Amphibious warfare ship
An amphibious warfare ship (or amphib) is an amphibious vehicle warship employed to land and support ground forces, such as marines, on enemy territory during an amphibious assault.
Specialized shipping can be divided into two types, most crudely described as ships and craft. In general, the ships carry the troops from the port of embarkation to the drop point for the assault and the craft carry the troops from the ship to the shore. Amphibious assaults taking place over short distances can also involve the shore-to-shore technique, where landing craft go directly from the port of embarkation to the assault point. Some
History
In the days of sail, ship's boats were used as landing craft. These rowing boats were sufficient, if inefficient, in an era when
In order to support amphibious operations during the
Origins
During World War I, the mass mobilization of troops equipped with rapid-fire weapons quickly rendered such boats obsolete. Initial landings during the Gallipoli campaign took place in unmodified rowing boats that were extremely vulnerable to attack from the Ottoman shore defences.
In February 1915, orders were placed for the design of purpose-built landing craft. A design was created in four days resulting in an order for 200 'X' lighters with a
The first use took place after they had been towed to the Aegean and performed successfully in the 6 August landing at Suvla Bay of IX Corps, commanded by Commander Edward Unwin.
'X' lighters, known to the soldiers as 'beetles', carried about 500 men,
During the
Despite this outlook, the British produced the
It weighed 16 tons and had a box-like appearance, having a square bow and stern. To prevent fouling of the propellers in a craft destined to spend time in surf and possibly be beached, a crude waterjet propulsion system was devised by White's designers. A Hotchkiss petrol engine drove a centrifugal pump which produced a jet of water, pushing the craft ahead or astern, and steering it, according to how the jet was directed. Speed was 5 to 6 knots (9.3 to 11.1 km/h; 5.8 to 6.9 mph) and its beaching capacity was good.[6] By 1930, three MLC were operated by the Royal Navy.
The United States revived and experimented in
In 1939, during the annual Fleet Landing Exercises, the FMF became interested in the military potential of Andrew Higgins's design of a powered, shallow-draught boat. These LCPL, dubbed the 'Higgins Boats', were reviewed and passed by the U.S. Naval Bureau of Construction and Repair. Soon, the Higgins boats were developed to a final design with a ramp - the LCVP, and were produced in large numbers. The boat was a more flexible variant of the LCPR with a wider ramp. It could carry 36 troops, a small vehicle such as a jeep, or a corresponding amount of cargo.
Second World War
Specialized infantry landing craft
In the run-up to WWII, many specialized landing craft, both for infantry and vehicles, were developed. In November 1938, the British
J. S. White of Cowes built a prototype to the Fleming design.[9] Eight weeks later the craft was doing trials on the River Clyde. All landing craft designs must find a compromise between two divergent priorities; the qualities that make a good sea boat are opposite those that make a craft suitable for beaching.[10] The craft had a hull built of double-diagonal mahogany planking. The sides were plated with "10lb. DIHT" armour, a heat-treated steel based on D1 steel,[11] in this case Hadfield's Resista ¼".[12]
The
The Landing Craft Infantry was a stepped up amphibious assault ship, developed in response to a British request for a vessel capable of carrying and landing substantially more troops than the smaller Landing Craft Assault (LCA). The result was a small steel ship that could land 200 troops, traveling from rear bases on its own bottom at a speed of up to 15 knots. The original British design was envisioned as being a "one time use" vessel which would simply ferry the troops across the English Channel, and were considered an expendable vessel. As such, no troop sleeping accommodations were placed in the original design. This was changed shortly after initial use of these ships, when it was discovered that many missions would require overnight accommodations.
The first LCI(L)s entered service in 1943 chiefly with the Royal Navy and the United States Navy. Some 923 LCI were built in ten American shipyards and 211 provided under lend-lease to the Royal Navy.
Specialized vehicle landing craft
Following the successful development of the infantry carrying LCA by the
Design work began at John I. Thornycroft Ltd. in May 1938 with trials completing in February 1940.[6] Constructed of steel and selectively clad with armour plate, this shallow-draft, barge-like boat with a crew of 6, could ferry a tank of 16 long tons to shore at 7 knots (13 km/h). Depending on the weight of the tank to be transported the craft might be lowered into the water by its davits already loaded or could have the tank placed in it after being lowered into the water.
Although the Royal Navy had the
The first LCT Mark 1 was launched by
The Mark 3 had an additional 32-foot (9.8 m) midsection that gave it a length of 192 feet (59 m) 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. The Mark 4 was slightly shorter and lighter than the Mk.3, but had a much wider beam (38 ft 9 in (11.81 m)) and was intended for cross channel operations as opposed to seagoing use. When tested in early assault operations, like the ill-fated Allied 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.
