Chapter 3: Development of Landing Craft
IntroductionThe amphibious warfare doctrine laboriously developed by Marines between the two World Wars could never have been successfully executed without special equipment to transport the assaulting troops and their supplies from ship to shore and to land them on an enemy-defended beach.
No one was more aware of the need for such equipment than the Marines. Shortly after the end of World War I they induced the Navy to undertake design studies on two landing craft, one for personnel and one for materiel. Troop Barge A, as the first of these types was called, was tried out at Culebra in the winter of 1923-24. A shallow draft, twin-engined, 50-foot craft with a rated speed of about 12 knots and carrying capacity of 110 fully equipped Marines, it had good beaching qualities and could retract from the beach with aid of a stern anchor. Three years later the second type, a 45-foot artillery lighter, was built and tested. Equipped with two parallel hinged ramps in the stern, it could be beached successfully stern-to and 155mm guns and other pieces of heavy Marine equipment unloaded. It lacked a power plant, however, and had to be towed by another craft.1
Another item of equipment tried out in 1924 was the Christie "amphibian tank." Afloat, this unusual machine was driven by twin-screw propellers at a rated speed of seven knots. On shore, as a tractor, it could make 15 mph; or, where good roads were available, the de mountable tracks could be removed, and on wheels it could do 35 mph. It functioned well enough on land and in the sheltered waters of rivers. But in the open sea, under conditions that must be realistically anticipated for an assault landing, it proved so unseaworthy that the Marine Corps directed its attention to other types.
The construction of these types of amphibious equipment constituted a beginning, however humble, towards the solution of the problem of transporting troops and equipment from ship to shore. But a shortage of funds made it impossible to follow up these developments until 1935, when appropriations became more plentiful as a result of the naval expansion program begun in the first Roosevelt administration.
Landing BoatsWith the publication of the Tentative Landing Operations Manual in 1934 and the resumption of landing exercises the following year, work on the landing craft
was resumed. Three types of boats for landing operations were contemplated by Marine planners of the mid-thirties. These included fast, small, surf boats to lift the leading waves; standard Navy boats and life boats of merchant vessels for the bulk of troops; and barges and lighters for heavy material.2
Steps to solve the first problem, provision of special troop landing boats, were initiated in 1935. The Marine and Navy officers who tackled the problem that year had to start pretty much from scratch, for Troop Barge A, a promising early development, fell victim to the size and weight restrictions imposed by naval ships in those days. Navy thinking and planning for the development of amphibious equipment was restricted by the types of ships then serving the fleet. Troop transports were practically nonexistent, so it was planned as an emergency measure to lift Marine landing forces in battleships and cruisers. A length of 30 feet, the size of davits on these ships, and a weight of five tons which was the maximum capacity of the davits, were therefore imposed as basic requirements for all new landing craft.
