Landing Ship, Tank (LST), or tank landing ship, is the naval designation for ships first developed during World War II (1939–1945) to support amphibious operations by carrying tanks, vehicles, cargo, and landing troops directly onto a low slope beach with no docks or piers. The shallow draft and bow doors and ramps enabled amphibious assaults on almost any beach.

The LST had a highly specialized design that enabled ocean crossings as well as shore groundings. The bow had a large door that could open, deploy a ramp and unload vehicles. The LST had a flat keel that allowed the ship to be beached and stay upright. The twin propellers and rudders had protection from grounding. The LSTs served across the globe during World War II including in the Pacific War and in the European theatre.

The first tank-landing ships were built to British requirements by converting existing ships; the UK and the US then collaborated upon a joint design. The British ships were used in late 1942 during the Allied invasion of Algeria, by 1943 LSTs participated in the invasion of Sicily and mainland Italy. In June 1944 they were part of the huge invasion fleet for the Normandy landings.

Over 1,000 LSTs were laid down in the United States during World War II for use by the Allies; the United Kingdom and Canada produced eighty more.^[1][2][3]

LST Mk.1

Universal Carriers being loaded at Bone Harbour through the bow doors of HMS Bachaquero
Class overview
Name	LST Maracaibo class
Builders	Furness Shipbuilding Company, Haverton Hill-on-Tees
Operators	Royal Navy
Succeeded by	Boxer
Completed	3 (Misoa, Tasajera & Bachaquero)
Preserved	1
General characteristics
Tonnage	4,800 long tons (4,877 t) GRT
Length	382 ft (116 m)[4]
Beam	64 ft (19.5m)
Draught	Fully laden : 15 ft (4.6 m) aft 4 ft (1.2 m) forward
Ramps	Double hinged ramp, effective length of 100 ft (30 m)
Propulsion	Reciprocating steam engine, 2 shafts, 3,000 shp
Capacity	18 × 30 ton tanks or 22 × 25 ton tanks or 33 × 3-ton trucks[4]
Troops	Berths for 217 troops[4]
Complement	98 Combined Operations personnel
Armament	1 × twin 40 mm gun 6 × 20 mm guns[4] 3 × Lewis guns 2 × 4 in (100 mm) smoke mortars[4]
Notes	Equipment: 2 × 50 ton derrick cranes

HMS Thruster
Class overview
Name	LST (1) Boxer class
Builders	Harland and Wolff
Operators	Royal Navy
Preceded by	Maracaibo
Succeeded by	LST (2)
Completed	3 (Boxer, Bruiser, Thruster)
General characteristics
Type	Landing Ship, Tank Mark I
Displacement	3,620 long tons (3,678 t) standard 5,410 long tons (5,497 t) full load
Length	400 ft (120 m)
Beam	49 ft (15 m)
Draught	14 ft 6 in (4.42 m)
Propulsion	Steam turbines, 2 shafts, 7,000 shp (5,200 kW)
Speed	18 knots (33 km/h; 21 mph) laden to beaching draught 16.5 knots (30.6 km/h; 19.0 mph) at deep
Range	9,000 nmi (17,000 km; 10,000 mi) at 14 kn (26 km/h; 16 mph)
Capacity	13 Churchill tanks or 20 medium tanks, 27 vehicles on upper deck, 193 men
Complement	169
Armament	4 × QF 2 pdr 8 × 20 mm Oerlikon 2 × 4-inch smoke mortars
Notes	Equipment: 1 × 40 ton crane[5]

Maracaibo landing ships

The British evacuation from Dunkirk in 1940 demonstrated to the Admiralty that the Allies needed relatively large, ocean-going ships that could handle shore-to-shore delivery of tanks and other vehicles in amphibious assaults upon the continent of Europe. As an interim measure, three 4,000 to 4,800-gross register ton "Lake tankers", built to pass over the restrictive bars of Lake Maracaibo, Venezuela, were selected for conversion because of their shallow draft. Bow doors and ramps were added to these ships, which became the first tank landing ships, LST (1): HMS Misoa, Tasajera and Bachaquero.^[4] They later proved their worth during the invasion of Algeria in 1942, but their bluff bows made for inadequate speed and pointed out the need for an all-new design incorporating a sleeker hull.

