1. Organization of Air Defense of Objects in the Rear and Ways to Inform the Forces of the Korean Peoples' Army and Chinese Volunteers
Changes in the makeup and organization of air defense artillery units and formations. During the course of the war the amount of air defense artillery in the KPA grew continuously, and the methods of controlling were also improved. In October 1950 one additional air defense artillery regiment, ten independent antiaircraft artillery battalions, and two antiaircraft machine gun companies were formed. There was a particularly significant growth in antiaircraft artillery means once the Chinese Volunteers entered the war, the troops of which had both antiaircraft artillery divisions as well as independent antiaircraft artillery regiments. The CPV independent antiaircraft artillery regiments had the same organization as those of the Korean forces.
By early 1952 the makeup of the antiaircraft artillery of the KPA and CPV included 4 antiaircraft artillery divisions, 18 independent antiaircraft artillery regiments, more than 80 independent antiaircraft artillery battalions and around 20 independent antiaircraft machine gun companies.
The quantity and quality of the rise in antiaircraft artillery means of the KPA and CPV during the course of the war is shown in Table 24.
Table 24.
Weapons and machine guns Time Frame Prior to the start of the war in 1950 Up to November 1950 Up to November 1951 Up to early 1952 Up to mid 1953 85mm guns 24 36/51 = 87* 12/64=76 55/95=150 195/144=339 76mm guns - - - 0/12=12 32/12=44 37mm guns 48 88/77=165 41/256=297 270/747=1017 509/979=1488 Total guns 72 124/128=252 53/320=373 352/854=1179 736/1135=1971 12.7mm
AA MG30 227 112/144=256 961/2556=3517 853/2442=3295 *The numerator is KPA weapons/denominator is CPV
For command and control of the antiaircraft artillery armaments, the PUAZO-2, PUAZO-3, the SON-2, SON-3k, and SCR-584 fire control radars, and the all-around search radar AN/TPS-3 and LV were used. (2) The number of weapons aiming stations was insufficient. Only 5 antiaircraft artillery regiments in the CPV had weapons aiming stations for all of the medium caliber weapons in those regiments. The rest of the antiaircraft artillery units in both the KPA and CPV had a nearly complete lack of weapons aiming stations, or had only one weapons aiming station per unit.
Organization of antiaircraft artillery cover of objects. The KPA and CPV antiaircraft artillery provided cover for Pyongyang and objects on its periphery up through mid 1951 and part of the forces also protected the lines of communications in the belt just behind the front.
Starting in June 1951 additional air defense protection was organized to cover the crossings over water obstacles in the areas of Anju, Siniuju, and Supungdon, built near the operational airfields of the KPA and CPV, the hydroelectric station in the Supungdon area, storehouses and supply centers. Protection of the railway stations and bridges and road sectors Siniuju-Tonju-Anju; Ponwonri-Sungchon-Pyongyang; Songchon-Tonju-Anju-Pyongyang was given to light antiaircraft artillery, allocated in regimental strength, to defend the crossings. Up to 1952 there was no centralized control over the antiaircraft artillery covering objects in the rear area. Antiaircraft artillery units operated independently, based upon their situation.
In February 1952 the Unified Command of the KPA and CPV took measures to subordinate the combat use of antiaircraft artillery as part of the overall air defense protection of objects in the DPRK. With this goal in mind, 40% of the antiaircraft units were dedicated to railway protection, 20% to protecting storehouses and supply points, 20% to covering airfields and electrical power stations, and 20% to protection of troops on the battlefield.
The conduct of these measures increased the responsibility of the corresponding chiefs for correct use of antiaircraft artillery and methodological improvement in the organization of antiaircraft artillery in covering objects and ways of informing them.
Antiaircraft artillery in air defense of objects in the rear area (airfields, electrical power stations, bridges and crossings) was used in consideration of the nature of enemy aviation operations, the tactical and technical data of his aircraft, and most important, the tactical and technical capabilities of the antiaircraft weapons themselves. (3)
The primary requirement for the force grouping of antiaircraft artillery was to ensure the largest density of fire possible along the routes of ingress for aircraft to the probable bomb line, which was based on a speed of the target of 130 meters per second and at an altitude of 8,000 meters.
The mountainous nature of the terrain placed a corresponding influence on the organization of the antiaircraft artillery coverage of the objects. Normally the combat order of antiaircraft artillery units and subunits was determined by the most approachable way to their positions and areas on the peaks that provided them room to deploy their weapons and devices. The battery moved forward in the direction of the possible approach of enemy bombers to their objectives.
Besides the primary firing position, each battery had one or two reserve firing positions. The reserve positions were selected such that occupying them would not disrupt the system of fires along the primary approaches of enemy aircraft to their objectives. The changing of firing positions, if the situation required it, was carried out by medium caliber antiaircraft artillery batteries once a month, and once every two weeks for light antiaircraft batteries.
When defending an object the medium antiaircraft batteries were deployed 1.5-2 kilometers from the object and with intervals of 3-4 kilometers between the batteries; light antiaircraft batteries deployed closer to the object, based on the terrain.
An exclusive item was the antiaircraft artillery force grouping covering the railway bridge over the Yalu River in the Siniuju area. When creating this force grouping it was assumed that the USAF would not violate the state borders of the PRC. Therefore the bulk of the medium and light antiaircraft artillery batteries were deployed in Korean territory and in a wider disposition of combat order (see Figure 26).
Medium antiaircraft guns were deployed at the corners of a trapezoid at a distance of 25-30 meters from the PUAZO. If the area did not permit such a deployment, the weapons were placed in two lines on the slope of a hill with the PUAZO located higher up the hill by 100-150 from the center of the firing positions. In isolated cases the weapons would be deployed on two neighboring hills.
The weapons tracking station of the SON-3k was deployed to the flanks or the rear of the battery commander's observation post, but the seeker component was located on the military crest of a hill. The place for its deployment was selected to provide the seeker with the greatest possible range of acquisition on various azimuths.
