navy-Marine Corps team has not significantly altered its method of beach assault or the landing vehicles used for the assault. Landing craft are deployed form amphibious ships at three to five miles offshore and then proceeded to the beach at 8 knots. Unfortunately the enemy will no longer allow the United States the luxury of preparing the beach for several days prior to an amphibious assault. Modern radars will eliminate the chances for surprise and modern weapon systems will require amphibious shipping to remain a healthy distance from the beach. The Landing Craft Air Cushion (LCAC) will change the way of landing Marines on hostile shores by introducing the capability to launch from over-the-horizon. The LCAC's speed and range offer significant capabilities over the current LCM-8 landing craft. However, the LCAC's size, high technology, and design features present some drawbacks. Additionally, use of the Amphibious Assault Vehicles (AAV) in an over-the-horizon amphibious operation is not practicle. Conclusion. Continued evaluation and improvements in amphibious assault doctrine and equipment are necessary, in order to keep up with the technological improvements in combat systems. Beyond the Horizon Outline Thesis Statement: The introduction of the Landing Craft Air Cushion (LCAC) serves to preserve the significant military capability of amphibious assaults but not without its shortcomings. I. Introduction A. Definition of amphibious operation B. Amphibious assault concept C. Past method of assault D. Introduction of LCAC II. LCAC characteristics and capabilities A. Characteristics B. Capabilities 1. Over-the-horizon assault 2. Tactical operational capabilities 3. Anti-mine capabilities 4. Communications 5. Navigation III. LCAC operations in the over-the-horizon assault A. Advance force operations B. Naval gunfire IV. LCAC drawbacks A. Design characteristics 1. LCAC size compared to LCM-8 2. New technology B. AAVs compatibility with LCAC C. New equipment costs V. Conclusion Beyond The Horizon The joint service publication, Doctrine For Amphibious Operations, defines an amphibious operation as "...an attack launched from the sea by naval and landing forces embarked in ships or craft involving a landing on a hostile shore."1 Perhaps the most famous and best remembered amphibious operations were conducted during World War II and the Korean War. These operations were critical to the United States and its allies to introduce forces on a hostile shores and proved to be turning points in the wars. More recently, amphibious operations by the United States in Grenada and by the British in the Falkland Islands War, once again revealed the value of amphibious operations. A successful amphibious assault relies on many factors. Surprising the enemy is probably the most important. For example, General Eisenhower realized its importance during World War II, when he went to great lengths to ensure the Normandy invasion was kept secret from the enemy. Another important aspect is control of the Area of Action (AOA). The chances of success are greatly increased when the Commander of the Amphibious Task Force (CATF) has control of surface and subsurface, in addition to air superiority. Without control of the AOA, assault echelon shipping is subject to attack even before the landing force is disembarked. Additionally, an amphibious landing should be located where enemy forces are not. Amphibious assaults are complicated and success relies on detailed planning and realistic rehearsals. Since World War II, the Navy-Marine Corps team has not significantly altered its method of beach assault or the landing vehicles used for the assault. World War II assault forces typically spent days clearing underwater obstacles and preparing the beach with naval gunfire. Landing craft were deployed from amphibious ships at three to five miles offshore and then proceeded to the beach at 8 knots. The Navy-Marine Corps team still practices this method of beach assault. Part of the reason for the lack of change in amphibious operations stems from post war thinking. After both World War II and the Korean War, military leadership predicted that the introduction of forces using amphibious assault would become outdated and not practical in future conflicts. Prior to the Falkland Islands War, the British had intensions of greatly decreasing their amphibious capability. They too thought amphibious warfare had no place in today's high technological world. Their experience at the Falkland Islands turned that thinking around. Modern enemy capabilities complicate the traditional amphibious assault and greatly increase the risk of failure. Amphibious warfare is not outdated, however, much of our equipment and doctrine need updating. Our amphibious warfare capabilities can no longer be neglected. The enemy will