Boxer class

The first purpose-built LST design was HMS Boxer.^{[dubious – discuss]} It was a scaled-down design from ideas penned by Prime Minister Winston Churchill. In order that it could carry 13 Churchill infantry tanks, 27 other vehicles and nearly 200 men (in addition to the crew) at a speed of 18 knots (33 km/h; 21 mph), it could not have a shallow draught sufficient for easy unloading. As a result, each of the three (Boxer, Bruiser, and Thruster) ordered in March 1941 had a very long ramp stowed behind the bow doors.^[6]

The ships were built at Harland and Wolff from 1941 and completed in 1943. Bruiser and Thruster took part in the Salerno landings. All three were intended to be converted to fighter direction ships in order to have ground-controlled interception of enemy aircraft during landing operations but only Boxer was converted.^[7]

The U.S. were to build seven LST (1) but in light of the problems with the design and progress with the LST Mark II the plans were cancelled. Construction of the LST (1)s took until 1943 and the first US LST (2) was launched before them.^[8]

LST Mk.2

LST-942 underway soon after completion, late in 1944
Class overview
Name	LST (2)
Builders	Dravo Corporation Kaiser Shipyards Jeffersonville Boat & Machine Co. Missouri Valley Bridge & Iron Co. Chicago Bridge & Iron Co. American Bridge Co. Bethlehem Hingham Shipyard Boston Navy Yard Newport News Shipbuilding
Operators	United States Navy  United States Coast Guard  Royal Navy  Royal Canadian Navy  Japan Maritime Self-Defense Force  Republic of Singapore Navy  Philippine Navy  Royal Malaysian Navy  Republic of China Navy  People's Liberation Army Navy  Royal Thai Navy  Vietnam People's Navy  Hellenic Navy  German Navy  Argentine Navy  Peruvian Navy  Turkish Naval Forces  Indonesian Navy  Republic of Korea Navy  Bolivarian Navy of Venezuela  Mexican Navy  Italian Navy
Succeeded by	Talbot County class
Subclasses	LST-1 class LST-491 class LST-542 class
Built	1942–1945
In commission	1942–1971 (US)
Completed	1052
Cancelled	100
Active	1 (Singapore) 1 (Mexico) 4 (Taiwan) 2 (Vietnam) 3 (Philippines) 1 (US Maritime Sealift Command)
Preserved	USS LST-325 USS LST-393 USS LST-510 ROKS Hwa San ROKS Un Bong ROKS Wi Bong HTMS Pangan HTMS Lanta
General characteristics
Displacement	1,780 long tons (1,809 t) light 3,880 long tons (3,942 t) full load
Length	327 ft 9 in (99.90 m)
Beam	50 ft (15 m)
Draught	Unloaded : 3 ft 4 in (1.02 m) bow 7 ft 6 in (2.29 m) stern Loaded : 8 ft 2 in (2.49 m) bow 14 ft 1 in (4.29 m) stern
Propulsion	2 × General Motors 12-567 diesel engines, two shafts, twin rudders
Speed	12 knots (14 mph; 22 km/h)
Boats & landing craft carried	2 to 6 LCVPs
Troops	About 140 officers and other ranks
Complement	8 to 10 officers, 100 to 115 enlisted
Armament	1 × 3 in (76 mm) gun 6 × 40 mm Bofors guns 6 × 20 mm guns 2 × .50 cal (12.7 mm) machine guns 4 × .30 cal (7.62 mm) machine guns

Development

At their first meeting at the Atlantic Conference in Argentia, Newfoundland, in August 1941, US President Franklin D. Roosevelt and British Prime Minister Winston Churchill confirmed the Admiralty's views. In November 1941, a small delegation from the Admiralty arrived in the United States to pool ideas with the United States Navy's Bureau of Ships with regard to development of ships and the possibility of building further Boxers in the US.^[9] During this meeting, it was decided that the Bureau of Ships would design these vessels. As with the standing agreement, these ships would be built by the US so British shipyards could concentrate on building vessels for the Royal Navy. The specifications called for vessels capable of crossing the Atlantic, and the original title given to them was "Atlantic Tank Landing Craft" (Atlantic (T.L.C.)). Calling a vessel 300 ft (91 m) long a "craft" was considered a misnomer and the type was re-christened "Landing Ship, Tank (2)", or "LST (2)".

The LST (2) design incorporated elements of the first British LCTs from their designer, Sir Rowland Baker, who was part of the British delegation. One of the elements provided for sufficient buoyancy in the ships' sidewalls so that they would float the ship even when the tank deck was flooded.^[9] The LST (2) gave up the speed of HMS Boxer, at only 10 knots (19 km/h; 12 mph), but carried a similar load while drawing only three feet (91 cm) forward when beaching.