In an effort to explore the suitability of existing commercial craft for landing operations, the Navy, at the request of the Marine Corps, agreed to test as wide a variety of small craft from the yards of private builders as the limited funds available would permit. Bids were advertised, and nine replies were received, four of which met with the approval of the Marine Corps Equipment Board and were accepted.3
Tests of these approved types were conducted at Cape May, New Jersey, in the summer of 1936. But the experiments fell short of the original intention, "to test as wide a variety of forms as was practicable," because Andrew Higgins, a New Orleans boat builder with a promising design, declined to submit a bid. In 1926 Higgins had designed a special shallow draft craft called the Eureka for the use of trappers and oil drillers along the lower Mississippi and Gulf coast. It had a tunnel stern to protect the propeller and a special type of bow, called by Higgins a "spoonbill," which enabled it to run well up on low banks and beaches and retract easily. In 1934 the inventor had visited Quantico to interest Marines in his boat, and the Navy was now particularly anxious to test it with other comparable types of small craft.4
The four boats which showed up at Cape May for the test were of two general types. The sea skiff, a boat employed by Atlantic coast fishermen, was represented by the Bay Head, Red Bank, and Freeport boats. This type appeared in theory to offer a solution to the landing craft problem, as it was normally launched and landed through the heavy surf of the Atlantic beaches in fishery work. The other boat, a sea sled built by the Greenport Basin and Construction Company, was a high speed craft not normally employed in surf nor landed on beaches. The test board, comprising representatives of the Navy general line, Bureau of Construction and Repair, Bureau of Engineering, the Coast Guard, and the Marine Corps, reported that none of the boats were wholly satisfactory. They eliminated the sea sled entirely
EXPERIMENTAL AMPHIBIAN TRACTOR developed for the Marine Corps in 1924 began the long line of test vehicles that culminated in the LVT. (USMC 13562)
AN EARLY VERSION OF THE LANDING CRAFT USED in World War II which resulted from joint Navy-Marine Corps experiments in the 1920's and 30's. (USMC 515227)
and recommended that the three remaining craft be modified and sent to the Fleet for further tests.5
These tests took place at Culebra during Flex 4 in the winter of 1938. Though superior in speed and beaching ability to standard Navy boats, the modified fishing craft still had serious drawbacks. Owing to their exposed rudders and propellers
they tended to dig in when retracting. They were so high forward that Marines debarking had to drop 10 feet from the bow to the beach. They were, moreover, all unsuitable for lowering and hoisting.6
In the light of the drawbacks revealed by tests, the Bureau of Construction and Repair undertook the construction of a boat embodying all the best features of the fishing craft.7 This was the beginning of a long and unsuccessful effort by the Bureau to develop a satisfactory landing craft. The "Bureau Boat" in various forms showed up regularly at Fleet Landing Exercises from 1939 through 1941, but efforts to get the "bugs" out of its design were abandoned in 1940.
Experiments with standard Navy ships' boats proceeded simultaneously with the development of special types. From the first they proved unsatisfactory. After five of them foundered in a four-foot surf at San Clemente during Flex 3, efforts to adapt standard Navy boats for beach landings were abandoned. The fact was that, having been designed for other purposes, none of them were suitable for beaching operations. As the Commanding Officer of the 5th Marines concluded: "Navy standard boats are totally unsuited for landing troops of the leading waves, even under moderate surf conditions. They are in no sense tactical vehicles, lacking in speed and maneuverability and are extremely difficult to handle in surf. They do not permit the rapid debarkation of troops at the water's edge."8
By 1938 a beginning had been made towards the solution of the landing craft problem. As a result of the early experiments the Marines had proved to their own satisfaction what they had suspected all along--that none of the standard Navy boats could be adapted satisfactorily for the landing through surf of troops or heavy equipment. Nor were the experimental models based on commercial craft, though superior to Navy boats, a satisfactory means for landing of assault waves on a defended beach. These results, though negative in character, at least cleared the way for concentrating development on specially designed landing craft.
The fruitful line of development came into view with the re-entrance of Andrew Higgins into the picture. In October 1936, about a year after declining to bid on the experimental landing boat contract, Higgins had written the Navy offering his Eureka as a troop landing craft. As funds for the purchase of experimental boats had been exhausted, the Navy was unable to purchase the Higgins craft at that time.9
A year later Commander Ralph S. McDowell, who was responsible for landing craft development in the Bureau of Construction and Repair, learned of the Eureka boat. He wrote Higgins inviting him to visit the Navy Department and discuss this boat if he ever came to Washington. Higgins and his naval architect
caught the first train for Washington. They spent about a week in McDowell's office working out a conversion of the standard Eureka into a landing craft. As funds for the purchase of experimental boats had been exhausted, the Navy Department at first refused to purchase the Higgins craft. But after the inventor offered to build a boat for less than cost, the Department relented, found the necessary funds, and gave Higgins a contract for one boat. Higgins delivered it to Norfolk in 30 days.10
The Eureka was tested in surf at Hampton Roads in the spring of 193811 and made its first maneuver appearance at Flex 5 in 1939 where it competed against several Bureau boats and the by now venerable fishing craft. Marines were enthusiastic about its performance. "The Higgins boat gave the best performance under all conditions. It has more speed, more maneuverability, handles easier, and lands troops higher on the beach," reported the commanding officer of the 1st Battalion, 5th Marines. "It also has greater power in backing off the beach; not once was the boat observed having difficulty in retracting."12
Lieutenant Commander R.B. Daggett, the representative of the Bureau of Construction and Repair at Flex 5, did not share the Marines' enthusiasm for the Higgins Eureka. "The Higgins ... boat is too heavy. ... The speed is too slow. ... All the Higgins boats have 250 horsepower with accompanying excessive gasoline consumption for the speed obtained."13 he reported to his bureau.
