Sunday, February 19, 2012


  1. 1. The elaborate air defenses of Pyongyang.
    The North Korean capital is probably the most heavily defended city on the planet. I’ve cataloged over 150 AAA positions around the capital in Google Earth and there are more waiting to be discovered with the next high resolution image update. In fact I’ve cataloged over 500 AAA sites in DPRK… there are simply loads. For those with a schoolboy love of stupendously gigantean statics, there are so many AAA positions around Pyongyang that if they were all to fire at once they’d throw up over 63,000t of high explosive shells in the first minute – think about that, that’s more than the weight of an Iowa class battleship, and it’s traveling at about Mach 2!

    There are also at least four SAM sites, two with SA-2 Guideline missiles and two hardened sites with the more potent SA-3 Goa missiles.

    Satellite image with AAA positions marked by their effective ranges (*37mm AAA used as a median, each circle is 2.5km in radius).

    If we look carefully at the distribution of air defenses we see two clear belts of AAA arranged concentrically, with the greatest concerntration on the South East side of the city:

    One curiosity is the apparent gap in the outer AAA ring on the West side of the city. There is no clear explanation for that.

    1.1 AAA positions dissected
    The sites around Pyongyang are fixed, with approximately 75% occupied at any one time. We cannot easily identify which of the various AAA equipments relates to which sites, but there are certain characteristic layouts employed. The most common is a “rose” layout, with 4-8 AAA guns arranged in a circle with communication paths and trenches either around in a circle, or spidering out from the middle. A typical layout from South East Pongyang:

    Another site, this time un-annotated; it’s easy to spot the same components:

    Many of these sites will have a fire-control radar (FCR) although there is no indication that these have been upgraded beyond 1960s Soviet technology. The main AAA fire control radars reported are ‘Flap Lid’, ‘Fire Can’ and ‘Tilt Drum’. Although they can be jammed their advantage is that they are low powered and highly localized so stand-off jamming works less well.

    The ‘rose’ pattern is designed to give 360 degree coverage, but it is giving way to linear (and thus mono-directional) emplacements, sometimes even built on a previously rose-pattern site:

    The logic behind the newer layout is not clear, but we can speculate that the North Koreans consider it superior for concentrating a high volume of fire in a single direction (note, they all face outwards around Pyongyang). Also, this layout means that the guns don’t get into each-others way whilst engaging low altitude targets. It’s not clear when these linear sites were made or if more sites will be converted, but there is video evidence that the formation has been in use for some time:

    1.2. AAA equipment
    North Korea operates a variety of static AAA equipment but most of it is widely considered obsolete in modern warfare. The AAA can be loosely divided between Light, Medium and Heavy.

    The cornerstone of North Korean AAA is the ZPU-2 and ZPU-4 series light AAA. Although it is difficult to get confirmation that this is still the case, the ZPU-4 14.5mm quad machine gun is likely to be the most prevalent system. Of Soviet origin, this is now produced in North Korea also.

    In the right circumstances the ZPU-4 can be devastating, particularly to unarmored helicopters, but it is very short ranged (far shorter than the range of a Hellfire missile for example) and is much less effective against armored helicopters and fast jets.

    Other prevalent AAA systems include M-1939 37mm AAA and S-60 57mm AAA. North Korean S-60 57mm AAA with ‘Fire Can’ radar:

    This more recent picture of Chinese operated S-60s with ‘Fire Can’ radar is useful although obviously it’s not from DPRK:

    Additionally North Korea has produced an indigenous 57mm gun mount which appears to combine the twin 57mm guns of the ZSU-57-2 SPPAG with the mount of the S-60:

    DPRK also operates some KS-19 100mm AAA guns but these are obsolete – um, as is much of what I’ve just described.

    An interesting AAA piece is the M-1990 30mm gatling gun. I can’t find any photos of it but it is described as having four barrels and being externally powered. On paper this gun is probably the most potent of all North Korean AAA, with an incredible rate of fire. But it also probably has drawbacks, being much more complicated than the ZPU-4s and M-1939s. It is probable that it requires external power supply for sustained readiness (electrically powered gun), as batteries would be short lived especially in the cold temperatures of a North Korean winter. Having said that a battery is probably included to provide limited contingency. This means however that the M-1990 is probably much less mobile than the ZPU-4 et al.

