The internal design of an underground shelter
Photos made inside underground shelters PLA Air Force, usually strongly enough and they are usually low-properties. Most likely, this is done intentionally. Naturally, the PLA Air Force has nothing to gain from the spread of such materials, moreover, it indicates a possible opponent in the feeble hand of their design and use.
Inside of the explosion-proof device of external gate width of 14 meters in the air base Gjadër Lezhë-Zadrima in Albania. On the frontal plane posed by China J-6 Farmer Albanian Air Force, with the covers guns NR-23.
The appearance of open convex outer gate of the underground blast proof shelters width of 14 meters in the air base Gjadër Lezhë-Zadrima in Albania. The main convex outer gate Blastguard strengthened so that the excess pressure to pass the explosion on the outer frame. The upper outer Blastguard gate closed.
Another appearance of the open convex outer gate blast proof underground shelter width of 14 meters in the air base Gjadër Lezhë-Zadrima in Albania. The upper gate is hinged on the right side of the gate. The concrete arch over the main entrance is the appropriate features observed on Chinese airfields. On the frontal plane posed by China J-6 Farmer Albanian Air Force.
Chinese airfields candidate can serve airports in other countries, built according to the same rules, design and technical features. Several countries have purchased a significant number of Chinese aircraft from the 1960s, but only North Korea and the former regime of Hoxha in Albania also imported design data and built airfields with underground shelters on the specifications of the PLA. Albania has received constant support from China before the end of the 1970s, before their cases dropped.
The geometry of the outer gate of the underground blast proof shelters width of 14 meters.
The geometry of the internal explosion-proof gate underground shelter width of 14 meters.
The main tunnel width of 14 meters in the air base Gjadër Lezhë-Zadrima in Albania. On the frontal plane posed by China J-6 Farmer Albanian Air Force. The right of the aircraft available for traffic tf.
The main tunnel is 14 meters wide Gjadër Lezhë-Zadrima airbase in Albania. The design is a linear segments. Pay attention to the sheet lining.
Small branching tunnel width of 14 meters in the air base Gjadër Lezhë-Zadrima in Albania. This example is used to illustrate the maintenance of aircraft, in a case of substitution of the motor J-7 Fishbed.
View from a different point of the same tunnel underground shelter 14 meters wide Gjadër Lezhë-Zadrima airbase in Albania.
Chief tonnel width of 14 meters in the air base Gjadër Lezhë-Zadrima in Albania.
Chief tonnel width of 14 meters in the air base Gjadër Lezhë-Zadrima in Albania, is seen as wriggle tunnel and aircraft J-7 Fishbed of early models.
Kutsee offshoot of a width of 12 meters underground shelter at Tirana-Rinas airbase in Albania. This tunnel is about 60 feet long, which is rather for 4 aircraft J-6 Farmers.
A number of key observations that can be made by analyzing the image shown:
Placing a: The main tunnel connecting the pair of main entrances, usually consists of straight sections, which are flanked by a curved portions. This is one of the possible major layouts and may be the most common for the building;
B Accommodation: Blind tunnels branching off a length of about 60 meters, connected to the main entrances to the tunnel. In the Albanian underground shelters they are used to perform a more profound aircraft maintenance unit or to accommodate several aircraft parked nose to tail. Of available images can be concluded that the blind tunnels connected to the main tunnel at right angles;
Geometry: There are two main section of the tunnel. The first has the usual cross-section width of about 12 meters straight to the floor tunnel. This geometry is used in an underground shelter in Tirana-Rinas. The other has a cross-section of approximately 14 meters in width coupled with vertical walls 3.4 meters in height with a total internal height of the arch at 6.3 meters. Last geometry used in air bases in Gjadër / Lezhë-Zadrima and Kuçovë;
Inputs and internal gate: The main entrance to the tunnel at air bases in Gjadër / Lezhë-Zadrima and Kuçovë through the inverted T-shaped main gate. Suspended external Blastguard gates consist of several parts of the iron horizontally opening complemented lowest vertical iron gate opening for the passage of the vertical tail plane (see illustration above). It is unclear whether such a structure is quite tight when using weapons of mass destruction, although it may be unnecessary to maintain the pressure inside the shelter to ensure germitizatsii closed inner gate. Internal door naturally used for weather protection criteria;
Explosion proof outer gate; The left and right main and upper wing blast-resistant convex small radius of curvature of the gate made of steel. Photos available at the gate or have a circular cross-section or chain distortion created to transfer the load from the pressure of the explosion on the outer frame of the gate. Swing gates open outward on hinges so that they are aligned with the inner side of the left and right inner wall of the tunnel. Explosion proof gate and the upper walls of the concrete structure located at a distance of 7 meters from the tip of the mound to defend a Blastguard open the gates;
Internal Explosion proof gate: In the hangar at the air bases in Gjadër / Lezhë-Zadrima and Kuçovë second pair of swing gates makes a typical explosion-proof lock for increased protection from shock.
