Landing Craft, Tank (LCT)
The LCT was the largest of all U.S. shipborne amphibious warfare craft and the smallest U.S. landing craft to receive numbers in their own right. LCTs were the result of a November 1941 British request for a U.S. version of a tank lighter for a projected European invasion. The first LCT was completed on June 29, 1942; the last wartime-built LCT was finished on December 22, 1944. In all, five hundred LCTs, Mark 5 models were built, along with 965 Mark 6 LCTs.
When early in June 1940 Mr. Churchill first urged his plans for Commando raids on enemy-held territories, he also foresaw that the raiding parties would have to be carried by special craft, lightly armoured and capable of landing on beaches. Churchill traced the suggestion to the bullet-proof lighters and tank-landing lighters which he suggested in 1917 as part of a proposal for an amphibious operation against Borkum and Sylt [The Second World War, Vol. II, pp. 215-17].
The initiative in development of large landing craft was left to the British who, for obvious reasons, were much more seriously impressed with the need for such craft. British experimentation with specialized landing craft began after World War I as a result of the invention of the tank. Whereas experience had seemed to show that personnel could be landed on hostile shores by the regular vessels of the fleet, the tank clearly could be beached only from a special ramp boat. In 1920 the British produced a tank lighter which, with very few changes, became the LCM(l) (Landing Craft, Mechanized). The Inter-Service Training and Development Centre (I.S.T.D.C.) was experimenting with light assault boats in 1938 and 1939.
In June 1940 Prime Minister Churchill personally ordered the design and production of the first landing craft capable of carrying expeditionary forces. Worked out by the Combined Operations staff within the British Admiralty, this became the LCT (Landing Craft, Tank), designed to carry three 40-ton tanks and disembark them in three and a half feet of water on steep-gradient beaches such as those of Scandinavia. Churchill's request brought forth the earlier version of the tank landing craft (LCT) of 226 tons light displacement.
Twenty of these craft were ordered in July 1940 and a further ten in October 1940. The first LCT was delivered in November 1940. Subsequent development of the LCT was comparatively rapid. In December 1941 orders were placed for the fourth model, LCT (4), the first landing craft designed specifically for the shallow- gradient beaches of the French coast. It was to be able to carry six medium tanks and to be capable of rapid mass production. While the LCT-the basic vehicle-carrying landing craft of World War II-was being perfected, the British also began experimenting with a much larger ocean-going ship capable of discharging vehicles directly across the beach - the LST (Landing Ship, Tank).
The most important practical experience came from the Dieppe raid in August 1942. The raid carried out under joint British and Canadian command and largely with Canadian troops-about one thousand British troops and fifty US Rangers also took part-was originated in Mountbatten's Combined Operations headquarters in order to test amphibious tactics and techniques in a large-scale operation. The most ambitious attack on the French coast up to that time had been the raid on St. Nazaire in March 1942. But St. Nazaire was still only a hit-and-run commando foray. Dieppe was planned as a miniature invasion, involving the full use of combined arms and mass landings of infantry and armor with the object of seizing a beachhead. Except that there was no intention of holding the beachhead, Dieppe was drawn as closely as possible to the pattern of a full-scale amphibious attack.
Specifically it was designed to test the newly developed LCT in landing tanks across the beaches and to find out whether it would be possible to take a port by direct frontal assault. It would also test naval organization in managing a considerable landing fleet (253 ships and craft), and air organization in gaining air supremacy over the landing area and providing support for the ground troops.
The LCT (Landing Craft, Tank) was a welded steel light but extremely rugged vessel designed for direct 'on-the-beach' loading and unloading. Equipped with a bow ramp, the bottom is especially designed for 'beaching' - docking facilities are not required. These standardized craft were 117.5 feet long overall, with a beam of 32 feet, and a light draft of 1.5 feet forward. The loaded draft was 3.75 feet forward. LCTs displaced 134 tons light and 286 tons loaded and could carry 150 tons of cargo; this could be four medium or three heavy tanks.