When defending operational airfields part of the light antiaircraft batteries were moved 4-5 kilometers from the airfield in the direction of landing/takeoff from the runways in order to provide fire support against enemy fighters attempting to attack the UAF aircraft when landing or taking off. (4) The command posts for the chiefs of air defense posts and regimental commanders were placed on hills in order to provide all around visibility and the ability to see both the combat order and the protected object. Regrouping of forces and means was carried out, as is correct, during the hours of darkness.
Organization of the control of antiaircraft artillery fire. In order to control antiaircraft artillery fire covering objects in the rear area, chief of air defense posts were designated who were able to make independent decisions on repulsing air raids.
Control of antiaircraft artillery fire, in the defense of airfields and electrical power plants, responded to the chiefs of air defense posts based on the decisions to repulse raids made by the commanding general of the UAF. Under the UAF commanding general an antiaircraft artillery command post was established which responded to the overall leadership in combat operations of antiaircraft artillery. The command post had landline and two radio channels for direct communications with the chiefs of the air defense posts. The air defense command post controlled the overall mission to repulse air raids.
The chief of an air defense post gave orders to the regiments (batteries) when repulsing an air raid, which was drawn from the overall air situation in comparison with their own weapons firing capabilities.
Decentralized fire control was only permitted in those instances when friendly fighter aviation and small groups of enemy fighters were active in the same zone at the same time.
Reconnaissance of aerial targets was carried out by all-around radar stations (SKO), fire control radar stations (SON), and observers who were placed at all command posts and firing positions.
The SKO picked up the raid when they were 130 kilometers from their objectives, and the SON radar picked them up at 100 kilometers. When the targets were moving at speeds of 750-900 kph this range of acquisition provided for opening fire at predetermined range limits.
The basic variations on antiaircraft artillery battery operations were based on careful study of the nature of enemy air operations.
The proposed variations of battery and regimental operations were as follows: when repulsing enemy bomber raids against an objective from one direction and with various intervals between aerial targets (1, 1.5, 2, 3 or more minutes) and under conditions of enemy use of radar jamming; when repulsing enemy bomber raids from two directions simultaneously and at various intervals under conditions of enemy use of radar jamming; and when repulsing enemy bomber or attack aircraft raids against an objective from one or two directions with simultaneous strikes against the antiaircraft artillery combat order.
Combat practice underscored having all officer staffs develop and study the variations of operations by antiaircraft artillery batteries and regiments, and that provided them with the ability to successfully repulse enemy air raids, reduce the amount of time to make decisions, and in case of a disruption of communications provide for the correct independent operations by commanders of batteries and regiments.
Antiaircraft artillery fire control was supported by communications organized as follows: from the antiaircraft artillery divisions to the antiaircraft artillery regiment command posts using three landlines and two radio channels (one radio net and one radio link); from the antiaircraft regimental command posts to the light antiaircraft battalion command posts and medium antiaircraft battery command posts via two or three landlines and two radio channels (one radio net and one radio link); from the light antiaircraft battalion command posts to the battery command posts via one landline and one radio channel; from the division and regimental command posts to the all-around radar stations and two or three fire control radar stations via one landline and one radio channel.
Beside that, all medium antiaircraft gun batteries were hooked together in a field telephone loop via two lines and with radio via two channels in order to support firing by SON radar data from a neighboring battery. Practice validated that this communications arrangement had to be organized on two lines - one for transmission of azimuth and one for transmission of point-of-aim angle. (5) These communications lines could be used as backup in case of a disruption of the primary lines.
In order to ensure communications survivability all communications nodes were placed under cover, telephone lines in the areas of batteries and command posts were buried in shallow trenches of up to 70 centimeters deep. In case of a broken antenna from a shock wave of a strike on a command post, all posts had spare antennas prepared which could be set up in one minute.
The permanent duty command posts were manned by full combat crews, but in case of repulsing a surprise attack by low-flying aircraft 50% of the antiaircraft artillery assets were kept at Readiness No. 1 all the time.
Organization for Cooperation Between Antiaircraft Artillery and Fighter Aviation. In order to repulse enemy air raids, commensurate forms of cooperation were established, based upon the prevailing conditions.
When repulsing mass enemy bomber raids during daylight, and under conditions of clear skies or with the cloud ceiling at 6,000 meters or higher, fighter aviation was used to destroy the enemy in their zone of responsibility and antiaircraft artillery in their zone at all altitudes. Antiaircraft artillery fired only when their own fighters were not attacking the targets or when they were prepared to open fire upon the enemy when their fighters disengaged from combat.
When repulsing large raids, as well as small groups and single enemy aircraft during daylight when the lowest cloud level was at 1,000-3,000 meters, fighter aviation would destroy the enemy in their zone at all altitudes and in the antiaircraft artillery zone above the cloud deck. Antiaircraft artillery would engage the enemy below the cloud deck. In isolated incidents, at the command of the command post of the Unified Air Forces commander, fighter aviation would destroy an enemy aircraft inside the zone of antiaircraft artillery below the cloud deck. In these cases light antiaircraft guns would open fire on non-attacking enemy aircraft and targets, but medium antiaircraft guns were placed on standby readiness to open fire.
When repulsing daylight raids by ground attack aviation antiaircraft artillery would destroy them at all altitudes in their zone of responsibility. Light antiaircraft guns would open up only on non-attacking aircraft, but the medium antiaircraft guns were placed on standby readiness to open fire once friendly fighters had left the zone of responsibility or disengaged from combat.
When repulsing night raids under conditions of clear skies or when the lowest layer of clouds was at least 6,000 meters and more, targets were illuminated by searchlights for fighters to destroy them within the light of the searchlight beam field ((in Russian - svetov prozhektornom polye or SPP - translator)) and in the zone of unlimited antiaircraft fire. If the target was not illuminated by the searchlights, then the fighters would move to an altitude 1,000 meters above the estimated altitude of the target and follow them on a parallel course; antiaircraft guns would fire without limitations.
