Landing craft tank

The Landing Craft, Tank (or Tank Landing Craft) was an amphibious assault ship for landing tanks on beachheads. They were initially developed by the British Royal Navy and later by the United States Navy during World War II in a series of versions. Initially known as the "Tank Landing Craft" (TLC) by the British, they later adopted the U.S. nomenclature "Landing Craft Tank" (LCT). The United States continued to build LCTs post-war, and used them under different designations in the Korean and Vietnam Wars.

Development
Although the Royal Navy had built and used powered lighters to land horses and men during the ill-fated Gallipoli Campaign of World War I, the invention of the tank meant that a specialized landing craft would be needed. In 1926, the first Motor Landing Craft (MLC1) was built by the Royal Navy. It weighed 16 tons, with a draught of 6 ft, and was capable of about 6 kn. It was later developed into the Landing Craft Mechanised.

However, it was at the insistence of the British Prime Minister Winston Churchill that the LCT was created. In mid-1940, he demanded an amphibious vessel capable of landing at least three 36-ton heavy tanks directly onto a beach, able to sustain itself at sea for at least a week, and inexpensive and easy to build. Admiral Maund, Director of the Inter-Service Training and Development Centre (which had developed the Landing Craft Assault ), gave the job to naval architect Sir Roland Baker, who within three days completed initial drawings for a 152 ft landing craft with a 29 ft beam and a shallow draft. Ship builders Fairfields and John Brown agreed to work out details for the design under the guidance of the Admiralty Experimental Works at Haslar. Tank tests with models soon determined the characteristics of the craft, indicating that it would make 10 kn on engines delivering about 700 hp. Designated the LCT Mark 1, 20 were ordered in July 1940 and a further 10 in October 1940.

Mark 1
The first LCT Mark 1 was launched by Hawthorn Leslie in November 1940. It was an all-welded 372-ton steel-hulled vessel that drew only 3 ft of water at the bow. A 12 ft wide hinged ramp enabled tanks to exit directly onto the beaches, while a second steel door behind the ramp sealed the bow area from the tank deck. On both sides, watertight bulwark coamings contained storage compartments, which added to the buoyancy provided by the double bottom under the tank deck. Within the double bottom were ballast and fuel tanks, which allowed the fore and aft trim to be adjusted for beaching. At the rear was a small bridge, beneath which were two 350 hp Hall-Scott petrol engines, an auxiliary generator, batteries and pumps. The hull tanks contained enough fuel for a range of 900 nmi. Aft of the engine room were quarters for ten crewmen with galley and storage. Behind the bridge was a wardroom for two officers, and mounts for port and starboard 2-pounder pom-pom machine guns. Key to the LCT's operation was the large stern-mounted kedge anchor which was dropped while inbound to the beach. This anchor stopped the LCT from slewing or broaching, and, with its powerful winch, enabled the craft to pull itself off the beach once the cargo was unloaded. The bow ramp was initially raised and lowered by hand cranks, but in later versions a powered winch was installed. In each subsequent model, despite the size differences, the basic arrangement of power ramp, long tank well and aft steering station was retained.

Sea trials soon proved the Mark 1 to be difficult to handle and almost unmanageable in some sea conditions. During its tests on the Tyne, the LCT's shallow draft made steering by the helm alone all but impossible, and a quick response from the engines was essential. Below, the crew compartment was damp and the sound level deafening. The engine spaces were no better, being insufferably hot and cramped. However, despite its many shortcomings, the prototype LCT delivered its promise of putting tanks ashore on any beach.

The Mark 1 first saw action during the British evacuation from Greece and Crete early in 1941. The LCTs played a key role in saving much of the armoured equipment that would soon serve in North Africa. Though the campaign in Greece was a defeat, it was not a disaster on the scale of Dunkirk, where the Army was forced to abandon all of its vehicles, artillery, and armour. During the evacuation, 17 Mark 1s were lost.

Mark 2
The designers set about correcting the faults of the Mark 1 in the LCT Mark 2. Longer and wider, three Paxman diesel or Napier Lion petrol engines replaced the Hall-Scotts, and 15 and 20 lb. armoured shielding was added to the wheelhouse and gun tubs. Built in four sections, the increased length and beam also allowed for the loading of two rows of 25-ton tanks and enough fuel to triple the range to 2700 nmi. In handling and reliability, the Mk.2 was a vast improvement on its predecessor. Seventy-three Mk.2s were built.