When the United States entered the war in December 1941, the U.S. Navy had no amphibious vessels at all, and found itself obliged to consider British designs already in existence. One of these, advanced by K.C. Barnaby of Thornycroft, was for a double-ended LCT to work with landing ships. The Bureau of Ships quickly set about drawing up plans for landing craft based on Barnaby's suggestions, although with only one ramp. The result, in early 1942, was the LCT Mark 5, a 117-foot craft with a beam of 32 feet that could accommodate five 30-ton or four 40-ton tanks or 150 tons of cargo. With a crew of twelve men and one officer, this 286 ton landing craft had the merit of being able to be shipped to combat areas in three separate water-tight sections aboard a cargo ship or carried pre-assembled on the flat deck of an LST. 470 Mk.5s were built. The Mark 6 version was an improved design that permitted stern loading and had increased living accommodations. One purpose of the Mark 6 modification was to serve as links in floating causeways between LSTs (Landing Ships, Tank) and the shore. They had a detachable stern plate, "with a lip beneath it for the LST ramp to engage;...the superstructure was split in half to permit vehicles to run the entire length of the craft." LCTs were propelled by three screws, each driven by a single 225 HP Gray Marine diesel engine that developed a maximum speed of 9 knots. The fuel capacity was 11.12 tons in addition to 140 gallons of lube oil. These craft were usually armed with two single 20mm antiaircraft guns. According to a wartime manual, the LCT was often seen "transported on LSTs or in sections on APAs and AKAs. They are the largest of the U.S. open-deck, bow-ramp types."
"To the layman, the LCT-landing craft, tank-looks like a tin shed with a false front, traveling upside down and backwards through the water. The major difficulty of the LCT as a water-going vehicle is that is has no sense. Instead of trying to ride the waves, it tries to club them to death. Another difficulty is the skippers of these crafts. They are all male Tugboat Annies, ninety-day wonders, graduated as Ensigns, truculent, fretful, quarrelsome, eager and more friendly than anything else on two legs that I have found. They bow before nothing. An LCT in the South Pacific that cut across the bow of one of our mightiest battleships did not give way. Instead, the skipper grabbed up a megaphone and shouted in the direction of the Admiral on the bridge, `Can't you see where the hell you're going with that damn thing?' In general, an LCT is something only a mother can love, and their skippers love `em. . . . They have bestowed on them fond names, the regular Navy's names for them are not so tender. They call them water mules or spitkits, seagoing jalopies, sea jeeps, or just plain four-letter words." [Ira Wolfert The Saturday Evening Post (January 8, l944)]
The new landing craft were flat bottomed, which allowed them to get close enough to the shore to put men and equipment into shallow water. The landing ship, tank (LST) could carry 1,900 tons or 20 medium tanks and used the landing craft, tank (LCT) as a lighter.
Operation "Husky" -- the invasion of Sicily in July 1943 -- involved 1400 ships and over 1800 landing craft to support or disembark nearly one-half million men. In the initial assault, nearly eight reinforced divisions were to come ashore abreast on a broad front nearly 150 miles wide. The secondary landings in Sicily by larger amphibious craft were difficult due to the nature of the beaches. The coast had many sandbars just off the shore called "false beaches." The LSTs were too deep-drafted to pass over some of these bars. The LSTs brought pontoons along that were strung from the false beaches to the shore. The LSTs unloaded at the outer ends of these man-made causeways. The 112 foot Landing Craft, Tank (LCT), however, could get over the bars. The lack of a sufficient number of pontoons forced the LCTs to bring material to the beaches. Some were secured athwartship to the LSTs to allow tanks and vehicles to drive onto them whereby they drove into a second LCT to be transported to the beaches.