Design

Within a few days, John C. Niedermair of the Bureau of Ships sketched out an awkward looking ship that proved to be the basic design for the more than 1,000 LST (2) that were built during World War II. To meet the conflicting requirements of deep draft for ocean travel and shallow draft for beaching, the ship was designed with a large ballast system that could be filled for ocean passage and pumped out for beaching operations.^[10] An anchor and mechanical winch system also aided in the ship's ability to pull itself off the beach. The rough sketch was sent to Britain on 5 November 1941 and accepted immediately. The Admiralty then requested that the United States build 200 "LST (2)" for the Royal Navy under the terms of lend-lease.

The preliminary plans initially called for an LST 280 feet (85 m) in length; but, in January 1942, the Bureau of Ships discarded these drawings in favor of specifications for a ship 290 feet (88 m) long. Within a month, final working plans were developed that further stretched the overall length to 328 feet (100 m) and called for a 50-foot (15 m) beam and a minimum draft of 3.8 feet (1.2 m). This scheme distributed the ship's weight over a greater area, enabling her to ride higher in the water when in landing trim. The LST could carry a 2,100 short tons (1,900 t) load of tanks and vehicles. The larger dimensions also permitted the designers to increase the width of the bow door opening and ramp from 12 to 14 feet (3.7 to 4.3 m) in order for it to be able to accommodate most Allied vehicles. As the dimensions and weight of the LST increased, steel plating thickness increased from 1⁄4-inch (6.4 mm) to 3⁄8-inch (9.5 mm) on the deck and sides, with 1-inch-thick (25 mm) plating under the bow.^[11] By January 1942, the first scale model of the LST had been built and was undergoing tests at the David Taylor Model Basin in Washington, D.C.

Provisions were made for the satisfactory ventilation of the tank space while the tank motors were running, and an elevator was provided to lower vehicles from the main deck to the tank deck for disembarking. In April 1942 a mock-up of the well-deck of an LST was constructed at Fort Knox, Kentucky, to resolve the problem of ventilation within the LST well-deck. The interior of the building was constructed to duplicate all the features found within an actual LST. Being the home to the Armored Force Board, Fort Knox supplied tanks to run on the inside while Naval architects developed a ventilation system capable of evacuating the well-deck of harmful gases. Testing was completed in three months. This historic building remains at Fort Knox today.^[12]

Early LST operations required overcoming the 18th-century language of the Articles for the Government of the United States Navy: "He who doth suffer his ships to founder on rocks and shoals shall be punished..."^[13] There were some tense moments of concept testing at Quonset, Rhode Island, in early 1943 when designer Niedermair encouraged the commanding officer of the first U.S. LST to drive his ship onto the beach at full speed of 10 knots (12 mph; 19 km/h).^[11]

Production

The LST(2) was built as the LST-1 class and the LST-491 class.

In three separate acts dated 6 February 1942, 26 May 1943, and 17 December 1943, Congress provided the authority for the construction of LSTs along with a host of other auxiliaries, destroyer escorts, and assorted landing craft. The enormous building program quickly gathered momentum. Such a high priority was assigned to the construction of LSTs that the previously laid keel of an aircraft carrier was hastily removed to make room for several LSTs to be built in her place. The keel of the first LST was laid down on 10 June 1942 at Newport News, Virginia, and the first standardized LSTs were floated out of their building dock in October. Twenty-three were in commission by the end of 1942.

The LST building program was unique in several respects. As soon as the basic design had been developed, contracts were let and construction was commenced in quantity before the completion of a test vessel. Preliminary orders were rushed out verbally or by telegrams, telephone, and air mail letters. The ordering of certain materials actually preceded the completion of design work. While many heavy equipment items, such as main propulsion machinery, were furnished directly by the Navy, the balance of the procurement was handled centrally by the Material Coordinating Agency—an adjunct of the Bureau of Ships—so that the numerous builders in the program would not have to bid against one another. Through vigorous follow-up action on materials ordered, the agency made possible the completion of construction schedules in record time.

