At the end of the twentieth century, the aircraft pushed the ship's artillery and became a universal tool of the Navy. Modern steam catapult accelerates 35-ton aircraft to 250 km / h in 2,5 with a plot in 100 m. With the help of four catapults, radio-electronic equipment and well-trained aircraft carrier specialists in the daytime can launch two and take one plane every 37 seconds. But if the catapults cease to work, this hundred-thousand-meter ship becomes a complete military impotent.
With the need to accelerate the aircraft so that it could take off, the creators of the first vehicles were already heavier than air. In the 1894 year, 10 years before the flight of the Wright brothers, Alexander Bell (the inventor of the telephone) and Samuel Langley (at that time, the scientific secretary of the Smithsonian Institution in Washington) observed the launch of a model with a steam engine on the bank of the Potomac River. Langley gave the command, the aircraft "Airfield number 4" accelerated and ... flopped into the river.
After that, Langley formulated the problem, which to this day faces aviation Engineers: “An airplane, like a bird, needs a certain speed in order for it to start using its flying mechanism. Difficulties with a set of initial speed turned out to be significant, and in ordinary field conditions generally exceeded all expectations. " The device that Langley invented can be called the great-grandfather of all air catapults: the plane was fixed on a trolley that rolled along two wooden rails about 25 m long. The trolley was accelerated using a cable attached to a coil spring removed from the tram and passed through the chain hoist system . When the trolley reached the edge of the runway, the lock was opened, and the trolley moved further by inertia.
In 1903, the Great Airfield, the 300-kilogram “bird with steel ridge and gasoline engine,” waited for its launch from a catapult mounted on a small barge owned by Samuel Langley. The rope was cut down, the springs pulled the plane. Volunteer pilot Matthew Manley, assistant Langley, later recalled: “The car quickly, like lightning, picked up speed 35 km / h. When the plane reached the end of the upper stage, I felt an unexpected blow, followed by an indescribable feeling of free flight. But I did not have time to enjoy this joy, having understood that the car was flying down at a sharp angle ... The blow of the wings against the water was so powerful that I did not immediately come to my senses. Fortunately, I did not drown. ” The lock of the catapult that held the plane and was supposed to release it at the moment of the end of the acceleration did not work. The "airfield" could not gain altitude and, like a load on a rope, flew into the river.
One of the pioneers of aviation - a competitor of the Wright brothers - Professor Samuel Langley. It was he who tried to build the first catapult to launch aircraft
Two months later, Langley made another attempt. Alas, this time the "Great Airfield" did not even get to the end of the acceleration site. The design flaws of the aircraft itself were to blame. Time did not give Langley a third chance - he ran out of money (he spent $ 50 000 on a catapult!), And just nine days after this accident, the Wright brothers made their first successful flight, speeding up a $ 2 4 wood bar using the engine and ... strong wind. The Wright brothers quickly realized that without a wind their plane could not take off. Therefore, they had to create the first working aviation catapult. The energy source was an 500-kg load lifted to the height of 5 m. A finger-thick cable went from the load to the tackle at the base of the supporting tripod, and then along the guide rail to the aircraft. When the load fell, the chain hoist increased the trip length by three times to the required 15 meters. This invention was another proof that all ingenious is simple.
The catapult operated so successfully that the Wright brothers were convinced that all future aircraft will be heavier than air and take off with the help of a catapult. But over time, the aircraft engines became more and more perfect and more powerful, and European pilots mastered the unattended takeoff on pneumatic tires. Soon, the Wright brothers switched to inflatable wheels. However, the catapults not only did not disappear, but bloomed in bloom where planes did not have enough room for dispersal. The main scope of their activities was the deck aircraft.
And although his attempts did not end in success, his achievements became the basis for modern catapults.