    This is my artist’s impression of the type, based purely on descriptions:

    1.3. Hardened SAM site
    North Korea has attempted to improve the survivability of some of its SAM sites by building them into elaborate underground bunker complexes. This is an interesting and not necessarily foolhardy idea, although it flies in the face of contemporary wisdom that seeks to improve survivability by increasing mobility. The North Koreans however like digging underground complexes and perhaps because they are unable to buy more modern truly mobile systems, have dug purpose built SAM complexes, mainly for SA-3 SAMs. There exists at least one hardened SA-2 site but it is not fully underground, simply having individual bunkers for each missile. The clearest example of a hardened SAM site are the two SA-3 sites around Pyongyang, both of which are similar in layout:

    Sketch showing approximate internal arrangement; this is my speculation and not intended as 100% accurate, but gives a good indication.

    Ten years ago these positions made a lot of sense; underground facilities proved very difficult to destroy even with precision guided munitions (PGM) – as demonstrated in GW1 and the Balkans. But, we now live in the age of the “bunker buster” and these comparatively weak bunkers are easy prey. As an aside, these sites probably offer reasonable NBC protection.

    The radar sites to provide early warning and surveillance for the AAA and SAM sites are also often hardened in this manner with caves and sometimes radars that retract into hill-tops. This site, although not part of the Pyongyang localized defenses, is a good illustration:

    1.4. Air Defenses of Pyongyang: Conclusion
    We’ve seem that Pyongyang is heavily defended, but there is the inescapable reality that (*thankfully*) these types of defenses don’t count for much in a modern battle. It is possible that the huge volume of AAA concentrated is designed to tackle Tomahawk cruise missiles, but even then they seem weak. The logical counter to cruise missiles is sophisticated fast response targeting systems integrated with highly agile SAMs and autominous air defense guns or lasers. Clearly crewed AAA is going to have a very difficult time intercepting cruise missiles even if they are primed with approach angles etc. If North Korea possessed such systems then they would logically decommission the expensive AAA network and redeploy the resources to other activities – the high level of maintenance and preparedness visible at the AAA sites is evidence that this is not the case.

    If the cornerstone of North Korean AAA doctrine is intercepting cruise missiles, then time has once again overtaken it. With North Korea’s high altitude SAM systems now too outdated to provide credible deterrence against high flying aircraft, there’s nothing stopping an enemy air force simply flying over top of the AAA (which is not useful against high and fast targets) and dropping comparatively cheap JDAMs or other PGMs on the sites. Add an adversary with stealth aircraft to the equation….

    So is there, objectively speaking, a strength to the North Korean AAA rings? Well, if North Korea suddenly obtains high capability SAMs like S-300 to force an aggressor to fly low (as was the original doctrine it seems), then yes. But even then stealth technology would win again. So short of preventing the ROKAF from their flying F-15s in a lap of honor around Pyongyang at 2,000ft, no, it’s a huge waste of resources.
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    2. Underground air base
    Although several North Korean air bases use caves tunneled into nearby hills as hardened aircraft shelters, one unreported air base near Changchu’an-ni, West of Pyongyang, is of particular interest because it is almost entirely underground. It is possible that it is a secondary back-up airstrip for nearby Onchon, but it is quite distinct from that base:

    The base features three runways that give the appearance of converging on a large hill. There are in fact two aircraft tunnel entrances in the hill, each about 14m wide (wide enough for MiG-21, MiG-23 and MiG-29 but not Su-25), separated by a large headland of natural rock. This arrangement is intended to reduce the risk of a direct strike blocking the entrance. The arrangement of the entrances is virtually identical to those at PuckChang air base and several other air bases:

    Top: Google Earth imagery showing recent state of tunnels at PuckChang with MiG-23 ‘Flogger’ fighters. Bottom: 1960’s A-12 OXCART reconnaissance photo of same entrances. The A-12 was the precursor to the famous and essentially similar SR-71 Blackbird. It was operated by the CIA and only flew twelve operational missions, being retired in 1968.