not afford us the luxury of preparing the beach for an amphibious assault several days in advance. Modern surveillance radars will practically eliminate the chances for a surprise landing on a hostile shore. With the mobility of modern weapon systems, the enemy can prepare defensive positions (to include missile systems), in a matter of hours. Amphibious shipping closing the beach to a distance of three to five miles will be in danger of missile attack. This quickly became clear to the British during the Falkland Islands War when an Exocet missile on a trailer at Port Stanley damaged the British destroyer Glamorgan. One solution to update our amphibious assault equipment has been the introduction of the high speed and extremely mobile Landing Craft Air Cushion (LCAC). The LCAC will preserve the significant military capability of amphibious assaults but not without shortcomings. LCAC will lead Amphibious warfare into the twenty-first century. Its versatility and speed will permit the Navy-Marine Corps team to rewrite amphibious doctrine to account for technological changes in weapon systems, communication equipment, and surveillance systems. Additionally, it will include the concept of over-the-horizon amphibious assaults. As early as 1975, the Marine Corps has been investigating air cushion vehicles as an innovative method of landing forces on the beach. "The increased speed and mobility of hovercraft should make them less vulnerable than conventional craft. More importantly their speed would disperse the enemy defense making him more vulnerable to counterattack."2 This was the Commandant of the Marine Corps thoughts in 1975. This type of thinking has lead to two operational Assault Craft Units (twelve total LCAC), and the production program calls for a total of ninety craft by the year 1995. The Marines have long understood the value of the helicopter and its ability to quickly transport personnel and equipment to a landing site during an amphibious assault. The LCAC's speed and mobility is a valuable addition to the landing force during an assault. "Finally we will have a landing craft that truly complements the helicopter in speed, tactical surprise and the ability to attain a rapid buildup of Marine combat power ashore without exposing our amphibious ships to enemy fire. Coordinating helicopters with the LCAC's speed and amphibious capability, assault forces will be able to quickly move Marines and equipment to inland objectives. The LCAC is a new form of landing craft that employs air cushion technology. Gas turbine engines drive four centrifugal fans to supply an air cushion for the craft. A flexible skirt around the edge of the craft contains the air. Gas turbine driven propellers are used for propulsion. The hovercraft operates about four feet from the water's surface, when on cushion. The LCAC is made almost entirely of aluminum and measures 88 feet long, 47 feet wide, and 23 feet high when on cushion. It has forward and aft ramps for easy loading and unloading of its 60 ton maximum payload. Notional loads for the LCAC are listed in Appendix A. A significant capability of the LCAC over the conventional landing craft is its speed. Because the LCAC rides on a cushion of air over the water, it has the capability to achieve speeds in excess of 40 knots with a full load. This is a considerable difference from the conventional crafts maximum of eight knots. While conventional amphibious craft must be launched from three to five miles from the beach, assault shipping can launch the LCAC at distances of anywhere from a couple thousand yards to a hundred miles from the beach. Unlike the launching of conventional landing craft, amphibious ships do not have to ballast down to launch the LCAC. They can be launched from a dry well allowing the ship maximum maneuverability. The LCAC's speed and 150 mile range, allows assault shipping to remain over-the-horizon when deploying the LCAC and therefore significantly increasing their chances for survival. By launching the amphibious assault from over-the-horizon, amphibious shipping can remain integrated in the carrier task force layered defense. The importance of this cannot be overstated. Amphibious ships have weak anti-air defenses and no defense against submarine attack. With the over-the-horizon assault concept, the amphibious task force (ATF) will no longer be subject to certain failure prior to off loading the landing force. Combat air patrol (CAP) and carrier task force missile ships will protect the ATF from enemy aircraft and anti-ship cruise missiles. The anti-submarine warfare ships will screen the ATF from submarine attack. Lastly, by remaining over-the-horizon, the ATF ships minimizes their chances of encountering mine fields. When deployed from 25 to 50 miles offshore, assault forces can proceed into the