Daggett's preference was for a modified Bureau boat built by the Welin Company. The other Bureau types and the fishing boats he found unsatisfactory, and as the Marine Corps and the Bureau were in agreement, on this point at least, these craft were discarded.
Neither the Marine Corps nor the Bureau of Construction and Repair was to have the last word at Flex 5. The Commander Atlantic Squadron, as represented by his Landing Boat Development Board, recommended further tests for the Bureau and Eureka craft. Accordingly at Flex 6 the following hear the drama was reenacted. Again the Marines declared the Eureka to the "the best so far designed." The Atlantic Squadron, shifting slightly from dead center, decided that the Higgins "was the best all-around boat for the purpose intended ... [but] the Bureau was almost as good."14
By 1940 money for naval purposes was beginning to be more plentiful, and the Navy was now willing to purchase landing
craft in quantity. But in view of the fact that the Fleet was unable to make a clear-cut recommendation for either the Bureau or Higgins types, the Navy let contracts for the first 64 landing craft on a fifty-fifty basis.15
The question was finally settled in September 1940. The Navy was now converting large merchant ships for use as troop transports. These ships were equipped with davits capable of handling 36-foot boats, and as the Eureka of 36-foot length had twice the capacity of the 30-footer then in service and could make the same speed without an increase in horsepower, the Navy decided to adopt the larger as standard.16
After five years of work the Marines finally had the landing craft they wanted. The one feature that kept the Higgins boat from fulfilling the ideal that they had built up in their minds was the difficulty of emptying it on the beach: all troops, equipment, and supplies had to be unloaded over the fairly high sides. During a visit to Quantico in April 1941, Higgins was shown a picture of a Japanese landing craft with a ramp in the bow by Major Ernest E. Linsert. Higgins became enthusiastic about the idea and returned to New Orleans determined to examine the possibility of installing a ramp in the bow of his 36-foot Eureka. Linsert, who was serving as Secretary, Marine Corps Equipment Board, recommended to the President of the Board, Brigadier General Emile P. Moses, that the Marine Corps procure a ramp-bow 36-foot Eureka. Upon receiving the approval of Marine Corps Headquarters, Moses and Linsert went to New Orleans to assist Higgins, who had agreed to make a prototype, converting a standard 36-foot Eureka into a ramp-bow boat at his own expense.