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 that could accommodate five 30-ton or four 40-ton tanks or 150 tons of cargo. This 286-ton landing craft could be shipped to combat areas in three separate water-tight sections aboard a cargo ship or carried pre-assembled on the flat deck of a Landing Ship, Tank (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.[15]
A further development was the
In November 1941, a small delegation from the British Admiralty arrived in the United States to pool ideas with the United States Navy's Bureau of Ships with regard to the development of ships and also including the possibility of building further Boxers in the US.[16] During this meeting, it was decided that the Bureau of Ships would design these vessels. The LST(2) design incorporated elements of the first British LCTs from their designer, Sir Rowland Baker, who was part of the British delegation. This included sufficient buoyancy in the ships' sidewalls that they would float even with the tank deck flooded.[17] The LST(2) gave up the speed of HMS Boxer at only 10 knots but had a similar load while drawing only 3 feet forward when beaching.
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, Va., and the first standardized LSTs were floated out of their building dock in October. Twenty-three were in commission by the end of 1942. Lightly armored, they could steam cross the ocean with a full load on their own power, carrying infantry, tanks and supplies directly onto the beaches. Together with 2,000 other landing craft, the LSTs gave the troops a protected, quick way to make combat landings, beginning in summer 1943.[18]
Other
Nine-ton Landing Craft Navigation (LCN) were used by British "combined operations assault pilotage parties" (
The Landing Craft Control (LCC) were 56-foot (17 m)
Very small landing craft, or amphibians, were designed. The U.S.-designed Landing Vehicle Tracked, was an amphibious (and sometimes armored) personnel carrier. These were operated by Army personnel, not naval crews and had a capacity of about three tons. The British introduced their own amphibian, the Terrapin.
A Landing Craft Utility (LCU) was used to transport equipment and troops to the shore. It was capable of transporting tracked or wheeled vehicles and troops from amphibious assault ships to beachheads or piers.
The
The design was developed and built in the US for the USN and the Royal Navy. The LSD could carry 36 LCM at 16 knots. It had a large open compartment at the back. Opening a stern door and flooding special compartments opened this area to the sea so that LCI-sized vessels could enter or leave. It took one and a half hours for the dock to be flooded down and two and half to pump it out. When flooded they could also be used as docks for repairs to small craft.
Due to their small size, most amphibious ships were not given names and were just given serial numbers, for example, LCT 304. The LSTs were an exception to this, since they were similar in size to a small cruiser. In addition, three British-built LSTs were named: HMS Boxer, HMS Bruiser and HMS Thruster; these were all larger than the U.S. design and had proper funnels.
Special craft
It was soon realized that battleships, cruisers and destroyers could not necessarily provide all the fire support (including suppressive fire) that an amphibious assault might need. Therefore, specialized vessels were developed that incorporated various direct and indirect fire weapons. These included guns and rockets which could be mounted on landing craft and landing ships. As part of the final barrage before an assault, the landing area would be plastered by these types.
Amphibious landing craft of WWII were generally fitted out with minimal weaponry.
LCIs and LCTs carried heavier weapons, such as the Oerlikon 20 mm cannon, on each side of the bridge structure. LSTs had a somewhat heavier armament.
Some landing craft were converted for special purposes either to provide defence for the other landing craft in the attack or as support weapons during the landing.
- Landing Craft Assault (Hedgehog)
The LCA(HR) was a converted British LCA. It carried a battery of 24
Three flotillas (of 18, 18 and 9 craft) were used at Juno, Gold and Sword beaches.[21]
- Landing Craft Flak
The
- Landing Craft Gun
The
- Landing Craft Rocket
The
The method of operation was to anchor off the target beach, pointing towards the shore. The distance to the shore was then measured by radar and the elevation of the launchers set accordingly. The crew then vanished below, apart from the commanding officer who retreated to a special cubbyhole, and the launch was then set off electrically. The launch could comprise the entire set or individual ranks of rockets.[23]
A full reload was a very labor-intensive operation and at least one LCT(R) went alongside a cruiser and got a working party from the larger ship to assist in the process.
- Landing Craft Support
The Landing Craft Support was used to give some firepower at close range.
The Landing Craft Support (Medium) (LCS(M)), Mark 2 and Mark 3 were used by the British forces at Normandy. The crew was Royal Navy, with Royal Marines to operate the weapons: two 0.5 inch Vickers machine guns and a 4-inch mortar to fire smoke shells.
The
The American Landing Craft Support was larger, each was armed with a 3-inch gun, various smaller guns, and ten MK7 rocket launchers.