Mark 3
The Mark 3 had an additional 32 ft midsection that gave it a length of 192 ft and a displacement of 640 tons. Even with this extra weight, the vessel was slightly faster than the Mark 1. The Mk.3 was accepted on 8 April 1941, and was prefabricated in five sections. The increase in length allowed it to carry five 40-ton tanks and all their related support equipment, or 300 tons of deck cargo. Though the Royal Navy appreciated the higher load capacity of the Mk.3, it soon discovered several construction deficiencies. The craft had evidently been pressed into service without sufficient testing; combat operations demonstrated the need to add longitudinal stiffeners to the Mk.3s (and later the Mk.4s) in order to avoid torsional stresses to the hull. Two hundred and thirty-five Mk.3s were built.

Mark 4
The Mark 4 was slightly shorter and lighter than the Mk.3, but had a much wider beam (38 ft) and was intended for cross channel operations as opposed to seagoing use. Better accommodation for tank crews was also made possible by the increased beam. It had a displacement of 586 tons and was powered by two 460 hp Paxman diesels. With a capacity of 350 tons, it could carry nine M4 Sherman or six Churchill tanks. Eight hundred and sixty-five Mk.4s were built, the largest LCT production in British yards.

When tested in early assault operations, like the ill-fated Canadian commando raid on Dieppe in 1942, the lack of manoeuvring ability led to the preference for a shorter overall length in future variants, most of which were built in the United States.

Mark 5
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. The Mk.5 would be launched by heeling the LST on its beam to let the craft slide off its chocks into the sea, or cargo ships could lower each of the three sections into the sea where they were joined together. Powered by three 225 hp Gray marine diesels, the Mk.5 had a range of only 700 nmi. They were only capable of making 8 kn at best; a speed too slow for independent passage across the Pacific. Shipped aboard other vessels, Mk.5s soon proved themselves in operations. Inland yards would lead LCT production and it was not long before yard workers boasted that "they built them by the mile and cut them up in feet". Four hundred and seventy Mk.5s were built.

First used in the invasion of North Africa, the Mk.5 crews immediately earned a reputation for efficiency under fire and in the worst of weather or sea conditions. Enjoying little priority in fleet maintenance schedules, the LCT crews also gained a reputation for "finding" whatever they needed. Much of this lack of status within the amphibious forces was because the LCT was the smallest landing craft organized into independent assault flotillas. Almost entirely manned by reservists and draftees, LCT crews operated in a free and easy manner that horrified professional naval officers. By late 1943, most early Mk.5s were relegated to training or harbor duties in the United States.

Mark 6
The LCT Mark 6 had the same engines, equipment and crew as the Mk.5, but was a slightly longer, at 120-feet. The main difference was the addition of a stern gate that allowed the LCT to moor in front of larger LSTs to become a bridge for tanks and vehicles disembarking the deeper draft vessel. In practice, this method of use was more difficult to carry out than the vessel's designers anticipated. Strong tidal currents in the uncharted reef shoals of the Pacific limited the employment of this form of beaching to heavy armoured vehicles. To allow for the passage of traffic, the small wheelhouse was moved to the starboard side of the fourteen-foot wide passageway. The winch for the stern kedge anchor was relocated atop the port side deckhouse, just aft of the port side 20 mm mount. Nine hundred and sixty Mk.6s were built. One hundred and sixty Mk.5 and Mk.6 LCTs were lend-leased to the Royal Navy, and a small number to the Soviet Union.

Though never designed to cross the Pacific under their own power, several flotillas of LCTs did make the journey from Pearl Harbor to forward areas. Success in towing strings of LCTs behind LSDs led to the decision to let Flotilla No. 31, comprising 24 Mk.6s, make an island hopping voyage under their own power. The passage was slow and breakdowns numerous, however the flotilla safely arrived at its destination. Three months later, Groups 91 and 92 of this flotilla encountered six days of high seas during a typhoon off Okinawa. Fighting 50 foot swells and hurricane force winds the craft made only 26 miles in nine hours, and were almost impossible to steer or control. When the typhoon finally abated, all the LCTs had survived and took stock of the damage. Halyards, antennas and masts were blown away, guns ripped from their mounts, and the craft had been so severely overstressed that each had to replace the stripped bolts or welds holding their sections together before they could proceed to their destination.

Mark 7
So successful was the Mk.6 that naval architects were soon ordered to draw up plans for an even larger LCT, the Mark 7, which would have troop-carrying accommodations that Mk.6 lacked. As the design evolved, more emphasis was placed on speed and range for long Pacific transits, with the result that the Mk.7 outgrew itself by virtue of needs far greater than the LCT could provide. In 1944, when the Mk.7 design reached a length of 203 feet, its designation was changed to Landing Ship Medium (LSM). Placed in production and proving itself able to maintain convoy speeds of up to 12 knots, the LSM quickly took over much of the role of the LCTs in the Pacific, and 558 were built.