On 21 May, informal tests were conducted on Lake Pontchartrain. The new craft proved to be seaworthy. She beached and retracted with ease, and while on the beach the ramp was lowered and personnel and a light truck were debarked and reembarked. On the recommendation of the Navy Department Continuing Board for the Development of Landing Boats,17 a special board of Marine Corps and Bureau of Ships officers was appointed to conduct official acceptance tests. With General Moses as senior member the board carried out the tests during the first week in June. The ramp-bow craft passed with flying colors.18
Thus was born the precursor of the LCVP (landing craft vehicle, personnel), the craft which, in the opinion of General H.M. Smith, "... did more to win the war in the Pacific than any other single piece of equipment."19
Lighters and BargesThe design of a successful tank lighter proved a longer and more difficult process than did the development of the personnel landing craft. The old 45-foot artillery lighter, developed in 1927, was considered to have a limited usefulness for landing heavy equipment in the later stages of an operation, but the Marine Corps hoped to obtain a lighter, self-propelled craft particularly suited to landing tanks during the early stages.20
As a stop-gap measure, Marines at Quantico came up with a device to adapt the standard Navy 50-foot motor launch for landing light vehicles and artillery. "Boat Rig A," this contraption was called. It consisted of a platform fitted within the hull of the boat, together with a portable ramp by means of which the vehicle could go ashore over the bow when the craft beached. The ramp was carried into the beach broken down, where it was assembled and hitched up for debarkation. This completed, it would be disengaged and left on the beach to accommodate the next boat coming in. The ramp could be assembled and made ready for use by eight men in about 10 minutes. on subsequent trips, it took about four minutes to connect the ramp to the boat. Under ideal conditions vehicles up to five tons in weight could be landed from a 50-foot motor launch using Boat Rig A. In calm water Boat Rig A worked fairly well, but when it was tried out at Culebra in 1935, it proved so top heavy that it nearly capsized in a moderate swell. The experiment was accordingly written off.21
With the failure of Boat Rig A, the Marine Corps turned its attention to developing a self-propelled lighter designed specifically for landing tanks and heavy equipment through the surf. In December 1935 the Commandant requested the Bureau of Construction and Repair to design such a craft. It was to be capable of landing the 9,500-pound Marmon-Herrington tank which the Marine Corps was then considering. negotiations dragged on for more than a year, until in April both the Marine Corps and the Bureau had agreed upon a design. A 38-foot craft, it made its first appearance at a fleet landing exercise in 1938.22 The Marines reported it to be "a distinct improvement over previous experimental designs. It is self-propelled, has sufficient speed, and is sound and practicable in construction. It is equally adaptable for landing artillery and is an efficient cargo carrier."23
A 40-footer, built at the Norfolk Navy Yard in the autumn of 1938, showed up at Culebra the following winter for Flex 5. It was used successfully in transporting ashore tanks and trucks of the types then standard in the Marine Corps. Under the conditions encountered at Culebra in 1939, both the 38- and 40-foot lighters were judged to be "... good sea boats, handle well, have sufficient power and speed, and are capable of retracting themselves from the beach by use of their stern anchors. ... Both types ... proved suitable for landing tanks and motor vehicles. The new
lighter proved superior to the old in respect to ease and safety of loading in a seaway as well as cargo-carrying capacity."24
All tank lighter experiments conducted up to the end of Flex 5 had been built around the Marmon-Herrington tank. This vehicle, adopted by the Marine Corps in 1935, had been designed to fit within the weight limitations imposed by the Navy for amphibious equipment. Lightness was just about the only virtue possessed by this tank. By 1939 the Marine Corps had given up on it and was testing the Army light tank for its suitability in amphibious operations. As the Army tank weighed about 15 tons, it could not be carried in any of the tank lighters then in existence. The Navy accordingly produced a new model 45-feet in length, capable of carrying one Army and two Marmon-Herrington tanks.25
One of the new 45-footers was completed in time for a trial at Culebra during the winter of 1940 in Flex 6. The tests lacked somewhat in realism, however, because none of the Army-type tanks were available. The new lighter performed adequately as a carrier of the Marmon-Herrington tank, for other vehicles, and miscellaneous heavy equipment. At the end of Flex 6, General Smith recommended to the Commandant that "... 20 of the 45-foot lighters be constructed, at the earliest practicable date, for use by the Atlantic Squadron in landing operations."26
