An aircraft catapult is a device used to allow aircraft to take off in a limited distance, typically from the deck of a vessel. They can also be installed on land-based runways, although this is rarely done. They are usually used on aircraft carriers as a form of assisted take off.
In the form used on aircraft carriers the catapult consists of a track, or slot, built into the flight deck, below which is a large piston or shuttle that is attached through the track to the nose gear of the aircraft, or in some cases a wire rope, called a catapult bridle, is attached to the aircraft and the catapult shuttle. Other forms have been used historically, such as mounting a launching cart holding a seaplane on a long girder-built structure mounted on the deck of a warship or merchant vessel, but most catapults share a similar sliding track concept.
Different means have been used to propel the catapult, such as weight and derrick, gunpowder, flywheel, air pressure, hydraulic, and steam power, and solid fuel rocket boosters. The U.S. Navy is developing the use of Electromagnetic Aircraft Launch Systems with the construction of the Gerald R. Ford-class aircraft carriers.
Historically it was most common for seaplanes to be catapulted, allowing them to land on the water near the vessel and be hoisted on board, although in WWII (before the advent of the escort carrier) conventional fighter planes (notably the Hawker Hurricane) would sometimes be catapulted from "catapult-equipped merchant" (CAM) vessels to drive off enemy aircraft, forcing the pilot to either divert to a land based airstrip, or to jump out by parachute or ditch in the water near the convoy and wait for rescue.
Aviation pioneer and Smithsonian Secretary Samuel Langley used a spring-operated catapult to launch his successful flying models and his failed Aerodrome of 1903. [1] Likewise the Wright Brothers beginning in 1904 used a weight and derrick styled catapult to assist their early aircraft with a takeoff in a limited distance. [2]
On 31 July 1912, Theodore Gordon Ellyson became the first person to be launched from a U.S. Navy catapult system. The Navy had been perfecting a compressed-air catapult system and mounted it on the Santee Dock in Annapolis, Maryland. The first attempt nearly killed Lieutenant Ellyson when the plane left the ramp with its nose pointing upward and it caught a crosswind, pushing the plane into the water. Ellyson was able to escape from the wreckage unhurt. On 12 November 1912, Lt. Ellyson made history as the Navy's first successful catapult launch, from a stationary coal barge. On 5 November 1915, Lieutenant Commander Henry C. Mustin made the first catapult launch from a ship underway. [3]
Feature | First seen | First demonstrated on | First commissioned carrier | Entry into service | Notes |
---|---|---|---|---|---|
Naval catapult | 1915 | USS North Carolina | USS Langley – compressed air USS Lexington – fly wheel HMS Courageous – hydraulic | 1922 1927 1934 | Lt. Cmdr. Henry Mustin made the first successful launch on November 5, 1915, |
Steam catapult | 1950 | HMS Perseus | USS Hancock | 1954 | added to Hancock during her 1953 SCB-27C refit. |
EMALS | 2010 | Lakehurst Maxfield Field | USS Gerald R. Ford | 2017 | |
The US Navy experimented with other power sources and models, including catapults that utilized gunpowder and flywheel variations. On 14 December 1924, a Martin MO-1 observation plane flown by Lt. L. C. Hayden was launched from USS Langley using a catapult powered by gunpowder. Following this launch, this method was used aboard both cruisers and battleships. [4]
By 1929, the German ocean liners SS Bremen and Europa had been fitted with compressed-air catapults designed by the Heinkel aviation firm of Rostock, [5] with further work with catapult air mail across the South Atlantic Ocean, being undertaken during the first half of the 1930s, with Dornier Wal twin-engined flying boats.
Up to and during World War II, most catapults on aircraft carriers were hydraulic. United States Navy catapults on surface warships, however, were operated with explosive charges similar to those used for 130-millimeter (5-inch) guns. Some carriers were completed before and during World War II with catapults on the hangar deck that fired athwartships, but they were unpopular because of their short run, low clearance of the hangar decks, inability to add the ship's forward speed to the aircraft's airspeed for takeoff, and lower clearance from the water (conditions which afforded pilots far less margin for error in the first moments of flight). They were mostly used for experimental purposes, and their use was entirely discontinued during the latter half of the war. [4]
Many naval vessels apart from aircraft carriers carried float planes, seaplanes or amphibians for reconnaissance and spotting. They were catapult-launched and landed on the sea alongside for recovery by crane. Additionally, the concept of submarine aircraft carriers was developed by multiple nations during the interwar period, and through until WW2 and beyond, wherein a submarine would launch a small number of floatplanes for offensive operations or artillery spotting, to be recovered by the submarine once the aircraft has landed. The first launch off a Royal Navy battlecruiser was from HMAS Australia on 8 March 1918. Subsequently, many Royal Navy ships carried a catapult and from one to four aircraft; battleships or battlecruisers like HMS Prince of Wales carried four aircraft and HMS Rodney carried two, while smaller warships like the cruiser HMNZS Leander carried one. The aircraft carried were the Fairey Seafox or Supermarine Walrus. Some like HMS Nelson did not use a catapult, and the aircraft was lowered onto the sea for takeoff. Some had their aircraft and catapult removed during World War II e.g. HMS Duke of York, or before (HMS Ramillies).
