LANDING on a strongly defended enemy coast - perhaps the most difficult operation of modern warfare - is the task for which Uncle Sam’s marines have been, and still are preparing. Deepest secrecy necessarily shrouds the training and development of methods. Working with army and navy forces which would cooperate with them in a major landing effort, the marines have been developing methods as unusual as anything uncovered by the European war. Their objective has been the creation of a formidable force with greater speed and mobility than any the world has ever seen - a force capable of striking from the sea and the air to seize and hold hostile beaches until supporting troops can arrive. To reach land in safety in the face of enemy fire calls for equipment that will transport the marines and their weapons across open water at the utmost speed - troop-carrying trucks that can swim and specially designed barges for carrying artillery and tanks to shore, and all constructed so that unloading is a matter of minutes, rather than hours. Other equipment must be available for dropping hundreds of heavily armed men by parachute and glider to seize open fields upon which troop-carrying planes may land. One of the latest vehicles to join the marines is the Roebling tractor which travels on land and water with equal ease while loaded with fighting men. Tank lighters, on which one or more tanks can be transported, already are in use. Marine engines propel the lighters from ship to shore at high speed. Built so their bows can be thrust high on the beach, the lighters have ramps which can be lowered quickly for the tanks to un- load under their own power and begin fighting. Thirteen-ton tanks may be carried by these lighters; not far in the future may be lighters for tanks twice as heavy. Just how could a landing operation be carried out Secret methods cannot be disclosed, but in general the operation might proceed in this manner. An expeditionary force - a strong naval force, including aircraft carriers, accompanying troopships - would approach the enemy coast. First would come bombardment of the beach and adjacent areas to drive enemy forces away from the territory to be occupied. Big guns of battleships and cruisers and bombing planes from the carriers would blast away, perhaps for hours. Then the transports would move closer and landing boats, amphibious tractors, tank lighters and artillery barges - probably preceded by swift “mosquito” boatsm- would sprint for the beach. Specially trained troops, armed with grenades, machine guns, automatic rifles and other light equipment, would spring from the landing boats and attack enemy machine-gun nests. Light tanks would lumber from their lighters to charge defense works, light artillery would be wheeled from the barges and put into action. Wave after wave of men would follow, as the landing craft continued to pour troops and equipment onto the beach. In the early stages of the operation, parachutists would drop from the skies to assemble into units of automatic riflemen and machine gunners for an attack on an airport or open space where gliders and planes carrying more heavily armed infantry and equipment might land. Here is where speed is vital a forces,must be whipped into an organization(able to defend the airport against counterattack and this must be done without a lost moment. Then can come more planes with reinforcements and heavy guns and light tanks. If the enemy could be pushed back far enough to make the beach-head fairly safe, engineers would construct sturdy docks on which still heavier equipment could be unloaded - a necessary operation because each man in the field requires several tons of equipment, including large-caliber guns and tanks. At this point the Marines might be said to have the situation well in hand. The Marine Corps has been developing another new fighting organization, which also is composed of specialists. Known as the defense battalion, its job is to dig in and hold a specified area against numerically larger attacking forces. This unit is intended to be sent ashore to hold islands or ports vital to the American Navy. Batteries of long-range naval guns are part of the battalion’s equipment for protection against enemy attacks from the sea and speed in mounting these guns is a part of the unit’s training. Machine guns are employed against enemy infantry and anti-aircraft guns against air raiders. Since speed and mobility are two necessary qualities in operations of Uncle Sam’s marines the “triangular” organization is employed. Instead of the cumbersome division consisting of some 25,000 men just after the World War, the 1942 division is composed of about 15,000, including three infantry regiments and one organic artillery regiment. The smaller force is, of course, easier to handle, making for speed. The Marine Corps has been training pilots, mechanics, gunners and parachutists' as rapidly as facilities and equipment became available. The flying marine learns to handle land and sea planes and to take off and land from the tossing deck of an aircraft carrier and rocky landing fields perhaps carved from the jungle. But the most recent development has been the parachutist and the air-borne infantry. Work in this field, too, is secret, but it is known that the Marine Corps has been perfecting’ an organization to exploit the possibilities of principles established in the successful air attack on the island of Crete by German ‘chutists and plane-transported soldiers. Candidates for ’chute units must be young men of specially robust physigue and unusual activity; their course consists of jumps from platforms set a few feet high, then from towers arranged so that captive parachutes may lower them to the ground and finally from airplanes. Special equipment is carried by the ’chutists so that they may go into action the instant they touch the ground. In addition to a formidable array of weapons, the parachute troops may be expected to carry a supply of folding bicycles on which they would be able to reach an objective, or protective cover, more rapidly than they could on foot. Machine guns and other equipment which would be too heavy for the individual to carry are dropped by separate parachutes. Marine Corps officers and enlisted men are being trained in preparation for immediate development of a glider division. It is understood the marines will use large gliders for supplying ground troops from the air and as transports for parachute troops and shock troops for landing behind enemy positions. Always maintained in a state of readiness, the Marine Corps today probably could put at least an entire division, with complete equipment, on an enemy coast faster than any other military organization in the world. Even in its early history, the Marines could embark a fully equipped battalion aboard ship on 24 hours notice; today they can do it even faster - the result of constant training, planning and research.