When the cloud cover was such that the lowest level of the cloud deck was above 3,000 meters, upon the command of the command post of the Unified Air Forces commander fighters would be permitted to operate inside the antiaircraft artillery zone of responsibility below the clouds against targets illuminated by searchlight.
The order of cooperation was studied by the antiaircraft artillery unit and subunit commanders as well as the pilots from fighter aviation. All command posts had receivers set on the command and cooperation radio nets. Beside that, with a goal of preventing engagement of friendly aircraft by antiaircraft artillery, flight personnel studied the dispositions of the antiaircraft artillery and the antiaircraft personnel studied how to differentiate the MiG-15 from the F-86, for which the MiG-15 pilots flew over them at different altitudes for training purposes. Along with this, there were established entrance and exit points established for the fighter barrier operations zones.
The experience of combined combat operations of antiaircraft artillery and fighter aviation in air defense of rear area objects in the DPRK validated the form of combined operations described under actual circumstances.
Operations by antiaircraft artillery in defending lines of communication. At the start of the war the enemy made wide use of B-26 and B-29 bombers to strike the lines of communication, normally flying against them in daylight at low (2,000-4,000 meters) altitudes.
A characteristic example of the use of a concentrated strike by a large force of enemy bombers against one single object on the lines of communications was the 12 April 1951 raid against the railway bridge over the Yalu River at Sinuiju (see figure 27).
In this raid the enemy committed 48 B-29 bombers and 80 jet fighter escorts. Bombing was carried out in three groups. Each group bombed in a "column" of flights formed into "diamonds". The first group, which had one aircraft armed with the radio-guided TARZON bomb of 5,400 kilograms, made its bomb run parallel to the bridge, and the second and third groups came in from angles of 30-35 degrees to the bridge's longitudinal axis. The first two bomber groups were engaged by UAF fighter aviation at a distance of 30-45 kilometers from the bridge. Only the third group succeeded in bombing the bridge, dropping several bombs in its vicinity. The radio-guided TARZON bomb landed 150 meters from the bridge and did no damage to it. The enemy lost more than 20% of its bombers in this raid to the combination of fighters and antiaircraft artillery.
With the increasing number of antiaircraft artillery assets defending objects, enemy aviation was forced to fly at significantly higher altitudes, make more repeated raids against the same targets and bomb from a dive, but from mid 1951 onward they had to change over completely to night bombing operations. Operations against lines of communications then were levied upon fighter-bomber aviation - F-51, F-80 and F-84 aircraft - which did not always find success.
Thus as an example on 22 June 1951 16 F-80 and F-84 fighter-bombers twice attempted to destroy a railway bridge over the Yalu River in the Sinuiju area. Organized antiaircraft fire claimed 5 enemy aircraft shot down, and the bridge suffered no damage. On 30 June 1951 4 F-84 fighter-bombers, taking advantage of unfavorable weather conditions, again attempted to hit the bridge over the Yalu, but met without success.
Beginning in October 1951 the American air forces command decided to concentrate the primary effort of its aircraft against crossings in those sectors containing railways where it was difficult to carry out repair work. For covering these sections of trackage, the command of the KPA and CPV allocated several mobile groups of antiaircraft artillery batteries, which were operational in the roadway sectors of Sinuiju - Anju; Anju - Pyongyang; Anju - Ponwonri - Sunchon - Tonyan; Sunchon - Pyongyang. One searchlight platoon consisting of one RAP-150 and three 3-15-4 searchlights was assigned to two maneuver batteries operating along the Sinuiju - Anju section. The batteries carried out their marches secretly during the hours of darkness.
In the area of the protected object the batteries selected two or three firing positions. The batteries would move their positions after one or two engagements, so that the enemy aviation would not be able to detect them until they were engaged by surprise fire from the ground.
Thus, on the morning of 8 October 1951 one of the maneuver batteries took up firing positions with a mission of protecting a tunnel and the Koyu railway station. On that day 14 F-80 fighter-bombers made a raid against the station. The covering battery engaged them with surprise fire and shot down 4 enemy aircraft. On that same day, at 1700 hours a group of up to 20 F-80 aircraft made a repeat strike, with 5 of its aircraft detailed to hit the antiaircraft battery. In repulsing the strike another 2 enemy F-80 aircraft were shot down. The railway station and tunnel received no damage.
The enemy, taking losses from surprise fire by the maneuver batteries, began to be more careful in his operations and by December 1951 had nearly completely stopped daylight assault bombing raids on railway bridges and crossings in the Anju and Sinuiju sectors.
Maneuver batteries successfully fought against enemy aviation at night if the targets were illuminated by searchlights. Thus, during two months in the fall of 1951 9 B-26 bombers were shot down at night after being illuminated by searchlights.
Measures proposed by the enemy to deal with maneuver batteries did not always meet with success. For example in March 1952 one maneuver battery was operational in the Anju-Sinuiju railway sector to deal with enemy aviation attacks. At 0955 hours on 16 March 1952, two groups (32 F-84 aircraft) conducted a strike against the battery and its searchlight station. The battery, in repulsing this raid, shot down 4 enemy aircraft. The enemy managed to inflict an insignificant amount of damage on two searchlights and destroyed two trucks. The battery suffered no losses.
At the end of March 1952 the command of the KPA and CPV, in concert with the growth of enemy aviation activity against railways, took measures to reinforce their antiaircraft artillery cover. With this goal in mind, several more maneuver groups were created, consisting of two light antiaircraft batteries each. Three of these new groups were active in the Anju-Sinuiju sector. In order to support fire against B-26 bombers, operating at night as "free hunters," one group was assigned four 3-15-4 searchlights.
One battery of a group occupied firing positions in one spot that was 500-600 meters distant from the next battery, so that they could use cooperative fires to support each other.
As for the effectiveness of these operations by maneuver groups, examine a number of facts. At 1000 hours on 9 April 1952 an assault bomber strike was launched in the area of Kokusan to destroy troops and cargo. Using surprise fire the batteries of a maneuver group shot down 5 F-51 aircraft and 2 F-84 aircraft.