Mark 8
The British would produce one more large LCT design, the 225-foot LCT Mark 8, similar to the American LSM, in 1944. Intended for service in the Pacific and Far East, it carried eight heavy tanks or 350 tons of cargo and had accommodation for 50 fully armed troops plus a crew of 22. One hundred and eighty-six Mk.8s were ordered; however, when the war ended, most were cancelled and scrapped, or sold directly into civilian service. Only 31 entered service with the Royal Navy. Twelve were later transferred to the British Army; these were initially operated by the Royal Army Service Corps, then by the Royal Corps of Transport. Between 1958 and 1966, the other 19 ships were transferred to foreign navies or civilian companies, converted for other uses, or otherwise disposed of.

Mark 9
An even larger LCT Mark 9 was considered in 1944, but, by then, Allied amphibious shipping was at peak production and the Admiralty saw no further need for additional LCT variants. The Mk.9 design was never finalized.

Armament
Armament varied widely on the LCTs, with the British 2-pounder pom-pom mounts being gradually replaced by the faster firing 20 mm Oerlikon. The 40 mm Bofors was also widely used, and proved that the LCT was an excellent gunfire support vessel.

Conversions and modifications
Several special purpose versions were created for use during the Normandy landings. The British created the Landing Craft Tank (Rocket) (LCT(R)) modified to fire salvoes of 3-inch RP-3 rockets, while the Landing Craft Guns (Large) (LCG(L)) was armed with two QF 4.7 inch guns, eight Oerlikon 20 mm AA guns and two 2-pounder pom-poms. These ships did not beach; their mission was close-in gunfire support.

The Landing Craft Tank (Armored) (LCT(A)) was designed for use by the first wave and was equipped with additional armour protection for the crew stations and on the bows, while a heavy wooden ramp allowed the two forward tanks to fire forward. These were all U.S-built LCT Mk.5s, which had been lend-leased to the British for Mediterranean operations, then "reverse lend-leased" back to the U.S. for the invasion.

The Landing Craft Tank (Self-Propelled) (LCT(SP)) carried self-propelled guns for fire support; in U.S. vessels these were 155 mm, while the British used M7 105 mm self-propelled guns and called them Landing Craft Tank (High Explosive) (LCT(HE)). A related variant was the British Landing Craft Tank (Concrete Buster) (LCT(CB)), which carried three British Sherman Firefly tanks fitted with the 17-pounder high velocity gun, specifically deployed to attack fortifications. Other variants included the Landing Craft Tank (Hospital) (LCT(H)) for casualty evacuation, and one LCT served as a floating bakery at Normandy.

Other weapon combinations made the LCT into an effective floating anti-aircraft battery for harbour or support area defence. These were often manned by mixed Army and Navy crews. Others were modified post-war for other specific uses such as dredging, salvage, repair, and mine craft. Their shallow draft also made the LCT ideal for use in inland waterways.

Losses
Being in the forefront of assault landings, LCTs sustained the heaviest losses of any large landing craft. The Royal Navy lost 133 LCTs of all marks, 29 of which were U.S made Mk.5s. The U.S. Navy lost 67 Mk.5s and Mk.6s in storms, accidents or combat, with 26 lost in the Normandy landings alone, many in the gales that lashed the French coast after the initial landings.

Post-war
Unlike most wartime landing craft the LCT remained in active duty with the U.S. Navy after the war, and many LCTs were also loaned or given to the post-war navies of Allied countries. In late 1949, their designation was changed to Landing Ship Utility (LSU), and changed again on 15 April 1952 to Landing Craft Utility (LCU). New landing craft (the LCU 1610-, 1627- and 1646-classes) were also built to a modified Mark 5 design. Some were later reclassified during the Vietnam War as Harbor Utility Craft (YFU) as they no longer served in an amphibious assault role, but were used in harbor support roles such as transporting goods from supply ships.

In 1964, NASA converted an LCT Mk.5 for astronaut recovery training as MV Retriever.

Survivors
As of August 2007, at least one wartime LCT is still in use, the Mark 5 LCT-203, now renamed Outer Island, and operating on Lake Superior, working as a dredge and construction barge.

The British Mark 3 LCT-7074 served in Normandy. She was decommissioned in 1948, and presented to the Master Mariners' Club of Liverpool to be used as their club ship and renamed Landfall. Later converted into a floating nightclub, in the late 1990s the vessel was acquired by the Warship Preservation Trust and was moored at Birkenhead. In January 2006, the Trust went into liquidation and the ship was left to rot, and by April 2010 had sunk at her berth. Efforts are being made to raise the funds for restoration.