The need for LSTs was urgent, and the program enjoyed a high priority throughout the war. Since most shipbuilding activities were located in coastal yards that were mainly used for construction of large, deep-draft ships, new construction facilities for the LSTs were established along inland waterways, some converted from heavy-industry plants, such as steel fabrication yards. Shifting the vessels was complicated by bridges across waterways, many of which were modified by the Navy to permit passage. A dedicated Navy "Ferry Command" orchestrated the transportation of newly constructed ships to coastal ports for final fitting out. Of the 1,051 LSTs built during the war, 670 were supplied by five "cornfield shipyards" in the Midwest. Dravo Corporation's facility at Neville Island, Pennsylvania, designated the lead shipyard for the project, built 145 vessels and developed fabrication techniques that reduced construction time and costs at all of the LST shipyards. The Missouri Valley Bridge & Iron Co. built the most LSTs of any shipyard, with 171 constructed at Evansville, Indiana.^[14] Chicago Bridge and Iron's shipyard in Seneca, Illinois, launched 156 ships and was specifically chosen because of their reputation and skills, particularly in welding. The American Bridge Company in Ambridge, Pennsylvania, built 119.

Modifications

By 1943, the construction time for an LST had been reduced to four months. By the end of the war, this had been cut to two months. Considerable effort was expended to hold the ship's design constant, but, by mid-1943, operating experience led to the incorporation of certain changes in the new ships.

From LST-513, the elevator to transfer equipment between the tank deck and the main deck was replaced with a 12 by 32 ft (3.7 by 9.8 m) ramp that was hinged at the main deck. This allowed vehicles to be driven directly from the main deck down to the tank deck and then across the bow ramp to the beach or causeway, speeding the process of disembarkation.^[15]

Changes in the later LST-542 class included the addition of a navigation bridge; the installation of a water distillation plant with a capacity of 4,000 imperial gallons (18,000 L) per day;^[16] the removal of the tank deck ventilator tubes from the center section of the main deck; the strengthening of the main deck in order to carry a smaller Landing Craft Tank (LCT); and an upgrade in armor and armament, with the addition of a 3"/50 caliber gun.

LST Mk.3

HMS LST-3035
Class overview
Name	LST (3)
Builders	R & W. Hawthorn, Leslie & Co. Ltd, Harland and Wolff, Swan, Hunter & Wigham Richardson Ltd, Vickers-Armstrongs
Operators	Royal Navy  Royal Australian Navy  Hellenic Navy  Royal Netherlands Navy  Indian Navy
Planned	119
Completed	UK: 31 × LST (3) 2 × LST (C) 2 × LST (Q) Canada: 26 × LST (3)
Cancelled	40 + 6 scrapped before completion
Active	0
Preserved	0
General characteristics
Displacement	2,140 tons light 4,980 long tons (5,060 t) full load
Length	347 ft (106 m) o/a
Beam	55 ft 2 in (16.81 m)
Draught	Loaded : 4 ft 7 in (1.40 m) bow 11 ft 6 in (3.51 m) stern
Ramps	23 feet by 14 feet ramp
Propulsion	Twin screws, steam reciprocating engines, 5,500 hp (4,100 kW), 10 ft (3.0 m) propeller
Speed	13 knots (24 km/h; 15 mph)
Capacity	10 tanks plus 15 vehicles
Troops	13 officers and 150 men
Complement	14 officers and 90 men
Armament	8 × 20 mm Oerlikon for A/A defence on some ships

Design

The LST (2) design was successful and production extensive, but there was still a need for more LSTs for British operations. As such, it was decided to build a further 80 of the ships in the UK and Canada to be available in the spring of 1945.

The British Staff drew up their own specification, requiring that the ship:

• Be able to embark and disembark tanks, motor transport, etc., on beaches of varying slopes; and amphibians and DD Sherman tanks into deep water
• Carry five Landing Craft Assault (LCA), or similar craft, and one LCT (5) or LCT (6) on the upper deck, in place of transport, and, as an alternative to the LCT (5), two NL pontoon causeway to be carried; the LCT (5) and NL pontoon causeways to be capable of launching directly from the upper deck.
• To carry 500 tons of military load and to beach with that and sufficient fuel and stores for a 1,000 mi (1,600 km) return journey at 10 knots (19 km/h), on draughts 4 ft 6 in (1.37 m) forward and 11 ft 6 in (3.51 m) aft.
• To carry a load of sixty tons over the main ramp and ten tons over the vehicle ramp (i.e., the 50 ft (15 m) ramp from the upper deck to the bow door. After trials, this was removed from some vessels)
• To be fitted for operations in the tropics and in cold climates

Two major problems made a redesign necessary. The preferred light weight medium-speed (locomotive type) Electro-Motive Diesel 12-567 diesel engines were not immediately available. Staff wanted more power and higher speeds if possible, which the EMD engines could have provided. However, the only engines available were very heavy steam reciprocating engines from frigates that had been cancelled. These delivered two and a half times the power of the diesels. So large were they that significant changes had to be made to accommodate them. Lack of welded construction facilities meant that the hull had to be riveted. This combination of heavy hull and heavy engines meant that speed was only 3 knots (5.6 km/h) faster than the LCT (2).

