Tank and Burning Well: the story of the birth of the Big Wing machine
A later version of the Big Wing based on the VT-55A. An early version based on the T-34 was in operation in Kuwait. Source: fotoload.ru
Working to the limit
In the previous stories it was about armored vehicles developed in the Soviet Union for extinguishing army arsenals.
Powerful armor and tracks allow the vehicle to come close to the hearth, protecting the crew from high temperatures. Burning flares of oil and gas wells are no less dangerous. A burning ammunition depot, in the most extreme case, can not be extinguished at all - it is enough to evacuate residents from the zone of potential damage.
But with a well, everything is much more complicated.
Suffice it to recall what hell in the desert was staged by Saddam Hussein in 1991 in Kuwait. On his order, the retreating troops set fire to several hundred oil and gas wells, staging a local apocalypse in the region. Residents suffered not only from the smoky stench, but also from acid rain - the oil was saturated with sulfur compounds, which were transformed into toxic substances in the atmosphere.
At the same time, you cannot simply throw fiery torches, they can burn for years, spending valuable resources and polluting the atmosphere.
That is why fire departments pay special attention to techniques and methods of suppressing such fire dragons.
In the "simplest" cases, when the well debit is relatively small, it is possible to do with extinguishing the wells with water from ordinary fire nozzles.
To do this, prepare up to 20-25 barrels, who line up around the wellhead at a distance of 30-40 meters, and fill it with water. The water flow from each barrel must be at least 7 liters per second, that is, at least 150 liters of water are consumed by the burning torch every second.
Special skill of firefighters is required for simultaneous mixing of water from the shafts at one point above the wellhead. At the same time, it is important not to get water into the lower edge of the flame, otherwise it will be impossible to tear off the fire from the flow of oil or gas.
To understand the specifics of extinguishing such fires, the gas outflow speed is close to the speed of sound, the height of the column of fire is up to 25 meters, the sound pressure exceeds 120 dB, and the temperature of the soil around the hearth can reach 150 degrees.
The technique of manual extinguishing of the torch in such conditions works only in fields with low productivity. If oil and gas are gushing with greater intensity, explosives are required. A shock wave from several hundred kilograms of explosives should tear off the gas-air medium between the pipe mouth and the lower edge of the flame.
In successful cases, the pressure of oil and gas simply did not keep up with the elusive flame and the fire stopped.
There were cases when it was necessary to detonate about half a ton of TNT, but the torch did not go out. Then underground nuclear explosions went into action, blocking the well forever.
For obvious reasons, no one approved of such fire pyrotechnics, and the engineers had to look for new technical solutions. The most effective extinguishing method turned out to be using decommissioned turbojets aviation motors.
Turbojet engines extinguish
The first who proposed to extinguish wells using the products of combustion of motor fuel was a Hungarian engineer and head of the fire brigade of Budapest, Cornel Silvai. He patented in 1924 an installation with an aircraft engine, the exhaust gases of which suppressed combustion. Sometimes not by themselves, but paired with a dry extinguishing powder, which the pre-cooled gases were taken with them from a special tank.
Fire fighters could vary the extinguishing method - remove powder from the mixture, add water, or simply put out the fire with exhaust gases. The installation in a single copy was mounted on a 5-ton truck and until 1944 successfully extinguished the burning Hungarian capital.
The inventor Silvai became famous not only for the development of a "motor-fire extinguisher", but also for the very idea of extinguishing the flame with gases - nitrogen, carbon dioxide and others.
The next step to the firefighter tank Big Wing (strong wind) are Soviet developments in gas-water extinguishing systems.
Research began in the 60s and initially used gases from the VK-107 turbojet engines of the MiG-15 fighter jet as a fire extinguishing agent. Each such engine per second produced up to 40 kilograms of combustion products with a temperature of 600 degrees. But in this hot mixture, unburned fuel came across, which did not contribute to fire extinguishing at all. And the gas temperature of 600 degrees was excessive.
Therefore, it was decided to supply water to the "exhaust gases" of the turbojet engine.
Firstly, it cooled the gas mixture well, and, secondly, a water mist was formed, which increased the extinguishing efficiency.
This is how the first Soviet installation AGVS-100 or a gas-water extinguishing vehicle with a fire extinguishing agent flow rate of 100 kg / s was born.
The outboard engine from the MiG-15 and MiG-17 was installed on the ZiL-157 chassis and equipped with a nozzle with three LS-20 water barrels. Naturally, at an exorbitant water flow rate of 60 l / s, at least two fire tankers were assigned to each AGVS-100 unit. Water was also required to cool the installation itself - here the motor itself warmed up, and the radiant energy from a burning well could disable the installation.
As a result, the burning fountain of the well received a jet stream from AGVS-100 at a speed of 2000 km / h, saturated with water, water vapor and cooled inert gases. The jet had a length of up to 40 meters and a diameter of up to 15 meters.
One machine could put out a well in 10-15 minutes with a debit of up to 3 million cubic meters of gas per day. For large volumes, three or four machines were brought together, which simultaneously suppressed combustion.
The developments on the AGVS-100 car were used by Hungarian engineers, only instead of the ZIL-157/131 wheelbase it was decided to use a tank chassis.
Big wing
For the first time, the idea that the capabilities of AGVS-100 were not enough appeared among the Hungarians in 1979, when they could not put out the gas fountain in the area of the town of Jean for a month.
It was decided to double the power by installing twin turbojet engines on the T-34 tank chassis.
The task was given to the Department of Aero and Thermal Engineering of the Budapest Technical University. The development was also attended by specialists from local oil and fire brigades.
As sprays on the roof of the tank, two turbojet TRD-11F300 were installed, each of which consumed more than 65 kg of air per second.
A tracked vehicle was built at the Central Aviation Equipment Repair Plant in Kecskemet only by the summer of 1991.
The result is a 38-ton monster, consuming more than 6 tons of kerosene per hour and hitting the flame with a 100-meter tongue of a gas-water mixture.
Hungarians have provided for a wide range of extinguishing agents - water, heavy foam, medium foam and dry powder materials. I must say that the T-34 with two turbojet engines was a real "lighter" - there were at least 3 tons of kerosene on board, not counting the diesel fuel for the tank engine. This did not allow the vehicle to approach the torch more than 30-40 meters.
The tracked fire engine received the name Big Wing during the elimination of the burning oil gushers in Kuwait - the Americans were very impressed with the efficiency of the installation.
This experience was not in vain for the Hungarian engineers, and immediately after the Kuwaiti business trip, the T-34 chassis was replaced with a VT-55A tractor platform. The re-equipment was carried out at the Danube Aviation Plant, after which the car was handed over to the local oil and gas company MOL.
At the moment, this is the only car in its class in the world, and in Hungary itself, work on the modernization and development of the structure is not being carried out.
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