User:RekonDog/Fleet Landing Exercises

The Fleet Landing Exercises, or FLEX were a series of annual large-scale amphibious landings exercises conducted to test the Marine Corps' legitimation of the Fleet Marine Force. Although, similar exercises were commenced in the 1920s, it was not until the early 1930s that these contigency plans gave the envision of importance in testing key maneuvers in amphibious landings that became proven in World War II. There were many events of problems and mistakes but their importance was still significant. The joint-Navy and Marine Corps effort corrected many deficiencies, and improved many techniques. The FLEX were commenced by the 1st Marine Brigade of the East Coast, stationed at Quantico comprised of two infantry battalions, an artillery battery from the 10th Marine Regiment, small engineer and service units, and light cruisers and gunboats of the Special Service Squadron. And 2nd Marine Brigade of the West Coast, where were stationed at Marine Corps Base, San Diego which were was built around the 6th Marine Regiment assuming the same structure but geatly undermanned.

Even though the Guantanamo Bay Naval Base played the preeminent role in the training and dispatching of Marines to several of these interventions. However, the islands around Puerto Rico, Culebra and Vieques remained important in training and in preparing military personnel for the 1st Marine Brigade in the Caribbean for the Fleet Landing Exercises. As distinct from the Outer Range, which is the open-sea range complex on 138,000 square miles of ocean northeast and southeast of Puerto Rico and Vieques, as well as south of Puerto Rico. The Outer Range is used primarily for missile firings, both surface-to-air and air-to-air, as well as for fleet exercises. In the Pacific, the 2nd Marine Brigade stationed at Marine Corps Base San Diego, California was the first unit to engage in Pacific Fleet maneuvers, and from that point on the Fleet Marine Force took part in each annual fleet problem. West Coast Marines made landings at San Clemente, in the Hawaiian Islands, and at Midway Atoll.

Great achievements were made in analyzing the ship-to-shore movements and debarkation, varieties of air and naval gun fire techniques, and communications equipment. Effortlessly the Marines had experimented with every amphibious technique discernible by touch and the tactical approachment of its limitations in equipment available. Most of the excercises were to include in day and night amphibious landings, concentrating assaults, dispersed infiltrations and amphibious reconnaissance. Major improvements were due to practice of various methods in uses of landing craft while the acting raiding parties fired many variants of weapons. Through trial and error, the Fleet Marine Force adopted a new, refined doctrine in landing operations, the Fleet Training Publication 167.

The United States Navy used old four smoke stacked World War I-era battleships converted for troop transport by removing two of the stacks and its boilers, it allowed the space for the Marines and their equipment. This allowed further development in the loading techniques and quick debarkation that was required in an amphibious landing, although it greatly reduced the efficiency of the cargo in stow but allowed improvement in amphibious assault capabilities. The Navy re-designated the converted battleships to APD classification.

FLEX 1
The first of the annual exercises commenced on January 15 on the beaches of Culebra and Vieques until March 15 in 1935. Fleet Landing Exercise Number 1 tested the doctrine oulined in the Tentative Manual and have included extensive landings, naval gunfire experiments, and use of aviation in landing operations, such as aerial reconnaissance and bombardment. The Caribbean fleet hve tested a large range of weapons while using the ship-to-shore movement in a wide spectrum of machine guns and 81-mm mortars, and the 75-mm pack howitzers against beach targets. The conclusion was that landing boats were needed to be improved, if not better due to the mixed results. One of the exercises, a landing craft were successfully covered in a protective smoke screen but caused the landing party to immediately halt, and the waves broke up the party, while many boats lost their way to the beachhead. While the landing parties were ashore, the Navy held naval gunfire tests with assessing the effects of different shells and fuzes. These test concluded that area fire was far more better than pin-point bombardment. However, many strafing practices both by the aviation and navy were strictly limited due to safety precautions for the Brigade conducting maneuvers along the beach. The outcome of these exercises have attested that better landing craft and boats are adequately needed, as well as more technologically advanced communications equipment and techniques.

FLEX 2
The Fleet Landing Exercise Number 2 was conducted from January 4 to February 24 in 1936 marking the beginning of the Culebra/Vieques Inner Range or the Culebra/Vieques Complex as it would be known until 1975 and the closing of the Culebra subranges. The amphibious exercises were transferred from Culebra’s Flamenco Beach to Vieques, and naval gunfire practice began on Flamenco Beach and on the adjacent Flamenco Point. The 1st Brigade had revealed many of the same mistakes seen in FLEX1 but encountered several new problems. The Marines needed to get closer to the beach and the battleships were not able to tread in shallow waters. As for the landing craft boats, the problem was still not resolved as they were slow and extremely vulnerable. In several testing of various boats, they found that they proved to highly unstable for gun platforms, dangerous in disembarking the troops and were incapable in crossing submerged coral reefs. The uses of smoke and darkness to conceal the beachlandings were still causing confusion amongst the landing parties. While the artifical naval gunfire tests were being continued, the rapid area fire had made the aerial spotting difficult for the pilots. And still communications were a problems. However, the barrage-type bombardment met the approval for the Army Officer-Observers to reinforce a fundamentally sound doctrine. The Marine brigade gained tactical experience in the amphibious maneuvers ashore but the FLEX 2 had not made any significant breakthroughs in fixing the problems encountered during FLEX1.

