View source for 2K11 Krug

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{{Infobox weapon
| name               = 2K11 Krug <br /><small>[[NATO reporting name]]: SA-4 "Ganef"</small>
<!-- This infobox describes the TELs. The missiles themselves are described in an infobox in a later section. Please make this more clear. The range stated in this infobox is that of the vehicle, not the missiles.-->
| image              = 2P24 Krug spb.jpg
| caption            = 2K11 [[transporter erector launcher|TEL]] carrying two 3M8 missiles at Saint-Petersburg Artillery museum
| origin             = Soviet Union
| type               = Transportable [[Surface-to-air missile|SAM]] system
<!-- Type selection -->
| is_vehicle         = yes
| is_UK              = yes
<!-- Service history -->
| service            = 1965–present <br /> 1965–1990s (USSR)
| used_by            = See list of [[#Operators|operators]]
<!-- Production history -->
| designer           = [[NPO Novator|Lyulev Novator]]
| design_date        = 1957
| manufacturer       = [[Kalinin Machine Building Plant|MZiK]]
| unit_cost          = 
| production_date    = 
| number             = 
| variants           = Krug, Krug-A, Krug-M, Krug-M1, Krug-M2, Krug-M3{{clarify|date=October 2015}}
<!-- General specifications -->
| spec_label         = 2K11 Krug<ref name="Janes-lad" />
| weight             = {{cvt|28200|kg|lb|abbr=on}}
| length             = {{cvt|7.5|m|ft|abbr=on}} ({{cvt|9.46|m|ft|0|abbr=on}} with missiles)
| part_length        = 
| width              = {{cvt|3.2|m|ft|abbr=on}}
| height             = {{cvt|4.472|m|ftin|0|abbr=on}} (with missiles)
| diameter           = 
| crew               = 3 to 5
<!-- Vehicle specifications -->
| armour             = {{cvt|15|mm|in|abbr=on}}
| primary_armament   = 
| secondary_armament = 
| engine             = V59 V-12 water-cooled diesel
| engine_power       = 520 hp
| pw_ratio           = 17.33 hp/t
| transmission       = 
| payload_capacity   = 
| suspension         = 
| clearance          = {{cvt|0.44|m|ftin|abbr=on}}
| wingspan           = 
| propellant         = 
| fuel_capacity      = {{cvt|850|L|abbr=on}}
| vehicle_range      = {{cvt|780|km|mi|abbr=on}}
| ceiling            = 
| altitude           = 
| boost              = 
| speed              = {{cvt|35|km/h|mi/h|abbr=on}}
| guidance           = 
| steering           = 
| accuracy           = 
| launch_platform    = 2P24 SPU
| transport          = 
| traverse           = 360°
| elevation          = 45°
}}
The '''2K11 ''Krug''''' ({{langx|ru|2К11 Круг}}; English: '[[circle]]') is a [[Soviet Union|Soviet]] and now Russian medium-range, medium-to-high altitude [[surface-to-air missile]] (SAM) system. The system was designed by [[NPO Novator]] and produced by [[Kalinin Machine Building Plant]]. Its [[GRAU]] designation is "2K11." Its [[NATO reporting name]] is '''SA-4 ''[[wiktionary:ganef|Ganef]]''''', after the [[Yiddish]] (originally [[Hebrew language|Hebrew]]) word {{lang|yi|{{Script/Hebrew|גנבֿ}}|rtl=y}} meaning 'thief'; the name was used because the system resembled the [[Bloodhound (missile)|Bristol Bloodhound]].<ref>{{Cite web|url=https://www.britannica.com/technology/rocket-and-missile-system|title=rocket and missile system &#124; weapons system &#124; Britannica|website=www.britannica.com}}</ref>

== Development and service ==
Development of the Krug ZRK-SD (2K11) air defense system started in 1957 by the Lyulev OKB design bureau. It was first displayed during a parade in Moscow in May 1965. The system started to be fielded in 1967 and became fully operational in 1969. It was used by the Soviet Army as a long-range SAM.