beach in any number of directions. With its 200 mile range and high speed, the LCAC operator can try to deceive the enemy by fainting to one direction and then quickly changing directions toward the landing beach. Because the enemy cannot be certain of where the LCACs and helicopters will land, they will not know where to concentrate their forces. This requires the enemy to either spread out and weaken his defenses or wait for the assault forces to land. The over-the-horizon assault will keep the enemy off-balance and forced to assume a position of responding, instead of directing the battle. Next to the increased speed, the second greatest tactical advantage of the LCAC over conventional landing craft is the increase number of beaches to where it can travel. The LCAC is not limited by reefs, bottom gradients, swamps, tides, or current. It can assault beaches that are physically impossible for conventional craft. The LCAC is able to assault 73 percent of the worlds beaches vice only 17 percent available to conventional landing craft. Alone, this figure is subject to challenge but it is fairly safe to say that the percentage is much higher for the LCAC. The LCAC is more immune to adverse weather conditions than conventional landing craft. "Because of its self-fendering and ability to operate from a dry well, an LCAC can launch in sea states that would preclude LCU/LCM operations. "4 " Landings in higher sea states will be possible since the LCAC is less vulnerable to high seas and surf than present day landing craft. "5 Although sea state effects the maximum speed of the craft, the LCAC still maintains a significant speed advantage over conventional craft. In a sea state condition four, the LCAC is still capable of 25 knots. One major advantage of the LCAC in rough surf is its ability to transit the surf and offload on dry land. During World War II, a significant amount of equipment and lives were lost when LCMs lowered their front ramp in rough surf conditions. A major obstacle for conventional landing craft is underwater mine fields. "LCAC has a smaller signature for mine activation, while not producing any pressure signature, and thus substantially reduces or eliminates the mine threat. "6 The Soviets have an excellent mine laying capability. Even under short notice conditions, they can lay a mine field using indirect fire artillery or aircraft. This capability would be fatal to conventional craft. Although the LCAC is susceptible to land mines, LCACs have a better chance of survival against underwater mine fields. When above hump speed, 21 knots, the LCAC presents no pressure or magnetic signature and the air spray under the craft reduces its acoustic signature. This is a significant advantage over conventional landing craft. Although the LCAC is a large, noisy, undefended target, the LCAC's survivability from launch to beach landing is greater than conventional craft. In addition to its mine field survivability, the LCAC's speed and maneuverability make them virtually immune to indirect fire. Also "the LCAC IR signature is quite low when waterborne due to the masking by spray."7 Because the LCAC travels above the water, it is oblivious to torpedo attack by ships or submarines. With two propulsion units, one side of the LCAC can be damaged and the craft will still be operational and "...tests have shown that it (LCAC) can sustain considerable damage and continue to operate. "8 These factors greatly increase chances for a successful amphibious assault. The compactness of shipping in the current amphibious assault doctrine allows the Commander Amphibious Task Force (CATF) to observe the entire assault and to easily communicate with participants when adjustments are required. Even though communications are easier when all the participants are within the line of sight, this compactness is one of the main reasons for doctrine change. One enemy weapon system could take out any ship or all ships, not to mention the catastrophic results a chemical or nuclear bomb would have. Additionally, this compactness will be of less benefit if the enemy is jamming radio circuits. The LCAC has one HF, one VHF, and one UHF radio installed onboard, however, it has no secure voice capabilities. With such an unsophisticated communications suite, the over-the-horizon assaults will rely on decentralized control of the landing craft, thereby giving the landing craft commander more options for success. The LCAC's onboard navigation equipment is not sophisticated enough to accomplish a pin point landing from over-the-horizon. Its navigation radar, the LN66, is a short range radar (given the LCAC height of 23 feet). When launched from over-the-horizon, the craftmaster will rely on either his gyrocompass or backup magnetic compass for his initial course. This will make any kind of zig zag