    The south entrance at the underground air base, based on Google Earth imagery:

    All three runways are long enough for fighter aircraft take-off although only the longest, at 2.4km, is really adequate for safe ordinary operations and landings. There are no taxiways or further auxiliary runways. It is not clear whether the two shorter runways (North and South) actually have entrances into the mountain but my analysis suggests not.

    The active AAA sites near the entrances suggests that the base is still operational. Although underground aircraft tunnels have proved effective protection against bombing (Serbia as an example), this air base must be well known to the US and South Korean military. The base does not appear to have substantial facilities and any escalation in activity at the base preceding a ‘surprise’ attack could easily be monitored. The runways themselves are not well placed and the absence of taxiways would make high tempo operations impractical. The base is therefore only useful for launching a surprise attack or evacuating aircraft to for protection from bombing – at any rate the latest ‘bunker buster’ bombs are designed for just such a site.

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    3. Indigenous air defense equipment
    Although North Korea is not known to have produced any SAM systems they have produced several unique self propelled AAA systems.

    3.1. updates/ Inaccuracies on common sources of DPRK AAA disposition
    The main public sources for DPRK military doctrine and equipment are FAS and Global Security, both of which borrow heavily from mid-1990s US military handbooks. These handbooks are an invaluable source but they are now ten or more years old and even then they were based on public information. They do not include illustrations of several key units and their unit breakdowns, whilst good, are now out-dated. See my comments:

    3.2. M-1992 SPAAG
    Based on the chassis and fire control radar of the ZSU-23-4 Shilka, this type sports a noticeably taller turret with twin 30mm AAA guns. Unlike most North Korean adaptations, this is quite possibly a performance enhancement over the original type. As the US designation implies, it was first seen in 1992. This system is operational in some numbers. It is possible that it has replaced the older twin 37mm SPAAG (below) in some units.

    3.3. Twin 37mm SPAAG
    Similar in concept and capabilities to the 1950s American M-42 Duster, this design places a twin 37mm anti-aircraft gun (from Soviet M-1939 AAA) in an open top turret on an APC hull. Sighting is optical with no on-chassis radar. Although the system has some advantages over the basic M-1939 towed AAA, it is still somewhat obsolete today.

    3.4. M-1983 14.5mm SPAAG
    I couldn’t find any illustrations or photos of this type but it essentially consists of a ZPU-4 machine gun mounted on a tank chassis. The exact tank is not specified but probably a T-55. The gun probably has an open topped turret and probably relies on off-vehicle radar as the Twin 7mm SPAAG did. This unit is probably not operational in significant numbers and is not particularly credible in modern warfare.

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    4. Long Range Artillery hidden in tunnels
    Although there are numerous variations depending on terrain, resources and the time of construction, a typical hardened artillery position consists of caves or bunkers inside a hillside, with four firing positions immediately in front. This is an MRLS position:

    Note that all the vehicles in the right-hand line face the same direction and that the back-blast from each will not hit the next.

    Gun artillery positions are also often pre-prepared and hardened with caves and bunkers. Gun artillery positions however typically have more firing positions and ready to fire ammunition lockers next to each position. These lockers typically hold 80 rounds. Whilst rocket artillery positions require a clear area behind the launcher for the substantial back-blast, gun emplacements can be more compact and not necessarily all facing in exactly the same direction:

    4.1. SCUD tactical ballistic missiles
    North Korea manufactures two main variants of SCUD short range ballistic missile; the Hwasong-5 (SCUD-B): 300km, and the Hwasong-6 (SCUD-C): 500km. The latter is slightly larger but both use the classic Russian designed Maz 8x8 transporter-erector-launcher (TEL).