During World War II a number of ships were fitted with rocket-driven catapults, first the fighter catapult ships of the Royal Navy, then armed merchantmen known as CAM ships from "catapult armed merchantmen". These were used for convoy escort duties to drive off enemy reconnaissance bombers. CAM ships carried a Hawker Sea Hurricane 1A, [lower-roman 1] dubbed a "Hurricat" or "Catafighter", and the pilot bailed out unless he could fly to land. [6]
While imprisoned in Colditz Castle during the war, British prisoners of war planned an escape attempt using a falling bathtub full of heavy rocks and stones as the motive power for a catapult to be used for launching the Colditz Cock glider from the roof of the castle.
Ground-launched V-1s were typically propelled up an inclined launch ramp by an apparatus known as a Dampferzeuger ("steam generator"). [7] [8]
Following World War II, the Royal Navy was developing a new catapult system for their fleet of carriers. Commander C. C. Mitchell, RNV, recommended a steam-based system using a slotted cylinder as an effective and efficient means to launch the next generation of naval aircraft. Trials on HMS Perseus, flown by pilots such as Eric "Winkle" Brown, from 1950 showed its effectiveness. Navies introduced steam catapults, capable of launching the heavier jet fighters, in the mid-1950s. Powder-driven catapults were also contemplated, and would have been powerful enough, but would also have introduced far greater stresses on the airframes and might have been unsuitable for long use. [4]
At launch, a release bar holds the aircraft in place as steam pressure builds up, then breaks (or "releases"; older models used a pin that sheared), freeing the piston to pull the aircraft along the deck at high speed. Within about two to four seconds, aircraft velocity by the action of the catapult plus apparent wind speed (ship's speed plus or minus "natural" wind) is sufficient to allow an aircraft to fly away, even after losing one engine. [9]
Nations that have retained large aircraft carriers, i.e., the United States Navy and the French Navy, are still using a CATOBAR (Catapult Assisted Take Off But Arrested Recovery) configuration. U.S. Navy tactical aircraft use catapults to launch with a heavier warload than would otherwise be possible. Larger planes, such as the E-2 Hawkeye and S-3 Viking, require a catapult shot, since their thrust-to-weight ratio is too low for a conventional rolling takeoff on a carrier deck. [4]
Types previously or still operated by the British, U.S. and French navies include: [9] [10] [11] [12] [13] [14] [15] [16]
Type | Overall length | Stroke | Capacity | Carriers |
---|---|---|---|---|
BS 4 | 151 ft (46 m) [17] | HMS Ark Royal (2 catapults) | ||
C-11 and C-11-1 | 225 feet (69 m) | 211 feet (64 m) | 39,000 pounds (18 t) at 136 knots; 70,000 pounds (32 t) at 108 knots | SCB-27C Essex-class conversions, USS Coral Sea, bow installations on USS Midway and USS Franklin D. Roosevelt, waist installations on USS Forrestal and USS Saratoga |
C-11-2 | 162 feet (49 m) | 150 feet (46 m) | Waist catapults on USS Midway and USS Franklin D. Roosevelt | |
C-7 | 276 feet (84 m) | 253 feet (77 m) | 40,000 pounds (18 t) at 148.5 knots; 70,000 pounds (32 t) at 116 knots | USS Ranger, USS Independence, bow installations on USS Forrestal and USS Saratoga |
C-13 | 265 feet (81 m) | 250 feet (76 m) | 78,000 pounds (35 t) at 139 knots | Kitty Hawk class, USS Midway after SCB-101.66 modernization, USS Enterprise |
C-13-1 | 325 feet (99 m) | 310 feet (94 m) | 80,000 pounds (36 t) at 140 knots | One installation on USS America and USS John F. Kennedy, all on USS Nimitz, USS Dwight D. Eisenhower, USS Carl Vinson, and USS Theodore Roosevelt |
C-13-2 | 325 feet (99 m) | 306 feet (93 m) | USS Abraham Lincoln, USS George Washington, USS John C. Stennis, USS Harry S. Truman | |
C-13-3 | 261 feet (80 m) | 246 feet (75 m) | 60,000 pounds (27 t) at 140 knots | French aircraft carrier Charles de Gaulle |