In 1912, Orville Wright wrote a letter to the command of the newly created US Naval Aviation. The newly minted sea pilots had little idea what to do with the aircraft received. As a temporary measure, Wright proposed building a deck on warships that would serve as a runway. However, everyone understood that this “ceiling” in combat conditions would become an obstacle to guns. The ideal solution would be a special large ship with a full-size runway (which was then called a "floating airfield"), but it was obvious that the number of such ships would be limited. For small ships, Wright suggested a "launch system using a catapult."
Sailors created a catapult based on a pneumatic torpedo trigger. Something, and even compressed air on large warships was enough. In the same year, 1912, the first attempt was made to take an ejection from the Santi warship. Unfortunately, the military poorly studied the experience of Langley. The Curtiss A-1 flying boat was located on the trolley so that the nose was free. During acceleration, the nose rose, the plane sharply reared and ... collapsed into the water. After this incident, the aircraft’s nose was fixed and the air supply was adjusted with a special valve. Just four months later, the military carried out the first ejection start from a stationary barge, and in November 1915, the plane took off with the help of a catapult already from a moving ship.
In the 1916 year, the 30-meter catapults were installed on three American cruisers (North Carolina, Huntington and Seattle). The catapults occupied 20% of the upper deck area and covered half of the guns. In the year 1917, when America entered World War I, they were removed. Then the advantage of catapults and deck aircraft was still not obvious.
From pneumatics to hydraulics
At the start of the 1920's, it became obvious that without air protection, warships would become very vulnerable. Shipboard catapults got into big politics. The US Navy received an improved catapult, which they promised to quickly put on all warships. Experimental catapult length 24 m, installed on the ship "Maryland", could accelerate the aircraft mass 1,6 t to 75 km / h. Within a few years, 3,4 tons of aircraft began to be dispersed to 100 km / h at a distance of 17 meters. By the middle of the 1920's, the US Navy regularly used catapults on ships of various types. Launcher positioned on a turntable, which did not interfere with the guns and allowed to launch aircraft against the wind. At first, pneumatic, and later, gunpowder gas generator starting installations, serviced airplanes weighing up to 3,5 t. This was enough for a limited range and little armament of reconnaissance aircraft. The concept of catapult launches fighters gone into the shadows, the main priority was the creation of large aircraft carriers, providing take-off aircraft without a catapult.
On the first (experimental) aircraft carrier Langley, which entered service in the 1922 year, pneumatic catapults were installed, but in the 1928, after three years of inactivity, they were dismantled. In 1925, two serial aircraft carriers, the Lexington and Saratoga, were launched. Due to the fact that their speed reached the 30 nodes, the entire 120 m was enough for the aircraft to take off. The rest of the 270-meter deck was used for parking and pre-flight preparation of the aircraft. Both aircraft carriers were equipped with flywheels catapults. The electric motors spun the six-ton flywheel, which, using a conical friction mechanism, transferred the stored energy to the booster. The installation could accelerate an 4,5-ton aircraft to 90 km / h, but its main problem was the jamming of a rapidly rotating wheel. The Lexington and Saratoga catapults were rarely used, and soon they were also dismantled. Starting from a large floating airfield for planes of that time did not pose any particular problems, and the question of what happens when planes become heavier and faster doesn’t bother anyone.
In September, the United States Navy 1931 began to develop a new generation launcher, completely located below deck, so as not to interfere with the takeoff and landing. First, the device worked on compressed air, then gunpowder gas generators were tested, and in 1934, they decided to use hydraulics. Five years after that, the first aircraft launches from the new Yorktown and Enterprise ships proved the success of this concept. First time in stories deck aircraft could taxi to the starting position and start on their own wheels.
Unfortunately, these achievements were of no interest to anyone, because the sailors continued to exaggerate the old idea of creating even more high-speed and even larger aircraft carriers that would do without catapults.