    SCUDs and hardened artillery positions:

    Another suspicious vehicle found near a tunnel. At first glance this vehicle doesn’t appear to have a missile on it and is divided centrally. But at 14m long, it’s certainly a “possible”, although I don’t think this is a SCUD TEL:

    4.2. Nodong-I ballistic missile
    The Nodong-I (aka Rodong I) is an evolution of the SCUD, and in simplistic terms is about twice the size (in volume) and has three times the range, but in other respects it is similar. Although the range is increased the accuracy is not, and at 1,000km it is thought to have an accuracy of about 1km, which with its 1ton warhead is insufficient for striking military targets.

    Although no photo-evidence of the launch vehicle (TEL) is available in the West, the missile is closely related to the subsequent Iranian Shahab-3 and Pakistani Ghuari, both of which are carried on an articulated truck. The reason for this is that the Nodong missiles are about 5m longer than the SCUD so the characteristic SCUD TEL cannot be used without substantial modification; it is probably much cheaper to use a truck and trailer. This arrangement does however reduce off-road capability. Interestingly, other countries developing indigenous variants of the SCUD missile have also adopted this launcher layout, such as the Iraqi [FONT='Arial','sans-serif']al-Waleed launcher[/font] and Peruvian SCUD+.

    4.2.1. Missile site
    Ballistic Missile sites are relatively hard to locate on Google Earth, and even known sites tend to be somewhat unremarkable in satellite imagery. There is one site of note however south of Togu-ri, about 90km north of the boarder, and 145km north of the South Korean Capital. The site consists of two large tunnel entrances on the North East face of a hill. The tunnel doors are some 30m across and there are two leveled platforms each 60m x 30m. There are very few buildings around the site suggesting that it is almost entirely an underground complex. Although we cannot be certain that it’s a missile site, it is hard to think up alternative explanations: why would you require a very large leveled hard surface, with massive underground hangers, in the middle of no-where? The sheer size of the entrances and platforms suggests a missile much larger than a regular SCUD, which at any rate doesn’t require such elaborate (and easily spotted) facilities. The Taep'o-dong-I/II missiles require a more substantial launch apparatus which there’s no sign of. There are no rail tracks so whatever comes out of the hanger must be road-mobile. The likely system then is something more substantial than the SCUD but smaller than the Taep’odong, thus Nodong-I appears to be the likely system.

    4.3. KN-02 tactical ballistic missile
    Although it is shorter ranged than the SCUD and No-dong rockets, the KN-02 represents a major enhancement of North Korean military technology and represents a quantum leap in guidance technology; if North Korea can apply this technology to longer range missiles then the overall potency of her conventional forces will be greatly magnified. KN-02 is closely based on the Russian [FONT='Verdana','sans-serif']9M79 "Tochka" ([/font] SS-21 Scarab-A) tactical missile, and has the significant advantage over the SCUD because it uses a solid-fuel rocket instead of liquid fuel. This means that it doesn’t take as long to prepare before launch. North Korea obtained SS-21 technology from Syria in 1996 and produced a modified missile with longer range (120-140km, equivalent to Scarab-B missile). Test firings took place in 2004, 2005 and three in 2006 and three in 2007. By 2007 there was clear evidence of it having entered service in significant numbers. The vehicle is different from the SS-21’s Zil all-terrain truck but has a similar hatched-roof configuration. Each TEL is about 10m long and carries a single 6.4m missile which is fired in the near-vertical position.

    The KN-02 is reportedly capable of flying a shallow trajectory reaching only 30km in altitude – too low for exoatmospheric ABM defences, although still within the envelope of THAAD and Patriot PAC-III if the batteries are placed close enough to the target.

    4.4. Luna-M (FROG-7B) battlefield rocket
    North Korea operates several variants of the Soviet FROG (Free Rocket Over Ground) artillery rocket, although the most common and most potent is likely to be the FROG-7B:

    The FROG-7B is very inaccurate but can carry chemical or even nuclear warheads (though SCUD and NoDong missiles are more obvious candidates).

    4.5. M-1991 Heavy Rocket Artillery (MRLS)
    An indigenous weapon, the M-1991 and older M-1985 240mm MRLS are among the more potent artillery pieces in the North Korean inventory. The rockets have an effective range of about 35km and are generally comparable to western MRLS.