The protruding angled ramps (Van Velm Bridle Arresters or horns) at the catapult ends on some aircraft carriers were used to catch the bridles (connectors between the catapult shuttle and aircraft fuselage) for reuse. There were small ropes that would attach the bridle to the shuttle, which continued down the angled horn to pull the bridle down and away from the aircraft to keep it from damaging the underbelly. The bridle would then be caught by nets aside the horn. Bridles have not been used on U.S. aircraft since the end of the Cold War, and all U.S. Navy carriers commissioned since then have not had the ramps. The last U.S. carrier commissioned with a bridle catcher was USS Carl Vinson; starting with USS Theodore Roosevelt the ramps were omitted. During Refueling and Complex Overhaul refits in the late 1990s–early 2000s, the bridle catchers were removed from the first three Nimitz-class aircraft carriers. USS Enterprise was the last U.S. Navy operational carrier with the ramps still attached before her inactivation in 2012.[ citation needed ]
Like her American counterparts, the French aircraft carrier Charles De Gaulle is not equipped with bridle catchers because the modern aircraft operated on board use the same launch systems as in US Navy. [18] Because of this mutual interoperability, American aircraft are also capable of being catapulted from and landing on Charles De Gaulle, and conversely, French naval aircraft can use the US Navy carriers' catapults. At the time when the Super Étendard was operated on board of the Charles de Gaulle, its bridles were used only once, as they were never recovered by bridle catchers.
The carriers Clemenceau and Foch were also equipped with bridle catchers, not for the Super Étendards but only to catch and recover the Vought F-8 Crusader's bridles.[ clarification needed ]
The size and manpower requirements of steam catapults place limits on their capabilities. A newer approach is the electromagnetic catapult, such as Electromagnetic Aircraft Launch System (EMALS) developed by General Atomics. Electromagnetic catapults place less stress on the aircraft and offer more control during the launch by allowing gradual and continual acceleration. Electromagnetic catapults are also expected to require significantly less maintenance through the use of solid state components. [19]
Linear induction motors have been experimented with before, such as Westinghouse's Electropult system in 1945. [20] However, at the beginning of the 21st century, navies again started experimenting with catapults powered by linear induction motors and electromagnets. Electromagnetic catapult would be more energy efficient on nuclear-powered aircraft carriers and would alleviate some of the dangers posed by using pressurized steam. On gas-turbine powered ships, an electromagnetic catapult would eliminate the need for a separate steam boiler for generating catapult steam. The U.S. Navy's Gerald R. Ford-class aircraft carriers and PLA Navy's Type 003 aircraft carrier included electromagnetic catapults in their design. [21] [22]
From 1929, the German Norddeutscher Lloyd-liners SS Bremen and Europa were fitted with compressed air-driven catapults designed by the Heinkel Flugzeugwerke to launch mail-planes. [23] These ships served the route between Germany and the United States. The aircraft, carrying mail–bags, would be launched as a mail tender while the ship was still many hundreds of miles from its destination, thus speeding mail delivery by about a day. Initially, Heinkel He 12 aircraft were used before they were replaced by Junkers Ju 46, which were in turn replaced by the Vought V-85G. [24]
German airline Lufthansa subsequently used dedicated catapult ships SS Westfalen, MS Schwabenland, Ostmark and Friesenland to launch larger Dornier Do J Wal (whale), Dornier Do 18 and Dornier Do 26 flying boats on the South Atlantic airmail service from Stuttgart, Germany to Natal, Brazil. [25] On route proving flights in 1933, and a scheduled service beginning in February 1934, Wals flew the trans-ocean stage of the route, between Bathurst, the Gambia in West Africa and Fernando de Noronha, an island group off South America. At first, there was a refueling stop in mid-ocean. The flying boat would land on the open sea, be winched aboard by a crane, refueled, and then launched by catapult back into the air. However, landing on the big ocean swells tended to damage the hull of the flying boats. From September 1934, Lufthansa had a support ship at each end of the trans-ocean stage, providing radio navigation signals and catapult launchings after carrying aircraft out to sea overnight. From April 1935 the Wals were launched directly offshore, and flew the entire distance across the ocean. This was possible as the flying boats could carry more fuel when they did not have to take off from the water under their own power, and cut the time it took for mail to get from Germany to Brazil from four days down to three.
