"Krug" System (THICK EIGHT)
Identity
This record matches the Soviet/Russian Krug high-frequency direction-finding and signals-intelligence network rather than a single installation. Declassified CIA material describes KRUG as a Soviet HF direction-finding system derived from wartime German Wullenwever/Brommy work, and later reference material uses THICK EIGHT for the smaller eight-element circularly disposed antenna array variant in the same family; it is distinct from the unrelated 2K11 Krug surface-to-air missile system. ([cia.gov](https://www.cia.gov/readingroom/document/cia-rdp78-02646r000400160001-6?utm_source=openai))
Layout
Krug was a distributed collection architecture intended to intercept and geolocate long-range radio emitters, not one standalone base. Open sources place a main center at Gudok/Klimovsk and describe additional domestic and overseas listening nodes, but the full historical node list circulated in secondary literature is not independently confirmed in the sources reviewed. ([cia.gov](https://www.cia.gov/readingroom/document/cia-rdp78t04759a001900010018-8?utm_source=openai))
Klimovsk hub
Among the supplied placemarks, the Podolsk/Klimovsk entries are the most strongly corroborated. Registry-derived Russian records list military unit 34608 in Podolsk/Klimovsk, RFE/RL identifies 34608/Gudok as the main Krug center, and a 2024 specialist survey assessed the Klimovsk site as active and co-located with legacy Krug infrastructure. ([companies.rbc.ru](https://companies.rbc.ru/id/1095074011130-federalnoe-gosudarstvennoe-kazennoe-uchrezhdenie-federalnoe-kazennoe-uchrezhdenie-vojskovaya-chast-34608/?utm_source=openai))
Other nodes
Open-source corroboration for the other supplied placemarks is fragmentary. Investigative reporting links unit 34630 to Kildinstroy near Murmansk, and a 2025 OSINT study places unit 48260 near Khabarovsk as a GRU SIGINT facility with its own circular array; those fragments fit a distributed network, but they do not publicly confirm current Krug status for every supplied coordinate or unit number. ([cynews.is](https://cynews.is/rooftop-spooks-how-gru-and-svr-monitor-moldovan-authorities-using-russian-embassy-rooftop-antennas/?utm_source=openai))
Current status
As of March 12, 2026, the best-supported assessment is that legacy Krug-associated infrastructure survives inside broader Russian SIGINT architecture, but open sources do not authoritatively confirm that the original Cold War Krug network still operates today as a discrete named system. Recent analysis lists several Russian SIGINT sites as active and co-located with former Krug arrays, while the best-documented foreign sites at Lourdes, Cuba and Cam Ranh, Vietnam were ordered closed in October 2001 and wound down by 2002. ([thespacereview.com](https://www.thespacereview.com/article/4923/1?utm_source=openai))