The early version of the Krug entered service in 1965. The first operational deployment version, the Krug-A, entered service in 1967, with extensively modified versions, the Krug-M in 1971 and the Krug-M1 in 1974, which were developed to rectify problems discovered during army service.<ref name="Janes-lad">{{cite web |url=http://www8.janes.com/Search/documentView.do?docId=/content1/janesdata/yb/jlad/jlad0103.htm |title=Almaz/Antei Concern of Air Defence – 2K11 Krug (SA-4 'Ganef') medium to high-altitude surface-to-air missile system |access-date=2008-08-18 |date=2008-07-02 |publisher=[[Jane's Information Group]] |archive-date=2012-02-10 |archive-url=https://web.archive.org/web/20120210133339/http://www8.janes.com/Search/documentView.do?docId=/content1/janesdata/yb/jlad/jlad0103.htm |url-status=dead }}</ref> A target drone called '''9M316M Virazh''', developed from obsolete Krug missiles, was proposed for export in 1994.<ref name="Janes-sws">{{cite web |url=http://www8.janes.com/Search/documentView.do?docId=/content1/janesdata/binder/jsws/jsws0175.htm |title=Krug (SA-4 'Ganef') |access-date=2008-08-18 |date=2008-02-13 |publisher=[[Jane's Information Group]] }}{{Dead link|date=July 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref name="milparade19">Boris Dukhov, Anatoly Shiroky, [http://milparade.udm.ru/19/70-72.htm Building combat skills] {{webarchive|url=https://web.archive.org/web/20110717051607/http://milparade.udm.ru/19/70-72.htm |date=2011-07-17 }}, Military Parade</ref>

The 2K11 was briefly operated by the Soviet army during the [[Soviet–Afghan War|war in Afghanistan]] in 1979 and 1980, but was withdrawn several months after the initial invasion.<ref>Urban, Mark. ''War in Afghanistan'', 43, 66.</ref> In 1997, it was reported<ref name="Janes-sws" /> that, between 1993 and 1996, some 27 fire units of Krug and 349 missiles had been sold to [[Armenia]]. Poland flight tested four missiles in September 2006 against [[P-15 Termit]] (SS-N-2 'Styx') targets.
[[File:Longtrack.jpg|thumb|left|The P-40 "Long Track" radar set.]]

== Description ==

=== Vehicles ===
[[File:1S32 radar at the National Museum of Military History, Bulgaria.jpg|thumb|The 1S32 fire control and guidance radar vehicle]]
The [[transporter erector launcher|TEL]] vehicles are tracked based on a [[GM chassis|GM-123]] chassis and carry two missiles each on an elevating turntable for up to 360-degree rotation and 70-degree elevation. The two primary versions of the missile in service are the 9M8M1 (former designation 3M8M1)  ('''2K11M "Krug-M"''') and 9M8M2 (former designation 3M8M2) ('''2K11M2/3 "Krug-M1"'''), both of which are believed to be known to the [[United States Department of Defense|US DoD]] as '''SA-4B'''. The original 9M8 (former designation 3M8) ('''SA-4A''') was first introduced into service in 1965 and followed by the upgraded 9M8M (2K11A "Krug-A") in 1967 before the 9M8M1 in 1971 and the 9M8M2 in 1973. The 9M8M2 actually has a lower maximum engagement altitude and shorter range in exchange for better performance in engaging aircraft close to the battery. Each battery typically consists of two 9M8M1 missiles and four 9M8M2 missiles as well as the following radars:

* '''[[P-40 radar|P-40 "Long Track"]]''' (1S12) [[E band (NATO)|E-band]] [[early warning radar]] (also used by the [[2K12 Kub]] and [[9K33 Osa]], range 175&nbsp;km/108 miles) (modified AT-Ts), in divisions command post
* 1S32 '''"Pat Hand"''' [[H band (NATO)|H-band]] [[Continuous-wave radar|continuous wave fire control and guidance radar]] (range 128&nbsp;km/80 miles)
* PRV-9 '''"Thin Skin"''' E-band height finding radar (also used by the [[2K12 Kub]] and [[9K33 Osa]], range 240&nbsp;km/148 miles), in regiments or brigades command post

Only '''"Long Track"''' is mounted on a modified [[AT-T]] vehicle, TEL 2P24 and "Pat Hand" 1S32 are mounted on GM-123/ GM-124.  '''"Thin Skin"''' is mounted on a truck. Batteries may also feature [[Ural Automotive Plant|Ural]] 375D trucks 2T6 carrying spare missiles for reloading the launchers.