On the same day, at 1350 hours a group consisting of 12 F-84 aircraft and 15 F-51 aircraft attempted to suppress one of the batteries, but meeting organized antiaircraft fire, broke off from its assigned mission after losing 2 aircraft.
From 13 May 1952 onward enemy aviation strengthened their efforts against railways in the Tonju, Kuson, and Sakju sectors. The crossings in this area consisted of a large number of bridges whose destruction would disrupt the normal operations of railway transport. In order to cover these sectors two maneuver groups of light antiaircraft artillery batteries were sent into them, who inflicted significant losses upon the enemy.
It serves to pay attention to some of the tactical measures used in the operations of antiaircraft artillery. Thus, one CPV antiaircraft regiment was able to cover all of the lines of communication passing through its area. Prior to dawn the soldiers set up dummy positions (cleared snow, created firing pads, and set up dummy guns). The primary positions were well concealed. In the morning around 30 F-84 aircraft attacked the dummy positions; the antiaircraft gunners shot down 4 enemy aircraft. After the battle the firing positions were changed. During the second half of the day the enemy again made a raid on the positions that had previously been occupied by the guns. But at the same time, the bombers only hit barren spots. The gunners once again opened fire on the enemy and shot down several aircraft. In all, during the course of the day the enemy made 130 sorties into this area but could not smash his objective.
Maneuver operations by the KPA and CPV were able to disrupt the plans of the American command to a high degree and were carried out even in light of a considerable shortage of antiaircraft artillery assets. Maneuvering (roving) batteries and battalions, as was shown by reports from prisoner of war pilots, caused a great deal of interference with their operations; they were sure they were created only with the possession of a large number of antiaircraft assets. Individual units of antiaircraft artillery used maneuver to inflict tremendous losses on American aviation. The average expenditure of ammunition for each aircraft shot down was as follows: 85mm - 560 rounds; 37mm - 630 rounds; and 12.7mm - 2,500-3,000 rounds. Fire by heavy caliber machine guns was most effective when they could fire at low-level attackers (below 2,000 meters altitude) and the same target was engaged simultaneously by 3-4 machine guns.
Operations by antiaircraft artillery when defending industrial objects. In the period from 23 June to 8 July 1952 the USAF command conducted a special operation against electrical power stations in the DPRK. In order to carry out these missions, the enemy dedicated around one thousand aircraft sorties to the task. The primary strike objective was the "Supung" hydro-electric station on the Yalu River. In order to destroy it, the enemy allocated strikes from F-51, F-80, F-84 and other aircraft types.
On 23 June 1952 the enemy conducted an assault bombing strike on the station throughout the day, in which more than 140 F-51, F-80, F-84 and B-26 aircraft participated, as well as up to 40 aircraft providing cover. The raid was carried out in four echelons with intervals of 7-8 minutes between them. Each echelon included an antiaircraft suppression group of 8-12 F-84 aircraft.
All four echelons flew into the target area from the east and southeastern directions in a combat order of a "column: of flights at an altitude of 3,000-4,000 meters. When approaching the target the aircraft slipped into a "column of ones." They exited the target by flying along the river in a southwesterly direction. Bombing was conducted from a dive at an angle of 50-60 degrees. The strike simultaneously hit both the electrical power station building and the antiaircraft artillery combat order.
The CPV antiaircraft artillery regiment charged with repulsing the raid shot down 8 enemy aircraft. But at the same time, as a result of the raid the power station suffered serious damage. The regiment also suffered both personnel and equipment losses: two light antiaircraft batteries and one medium antiaircraft battery were suppressed.
To strengthen antiaircraft artillery cover of hydro-electric stations, the Unified Command of the KPA and CPV decided to relocate one antiaircraft artillery division of two regiments from the Taechen and Panhyong airfield areas to the Supungdong area.
Over the course of July, August and part of September enemy aviation carried out reconnaissance of the hydroelectric power station. So that they would not give away the new antiaircraft artillery coverage, specially designated batteries were the only ones permitted to fire upon the enemy reconnaissance aircraft.
On the night of 12 September 1952 45 B-29 bombers attempted to flatten the hydroelectric station, which by that time had been restored to operation. Bombing of the target was carried out in three echelons (each consisting of 10-20 aircraft) at an altitude of 6,800-7,500 meters and with intervals between echelons of 10-30 minutes, and with intervals between aircraft in each echelon of 1-5 minutes (see figure 28.)
11 B-29 aircraft, operating outside the antiaircraft artillery zone at 7,500-8,000 meters, dropped chaff and carried out active jamming of the antiaircraft artillery radar stations. Bombing was carried out in horizontal flight, one after the other; after the aircraft dropped their bombs, they turned right and left to the east or southeast.
Antiaircraft artillery used the PUAZO stations to fire on radar data from the SON stations as to the probable bomb drop line and shifted from that probable line towards the target; part of the batteries fired barrage fire according to the SON data. Artillery fire shot down 2 B-29 bombers.
Bombing accuracy was not high. Out of 500 bombs dropped during this raid, 447 fell 1000-2000 meters from the target; 50 bombs fell 150-200 meters from the target, and only 3 bombs hit their probable aiming point on the upper works of the station.
After this raid, the positions of the antiaircraft artillery units covering the "Supung" hydroelectric station were changed somewhat. The light antiaircraft artillery batteries were deployed to the southwest, e.g. to the side where ground attack aircraft were most likely to approach. The medium antiaircraft batteries were deployed around the hydroelectric station at a distance of 2000-3000 meters from it and at intervals of 3-4 kilometers between batteries (see Figure 29). But at the same time, the eastern direction remained weakly covered, primarily due to a lack of approaches and suitable positions to site the guns, equipment and radar stations. Ultimately, in order to improve the antiaircraft artillery protection organization a great deal of engineer work was carried out to build roads and areas for firing positions of the batteries along the eastern direction.
In February 1953 12 F-84 fighter-bombers attempted to make a strike against the station. Several days prior to the strike the antiaircraft artillery units had been changed. The newly formed units did not have sufficient combat experience, and that was reflected in the results of their gunnery. The enemy only lost 2 aircraft. The power station was not damaged.