At the same time, other improvements were made—as well as simplifications required so most of the structure could be assembled with rivets. The cutaway hard chine that had been dropped in the American version of the Mark 2 vessels was restored. The tank deck, which was above the waterline, was made parallel to the keel, there was to be no round down to the upper deck, and the ship was enlarged to accommodate the more bulky machinery.

Provision was made for carrying the British Landing Craft Assault (LCA) in gravity davits, instead of American assault craft. Provision was also made for carrying Landing Craft Tank (LCT) and Landing Craft Mechanized (LCM), and NL pontoon causeways.

When the design commenced, engineers knew that the beaches where the ships were expected to land would be very flat, but it was not possible to produce a satisfactory vessel with a 3 ft (0.91 m) draught forward, and very little keel slope, so the 1 in 50 keel slope was maintained. It was known that the 1:50 slope would often result in the LST grounding aft on a shallow beach, resulting in the vehicles being discharged into comparatively deep water.

Various methods had been investigated to overcome the problem, but heavy grounding skegs and the N.L. pontoon causeways were finally accepted as standard; the pontoon causeways were formed of pontoons 7 ft (2.1 m) × 5 ft × 5 ft (1.5 m), made up into strings and rafts. When offloading, the rafts were secured to the fore end of the ship, and the load discharged directly onto the shore, or towed on the raft to the shore.

The ships were fitted out for service in both very cold and tropical conditions. The accommodation provided for both crew and army personnel was greatly improved compared with LST (2). The main hazard, apart from enemy action, was fire on the tank deck. Fire sprinklers were provided, but the water drenching system installed in later American vessels could not be provided.

The bow door arrangements were similar to the LST (2), but the design arranged the bow ramp in two parts in an attempt to increase the number of beaches where direct discharge would be possible. The machinery for operating the bow doors and ramp were electrical, but otherwise, steam auxiliaries replaced the electrical gear on the LST (2).

The general arrangements of the tank deck were similar, but the design increased headroom and added a ramp to the top deck, as in later LST (2)s. Provision was made for carrying LCA on gravity davits instead of the American built assault boats. The arrangements were generally an improvement over the LST (2), but suffered from a deeper draught, and, to some extent, from the haste of construction.

The first orders were placed in December 1943 with British builders, and 35 with Canadian builders. Swan Hunter delivered the first ships in December 1944. During 1944, follow up orders were placed in Canada for a further 36. These programmes were in full swing when the war ended, but not all vessels were completed.

The ships were numbered numbers LST-3001 to LST-3045 and LST-3501 to LST-3534. LST−3535 and later were cancelled.

Fifteen 40-ton tanks or 27 25-ton tanks could be carried on the tank deck with an additional fourteen lorries on the weather deck.^[8]

Propulsion

Steam was supplied by a pair of Admiralty pattern 3-drum water-tube type boilers, working at 225 pounds per square inch (1,550 kPa). The main engines were of the 4-cylinder triple expansion 4-crank type, balanced on the Yarrow-Tweedy-Slick system, the cylinders being as follows:

High pressure	18.5 in diameter
Medium pressure	31.0 in diameter
Forward low pressure	38.5 in diameter
Aft low pressure	38.5 in diameter

The common stroke was 30 inches (760 mm). The piston and slide valve rods were all fitted with metallic packing to the stuffing boxes, and all pistons fitted with packing rings and springs. The high-pressure valve was of the piston type, whilst the remaining ones were of the balanced type. The main engines were designed to develop 2,750 hp (2,050 kW) at 185 rpm continuously.

With the ships being twin screw, the engines were fitted with a shaft coupling to the crank shaft at the forward end, allowing the engine to be turned end to end to suit either port or starboard side fitting.

Zdroj:https://en.wikipedia.org?pojem=Landing_Ship,_Tank
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