=== Missile ===
{{Infobox weapon
| name= 9M8
| image=ZRK Krug 2005 G1.jpg
| image_size=300px
| caption=TEL at Ukrainian Air Force Museum in [[Vinnitsa]].
| origin= Soviet Union
| type= [[Surface-to-air missile]]
<!-- Type selection -->
| is_ranged=
| is_bladed=
| is_explosive=
| is_artillery=
| is_vehicle=
| is_missile=yes
| is_UK=yes
<!-- Service history -->
| service=
| used_by=
<!-- Production history -->
| designer=
| design_date=
| manufacturer=
| unit_cost=
| production_date=
| number=
| variants= 3M8 (later 9M8) Krug, 9M8M Krug-M, 9M8M1 Krug-M1, 9M8M2 Krug-M2, 9M8M3 Krug-M3.
<!-- General specifications -->
| spec_label= 9M331<ref name="Janes-lad" />
| weight= {{cvt|2453|kg|lb|abbr=on}}
| length= {{cvt|8784|mm|ftin|0|abbr=on}}
| part_length=
| width=
| height=
| diameter= {{cvt|860|mm|ftin|abbr=on}}
| crew=
<!-- Explosive specifications -->
| filling= Frag-HE
| filling_weight= {{cvt|150|kg|lb|abbr=on}}
| detonation= contact and proximity fuzes
| yield=
<!-- Vehicle/missile specifications -->
| armour=
| primary_armament=
| secondary_armament=
| engine=
| engine_power=
| pw_ratio=
| transmission=
| payload_capacity=
| suspension=
| clearance=
| wingspan=
| propellant= kerosene fuelled [[ramjet]]
| fuel_capacity=
| vehicle_range= {{convert|55|km|mi}}
| ceiling=
| altitude= {{convert|24500|m|ft}}
| boost= four solid fuel booster rocket motors
| speed= Mach 4
| guidance= Radio [[command guidance|command]]
| steering=
| accuracy=
| launch_platform=
| transport=
}}
The [[missile]]s are launched with the aid of four [[solid rocket fuel]] [[rocket motor]]s inside [[booster (rocketry)|boosters]] attached to the outside of the missile. Once they have burned and the missile is aloft, a liquid-fuelled [[ramjet]] sustainer engine is ignited. It reaches speeds of up to [[Mach number|Mach]] 4 and has an effective range of 50–55&nbsp;km (31–34 miles) depending upon the version. It carries a 135&nbsp;kg (300&nbsp;lb) [[fragmentation warhead]]. Possible engagement altitudes range from 100 m to 27&nbsp;km (330-88,500 feet). The 3M8 missile was designed and produced by [[NPO Novator]].{{citation needed|date=October 2015}}

Optical tracking is possible for guidance in a heavy [[electronic counter-measures|ECM]] environment.

=== Survivability and anti-jamming capabilities ===
The Krug had several features that improved the survivability of the radar against anti-radiation missiles. In '''PI''' '''mode''' (ПИ) the system only briefly illuminated the target and the computer calculated its prolonged path based on data received from early warning radars. After a longer passive period the main radar illuminated the calculated flight direction of the target for a few seconds and recalculate path of the target if necessary (if the distance between the calculated track and the actual position is greater than 7&nbsp;km). As a result, the system emitted detectable signals only for a few seconds every few minutes, making it difficult to jam or launch an anti-radar missile against the Krug. The system was also able to track the target in full-passive automated '''PNS''' (ПHC) '''mode''' based on the data provided by "Long Track" mobile EWR via radio datalink. In this mode it was almost impossible to detect the Krug system until the moment of a missile launch, because the Krug did not emit radiation at all.

In 3M mode (3m aka three-point) the Krug could home on a jamming target (e.g., [[AN/ALQ-99]]). Jamming signals were supposed to protect the aircraft made it into a target in this mode.<ref>{{Cite journal|last=Szabó|first=Miklós|date=2011|title=A Krug légvédelmi rakétarendszer|url=http://real-j.mtak.hu/11404/5/Haditechnika%202011_5_teljes_red.pdf|journal=Haditechnika|volume=5|pages=33}}</ref>

== Structure of Krug missile system ==

SAM-regiment have two SAM-battalions, SAM-brigade have three SAM-battalions. In each headquarter, brigade, regiment and battalion, is one command battery.
In each SAM-battalion have three SAM-batteries.

* Self-propelled launch vehicle '''2P24''' on GM-123 base, three in each SAM- battery
* Rocket guidance station '''1S32''' on GM-124 base, one in each SAM- battery
* Target detection station '''1S12''' on modified AT-T base, one in each command battery
* Transporter-loader vehicle '''2T6''' on Ural truck base, one in each SAM- battery

== Variants ==
* 2K11A Krug A
: 2K11M
: 2K11M1
* M-31 Krug M – naval

== Operators ==
[[File:2K11 Krug Operator Map 25.10.2023.png|thumb|upright=1.35|Operators {{legend|#0a57c0|Current}}{{legend|#dc0023|Former}}]]

=== Current operators ===
* {{ARM}} - Still in use as of February 2023.<ref name="IISS2023">{{cite book |last1=International Institute for Strategic Studies |title=The Military Balance 2023 |date=15 February 2023 |publisher=Routledge |isbn=978-1032508955 |edition=1st |author1-link=International Institute for Strategic Studies }}</ref>{{rp|172}}
* {{TKM}} – 2 batteries as of February 2023.<ref name="IISS2023" />{{rp|200}}