During March and April 1953 the enemy again increased his reconnaissance of the hydroelectric power station, and on 10 May conducted an assault bombing strike against it using 8 F-84 aircraft bombing from 700-1300 meters altitude (see Figure 30). The aircraft came in from southeast, from the area with the least coverage by light antiaircraft artillery fire. Due to the low altitude of the raid and the danger of injuring neighboring batteries from exploding rounds, the medium antiaircraft batteries were unable to fire. The hydroelectric station suffered no damage.
Up to the end of the war in Korea enemy aviation made three more attempts to destroy the station, using F-86 type aircraft. The tactical use of these aircraft operated as follows.
At a range of 30-35 kilometers from the target, they would drop down sharply to 6500-7000 meters and move into a glide slope of 10-15 degrees while simultaneously moving into a "column of ones". At a range of 6-8 kilometers from the target the fighters, now at an altitude of 5500-5800 meters, would drop into a 30 degree dive, later increasing the angle to 50-60 degrees. Bombing was carried out from 800-1000 meters. The fighters flying immediate escort simultaneously followed the bombers down to an altitude of 2500-3000 meters.
After the first such raid of this type was carried out, careful analysis of the F-86 fighter-bomber strike tactics against an objective was conducted and it was determined that their bomb drop line was at a range of 1-1.5 kilometers from the target. Together with this, measures were taken to make some changes to the firing system. The medium antiaircraft artillery batteries, deployed along the course of the approach to the target, had to fire upon the diving aircraft when they changed their altitude by 1500 meters. Those batteries whose zone of fire was out to a range of 2-3 kilometers from the protected object, had to establish barrage fire at an altitude of 3000-4000 meters. The light antiaircraft artillery batteries had to fire at the second the aircraft came out of their dives.
In order to combat antiaircraft artillery the USAF command allocated special groups of suppression aircraft who were assigned the mission of effecting the antiaircraft artillery positions.
The characteristic use of such a raid on an object with simultaneous strikes on the combat order of the antiaircraft artillery was the raid carried out on the night of 30 September 1952 against a carbide factory near Chungsu. 48 B-29 bombers participated in this raid. They were supported by 35 B-26 bombers. The bombers approached the target in three echelons with intervals of 13-16 minutes between them. In this raid 6 B-26 bombers preceded the bombing and used machine gun fire against the antiaircraft artillery positions and searchlight stations (see Figure 31).
Operations of antiaircraft artillery when defending airfields. At the beginning of the war the DPRK made the decision to build 11 airfields on its territory. Airfield construction was carried out in river valleys that were at least 1.5-2 kilometers wide and had bordering peaks no more than 100-300 meters above them.
Several antiaircraft artillery regiments were allocated to cover the construction of these airfields. The firing positions for the batteries, as is correct, were deployed on the first range of peaks around the airfield at the corners of a quadrilateral or a triangle (when they only had three medium caliber batteries) with intervals of 2-3 kilometers between them and 1-1.5 kilometers from the runway.
Firing positions for light antiaircraft artillery were deployed around the airfield at intervals of 50-1500 meters and at ranges of 300-400 meters from the runway. In some cases six-gun batteries were deployed at intervals of 200-700 meters between platoons.
From May 1951 onward the American air forces systematically destroyed airfields under construction. The destruction of the airfields took place only a few days prior to their completion, when the work was 80-90% complete. In this, the bombers received heavy cover from fighter aviation.
From the end of October 1951 onward American aviation was forced to attack the airfields at night using single or pairs of aircraft and from altitudes of 7500 to 8200 meters. Repulsing night bombing raids by aircraft operating at these altitudes was only possible at airfields protected by four batteries of medium antiaircraft guns by using the following method: two batteries would fire using PUAZO data from the SON and two batteries would lay down a screen of barrage fire along their probable bomb release line or 1-1.5 kilometers before that line, if they had the tactical and technical data on the weapons.
Using such a method by batteries to repulse raids by single and small groups of aircraft operating at high altitude where the enemy had already proposed a line where he would drop his bombs resulted in poor bombing accuracy. Thus, out of 3,470 bombs dropped in November 1951 on Taechyon airfield only 167 fell within the limits of the airfield and the rest landed 1000-4000 meters from the airfield.
To ensure domination of the airspace US fighter aviation blockaded the KPA and CPV airfields. Airfield blockades were carried out by means of the "free hunt" by individual pairs and foursomes, operating to destroy UAF fighters on takeoff or on landing.
In order to destroy enemy aircraft attempting to attack UAF aircraft landing or taking off, part of the light antiaircraft batteries were moved to a distance of 4.5 to 5 kilometers from the airfield along the direction of the runway. If UAF aircraft returning to land from a mission were attacked by enemy fighters, the antiaircraft batteries would open fire on the enemy to swat them off friendly aircraft. Enemy fighters, as is correct, would break off their attacks when fired on by antiaircraft and stalking the MiG-15s, and by use of a counter-antiaircraft maneuver, get out of the zone of fire.
Firing against enemy fighters took place when they were closing or passing obliquely at a speed of 300 meters per second or more, and in those cases when the horizontal angle between aircraft was 100 mils (6 degrees) (6) and more. At angles less than 6 degrees, the horizontal difference would not permit safe firing in regard to the friendly aircraft.
When moving across the front at speeds of less than 300 meters per second, firing could commence the second that friendly aircraft had passed the battery.
Experience of the organization of antiaircraft artillery cover of DPRK airfields showed that four medium antiaircraft batteries and four light antiaircraft batteries were not sufficient to protect an airfield.
Use of radar stations. (7) Search ((all around)) radar stations were normally located 500 to 2000 meters from the formation (unit) command post.
Positions for weapons guidance stations were normally selected in consideration of the grouping of firing assets (batteries) as well as the conditions of the terrain. For normal operation the SON-2b station normally needed a flat area 50 to 70 meters in radius, which was nearly impossible to find in the mountainous conditions of deployment. In view of this, batteries so equipped with the SON-2b radar were normally deployed in rice paddies or sports stadiums, which were not always worthwhile for use in regard to antiaircraft artillery groupings.