In the fall of 1940 the Navy contracted for the construction of 96 45-foot tank lighters. After the contract had been awarded, doubt arouse as to the seaworthiness of the basic design. During a landing exercise in the Caribbean, one of the 45-footers capsized and sank when the Army-type tank it was carrying shifted to one side in a moderate sea.27
In the spring of 1941 the Marine Corps found itself in urgent need of all the lighters it could lay its hands on for use in a proposed amphibious landing in the Azores.28 None of the 96 lighters ordered by the Navy had been delivered, and not more than eight or ten were expected in time for the operation. Therefore, on 27 May 1941 the Navy Department Continuing Board for the Development of Landing Boats recommended that Higgins be given an opportunity to convert one of his 45-foot Eureka boats into a tank lighter by installing a ramp in the bow. If this craft met service tests he would be awarded a contract for 50 tank lighters. The Secretary of the Navy gave his approval on 29 May, and Higgins received this order by telephone the next day.29
Higgins rushed through the conversion, completing it in time for testing and acceptance during the first week in June by the same board of Marine Corps and Bureau
of Ships officers who had come to New Orleans to test the 36-foot ramp-bow Eureka. At the New River exercises that summer the Higgins tank lighters proved to be of excellent basic design. "They were found to be fast, subject to ready control and etraction, relatively light, and equipped with a reliable power plant," reported General Smith.30 They also proved to be too hastily constructed. The ramps were so weak that several collapsed, and the sill was too high for efficient handling of vehicles. Higgins, who was present, was confident that he could correct the deficiencies.31
ARMY LIGHT TANK is unloaded from its landing craft during joint Army-Marine amphibious exercises at New River, N.C. in August 1941. (SC 125129)
Before the reports of the New River exercises had been received by the Navy Department, a contract had been let for 131 additional tank lighters. These were of a 47-foot Bureau design, a prototype of which had never been built. As a result of the good showing of the Higgins tank lighter at New River, this contract was later reduced to ten. Higgins was the low bidder, and built one craft to Bureau specifications, although he was convinced that the design was unseaworthy. His fears proved to be well founded when the tests were carried out. By this time, however, the tank lighter program had again changed direction.32
On October 1941, the Auxiliary Vessels Board of the Navy had reported that there was no lighter capable of landing the newly developed Army 30-ton medium tank. The Secretary of the Navy directed the Bureau of Ships to remedy this deficiency. Accordingly, in December existing tank lighter contracts were changed to provide 50-footers in lieu of the 45-foot Higgins and 47-foot Bureau types still to be built. Both Higgins and the Bureau produced designs of 50-foot craft. Before any deliveries could be made, President Roosevelt, at a White House Conference on 4 April 1942, directed the procurement of 600 additional 50-foot tank lighters by 1 September for the North African operation. The Bureau of Ships, to meet this commitment, ordered 1,100 of it own design.33
Since this order was earmarked for service in a projected Army operation, the Army showed keen interest in a test of the two types held near Norfolk on 25 April 1942. Each carried a 30-ton tank, elaborately lashed down in the Bureau lighter, merely blocked in place in the Higgins. Wind velocity ran 18 to 23 miles per hour, with wave heights estimated between 1 1/2 and 2 feet. Both lighters showed a speed of 10 miles an hour over a measured 1 1/2-mile course. What happened after that is described by the Army observer who made the trip in the Higgins type:As we neared the [antisubmarine] net it became apparent that the Navy Bureau-type tank lighter was in trouble. She appeared to have a tendency to dive when headed into the seas and was taking considerable water aboard. She stopped several times and members of the crew could be seen manning hand pumps and attempting to better secure the tank in the lighter. Once when under way and making a wide turn, it appeared that the lighter was going to overturn. Some of the crew was seen straddling the higher bulwark and the coxswain had left the pilot house and was steering the vessel from the rail.
While this was going on, our [Higgins] lighter was standing by, as was a picket boat and two
Higgins 30-foot boats. None of these vessels was experiencing and difficulty. The Higgins tank lighter was maneuvering around in sharp turns into the sea, through the wave troughs.
We then [after Bureau lighter turned back] opened the engines up to 1,900 r.p.m. and proceeded past Little Creek to Fort Storey. The lighter took no water except a little spray. Performance was excellent in all respects. The lighter was beached in the surf and the tank ran off onto the beach despite poor handling by the coxswain who finally allowed the lighter to broach to. In spite of this the vessel had such power and retraction qualities [as] to get back into deep water.