From 1936 to 1938, tests including the Blohm & Voss Ha 139 flying boat were conducted on the North Atlantic route to New York. Schwabenland was also used in an Antarctic expedition in 1938/39 with the main purpose of finding an area for a German whaling station, in which catapult-launched Wals surveyed a territory subsequently claimed by Germany as New Swabia. All of Lufthansa's catapult ships were taken over by the Luftwaffe in 1939 and used as seaplane tenders in World War II along with three catapult ships built for the military.
After World War II, Supermarine Walrus amphibian aircraft were also briefly operated by a British whaling company, United Whalers. Operating in the Antarctic, they were launched from the factory ship FF Balaena, which had been equipped with an ex-navy aircraft catapult. [26]
The Chinese, Indian, and Russian navies operate conventional aircraft from "short take-off but arrested landing" (STOBAR) aircraft carriers. Instead of a catapult, they use a ski jump to assist aircraft in taking off with a positive rate of climb. Carrier aircraft such as the J-15, Mig-29K, and Su-33 rely on their own engines to accelerate to flight speed. As a result, they must take off with a reduced load of fuel and armaments.
All other navies with aircraft carriers operate short take-off and vertical landing (STOVL) aircraft, such as the B variant of the Lockheed Martin F-35 Lightning II, the BAE Sea Harrier, and the AV-8B Harrier II. These aircraft can take off vertically with a light load, or use a ski jump to assist a rolling takeoff with a heavy load. STOVL carriers are less expensive and generally smaller in size compared to CATOBAR carriers. [27] The British Queen Elizabeth-class aircraft carriers were built to use STOVL aircraft due to the expected cost of an electromagnetic catapult; they do not have the means to generate steam for a conventional catapult.
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a naval force to project air power worldwide without depending on local bases for staging aircraft operations. Carriers have evolved since their inception in the early twentieth century from wooden vessels used to deploy balloons to nuclear-powered warships that carry numerous fighters, strike aircraft, helicopters, and other types of aircraft. While heavier aircraft such as fixed-wing gunships and bombers have been launched from aircraft carriers, these aircraft have not landed on a carrier. By its diplomatic and tactical power, its mobility, its autonomy and the variety of its means, the aircraft carrier is often the centerpiece of modern combat fleets. Tactically or even strategically, it replaced the battleship in the role of flagship of a fleet. One of its great advantages is that, by sailing in international waters, it does not interfere with any territorial sovereignty and thus obviates the need for overflight authorizations from third-party countries, reduces the times and transit distances of aircraft and therefore significantly increases the time of availability on the combat zone.
A seaplane tender is a boat or ship that supports the operation of seaplanes. Some of these vessels, known as seaplane carriers, could not only carry seaplanes but also provided all the facilities needed for their operation; these ships are regarded by some as the first aircraft carriers and appeared just before the First World War.
In aviation, assisted takeoff is any system for helping aircraft to get into the air. The reason it might be needed is due to the aircraft's weight exceeding the normal maximum takeoff weight, insufficient power, insufficient available runway length, or a combination of all three factors. Assisted takeoff is also required for gliders, which do not have an engine and are unable to take off by themselves.
The flight deck of an aircraft carrier is the surface from which its aircraft take off and land, essentially a miniature airfield at sea. On smaller naval ships which do not have aviation as a primary mission, the landing area for helicopters and other VTOL aircraft is also referred to as the flight deck. The official U.S. Navy term for these vessels is "air-capable ships".
HMS Eagle was an Audacious-class aircraft carrier of the Royal Navy, in service 1951–1972. Until the arrival of the Queen Elizabeth-class aircraft carriers in the 21st century, she and her sister Ark Royal were the two largest Royal Navy aircraft carriers ever built.
HMS Ark Royal (R09) was an Audacious-class aircraft carrier of the Royal Navy and, when she was decommissioned in 1979, was the Royal Navy's last remaining conventional catapult and arrested-landing aircraft carrier. She was the first aircraft carrier to be equipped with an angled flight deck at its commissioning; her sister ship, HMS Eagle, was the Royal Navy's first angle-decked aircraft carrier after modification in 1954. Ark Royal was the only non-United States vessel to operate the McDonnell Douglas Phantom at sea.
Naval aviation is the application of military air power by navies, whether from warships that embark aircraft, or land bases.