The selection of a position for the SON-3k in the mountains was surrounded by a number of difficulties, such as the frequent problem of finding a position with a reasonably level surface that turned out to be disadvantageous in light of the search radar antenna receiving too much reflected power from local obstacles.
Once the position had been selected for the SON-3k tracking radar, no difficulties were met. Normally the SON-3k tracking radar was deployed on low peaks; a pit was dug for its control cabin, which permitted it 360 degree clear rotation but also provided protection from bomb and shell fragments. The blocked angle of coverage was 0-50 parts of an angle. The deployment of the SON-3k tracking radar on small peaks without angles of blockage or with only small angles of blockage turned out to be not worthwhile, as it was impossible to operate against low-flying targets against the background of the local obstacles.
The simplest solutions involved questions of the deployment of the SCR-584 station, as it provided for combat operations of batteries in all sorts of positions. But at the same time, for normal operation against low-flying targets it turned out to be necessary to have the angle of blockage of no more than 0-30 to 0-50 parts of an angle.
The engineer work for a radar station position, beside that of the SON-2b, had to take into consideration the protection of the station from bombing and machine gun strafing from aircraft. The cabins of the centimeter-band radar stations, as well as the cabins for the SON-3k search station, had to be placed in deep cover. All cables had to be buried in the earth to a depth of 50 to 70 centimeters.
In positions where it was impossible to provide deep protection for the stations, a breastworks formed from sandbags filled with dirt had to be built up around the cabins.
In one of the raids in November 1952 on the Sinuiju airfield, the enemy used bombs with proximity fuses, and the result was that two SCR-584 stations were damaged by bomb fragments penetrating the roof of the cabin. This demanded protection for the roof of the cabins of radar stations from aerial bomb fragments by means of adding a framework of heavy wooden beams as protection, which then contained a layer of sandbags filled with dirt. For protection of the SON-3k tracking station, the sandbags were placed directly upon the roof of the cabin. Generator power sets for the radar stations were dug into the ground.
Control of the antiaircraft artillery radar stations was centralized. Data on the air situation was sent to the command post of the formation or unit from the main air operations warning and communications center command post via radio over the warning net when the targets reached a range of 150-180 kilometers from defended objects.
The regimental search radar stations (SKO) used a two-wire telephone line connecting them with the tracking radar stations (SON) of all the batteries, and that provided immediate target designation from the SKO to the SON.
Wire and radio communications were established between the light antiaircraft batteries so that every battery would have access to the SON data of the neighboring battery (in case their own SON went down).
Radar station jamming established by the enemy significantly complicated the work of the station crew, especially during the first period of the war, when they had experience at how to work under conditions of radar jamming. The most severely effected radar stations were the SON-3k (meter band) search stations.
Frequent retuning of the receiver heterodyne system as well as regulating the contrast and brightness, while recommended to reduce the effects of active jamming, did not reduce its effectiveness. But at the same time, the antiaircraft gunners managed to find a method rather quickly to find the enemy using the immediate target tracking part of the SON-3k, which as it operated in the centimeter band, was not subject to enemy jamming.
The measures used to overcome enemy jamming by the SON crews when working under jamming conditions grew along with the effects of antiaircraft fire on enemy bombers.
As before the enemy could not create any jamming against the LV search radar stations (operating at 212 MHz).
Ultimately the enemy began to allocate special aircraft to fly jamming missions; they did not enter the area of antiaircraft fire, but operated at a range of 20-25 kilometers from the target objective, creating active jamming against the SON-3k search radar and providing support to the main bomber group in the implementation of its mission for the duration of its flight. The sector being jammed varied with the location of the aircraft establishing the jamming.
With a goal of reducing the effects of jamming against the SON-3k target tracking radar, they were retuned within the limits of frequency adjustment.
All bombing raids up until February 1952 flown by B-29 bombers against targest defended by antiaircraft artillery were escorted by active jamming using noise modulation targeted solely against the SON-3k search radar station. In February the first attempts to jam the LV search radar were noted.
On 12 September 1952, while attacking the "Supung" hydroelectric station, the enemy made the first joint use of both passive and active jamming. Active jamming was only created against the SON-3k search radar; passive jamming was used against the entire radar band, including the centimeter band.
Only passive jamming was effective against the SCR-584 station. As experience showed, the SCR-584 was far more stable under jamming conditions than the SON-3k and SON-2b stations. When operating under passive jamming conditions the main task of the SCR-584 operator was to pick out the target against the background of passive jamming on his indicator scope and then assign it to automatic tracking. Once automatic target tracking was switched on, the automatic power regulator (ARU) would overcome the jamming, as the amplitude of the target being tracked (e.g. the B-29 bomber) was greater than the amplitude of the jamming, and the automatic power regulator was stable. For the entire period of the use of passive jamming the SCR-584 was never suppressed, even though when the enemy raided an object protected by antiaircraft artillery he always created a reasonably large concentration of passive jamming.
Organization of the march for antiaircraft artillery units. At the start of the war the enemy managed to inflict significant losses on antiaircraft artillery units when caught on the march.
According to the measures determined from experience, unit staffs were responsible for developing the march plan, which laid out instructions for: the time, place and order of assembly of the convoy; starting time, march route, and time to arrive at the last place listed on the plan; phase lines, locations for short halts, and measures for antiaircraft defenses; and controlling signals for the march.
In order to provide antiaircraft defense, all light antiaircraft guns had to be prepared to fire either on the move or from the short halt.
After studying the characteristics of the air situation and the condition of the roads, an antiaircraft artillery regiment would make its march, as is correct, in eight convoys: four light antiaircraft battery convoys, two radar convoys, and two convoys carrying ammunition and rear services goods.
Each light antiaircraft artillery battery convoy was covered by four medium antiaircraft guns, but the radar convoys were protected by a six-gun medium antiaircraft gun battery. The medium antiaircraft guns followed the lead, center and trailing convoys. For covering the ammunition and goods convoys from their last stop with the medium antiaircraft artillery battery convoys, a battery of medium antiaircraft guns was provided, which was dispersed among their convoy.