As far as comparison of characteristics of the types of tank lighters are concerned, it may be stated that in the May 25 test there was no comparison. ..."34
As a result of these tests, the Bureau hastily notified all yards to shift to the Higgins type. Thus the Higgins 50-footer became the standard tank lighter of the Navy, the prototype of the LCM (Landing Craft, Mechanized) as the Marines knew it in World War II, and as they know it today in enlarged form.
Amphibious VehiclesAnother vehicle which was to play a vital role in the amphibious operations of World War II was the amphibian tractor (amtrack, LVT). It was built in 1935 by Donald Roebling, a wealthy young inventor living in Clearwater, Florida. The "Alligator," as Roebling called his creation, was a track-laying vehicle which derived its propulsion afloat from flanges fixed to he tracks, essentially the principle of early paddle-wheel steamships. Originally intended as a vehicle of mercy, for rescue work in the Everglades, the "Alligator" was destined for fame as an instrument of war.
The Marine Corps first took notice of the "Alligator" in 1937, when Rear Admiral Edward C. Kalbfus, Commander, Battleships, Battle Force, U.S. Fleet, showed major General Louis McCarthy Little, then commanding the Fleet Marine Force, a picture of the strange vehicle appearing in Life magazine. General Little was quick to grasp its potentialities and sent the picture and accompanying article to the Commandant. He, in turn, passed it along to the Equipment Board at Quantico.35 The Marine Corps had not forgotten the old Christie amphibian, of such bright promise and disappointing performance. Here appeared to be a possible answer. The Board dispatched its secretary, then Major John Kaluf, to Florida to see the vehicle perform and to consult with Mr. Roebling. Kaluf was favorably impressed, and on this basis the Equipment Board reported to the Commandant that "... subject boat has possibilities for use in landing troops and supplies at points not accessible to other types of small boats." In May 1938 the Commandant cited this opinion in recommending to the Navy that "... steps be taken to procure a pilot model of this type of amphibious boat for further tests under service conditions and during Fleet Landing Exercise No. 5."36
Both the Navy Board and the Bureau of Construction and Repair endorsed the recommendation unfavorably on the grounds of economy. The boat development
program was at last well under way, and it seemed unwise to divert any of the limited appropriations to a purely experimental project. CNO concurred in the recommendation of the Board.37
Marine interest in the amphibian tractor persisted, however, and in October 1939, General Moses visited Roebling at his shop in Clearwater, Florida, He inspected the latest model tractor, and persuaded Roebling to design a model including desired military characteristics.38
In January 1940, Roebling had completed the new design. An appropriation was secured from the Bureau of Ships, and work started on the first military model of an amphibian tractor. In November the completed machine was delivered at Quantico where it was demonstrated for the Commandant and a large party of high ranking officers of the Army and Navy.39 It measured up in every respect save one. Its aluminum construction was not considered rugged enough for hard military use. Still the tractor was so impressive in every other respect that the Navy contracted with Roebling for 200 of the machines constructed of steel. As Roebling did not have the facilities for mass manufacture, he subcontracted the actual construction to the Food Machinery Corporation which had a plant in nearby Dunedin. The first vehicle, now designated LVT(1) (Landing Vehicle Tracked), came off the assembly line in July 1941.40
Quantity procurement of LVT(1) did not halt further development of amphibian tractors. By October 1941, the prototype of LVT(2) had put in an appearance, but volume production of the new model was delayed by the entry of the United States into the war. To achieve maximum output, the design of LVT(1) was "frozen" shortly after Pearl Harbor and the vehicle put into mass production.41
The early LVT(1) was unarmed, though capable of mounting machine guns. The Marines, now that they had made a start, wanted something more: an armored, turreted model capable of mounting at least a 37mm gun and serving as the equivalent of a seagoing tank in landing operation. At Clearwater in January 1940, Roebling sketched a turreted version of the LVT, the plans for which Major Linsert, Secretary of the Equipment Board, later completed.42
Nothing more was done about the armored LVT until June 1941, when the Commandant recommended that such a vehicle be developed, using the existing LVT as a basis. The new vehicle should be "... capable of sustained point-blank combat against shore-based weapons. ... It should be able to approach a defended beach from the sea, land, over-run enemy weapons, destroy them, and continue operations ashore to support our ground troops."43 Armor protection against .50 caliber machine-gun fire and an armament
including a 37mm antitank gun and three .30 caliber machine guns would be required to accomplish this mission. The Chief of Naval operations approved the project and directed the Bureau of Ships to perfect a design.