The Anzio landing of VI Corps as originally conceived was to be the prelude to a short-term operation that would lead to a quick junction with an advancing main Fifth Army. When that advance failed to materialize, the initial plans for supplying the beachhead had to be radically revised and expanded. Supplies were brought in by preloaded trucks on LST's, by LCT's, and on Liberty ships. Beginning on 28 January 1944, a convoy of six LST's was dispatched daily from Naples, each vessel carrying fifty preloaded trucks. Each convoy brought in a 1,500-ton load, 60 percent of which was ammunition, 20 percent fuel, and 20 percent rations, Fifteen LCT's also made a weekly turnaround from Naples with supplies. Every ten days four Liberty ships, loaded with supplies at Naples or at North African ports, were scheduled to arrive at the beachhead. The LST's and LCT's could dock in Anzio harbor, while the Liberty ships had to be unloaded off shore and their cargo brought into the harbor or over the beaches by LCT's or (in calm weather) directly by DUKW's.
A shortage at Anzio of LCT's, needed to unload Liberty ships, developed at the beginning of February 1944. Most of these craft had been in service for more than a year without overhaul and they frequently broke down. On 6 February only fifteen were available, a number that was increased to twenty-two by 12 February. As a stop-gap, from ten to twenty LCI's were successfully employed in unloading supplies. An effort was made to persuade the Liberty ships to come in closer to shore so that they could be unloaded directly by DUKW's, but ship captains were reluctant to do so in the face of heavy shelling. Between 450 and 490 DUKW's were in use at Anzio. The craft situation greatly eased at the end of February, when sufficient LCT's again became available.
Of the 653 LCT's which the Washington Conference of May 1943 allotted to OVERLORD and which General Morgan from the outset complained constituted a bare and dangerous minimum for the task, 44 had been taken by the British Navy for net protection duties at Scapa Flow. It was possible, though not certain, that some might be released in time to take part in OVERLORD. Still more serious, a large number of LCT's had to be converted into close-support craft for the assault because the Combined Chiefs had made almost no provision for such craft.
By August 1943 about one-quarter of the 648 LCT's planned for the assault lift were, for various reasons, no longer available. In addition to the 44 already noted which were being used at Scapa Flow, 36 were to be converted to LCT(R)'s (rocket-carrying craft), 48 would be armored to carry direct-support high-explosive weapons, and 36 would probably be needed for close support of the U.S. assault division. The latter estimate, in reality, was very low. General Devers, ETOUSA commanding general, subsequently calculated that the American assault division would require 56 support craft of the types that used LCT hulls or the equivalent. The net deficit Navy planners set at 164 LCT's as well as 7 LCI(L)'s that had been converted into headquarters ships.
The problem of how to make good the deficit in landing craft for a three-division assault had received only a preliminary examination when word came from Quebec that the Prime Minister wanted the assault increased to four divisions. The new calculations of craft needed to permit the landing of two full divisions in the follow-up for use on D plus 1 showed a deficit of 251 LCT's for a three-division assault and 389 for a four-division assault. In addition, for a four-division assault there would be a shortage of more than 150 support craft using LCT or equivalent hulls.
In September 1943 Donald Nelson, chairman of the U.S. War Production Board, went to London and talked to General Morgan and his staff about landing craft requirements. As a result of his conversations he cabled Charles E. Wilson his conviction that LST's and LCT's were the "most important single instrument of war from the point of view of the European Theater," and that the requirements for them had been "grossly understated."
A new contribution to amphibious warfare that was attracting a good deal of attention in 1944 was the DD (duplex-drive) swimming tank. The British had developed a canvas float, or water wing, that would enable a tank to leave its LCT, swim to the beach, and go in firing. It was one of several new devices tested by Maj. Gen. Sir P. Hobart of the British Army and his 79th Armoured Division at their research center on the coast of Suffolk. The British called these contraptions "Hobo's funnies."