A submarine aircraft carrier is a submarine equipped with aircraft for observation or attack missions. These submarines saw their most extensive use during World War II, although their operational significance remained rather small. The most famous of them were the Japanese I-400-class submarines and the French submarine Surcouf, although small numbers of similar craft were built for other nations' navies as well.
HMS Ark Royal was the first ship designed and built as a seaplane carrier. She was purchased by the Royal Navy in 1914 shortly after her keel had been laid and the ship was only in frames; this allowed the ship's design to be modified almost totally to accommodate seaplanes. During the First World War, Ark Royal participated in the Gallipoli Campaign in early 1915, with her aircraft conducting aerial reconnaissance and observation missions. Her aircraft later supported British troops on the Macedonian Front in 1916, before she returned to the Dardanelles to act as a depot ship for all the seaplanes operating in the area. In January 1918, several of her aircraft unsuccessfully attacked the German battlecruiser SMS Goeben when she sortied from the Dardanelles to attack Allied ships in the area. The ship left the area later in the year to support seaplanes conducting anti-submarine patrols over the southern Aegean Sea.
The Attacker class were a class of escort aircraft carriers in service with the British Royal Navy during the Second World War.
HMS Avenger was a Royal Navy escort aircraft carrier during the Second World War. In 1939 she was laid down as the merchant ship Rio-Hudson at the Sun Shipbuilding & Drydock Company yard in Chester, Pennsylvania. Launched on 27 November 1940, she was converted to an escort carrier and transferred under the lend lease agreement to the Royal Navy. She was commissioned on 2 March 1942.
CATOBAR is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier. Under this technique, aircraft launch using a catapult-assisted take-off and land on the ship using arrestor wires.
The aircraft cruiser is a warship that combines the features of the aircraft carrier and a surface warship such as a cruiser or battleship.
An amphibious assault ship is a type of warship employed to land and support ground forces on enemy territory during an armed conflict. The design evolved from aircraft carriers converted for use as helicopter carriers. Modern designs support amphibious landing craft, with most designs including a well deck. Like the aircraft carriers they were developed from, some amphibious assault ships also support V/STOL fixed-wing aircraft and have a secondary role as aircraft carriers.
The Heinkel HE 12 was a pontoon-equipped mail plane built in Germany in 1929, designed to be launched by catapult from a liner at sea.
Aircraft carriers are warships that evolved from balloon-carrying wooden vessels into nuclear-powered vessels carrying many dozens of fixed- and rotary-wing aircraft. Since their introduction they have allowed naval forces to project air power great distances without having to depend on local bases for staging aircraft operations.
A carrier-based aircraft is a naval aircraft designed for operations from aircraft carriers. Carrier-based aircraft must be able to launch in a short distance and be sturdy enough to withstand the abrupt forces of launching from and recovering on a pitching deck. In addition, their wings are generally able to fold up, easing operations in tight quarters.
The first involvement Australia had with naval aviation was in 1911, when an Australian-born Royal Navy officer became one of the first four naval officers to receive pilot qualifications. During World War I, the Royal Australian Navy (RAN) experienced several forms of airborne operation, with HMAS Brisbane operating a seaplane, while HMA Ships Sydney and Australia were used for experiments with aircraft launch platforms. An aircraft embarked aboard Sydney was also involved in one of the first naval air battles. Several Australians also flew as part of the Royal Naval Air Service.
In aviation, a ski-jump is an upward-curved ramp that allows aircraft to take off from a runway that is shorter than the aircraft's required takeoff roll. By forcing the aircraft upwards, lift-off can be achieved at a lower airspeed than that required for sustained flight, while allowing the aircraft to accelerate to such speed in the air rather than on the runway. Ski-jumps are commonly used to launch airplanes from aircraft carriers that lack catapults.
Observation seaplanes are military aircraft with flotation devices allowing them to land on and take off from water. Their primary purpose was to observe and report enemy movements or to spot the fall of shot from naval artillery, but some were armed with machineguns or bombs. Their military usefulness extended from World War I through World War II. They were typically single-engine machines with catapult-launch capability and a crew of one, two or three. Most were designed to be carried aboard warships, but they also operated from seashore harbors.
THE HEINKEL K2 catapult installed upon the North German Lloyd liner "Bremen," which figured prominently in the establishment of the recent trans-Atlantic mail record, is the result of two years of experimentation and development by Dr. Ernst Heinkel, its designer.
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: CS1 maint: archived copy as title (link)THE HEINKEL K2 catapult installed upon the North German Lloyd liner "Bremen," which figured prominently in the establishment of the recent trans-Atlantic mail record, is the result of two years of experimentation and development by Dr. Ernst Heinkel, its designer.