The internal structure: The inner walls of the tunnels are made of reinforced concrete. It appears that the method of construction provides for the creation of frames, wood flooring for the formation of mold and pouring concrete in rather short intervals of 2 to 3 meters. Twelve-meter tunnel in the Tirana-Rinas has traces of the adjacent parts of the concrete is poured. Cheryrnadtsatimetrovye tunnels in Gjadër / Lezhë-Zadrima and Kuçovë have an additional internal reinforcement of iron I-beam with an interval of 3 meters per linear sections of the tunnel, and only 1 meter by turning the tunnel . Most likely it was the reinforcement of the final construct was also used to support the formwork during construction. Of the tunnel in Gjadër / Lezhë-Zadrima show sagging mold during the pouring of concrete.
Pebbles: Seepage water is clearly seen in the tunnel connections between sectors in sufficient quantities to keep puddles in both tunnels in Gjadër / Lezhë-Zadrima and Kuçovë;
Surface finish: Parts of the walls of the tunnel in Gjadër / Lezhë-Zadrima lined snow-white or bright enamelled metal sheets, the same thing is observed in the tunnels of the PLA. The walls of the other tunnels in Gjadër / Lezhë-Zadrima and Kuçovë or plastered or smoothly plastered. A probable prerequisite facing metal sheets can be improved tunnel lighting, improved VHF propagation of radio waves in a tunnel or corridor hide communications;
Layout: Chetyrnadtsatimetrovye tunnels snowy broken line marking 10 meters along one side of the storage planes, and the other four meters for cars driving on the length tunnel. Tunnels PLA Air Force seems to use a similar system.
The design of the tunnel is very chetyrnadtsatimetrovogo vserasprostranennoy in Chinese shelters and apparently is even more recent than the twelve-tunnel design. The internal volume of the hangar large enough to aircraft and provides considerable freedom of movement for refueling, loading guns and ensure the movement of other vehicles.
Chart location of shelters on Gjadër / Lezhë-Zadrima and Kuçovë Roland Büchler were compiled after his visits and have photographic confirmation.
Gjadër / Lezhë-Zadrima (see above) and Kuçovë (see below) shelter use horseshoe / linear segmented arrangement (© Roland Büchler).
Most likely, the aircraft is always towed in one entrance and removed from the other. Aircraft returning from operations, will be located at the end of the queue and then the tunnel will be equally appropriate service, refueling and loading of ammunition as they approach the other end of the tunnel. Aircraft that require more maintenance time, will be located in the branches of the tunnel, so as not to interfere with routine maintenance, refueling and re follow the tunnel aircraft.
The design of the outer blast proof doors, observed in Albania, like the famous image of Chinese explosion-proof gate underground shelters, but differs from the others, having a variety of different design features. Explosion proof gate Albanian structures capable of withstanding the shock wave and shrapnel bombardment. It is unlikely that one would rather blast proof doors to withstand the modern penetrating munitions, such as the GBU-39 / B or BLU-116 / B. Maybe they reflect the chronological age structure, built in the era of "dumb" munitions. If closed, the inner and outer gates, inner gate is likely to suspend small ammunition that will be able to seep through the outer gate.
The design of the inner gate in these tunnels is not particularly reliable in danger of attack by guided missiles of "air — land." Penetrating ammunition, broke through the outer gate is likely to knock out the inner door panels or the connection between the panels and even if the ammo will not penetrate inside the refuge, then, most likely, his power will be quite so jam one or two gate leaves, except for their effective functioning.
The design of the outer blast proof doors asylum
Materials from public sources indicate the existence of several different structures blast proof doors, at least two types of gates are used to shelter the size of a "MiG" and at least the last one for the size of the shelter under the "Beagle" and one for hiding the size of "Badger". They carefully described below. Images provided razlyubezno Roland Büchler.
Shelter at the airbase Luyan / Ranghe-Zhen Sliding segmented outer gate size under "Badger". Were produced more side tunnels to provide regular input to the shelter at the open outer gate.
Above and below in detail outer gate at the airbase Luyan / Ranghe-Zhen.
The air base Luyan / Ranghe-Zhen (see above) and Zhangjiakou (see below) Explosion proof exterior doors up under the "Beagle". Sliding sash usually open at one side.
The air base Zhangjiakou, Explosion proof exterior doors up under the "Beagle".
Satellite imagery indicates that this is the size of the hangar under the "Beagle" at the airbase Luyan / Ranghe-Zhen on the eastern slope of the mountain to the south of the size of a pair of hangars "MiG" abandoned. Built a brick wall to block the entrance.
Above and below: Suspended Blastguard gate size asylum under the "MiG" on an unidentified Air Force Base.
Open suspended Blastguard gate size asylum under the "MiG" on an unidentified Air Force Base. Pay attention to camouflage net stretched over the entrance.
Shelter at the airbase Luyan / Ranghe-Zhen Sliding segmented outer gate size by "MiG" on the eastern slope of the mountain.
Suspended Blastguard gate underground shelter under the size of the PLA Air Force "MiG".
In the continuation of the article:
Strategy, design and capacity of underground air bases PLA
The vulnerability of underground air bases
Overview of all underground air bases PLA
Rate of capacity underground air bases PLA
Details of the design and construction of underground air bases
The general plan of the location of the air base