Darkness over the English Channel on the night of 5 June 1944 concealed five thousand ships, spread over twenty miles of sea, plowing the choppy waters toward Normandy. Force "O" would carry the assault against Omaha Beach. The magnitude and complexity of the movement may be suggested by figures. To lift and land this initial assault force of 34,000 men and 3,300 vehicles required 7 transports, 8 LSI's, 24 LST's, 33 LCI(L)'s, 36 LCM(3)'s, 147 LCT's, and 33 other craft. LCTs carried the duplex-drive amphibious Sherman tanks that would play a vital part in the first moments of the invasion. The spearhead of the assault on OMAHA, the tanks were to enter the water 6,000 yards offshore, swim to the waterline at Dog White and Dog Green, and engage the heavier German emplacements on the beaches five minutes ahead of the first wave of infantry.
For the first troops in, OMAHA was "an epic human tragedy which in the early hours bordered on total disaster." The 741st Tank Battalion launched twenty-nine of its thirty-two duplex-drive tanks offshore and immediately lost twenty-seven when they foundered or plunged directly to the bottom of the Channel upon leaving their LCTs. Two swam ashore, and the remaining three landed from beached LCTs, only to fall prey at the waterline to German gunners.
The tank landing craft of World War II is the predecessor of the LCU. Because of the LCT's versatility and use in landing almost anything, the name was changed to LCU. This highly adaptable craft, like others of the landing craft family, has been adapted for many purposes including salvage operations, ferry boats for vehicles and passengers, and underwater test platforms. During World War II, Pacific Fleet Landing Craft Utility (LCU) operated as commissioned Landing Craft Tank (LCT) under local flotilla commanders. The LCT had an Ensign or Lieutenant Junior Grade as Commanding Officer, and either operated independently or were transported aboard larger ships. Upon reaching their operating areas, they would form up with other units for assault landings or other operations in support of the war effort. At the end of the war, most of the several hundred LCU in service were decommissioned and mothballed.
LCT-1114 was a late-model Mark 6 unit. The vessel was one of ten LCTs requisitioned for Operation Crossroads and placed in the target array. LCT-1114 capsized as a result of the Baker test detonation and the resulting wave of water. After the blast, it was observed floating bottom up, bow ramp secured, with the "stern awash and the bow four feet out of the water" next to ARDC-13.  LCT-1114 remained afloat for four days, gradually drifting in a westerly direction "until it was finally sunk off Amen Island with a demolition charge to prevent it from becoming a menace to navigation."
Similarly, the other LCTs were sunk in the days after the Baker test as hazards to navigation. A total of 18 vessels were beached off Bikini Island during the Baker test; among them were six LCTs: the Mark 5 LCT-412, and five Mark 6 LCTs--Nos. 812, 1175, 1187, and 1237, which were beached between the high and low tide mark on the lagoon side of the island. LCT-1187 and LCT-1237 "suffered major flooding as a result of apparent bottom damage due to pounding against coral ledges and working in the surf."  They were also displaced by wave action. LCT-812 suffered major damage, with its bow ramp torn free and missing after the test; both it and LCT-412 became waterborne "as a direct result of the waves which immediately followed the test...."
Post-Baker inspection of LCT-1187 found that the tanks from about midships aft were completely flooded. The manhole cover plate to the void below the forward starboard wing tank deckhouse was not secured in place. This void was flooded. The galley was flooded to a depth of two feet from water coming in over the stern.... This craft was slightly above radiological tolerance when boarded on 1 August 1946.
After the Baker detonation, LCT-1237 was displaced about 20 feet along the beach and swung around parallel to the water's edge. This craft was leaking badly before the test and by Baker day the engine room were completely flooded. The tanks just forward of the crew's quarters was completely flooded. The tanks just aft of the forward stowage compartments contained about one foot of water. The after end of the galley contained 1-1/2 feet of water. The sounding hole covers were missing from the flooded tanks. Indications are that much of the tank flooding was due to waves washing over the vehicle deck, but leaky propeller shaft glands probably caused flooding of the engine space.
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