FLEX 3
The Fleet Landing Exercise Number 3 was conducted on San Clemente, California from January 26 to March 3, 1937, in agreement with U.S. Attack Force Operation Plans 1-37 and 2-37. The 1st Marine Brigade was transferred to San Diego and was absorbed by the small-sized 2nd Marine Brigade, the whole Fleet Marine Force and the understrength provisional Army 1st Expeditionary Brigade. And once again, the reemergence of the testing problems of FLEX 1 and FLEX 2 were proven. The heavy Californian surf have proven that the landing boats were infeasible for beach landings; the Navy coxswains disembarked their troops to far from the beach, broached their boats, or were scattered in scouting out better, safer landing spots. It also proved conclusively that a special type landing boat with superior power, maneuverability, surf-riding qualities and protection was a highly desirable adjunct to the equipment for landing operations. The smoke and darkness continued huge problem as it did in earlier tests. Bombardment tests were extensive but the ordnance, communications and spotting techniques remained unsatisfactory because of the available equipment. The only significant improvements for the landing forces were the new Army Radios that became highly effective for communications and that the Marine pack howitzer batteries have shown that they can mobilize into the shore efficiently. Plus, they learned that aerial attacks had to be made at certain right angles to the direction of the attack to avoid friendly fire. The pilots however argued that they lacked the special-type of attack aircraft and the proper air-ground communications before they were to gain precision in strafing and bombing. Two aircraft squadrons, from Quantico, VA. and North Island, comprised of the VF, VO, VB, and VJ aircraft. Also, the first time of cargo nets used for disembarking troops to the landing boats were a success, as in the past, the Marines were using the gangways.

The origins of the destroyer-transports, or APDs were not widely known at that time until it was first mentioned in an after action report when Brigadier General James J. Meade suggested destroyers might solve the dual problem of a shortage of amphibious transports and naval gunfire support. With such ships "troops could move quickly close into shore and disembark under protection of the ships' guns." The Navy apparently agreed and decided to experiment with one of its flush-deck, four-stack destroyers. It had built a large number of these during World War I and most were now in obsolete compared to the battleships that were being used as troop transports during those times. And he further concluded that the battleships can be pressed on to other naval missions instead of being relied for troop transporation. Although the APD provided lesser carrying capacity and limited ability in carrying landing craft and heavy equipment. Of these various naval elements of APDs, the Navy detached Battleship Division One including the USS Wyoming (AG-17), USS New York (BB-34), USS Utah (AG-16), which was being used as a mobile aerial bombing target configuration for Patrol Wing One. It became one of the victims at Pearl Harbor five years later., and USS Nevada (BB-36), Cruiser Divisions 4 & 5 including the USS Salt Lake City (CA-25), and USS Houston (CL-81), would later be lost on March1, 1942 in the battle of Sundra Strait off the Netherlands East Indies, and Destroyer Division 11. The total amphibious landing force was comprised of approximately 4700 Army and Marine Corps personnel. Tragically, while firing a scheduled secondary battery practice on board the USS Wyoming on the last day of the exercises at San Clemente Island, an explosion occurred in the #13 5-inch gun mount, killing one officer and six enlisted personnel. Thirteen other personnel were injured in the blast.

FLEX 4
The Fleet Landing Exerice Number 4 partipated from January 13 to March 15 in 1938. As the world situation worsened World War II, the Fleet Marine Force returned to the Caribbean to avoid any spying of the Japanese. The tests were conducted on the beaches of Vieques and the main island of Puerto Rico. During these exercises, three Army National Guard regiments participated by staying ashore while the Marines of the 1st Brigade attempted a "mock" assault against them. It was the first time that reconnaissance elements were added was first tested to reflect the reconnaissance doctrine outlined in the Fleet Training Publication 167. Army's contribution climbed to three infantry regiments with supporting arms and brigade alternated in the part of landing force and shoreline defender. Brigadier General James Roosevelt, eldest son of the late President Franklin D. Roosevelt, who as a Lieutenant Colonel was in the Marine Corps Reserve on active duty aboard the USS Indianapolis during one of the reconnaissance patrols and experiments with raiding and patrolling parties. 1st Marine Brigade tested the concept of delivering 4-man patrols by submarines. The exercise missions were a mixed success at Vieques and Puerto Rico when two patrols were captured, but it was realized that with experience and refinement the concept held promise.

The Vieques Phase, three patrols of one Army and two Marines with four men each were assigned by Rear Admiral A. W. Johnson, Commander of the Attack Force, in reaching the beach under the cover of darkness by inflatable rafts. They launched from submarines S-42, S-46 and S-47 with intentions of conducting a reconnaissance ashore and return back to the submarines the following night at certain appointed rendevouz. Four Marines from the Headquarters Company of the 1st Brigade marked the first amphibious reconnaissance patrol launching from a submarine by raft in United States history. Those four Marines reported aboard S-47 but was unsuccessful in locating the beach on Vieques.