On the march, each convoy would deploy a radar station, from which the convoy leader would receive information on the air situation and supporting communications from the unit command post. Communications inside the convoys was organized to provide communications between the head and tail of the convoy, which gave the leader the ability to control movement, adjust the speed of movement, provide assistance to halted vehicles, and control their approach and departure.
Each truck had four observers, each of which was assigned an airspace observation sector of responsibility. Regulation of the convoy corresponded with traffic control posts that were set up every 30-40 kilometers along the route. Out of service vehicles were provided with assistance.
These measures, along with the accumulation of experience, served to reduce losses on the march from enemy air strikes.
Combat use of antiaircraft searchlight units. In June 1951, the air defense of the KPA formed its first antiaircraft searchlight regiment, which consisted of two battalions. The regiment was equipped with the RAP-150 radio controlled searchlight and the 3-15-4 antiaircraft searchlight. In December 1952, the air defense was provided with three CPV independent searchlight battalions.
The antiaircraft searchlight units had the mission of supporting night operations of fighter aviation and antiaircraft artillery.
Initially, searchlight stations were deployed by platoons. Each platoon consisted of two RAP-150 stations and two 3-15-4 stations occupying a single position. The interval and distance between positions was 6-10 kilometers. But at the same time, this disposition made maneuvering the searchlight beams more difficult, especially when trying to simultaneously engage low-flying and high-flying targets, worsened observation of an illuminated target from the observation post, and would not provide for continuous tracking of targets at low altitude.
In an effort to fix this, searchlights were next deployed in pairs (one RAP-150 and one 3-15-4 per position) and then by individual searchlight stations, which increased the illumination capability of the regiment by a factor of more than 2 (with the same number of searchlights), improved maneuver of the beams and provided continuous tracking of low-flying targets with searchlight beams.
In order to support night combat operations by the light antiaircraft maneuver groups, searchlight platoons were attached to them, which initially consisted of one RAP-150 and up to three 3-15-4 stations. Practical combat work showed that it was not worthwhile to use the RAP-150 against low-flying targets, as well as the fact that mountainous conditions interfered with observation to the complete range of the searchlight. Beside that, it was impossible to adjust fire using the radar-controlled RAP-150 using the angle-range method with frequent positional changes, the stations had insufficient mobility, and were difficult to conceal; as a result, the RAP-150 was pulled from use in the maneuver groups.
Illumination and tracking of enemy aircraft targets within the zone of operations of a battery were carried out, as is correct, using three searchlight beams, and one searchlight station, with its light on standby, observed the aerial situation and remained ready for immediate illumination of a new target.
Data on the aerial enemy, prior to his falling into the beam of the radar-controlled RAP-150, required three or four instances of location. Sending this data required 2-3 minutes. In September 1952 an information system was established linking the LV search radar to the KPA antiaircraft searchlight regiment.
Control of searchlight subunits during the repulsion of an enemy air raid was carried out by the antiaircraft searchlight regiment command post. The antiaircraft regiment staff provided information to the antiaircraft searchlight battalion, who then informed their subunits on the air situation, and passed current coordinates for subunit target designation and the RAP-150 stations. Control over the searchlight beams was personally carried out by the searchlight company commander. The chief of the RAP-150 station could be granted the right for independent search for targets, illumination and tracking of low-flying targets.
Search and illumination of low-flying aircraft was carried out, as is correct, by the means of the searchlight operators using sound (the aircraft engine noise). Search for high-altitude targets using the RAP-150 was carried out by radar. When repulsing a concentrated raid, search for the target corresponded with the 3-15-4 searchlights following the beam from the RAP-150 station.
As well as those methods, the searchlights were also pointed by using the TPZ optical device (the searchlight antiaircraft tube) that assisted in locating the target visually.
The RAP-150, which did not have a control position, used the TPZ observation device by mounting on the frame of the RAP-150 and using technical rotation for finding angle-distance.
The mounting of a more powerful device than binoculars - the TPZ - served to improve the conditions of observation when illuminating aircraft and increase the range at which they could be tracked to 18-20 kilometers.
The primary types of radar jamming which the enemy created for use against meter-band radar stations guiding the RAP-150, included noise modulation from the APT-1 and APT-2 and passive jamming from harmonic and non-harmonic metallic reflectors.
The intensity of jamming operations against the RAP-150 radar varied for the most part based on relative positions between the station and the aircraft and the angle of its concealed position.
Aircraft flying at 7,000-8,000 meters altitude under the cover of a jamming platform aircraft could be acquired by the RAP-150 at ranges of up to 20 kilometers.
The use by the enemy of radar jamming (active and passive) complicated the work of the antiaircraft searchlights, but with the accumulation of operational experience under jamming it did not prevent the successful work of the antiaircraft searchlights in illuminating enemy aircraft.
Under difficult meteorological conditions (5/10ths - 10/10ths cloud cover with layers above 3,000 meters, haze, fog) the antiaircraft searchlights would support fighter aviation operations by illuminating clouds, creating a lighted background for fixed and moving objects - a "light screen" - or short bursts of illumination of enemy aircraft through breaks in the clouds.
The experience of operations by antiaircraft searchlights under disadvantageous weather conditions by means of establishing fixed and moving objects on the "light screen" was seen to be worthwhile as a method of combat use of searchlights.
Brief conclusions. During the course of the war the KPA and CPV effectively used antiaircraft artillery for covering objects in the rear, lines of communication and airfields. The use of antiaircraft artillery forced enemy aviation to increase their operating altitudes from 3,000-4,000 to 7,000-8,000 meters, turn away from raids with large groups of aircraft, instead using single or pairs of aircraft to carry them out, and subsequently convert completely over to night operations.
Experience supported the worthwhile use of carrying out maneuver of antiaircraft artillery units with the goal of reinforcing antiaircraft artillery protection of individual directions or objects. These measures had the essential effect when they were carried out in secret, in the period between raids, or after careful study of the operational tactics in use by the enemy.