=== Former operators ===
[[File:Defe44-173.jpg|thumb|right|upright=1.35|UK MoD Intelligence assessment dated 1968.]]
* {{AZE}} - Operated at least until 2021.<ref name="IISS2021">{{cite book |last1=International Institute for Strategic Studies |title=The Military Balance 2021 |date=25 February 2021 |publisher=Routledge |isbn=978-1032012278 |edition=1st |author1-link=International Institute for Strategic Studies }}</ref>{{rp|181}}
* {{BUL}} – 30,<ref name="Janes-lad" /> in reserve
* {{CZS}}<ref name="IISS1991">{{cite book |last1=International Institute for Strategic Studies |title=The military balance. 1991-1992. |date=1991 |publisher=Brassey's |location=London |isbn=978-0080413259 |author1-link=International Institute for Strategic Studies}}</ref> - 9 batteries. Phased out in early 1990s.
* {{DDR}}<ref name="IISS1989">{{cite book |last1=Institute for Strategic Studies |title=The military balance, 1989-1990 |date=1989 |publisher=Brassey's |location=London |isbn=978-0080375694 |author1-link=Institute for Strategic Studies }}</ref>{{rp|47}} - Passed onto successor state.
* {{Flag|Germany}} – Phased out during the 1990s
* {{GEO}} – Operated at least until 2008.<ref>{{cite book |last1=International Institute for Strategic Studies |title=The Military Balance. 2008 |date=5 February 2008 |publisher=Routledge |isbn=978-1857434613 |author1-link=International Institute for Strategic Studies }}</ref>{{rp|177}}
* {{HUN}} - 18 batteries in 1991.<ref name="IISS1991" />{{rp|89}} Phased out in middle 1990s.
* {{KAZ}} - Operated at least until 2021.<ref name="IISS2021" />{{rp|187}}
* {{KGZ}} - Operated at least until 2021.<ref name="IISS2021" />{{rp|189}}
* {{POL}} – 30.<ref name="Janes-lad" /> Phased out in 2011.
* {{RUS}} – 500 launchers (2007)<ref>{{cite web |url=http://inbsite.com/missiles2.html |title=Missiles 2 |access-date=2012-08-13 |url-status=dead |archive-url=https://web.archive.org/web/20121223072244/http://www.inbsite.com/missiles2.html |archive-date=2012-12-23 }}</ref> (phased out in 1990s) Missiles used as targets for training(Virazh/-M 9M316M)<ref>{{Cite web|url=http://militaryrussia.ru/blog/topic-532.html|title = Люльев Лев Вениаминович &#124; MilitaryRussia.Ru — отечественная военная техника (после 1945г.)}}</ref>
* {{USSR}}<ref name="IISS1989" />{{rp|34}} - Passed on to successor states.
* {{UKR}} - 100 launchers in 2014.<ref name="IISS2014">{{cite book |last1=International Institute for Strategic Studies |title=The Military Balance 2014 |date=5 February 2014 |publisher=Routledge |isbn=978-1032508955 |edition=1st |author1-link=International Institute for Strategic Studies }}</ref>{{rp|195}} Phased out.
{{clear}}

== Notes ==
{{reflist}}

== External links ==
{{Commons}}
* [http://www.globalsecurity.org/military/world/russia/sa-4.htm SA-4 Ganef] at [[Global Security]] website
* [http://www.fas.org/man/dod-101/sys/missile/row/sa-4.htm SA-4 Ganef] {{Webarchive|url=https://web.archive.org/web/20160828093112/http://fas.org/man/dod-101/sys/missile/row/sa-4.htm |date=2016-08-28 }} at [[Federation of American Scientists]] website
* [http://pvo.guns.ru/foto/foto111.htm Photos of Polish Krug] at [[Vestnik PVO]] website
* [http://sites.google.com/site/samsimulator1972/home 2K11 KRUG-M1 (SA-4B Ganef) Simulator]
{{Russian SAM systems}}{{Navboxes
|list =
{{Russian and Soviet missiles|SAM}}
{{PostWWIISovietAFVS}}
}}

{{DEFAULTSORT:2k11 Krug}}
[[Category:Cold War surface-to-air missiles of the Soviet Union]]
[[Category:Self-propelled anti-aircraft weapons of the Soviet Union]]
[[Category:Science and technology in the Soviet Union]]
[[Category:Ramjet-powered missiles]]
[[Category:Surface-to-air missiles of the Soviet Union|2K11]]
[[Category:NPO Novator products]]
[[Category:Military equipment introduced in the 1960s]]