Bureau engineers began development in cooperation with Roebling and the engineers of the Food Machinery Corporation. But theirs was not to be the first armored LVT completed. Working independently and at its own expense, the Borg-Warner Corporation produced model "A," the first turreted amphibian tractor. Design work on the Roebling-Food Machinery model, LVT(A)(1) was not completed until December 1941, and the prototype did not emerge from the Food Machinery plant until June 1942. It was an LVT(2) hull mounting a 37mm gun in a standard light tank turret. It was quickly put in production, and the first vehicle rolled off the assembly line in August 1943.44
The craft described here were, of course, only a few of the wide variety of boats and beaching ships that performed yeoman service in all theaters during World War II. These ranged in size from the big lumbering LST (Landing Ship, Tank, or "Large, Slow Target"), originated by the British, to the Army-developed DUKW, an amphibious truck propeller-driven afloat. But Marines played no notable part in the development of any of these, and none had appeared during the period covered by this volume. They will be described in subsequent volumes as they came to play their part in the tactical picture of Marine operations.
Table of Contents ** Previous Chapter (2) * Next Chapter (4)
 LtGen K.E. Rockey ltr to ACofS, G-3, 21Jun57; 2dLt W.B. Trundle rept on experiments with Beetle Boat to CG, MarCorExpedFor, 3Mar24; Senior Member, BoatCom ltr to Pres, MCEB, 21Jul36, both in War Plans Sec HQMC files, folder "Landing Boats and Barges, 1924-1939," hereinafter cited as War Plans Files, 1924-1939.
 CMC to Chief BuC&R, 24Nov36, 2d endorsement to CominCh ltr to CNO, 14Oct36, War Plans Files, 1924-39.
 Asst Chief BuC&R ltr to Higgins Industries, 21Oct35, S82-3 (15) BuShips files.
 CMC to Chief BuC&R, 24Nov36, 2d endorsement to Cominch ltr to CNO, 14Oct36, War Plans Files, 1924-39.
 CG 1st MarBrig Flex 4 Rept, 12mar38; BriGen V.H. Krulak ltr to Head HistBr, G-3, HQMC, 1Feb57, w/attached comments.
 CMC to Chief BuC&R, 24Nov36, 2d endorsement to Cominch ltr to CNO, 14Oct36, War Plans Files, 1924-39.
 CO 5th Mar Flex 3 Rept, 26Feb37.
 Asst Chief BuC&R ltr to Higgins Industries, 21Oct36, S82-3 (15) BuShips Files
 Capt Ralph S. McDowell, USN, interview by HistBr, G-3, HQMC, 19Jun57; Asst Chief BuC&R ltr to Higgins Industries, 21OCt36, S82-3 (15) BuShips files.
 LCdr G. H. Bahm ltr to CNO, 7Jun38, S82-3 (15) BuShips files.
 CP 1/5 Flex 5 Rept No 14 to CG 1st MarBrig, 15Mar39.
 LCdr R.B. Daggett memo to Chief BuC&R, 13Feb39, encl to Chief BuC&R ltr to CNO, 16Feb39, War Plans Files, 1924-39.
 Comments & Recommendations of Umpires and Observers, Flex 6, January-March 1940; Experimental Landing Boat Group Officer ltr to ComLantRon, 10Mar40, War Plans Files, 1940-1941.