USAF bombers made use of a number of different jamming stations when striking objects in the rear area to interfere with weapons guidance radar stations, which strongly complicated their operation and in some cases made it completely impossible to use radar for fire control by antiaircraft artillery. Together with that, experience showed that the effectiveness of the actions of jamming were significantly reduced if the station crew had practical experience in working under jamming conditions.
Based on their proximity to the front lines, the enemy made wide use of fighter-bomber aviation to suppress antiaircraft artillery. Experience showed that medium caliber antiaircraft artillery could not carry out effective fire against these aircraft, especially when their raids were flown at low altitude. Therefore the combat order of medium caliber antiaircraft artillery had to be protected by light antiaircraft artillery assets.
Antiaircraft artillery possessing 85mm guns, PUAZO-3 and the SON-2b and SON-3k weapons guidance stations, could not provide for reliable defense of objects when dealing with either high-speed or high-flying enemy aircraft, as the technical and tactical data of these stations would not provide the necessary accuracy in determining coordinates, range to the blips or tracking of the targets while simultaneously opening fire against them.
When defending narrow and point objects (railway bridges, crossings, fields and airfields) a limited number of medium antiaircraft batteries were deployed 1.5-2 kilometers from the object at intervals of 2.5-3 kilometers and the light antiaircraft batteries were deployed no more than 500 meters from the object.
When the enemy made use of the SHORAN radio navigation system, a force grouping of antiaircraft batteries could be set up across the direction of the probable zone of combat courses they would fly, and the amount of barrage fire screens that had to be used was cut in half.
Control of antiaircraft artillery fire against mass enemy air raids under a difficult air situation was centralized. Decentralized control was only permitted when small groups of fighters and fighter-bombers were actively operating in the zone of responsibility.
Under a lack of sufficient antiaircraft artillery assets defense of the lines of communication saw the wide use of maneuver groups and batteries that controlled themselves. For support in night operations these batteries had attached searchlight platoons. Under conditions of a limited number of searchlight assets the searchlight illumination field was set up along the most probable directions of approach by enemy aviation, but in case of necessity it provided for timely maneuver of the searchlight assets.
When organizing illumination support to fighter aviation, the illuminated searchlight field was set up to the rear of the antiaircraft artillery zone from the distance to the rear edge of the SPP to the range of radar acquisition of the antiaircraft artillery fire control radar stations.
Searchlights in mountainous conditions had to be sited individually. This permitted an increase in the light capability of the subunits and improved the maneuver of the searchlight beams and methods of illuminating targets.
Control of antiaircraft searchlight subunits when repulsing mass enemy air raids under difficult conditions was centralized and corresponded with a previously developed combat option. Control of the beams was concentrated at company level.
The primary means of communications in searchlight units was radio using VHF radio sets as the most reliable during all periods of the war. Radio communications on the regimental command nets was most worthwhile when organized not by nets, but by links.
2. Use of Antiaircraft Artillery by UN Forces in Protecting Rear Area Objects
With a go (8)al of organizing air defense of rear area objects, the UN concentrated a great amount of antiaircraft artillery in Korea.
Out of 22 antiaircraft artillery battalions operating in Korea, 13 were self-propelled antiaircraft battalions armed with automatic weapons that were part of the infantry divisions and artillery reserve of the high command. A self-propelled automatic weapons antiaircraft artillery battalion consisted of four batteries and had 16 antiaircraft machine gun (quadruple) M19 mounts and 16 antiaircraft cannon (twin) mounts. The remaining 9 battalions were independent antiaircraft artillery battalions from the reserve of the high command and were armed with 90mm and 120mm cannon (up to 16 guns per battalion).
Together with the fact that the UAF forces could not threaten any objects in the rear area, antiaircraft artillery for the most part was used for firing against ground targets.
Only part of the antiaircraft artillery was dedicated to protect individual objects in the tactical and operational depths. Antiaircraft artillery units were used to cover airfields and runways, bridges, crossings and lines of communication, settlements where senior staffs were located, air and naval bases, and ports.
The antiaircraft artillery covering airfields consisted of from two firing sections up to a platoon from the antiaircraft artillery battalion from an infantry division.
Air bases, ports and other important objects were covered by antiaircraft artillery battalions with automatic weapons allocated from the reserve of the high command and amounted from one to two battalions. Thus, for example, the K-1 airfield near Pusan was covered by two batteries of automatic antiaircraft weapons. The airbase at Taegu was covered by one antiaircraft artillery battalion with automatic weapons and one armed with 90mm guns. The port of Kunsan was protected by a battalion with automatic weapons, and the Kimpo airbase and bridge over the Han River were covered by four antiaircraft battalions (two with automatic weapons, two with 90mm guns). Major airfields, as is correct, were covered by battalions armed with 90mm and 120mm guns. The automatic antiaircraft weapons were deployed around the object at intervals of 270-360 meters between weapons. In this the automatic quadruple machine gun mounts were deployed between the twin 40mm cannon mounts.
1.1 The use of fighter aviation with the goal of covering objects in the rear is covered in Chapter 9.
2.2 PUAZO - pribor upravleniya artillerskikh zenitim ognem or antiaircraft artillery fire director. Trans.
3.3 The characteristics of operations by US aviation in Korea against objects in the rear area is shown in Chapter 9.
4.4 Unified Air Forces, the combined KPA/CPV air forces under Chinese command. Trans.
5.5 "ugol-mesto" or angle-point aiming. This is elevating the gun to point at a fixed point in space to anticipate getting the shell to the area where the target must fly through; predictor aiming. Trans.
6.6 There are 6000 mils in a Soviet aiming circle; US aiming circles have 6400. Translator
7.7 Radar support provided by the P-3, P-3A, P-8, Lida-4, Lida-313 and other radar types is explained in Chapter 9.
8.8 The Soviets got this backwards. The M19 carried twin 40mm guns and the M16 carried four 12.7mm machine guns. Translator.