This thing is fucking insane.

The SA-4 is surface to air missile system (Russian designation 2K11 'Krug' - Russian for 'circle') produced by the Soviet Union and deployed there from about 1967 onwards. Apparently it is nearing retirement in Russia but is still used by Poland, Ukraine and possibly Czechoslovakia; it was also used in East Germany before reunification. Observers first spotted it at the 1964 May Day Parade, which was its official introduction in the Soviet Union. The SA-4 is the first example of a fully mobile anti-aircraft missile system.

The SA-1 and SA-2 were not really moveable at all and the SA-3 was not mobile enough to follow an active fighting force. Looking to fill this gap, the Lyulev Design Bureau designed the SA-4: a medium to high-altitude long-range missile system capable of moving with the forces it is protecting.

A single SA-4 unit consists of a tracked chassis with a 360º rotating hydraulic turret on which two missile rails, themselves capable of elevating up to 45º, are fitted. One missile is held on each. The 30-tonne launcher is powered by a water cooled V-12 diesel engine developing around 600bhp, capable of propelling the vehicle up to about 30mph for a maximum of 180 miles. Space not occupied by the engine is used to house the 5 crew who operate the vehicle and fire control systems. This completely new chassis design proved rather versatile and was later used as a basis for other mobile howitzers and minelayers.

The only part of the system that is separate from the launcher (apart from the ammo, which is carried separately on flatbed trucks) is the targeting and height-finding radars. A Long Track radar performs targeting - this is mounted on an artillery tractor at battalion headquarters, accompanied by the Thin Skin height-finding radar, mounted on a truck or trailer. These radars would typically serve three to four battalions of SAMs of various types (these radars were/are also used with the SA-6), as well as a number of ZSU-23 anti-aircraft guns. Together they can track targets 150km away, up to an altitude of 30km; targeting information is passed to SAM batteries.

The launcher's on-board Pat Hand radar is able to track targets passed to it by the base radars, once they are within 130km. One or both of the missiles can be launched once the target has closed to 80-90km (the radar is capable of guiding both missiles at the same time); each follows a radar guidance beam to the target, switching over to their own radar homing system at the terminal phase of the interception. During the flight the missile is tracked with a transponder mounted in one of its fins. It is believed that the SA-4 system also has a video guidance system similar to that used by the SA-3, so guidance is still possible when ECM is being employed against the battery.

The missile itself is a beast. Almost 9 metres long and 86cm wide, the rather bulbous SA-4 missile is over six feet longer than its launcher and is one of the largest anti-aircraft missiles the Soviet Union has ever manufactured. Almost four times the weight of the SA-3, its high explosive fragmentation warhead is more than double the size of that of its predecessor, at 150kg. Four stabilising fins are fitted at the missile's rear, and two pairs of hydraulically operated wings spanning 2.3m are fitted perpendicular to each other, about two-thirds of the way along the length.

The SA-4 has the distinction of being the first successful air-breathing missile since the V-1 and V-2 - it actually has a fucking ramjet in it. It is launched by four solid fuel booster rockets which burn for about 15 seconds, propelling the missile to the requisite speed for the kerosene-fuelled ramjet to take over (ramjets do not work at an intake speed of below ~400mph). At this point the boosters jettison and the missile accelerates beyond mach 1, up to a maximum of about mach 2.5. The warhead detonates on a contact fuse or proximity fuse once it reaches its target.

Several variants of the SA-4 exist. The fourth and final variant, introduced in 1967, was developed because the previous versions were pretty poor at medium range. All had rather large dead zones, meaning they couldn't reliably hit anything less than 8km away. The SA-4B (or variant 3M8M2) was about half a metre shorter than the original, with improved medium range capabilities at the expense of 3000m of service ceiling and 5-10km of range.

<<SA-3 Goa | SAM Index | SA-5 Gammon>>


Expect minor inaccuracies due to the subject matter; please /msg me if you know different to what I've written, particularly regarding the history of jet-powered missiles.

Sources:
  • (Author not specified); "SA-4 GANEF";
    <http://www.tayyareci.com/rusfuzeleri/sa04.htm>
  • (Author not specified); "SA-4 GANEF Medium to High Altitude Surface-to-air Missile System";
    <http://www.star.co.yu/armtech/pages/tekst018.htm>
  • Missile Index; "SA-4 Ganef";
    <http://www.index.ne.jp/cgi-bin/search?cat=missile_e&plate=type01b.html&fid=sa4&imgpath=/missile_e/gif/>
  • N.A.S.O.G; "SA-4 GANEF";
    <http://www.nasog.net/datasheets/armour/spsam/SA_4_Ganef.htm>
  • Federation of American Scientists; "SA-4 GANEF";
    <http://www.fas.org/man/dod-101/sys/missile/row/sa-4.htm>
  • Sword of the Motherland; "SA-4 'Ganef'/2K11 Krug Air Defense Missile System";
    <http://www.russianwarrior.com/1969vehicle_sa4.htm>;
  • "History, Development, and Use of the SA-4 'Ganef'/2K11 Krug Air Defense System";
    <http://www.russianwarrior.com/1969vehicle_sa4history.htm>

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