plan prior to landing difficult. When he is closer to land, he can begin plotting his position. Night operations will be more difficult because the craftmaster will not be able to see prominent landmarks to aid in navigation. The LCAC does not need a better radar, because undoubtably all assaults will be conducted in an emission controlled (EMCON) environment, to ensure tacticle surprise over the enemy. Over-the-horizon amphibious assaults will completely eliminate naval gunfire in support of the amphibious assault. All United States Navy ships, with the exception of the battleships, have gunfire ranges of less than 15 miles (Appendix B). "Because of the inability of naval gunfire ships to support the initial assault, greater reliance must be placed on close air and attack helicopter support. "9 Additionally, a greater urgency will be placed on landing artillery earlier. Although the lack of naval gunfire would be of great concern in past amphibious landings, one of the primary ideas behind the over-the-horizon amphibious assaults is to expand the enemy's battlefield and to land forces on undefended beaches. During the over-the-horizon assault, helicopters and the LCAC will be launched to quickly transport marines and equipment to undefended beaches, therefore, eliminating the requirement for naval gunfire support prior to the assault. Advance force operations can be greatly reduced when employing LCACs. They are not hindered by underwater obstacles so the need for Navy Seals to clear underwater objects and to conduct hydrographic surveys are no longer required. These operations have always been covert and their success was critical to a successful assault. Without advance force operations, the chances of surprise are increased. Intelligence gathering will be the most important advance force operation in an over-the-horizon operation. We must locate the enemy's position so assault forces can land where the enemy is not. The LCAC has some drawbacks that should be noted. The mere size of the LCAC has a great impact on the number that can be loaded into amphibious assault shipping. Although the LCAC has roughly the same cargo capacity as the LCM-8, the landing craft that it will replace, the LCAC is more than twice the size of an LCM-8. As a result amphibious ships in the Navy's inventory can hold two to three times more LCM-8 craft than LCAC. A new ship class, LSD-41, has been constructed specifically to transport the LCAC. The LCAC will compensate for its difference in size by making multiple high speed runs to the beach. When launched from 20 miles offshore"... there will be an hour and a half between the time an LCAC makes its initial landing and returns with a second load. "10 "LCACs are high-tech craft which require sophisticated, high tech maintenance and support. "11 There are potential growth problems as LCACs begin to deploy with amphibious ships. The LCAC requires 23 different personnel specialties for support. Although some of these support functions can be performed by the crew of the amphibious ship, several of these specialties are normally not assigned to amphibious ships. Of the ones that are, some of these personnel are not familiar enough with the LCAC to fill them. Therefore, additional personnel will embark with the LCACs to operate and maintain them. "LCAC detachments embarked on amphibious ships may occupy some spaces otherwise available to the landing forces. "12 Additionally, LCAC maintenance personnel will bring their own tools and repair parts, much the same as helicopter detachments do. "Embarkation plans must fully consider berthing and stowage losses due to LCAC assignments. "13 The question concerning the amphibious assault vehicle's (AAV) role in an amphibious assault when using LCACs has not been answered. The AAV is the primary personnel carrier in an amphibious assault and the primary means of mobility once ashore. This "... important piece of the amphibious system still has not kept up with the advanced shore capability provided by the helicopter and the LCAC. "14 The LCAC was not designed to be a personnel carrier. Its noise, considerable spray, and danger of foreign objects and debrie (FOD) through the large propulsion systems, limit personnel to the small control booth or inside equipment on deck such as a tank or Light Armored Vehicle (LAV). The LCAC has the ability to carry AAVs (two each). However, this would result in numerous additional round trips to the beach for delivery. An LCAC carrying AAVs must continue all the way to the beach. They cannot offload AAVs while still waterborne. The LCAC's ramps will not support the weight of an AAV unless the end of the ramp is supported by land. If we are going to shuffle AAVs to the beach in this fashion, the requirement for the assault vehicle to be amphibious is no longer