 DeptContBd for Dev of Landing Boats Rept to CNO, 18May40, and BuShips ltr to Cdt 5th Naval Dist, 8Jun40, both C-882-3(15) BuShips files.
 CNO ltr to Chief BuShips, 23Sep40, 2455-130-60 HQMC files.
 This board had been created by SecNav on 12Jan37 to coordinate landing craft development. It was composed of representatives of the CNO, BuC&R, BuEng, and MarCorps.
 LtCol E.E. Linsert interview by HistBr, HQMC, 3Jun57, hereinafter cited as Linsert interview; BriGen E.P. Moses msg to CMC, w/endorsements, 21May41, 2455-130-60 HQMC files; MajGen E.P. Moses ltr to ACofS, G-3, HQMC, 11Apr57; CNO ltr to CMC et al, 2Jun41, 2455-130-60 HQMC files.
 Gen H.M. Smith, Coral and Brass (New York: Charles Scribner's Sons, 1949), 72.
 CMC to Chief BuC&R, 24Nov36, 2d endorsement to Cominch ltr to CNO, 14Oct36, War Plans Files, 1924-39.
 Marines and Amphibious War, 47; Tentative Landing Operations Manual, 78-80.
 CMC ltr to Chief BuC&R, 19Dec35, 882-3(16) BuShips files; Senior Member, BoatCom ltr to Pres, MCEB, 21Jul36; CNO ltr to Chief BuC&R, 8Jul36; CMC ltr to Chief BuC&R, 17Apr37; Chief BuC&R ltr to Cdr R.H. English, 7Apr37, all in War Plans Files, 1934-39.
 CG 1st MarBrig Flex 4 Rept, 12Mar38.
 CO 1/5 Flex 5 Rept No 14 to CG 1st MarBrig, 15Mar39.
 BuC&R ltr to Cdt Norfolk Navy Yard, 6Jul39, War Plans Files, 1940-41.
 CG 1st MarBrig ltr to CMC, 29Apr40, War Plans Files 1940-41.
 ComLantRon ltr to CNO, 13Dec40, 2455-130-60 HQMC files; Senate Report No 10, Part 16, Additional Report of the Special Committee Investigating the National Defense Program, 78th Congress, 2d Session, hereinafter cited as Senate 10.
 See Part I, Chap 5 of this history.
 CNO ltr to CMC et al, 2Jun41, 2455-130-60 HQMC files; Senate 10, 139; Capt R.B. Daggett, USN, interview by Hist Br, G-3, HQMC, 20May57, hereinafter cited as Daggett Interview.
 CG PhibLant ltr to CinCLant, 9Sep41, FMFLant files.
 CNO ltr to CMC et al, 2Jun41, 2455-130-60 HQMC files; Daggett Interview; Linsert Interview; CinCLant ltr to CNO, 7Oct41, FMFLant files.
 Senate 10, 139-140.
 Ibid., 157.
 Ibid., 163.
 Linsert Interview; LtCol V.J. Croizat, "The Marines' Amphibian," MC Gazette, June 1953, 42-43 (Croizat takes his information from Linsert).
 CMC ltr to Senior Member, NavDept ContBd for Dev of Landing Boats, 18May38, War Plans Files, 1924-39.
 Ibid., and endorsements thereto.
 Pres MCEB ltr to CMC, 29 Aug40, 2455-130-20 HQMC files; Linsert Interview; Croizat, op. cit.
 Linsert Interview; Croizat, op. cit.
 Chief BuShips ltr to Cdt 5th Naval dist., 6Dec40, 2455-130-60 HQMC files; SecNav ContBd for the Dev of Landing Vehicle, Tracked, "History of Landing Vehicle Tracked," 1Dec45, hereinafter cited as LVT Hist.; Daggett Interview.
 LVT Hist.
 Croizat, op. cit.
 CMC ltr to CNO, 27Jun41, and CNO 1st endorsement thereto to Chief BuShips, 15Jul41, 2455-130-20 HQMC files.
 LVT Hist; Croizat, op. cit.