Saturday, July 21, 2007

The S-125 SAM System: A Site Analysis


The S-125 (SA-3 GOA) SAM system was developed to provide additional low-altitude coverage in areas already defended by S-25 and S-75 SAM systems. S-125 SAM systems were also deployed in areas identified by the Soviet Military as potential enemy low-altitude ingress routes en route to high-priority targets. Interestingly, the S-125 began life as the M-1 (SA-N-1 GOA) naval SAM system, and was chosen for land-based use early in development. Many S-125 SAM systems remain in operation to this day, and there are numerous odifications available. The most current modification is the Pechora-2M mobile variant.


The S-125 SAM system is a two-stage strategic SAM system. Two missiles are employed, the 5V24 and the 5V27. Both weapons are command guided. The 5V24 missiles possess a 60 kilogram HE fragmentation warhead, and have a range envelope of between 4 and 15 kilometers, with a reach of between 100 and 10,000 meters in altitude. The 5V27 missiles possess an 70 kilogram HE fragmentation warhead, and have ranges between 4 and 25 kilometers with a reach of between 20 and 18,000 meters, depending on the specific variant. The 5V27 can be identified by the addition of two braking fins on the booster section. Upgraded missiles used in Pechora-2 and Pechora-2M systems have a maximum range of 38 kilometers. The I-band RSN-125 (LOW BLOW) radar handles target engagement functions, with a range of 110 kilometers. The RSN-125 has the capability to track 6 targets simultaneously, with the ability to engage a single target at a time.


A typical S-125 SAM site consists of three or four launch positions arranged in various patterns around a central radar area. Two rail 5P71 or four rail 5P73 launchers are employed. 5V24 missiles are 5.89 meters in length, and 5V27 missiles are 6.09 meters in length, although the difference may not be discernable in overhead imagery. Missile length is sometimes not an effective indicator to use when identifying an S-125 SAM site as the missile rails are often elevated. The launch rails measure approximately 8 meters in length. There is a visible counterbalance and hinge assembly that extends approximately 3.7 meters behind the missiles when they are fitted to the launch rails. This is a convenient feature for identifying an actual launch position as opposed to a missile reload vehicle, which mounts two missiles. The following image depicts a typical three-launcher S-125 site in Syria. Major components and features are labeled.

CIA NIE 11-3-62 provides us with the following description of a typical S-125 site:


The following images depict the four most common S-125 site layouts. The first S-125 site configuration to be examined consists of three launch positions arrayed in a triangular fashion around the RSN-125 radar. The following site in Syria is an example of such a configuration, as is the annotated example shown above:

Some S-125 sites feature three launchers but four prepared launch positions. The following S-125 site in Libya is an example:

Some S-125 sites feature four launch positions arranged in a parallelogram-shaped configuration around the RSN-125 radar. The S-125 site detailed in the CIA document shown above is an example of such a configuration, as is the following site in the Ukraine:

The final common S-125 site configuration features four launch rails positioned in a square pattern around the central RSN-125 radar. The following site in the Ukraine is an example of such a configuration:


Some users have placed S-125 systems in sites formerly constructed for and occupied by S-75 SAM systems. This illustrates the need to not only identify a site's configuration, but also the components present as well. The following S-125 battery is located in a former S-75 SAM site in Egypt:

Some S-125-occupied S-75 sites found in Serbia and India are distinctive insofar as they lack revetments for the radar and launch rails. The following S-75 battery is located on a former S-75 site in Serbia:

Some Belarussian S-125 sites are located on prepared sites intended to house S-300P SAM systems. It is likely that these sites were constructed on the locations of former S-125 sites, and that the S-125 systems were retained pending availability of the S-300P systems. The following site is an example of such a Belarussian S-125 deployment:

Many North Korean SAM sites use unorthodox layouts to increase their survivability. The S-125 is no exception. The site depicted below illustrates North Korean survivability efforts, including placing the launchers and the RSN-125 radar inside of bunkers to protect them when they are not in use.

Finally, some S-125 users deploy their systems in seemingly random manner dictated by either terrain constraints or potential threat ingress routes. There are numerous other iterations of the S-125 site; the important factor in identifying the site is to identify the system components. Fortunately, the launch rails themselves, either loaded or unloaded, are readily identifiable in high-resolution imagery.

The following S-125 site in Algeria is an example of a "random" site configuration, in this case dictated by the limited space available for the site as it is located in an urban area:


Given the relatively short range of the S-125 SAM system, most nations commonly employ them as short-range systems complementing longer-range systems such as the S-75 that the system was originally designed to complement.

The following image depicts the coverage provided by identified active S-125 sites (blue) and S-75 sites (red) around the metropolitan areas of northeastern Egypt:

Other nations, such as Eritrea, Peru, and Zambia, employ the S-125 as their primary air defense system, positioning their launchers around key areas. In these cases it is likely that interceptor aircraft would serve as the primary means of air defense, as the SAM network is too short-ranged and widespread to provide accurate coverage.

The following image depicts S-125 coverage in Eritrea:


The nations listed below have been identified through analysis of Google Earth imagery as being current users of the S-125 SAM system. The number in parentheses following the nation's name is the number of occupied sites currently visible in Google Earth, followed by the number of currently unoccupied sites in that nation.

Algeria (4/0), Angola (7/0), Armenia (2/1), Azerbaijan (4/0), Belarus (4/0), Bulgaria (4/0), Cuba (4/0), Egypt (43/11), Eritrea (3/1), Ethiopia (4/1), Georgia (1/1), India (23/9), Kazakhstan (1/0), Kyrgyzstan (2/0), Libya (10/2), Mozambique (3/0), North Korea (1/0), Peru (7/8), Poland (4/6), Serbia and Montenegro (3/2), Syria (26/4), Tajikistan (2/0), Turkmenistan (3/0), Ukraine (2/2), Uzbekistan (3/0), Vietnam (7/3), Yemen (1/0), Zambia (2/0)


The nations listed below have been identified through analysis of Google Earth imagery as having been former users of the S-125 SAM system. The number in parentheses following the nation's name is the number of unoccupied sites currently visible in Google Earth, not including those currently occupied by other SAM systems.

Czech Republic (8), Hungary (8), Iraq (14), Romania (1), Slovakia (4)


-Jane's Land Based Air Defense 2002-03
-Fakel's Missiles, by Vladimir Korovin
-All satellite imagery provided courtesy of Google Earth
-The CIA FOIA website at provided the documents shown and referenced above

-Site measurements were acquired using Google Earth and as such may not be 100% accurate


victor said...

Hello, great site and excellent analysis! Could you post a map of the location of the Peruvian S-125 sites? It is extremely difficult to find any info on them on the web and on printed sources. Thanks in advance

Anonymous said...

Get my old maps readdy.