Floating airport. The aircraft carrier Constellation, commissioned in 1961 and taking part in the Vietnam War, was a formidable force. Up to 2003 of the year
Back to couple
During World War II, almost all ground-based fighters operating in the Pacific Ocean, were installed nodes for the ejection start. The development of catapults was one of the most important events of wartime in the conduct of naval operations. Immediately after the end of the war, when the first jets appeared, which did not differ in good take-off and landing characteristics, hydrocapults became indispensable elements even on the largest aircraft carriers. Carts, ropes and tackles Langley were present in this design. The weight of the aircraft increased, and the requirements for catapults increased, their power, size and complexity increased. They could already accelerate 6-ton aircraft to 200 km / h, and 28-ton - to 115 km / h. The equipment worked at full load, which sooner or later inevitably should have led to trouble. In 1954, a hydrocapult explosion occurred aboard the Benington ship, killing 103 people and injuring 201. Hydro-catapults have reached their limit, but the aircraft have already outgrown it: the 37-tonne Douglas A-3 Skywarrior, first launched by the Benington catapult a year before the tragedy, exceeded the capabilities of any hydrocapult existing in nature.
In 1950, Englishman Colin Mitchell developed a new starter design that used the good old steam. The first American ships on which steam catapults were installed were aircraft carriers of the Abraham Lincoln class (four on each, with a total mass of 2000 tons, the destroyer of the Second World War weighed so much). Steam catapults are used now - it is these that stand on the most modern aircraft carriers.
The control station for catapults is actually at deck level, provides all-round visibility and is protected by bulletproof glass
Writer Sherman Baldwin in the book about the naval pilots who participated in the operation “Desert Storm” described the night start in the following way: “My head was pressed against the head rest of the chair. The devices became unsharp, the eyes went to the eye sockets, the plane shook violently until it finally broke out into the pitch black of the night. ”
At the very beginning of the start, the pilot experiences an overload in 6 g, and then it quickly decreases to 3 – 4 g. Since the deck aircraft must withstand heavy loads at launch, it must have an additional margin of safety, which increases the weight of the structure and degrades the flight characteristics. The human body is sensitive to acceleration, so the pilots have to select and prepare for a special program. Smooth, without jumps, acceleration has a positive effect not only on the health of the pilot, but also on the life expectancy of the aircraft.
To resolve this issue, the US Navy is developing an electromagnetic aircraft launcher, in which the aircraft instead of steam pistons will be accelerated by a linear induction engine (LEAD). This principle is applied on monorail roads, as well as in some high-speed magnetically levitating trains, which can reach speeds up to 400 km / h. The main difficulty is how to get enough energy. The new American aircraft carrier, which must get off the stocks in 2014 – 2015, will need 100 million joules for just one launch. This energy is enough, for example, to throw a car over a distance of 15 km. The new “purely electric” aircraft carrier CVN-21, whose power is three times greater than that of any Nimitz-class aircraft carrier, simply cannot generate this amount of energy. However, it can be saved: electric generators will supply energy to special drives for each of the catapults. Upon command, the electric power will go to the LEAD, in the process of acceleration, the winding segments behind the aircraft will be disconnected, and ahead of the aircraft - to be connected. This will help save energy, and most importantly - more precisely control overclocking. At the end of the acceleration, the cart will not be stopped by a hydraulic brake, as in the steam system, but by electric forces.
The electromagnetic plant has a performance of 29% more than a steam one, and it is able to accelerate an 45-ton aircraft to a speed of 250 km / h. It is assumed that a softer launch mode will increase the aircraft's life by 30%. The novelty will make more departures with a smaller number of technical staff. All this sounds attractive, but it is still unknown how this system will work in real conditions at sea. Will the screens reliably protect people working near the catapult? How will the electronic equipment of the ship and aircraft respond to such powerful electrical installations? LEADs are much less studied than steam engines, so a full-sized ground-based electromagnetic catapult is currently being built at a naval base in Lake Jersey, New Jersey (the world capital of the ejection case).
But despite the extensive experience in the construction of aircraft carriers, the United States is not a "monopolist" in the field of catapults.
At deck level, view of the catapult