- Inflatable landing craft
The first and last instances of the large use of rubber boats in amphibious operations in World War II were the
Early Cold War developments
Despite all the progress that was seen during World War II, there were still fundamental limitations in the types of coastline that were suitable for assault. Beaches had to be relatively free of obstacles, and have the right tidal conditions and the correct slope. However, the development of the helicopter fundamentally changed the equation.
The first use of helicopters in an amphibious assault came during the
The US Navy built five
The Tarawa and Wasp class types resemble aircraft carriers. However, the role of an amphibious assault ship is fundamentally different from that of an aircraft carrier. Its aviation facilities are not to support strike or air defense aircraft, but for hosting helicopters to support forces ashore.
Future developments
One of the most recent innovations is the
Amphibious assault submarines, while proposed during the 1950s, and almost brought to actual construction by the Soviet Union in the 1960s, are currently not being designed. However, if the predictions of military experts such as John Keegan or others[26] hold true, and surface shipping becomes extremely dangerous during future wars of evenly matched powers (due to satellite reconnaissance and anti-ship missiles), then transport and amphibious assault submarines might deserve another look.
The
The
- An LSD has a helicopter deck.
- An LPD has a hangar in addition to the helicopter deck.
- An LHA has a full-length flight deck.[citation needed]
Examples:
- LHA: Landing Helicopter Assault (Tarawa class, America class)
- LHD: Landing Helicopter Dock (Wasp class)
- LPH: Landing Platform Helicopter (Iwo Jima class)
- LPD: Landing Platform Dock (San Antonio class)
- LSD: Landing Ship Dock (Whidbey Island class, Harpers Ferry class)
- LSI: Landing Ship, Infantry was previously designated as Landing Craft, Infantry
- LSL: Landing Ship Logistics
- LSM: Landing Ship Medium
- LST: Landing Ship Tank
- LCC: Amphibious Command Ship, unrelated to the Landing Craft, Control (LCC)
- AGF: Auxiliary Command Ship
- AKA/LKA: Attack cargo ship
- AP/APA/LPA: Auxiliary Personnel Assault
- ARL: Landing Craft Repair Ship (Achelous class)
See also
References
- ISBN 978-1-4357-1183-9.
- ^ Fletcher, D British Mark IV tank New Vanguard, Osprey Publishing [page needed]
- ISBN 1-55750-152-1
- ISBN 1-84067-533-0
- ISBN 1-55750-152-1, p. 11
- ^ a b Fergusson, Bernard The Watery Maze; the story of Combined Operations, Holt, New York, 1961. pp. 38-43
- ^ Allan R. Millett, "Semper Fidelis: The History of the United States Marine Corps", (New York City, NY: The Free Press, 1991). [page needed]
- ^ a b c Maund, LEH. Assault From the Sea, Methuen & Co. Ltd., London 1949. pp. 3–10
- ^ Buffetaut, p. 26
- ^ Saunders 1943, p. 11.
- ^ Welding & Fabrication of Ships Structure Archived 6 July 2001 at the Wayback Machine MOD
- ^ Buffetaut 1994, p. 49
- ^ Bruce, p. 10
- ^ Ladd, 1976, p.42
- ^ a b Basil Hearde. "The Tin Armada: Saga of the LCT". ww2lct.org. Archived from the original on 2 September 2011. Retrieved 15 January 2011.
- ISBN 0-85177-675-2, p.143
- ^ Brown, D.K. p.143
- ^ Isely and Crowl, The U.S. Marines and Amphibious War Its Theory and Its Practice in the Pacific (1951) ch 3 [page needed]
- ^ "Accessed 18th March 2008". Combinedops.com. 9 March 1943. Retrieved 10 May 2009.
- ^ US Navy ONI 226 Allied Landing Craft and Ships, US Government Printing Office, 1944.[page needed]
- ^ "Major Landing Craft of World War II". The Royal Marines Museum. 6 October 2011. Archived from the original on 9 June 2014. Retrieved 16 June 2014.
- ^ Brown D K, Nelson to Vanguard p 145
- ^ British Landing Craft of World War II » Naval Historical Society
- ^ "US Navy Small Landing Craft, 1940-1945". Ibiblio.org. 25 May 2006. Retrieved 10 May 2009.
- ^ Jablon, Howard David M. Shoup: A Warrior Against War, Rowman & Littlefield, 1 Jan 2005, p. 46
- ^ Submarine aircraft carriers Archived 5 October 2011 at the Wayback Machine (uneven-quality private website, but has third-party citations in support)
- ^ "Navy Light Amphibious Warship (LAW) Program: Background and Issues for Congress" (PDF). Federation of American Scientists. 7 June 2021. Retrieved 10 June 2021.