valid. The AAV will be the weak link in the amphibious assault. Unless another vehicle is designed, the concept of over-the-horizon amphibious assault for anything other than a small raid force is not possible. Improvements and new systems cost substantial amounts of money. In a period of decreased military spending, it will be difficult to purchase the equipment required to keep our amphibious assault forces updated. The Mv-22 Osprey, with its significant improved capability over the helicopter to land marines, is quite close to being cancelled. The LCAC requires new shipping to transport it to the Area of Action. All this new equipment means more money, money that probably will not be available to design a new AAV or a vehicle to quickly transport AAVs close to the beach. The LCAC is an amphibious assault vehicle that can keep the enemy off-balance. With this asset many innovative methods of amphibious assault can be developed, instead of continuing with World War II tactics. It provides an over-the-horizon capability thereby keeping ships away from the beach and at the same time concealing the identity of the landing sites. Due to the LCACs ability to land on approximately 73 percent of the world's beaches, the Navy-Marine Corps team can avoid the enemy defenses and achieve the element of surprise on a hostile shore, ensuring a successful amphibious assault. The amphibious assault is still a viable means of introducing friendly forces onto hostile territory. The United States and its allies can no longer endanger the lives of personnel on amphibious shipping by practicing World War II style amphibious assaults. Although the conventional method may again be useful in special circumstances, advances in gunnery and missile systems are making it more impractical. The LCAC along with the helicopter will play an important role in future amphibious landings. However, in order to keep up with the technological improvements in combat systems, continued evaluation and improvements in amphibious equipmemt and doctrine are necessary. FOOTNOTES 1MCDEC,USMC, Marine Division, FMFM 6-1 (Quantico, 1978) ,p.39. 2LtCol Alvin Doublet, "The Air Cushion Vehicle and Its Future Applicable to National Defense," dtd April 1986 (Maxwell AFB, Alabama).p.87. 3Joc W.D. Christensen, Jr., "LCAC Ushers in New Amphibious Era From Over the Horizon," Surface Warfare (Mar/Apr 1984) ,p.9. 4Col Marshall Darling, "LCACs: Characteristics and Tactical Improvements," Marine Corps Gazette (December 1984) ,p.43. 5Doublet,p.87. 6Doublet,p.80. 7MCDEC,USMC, TACMEM0 PZ 005070-1-85, OH 7-15 (Quantico, 1985) ,p.3-3. 8Maj Thomas Bailey, "Over-the-Horizon Assault by LCAC," Marine Corpds Gazette (January 1986) ,p.76. 9Bailey,p.77. 10Bailey,p.80. 11Ltjg Kenneth Heine, "Beyond the Beach," Surface Warfare (Jan/Feb 1988),p.11. 12TACMEM0,P. 5-2. 12TACMEMO,p. 5-2. 14Col Wendell Vest, "Amphibious Warfare System for the 21st Century," Marine Corps Gazette (December 1986),p.19. BIBLIOGRAPHY Bailey, Thomas, Maj, USMC. "Over-the-Horizon Assault by LCAC Marine Corps Gazette (January 1986) ,74. Christensen, Joc Jr. "LCAC Ushers in New Amphibious Era From Over the Horizon." Surface Warfare (March/April 1984) ,8. Cocks, Allen A., Capt, USN. "Communications From Over-the-Horizon." Marine Corps Gazzette (December 1987) ,48. Darling, Marshall B., Col, USMC. "LCACs: Characteristics and Tactical Implications." Marine Corps Gazette (December 1987) ,p43. Doublet, Alvin J., LtCol, USMC. "The Air Cushion Vehicle and Its Future Applicability in National Defense." Research paper, Maxwell AFB, Alabama, April 1976. Earl, Robert L., LtCol, USMC. "The Over-The-Horizon Alternatives. Marine Corps Gazette (October 1988) ,37. Heine Kenneth A., Ltjg, USN. "Beyond the Beach." Surface Warfare (Jan/Feb 1988),11. Kippen, Roberick M., Maj, USMC. "Out of Area Logistical Support and Amphibious Operations During the Falkland Island Crisis - Reflections, Reconsiderations, and Reinforcements." Naval War College, April 1983. Linn, Thomas C., Maj, USMC. "Over-the-Horizon Assault: the Future of the Corps. Marine Corps Gazette (December 1987) ,44. Mead, P.J., Capt, USMC. "An Air Cushion for AAVs." Marine Corps Gazette (January 1986) ,22. Riley, William E. Jr., Col, USMC(Ret). "The Need for an Amphibious Force Structure." Marine Corps Gazette (December 1987) ,41. Rothwell, Richard B., Col, USMC. "A Window on the Future of Amphibious Warfare Kernel Blitz 88-1." Marine Corps Gazette (August 1988) ,82. Simmons, Dean L. "The Future of Amphibious Fire Support." Proceedings (November 1983) ,127. Vest, Wendell N., Col, USMC. "Amphibious Warfare System for the 21st Century." Marine Corps Gazette (December 1986) ,19. Watson, Bruce W. Military Lessons of the Falkland Islands War: Views From the United States. London: Arms and Armor Press, 1984. Click here to view image