 * "The weather conditions under which the night phase was carried on could not have been more adverse to a successful ship to shore movement. The heavy seas were awash the decks with every wave driven by a wind of between a force of 4 and 5 [knots] in velocity and varying direction from 70 degrees to 120 degrees which approximately paralleled the island.  A brilliant full moon extended the visibility to at least 1500 yards, making a close approach to the beach impossible."

The Puerto Rico Phase in the reconnaissance landing was however quite different. After sunset in the darkness, the submerged submarines navigated to two miles within the shoreline, following channels until it was able to reach within 1000-1200 yards from the beach of Ponce Playa. This made it easy to discharge the patrols successfully to reach the beachhead without detection from the "enemy" zone of the Army National Guard. Although one was subsequently captured at the night of the landing.

It was again concluded that the landing force of the main landing parties were still in dispute over the landing craft, but the tests in reconnaissance have added that the small, inflatable air rafts were feasible in transporting recon teams onto the beaches. However, both the landing teams and recon teams both agreed that communications was still a major deflection in achieving the total success of the Fleet Landing Exercises. Means of communications were important to transmit significant information quickly and not waiting for it to be relayed once the troops have landed for it to be available for those who would need it.

FLEX 5
The Fleet Landing Exercise Number 5 commenced on January through March in 1938 and 1939 on the islands of Culebra and Vieques. These exercises again became only Navy-Marine Corps cooperation as they no longer had the United States Army participate in the movement. The Marine Corps successfully landed amphibious reconnaissance patrosl on Vieques during on when two partrols disembarked from the USS Manley (DD-74) during the exercises in January 13 to March 13, 1939. The Navy reclassified Manley as a miscellaneous auxillary (AG 28). After a few weeks of hasty work in the New York Navy Yard, the ship served as a transport for Marine units in the Caribbean. In the fall of 1939 Manley went back into the yards for a more extensive conversion. Workers removed all torpedo tubes, one gun, two boilers, and their stacks. That created a hold amidships for cargo and troops. Again, the Navy reclassified the Manley to a destroyer-transport class, APD-1. The Chief of Naval Operations made it a rush job so the ship would be available for FLEX 6 in early 1940.

Using experiemental rubber boats, the inserted teams would deflated upon reaching the shore and reinflate to rendevouz with the awaiting submarine at a predestined point. As for the the Marine assault teams tehy found that getting their equipment to the beachhead during an amphibious landing and was a strenuous task and was extremely difficult with the landing craft. Most of the landing boats were incapable in hauling amphibious tractors, artillery and other important supplies necessary for setting up an advanced base. They requested the Naval Bureau of Construction and Repair for construction of feasible landing craft but no avail and soon began to express interest in variety of different boats. Of all the other boats they had tested and researched, the Higgins' boats became the best choice. When tested during the FLEX 5 by the Navy and Marine Corps, Higgins' Eureka boat surpassed the performance of the Navy-design. Although the drawback was that the equipment had to be unloaded, and men disembarked, over the sides, thus exposing them to enemy fire in a combat situation. They requested that the boat have retractable hinged door at its bow-replacing the machine gun mounts; and it was adopted as the standard personnel landing craft, the Landing Craft Vehicle Personnel (LCVP) by 1940. Thus were two of the major impacts of San Clemente Island on the outcome of WWII, and our nation’s history.

FLEX 6
The Fleet Landing Exercise Number Six commenced from 1940—1941, was the first wartime exercise in amphibious training in 1941. It became paramount that the Navy and Marine Corps was in dire need for amphibious transports larger than destroyers as the 1st Brigade could barely send two thousand Marines to land in the Caribbean and only adequate experiment landing craft were provided. As a partial response to this problem, H.M. Smith seized the newly developed destroyer-transport. During FLEX 6, his plan called for the USS Manley to land Company A, 1st Battalion, 5th Marines via rubber boats at H-minus three hours (prior to dawn) at a point away from the primary assault beach. This force would advance inland, seize key terrain dominating the proposed beachhead, and thus protect the main landing from counterattack. They were the first unit to use the revamped Manley. It used rubber boats to execute its 23 February 1940 assault landing against Culebra. In 1940, patrols were successfully infiltrating ashore and reporting information and became an accepted doctrine in amphibious reconnaissance.

FLEX 7
A year later, during Fleet landing Exercice Number 7, Smith had three destroyer-transports. He designated the three companies of the 7th Marines embarked on these ships as the Mobile Landing Group. During the exercise these units again made night landings to protect the main assault, or conducted diversionary attacks.

The First Marine Division was one of the first two division-sized unit ever formed by the Corps. It was established in February 1941 aboard the USS Texas in Cuba around the nucleus of the pre-war First Marine Brigade. The Division's first commander was the amphibious warrior, BrigGen Holland M. Smith. There was no record of an activation ceremony since the division was deep in the preparations for FLEX 7, the last of the pre-war fleet landing exercises.