Russian Military Moves to Revive Secret Soviet Submarine Base

Executive Summary:

• Russia is reviving the Cold War-era Balaklava submarine base in Crimea as it faces frequent and precise maritime strikes from Ukrainian forces. The base’s outdated dimensions, however, prevent it from housing modern submarines, limiting its strategic value and forcing Russia to reposition key assets elsewhere.
• Ukraine has inflicted severe damage on Russia’s Black Sea Fleet, despite its limited naval resources, sinking key vessels and forcing relocations. The closure of the Turkish Straits further isolates Russian warships, exposing their vulnerabilities.
• Russia’s struggles in the Black Sea highlight broader operational challenges, necessitating a reassessment of naval infrastructure and strategy. The Balaklava base’s revival underscores Russia’s commitment to defending Crimea, yet its long-term viability remains uncertain.

As Russia’s war against Ukraine enters its third year, Ukraine’s growing offensive capabilities have forced the Russian military to work harder to protect its assets, including its battered Black Sea Fleet (BSF) (see EDM, November 8, 2022, March 11, 26, August 13 [1], [2], 2024). Media reports indicate that Russia is now reviving “Object 825GTS” (“Объект 825ГТС”), a Soviet-era underground submarine base in Balaklava, Crimea (Telegram/atesh_ua, January 19). Built during the Soviet era from 1953 to 1961 to house and repair diesel-electric submarines, the facility was designed to shelter submarines from aerial and nuclear attacks. Stalin personally reviewed and endorsed the Balaklava project, and was designed to survive a direct nuclear explosion of 100 kilotons (RIA Novosti, September 17, 2011). A deep-water canal, dry dock, underground roads, nuclear weapons arsenals, storage facilities for material and technical equipment, command posts, and berths were built and remained in operation until 1996 (Ibid). Even though the Ukrainian and Russian governments subsequently signed agreements about sharing BSF naval assets, the Ukrainian government decommissioned the base and turned it into a museum, as independent Ukraine had no need of it (Argumenty i fakty, June 9, 2015, November 24, 2017).

In the past, the base could contain nine Project 613 diesel-electric submarines North Atlantic Treaty Organization (NATO) designation Whiskey-class), and Project 633 submarines (NATO designation Romeo-class, a refinement of the earlier Whiskey-class), along with up to 1,500 personnel. The canal is 1,656 feet (505 meters) long, with a width of 19.6–27.8 feet (6–8.5 meters) and a depth of 19.6–27.8 feet (6–8.5 meters) (Gazeta.ru, August 21, 2020). Recent satellite imagery and Ukrainian intelligence reports show that the Balaklava site has seen increased activity. The ATESH Crimean Tatar resistance organization reports that the Russian military is building barriers in Balaklava to impede possible Ukrainian attacks with naval and aerial drones. It claimed, “Russian occupiers in Balaklava Bay are strengthening marine engineering barriers designed to protect against unmanned boats and sabotage groups. We are actively looking for weak points in this defense” (Telegram/atesh_ua, January 19).

The Balaklava site allowed submarines to enter the base through the canal, remain there unnoticed, and subsequently go directly on combat duty underwater. During the Cold War, the complex was also used to store the BSF’s nuclear-tipped torpedoes and short-range missiles. Research laboratories of almost all the Soviet Navy’s departments were located in Balaklava. It was a testing ground for the latest missiles, the first Soviet cruise and ballistic missiles, storing and servicing nuclear weapons, and providing them to BSF warships and coastal missile units (Nezavisimaia Gazeta, October 7, 2016). The secrecy of the facility was exceptional, and the base’s approaches were carefully guarded and camouflaged so that it remained concealed even from a distance of 16–32 feet (5–10 meters) (Focus.ua, January 22).

The BSF’s unexpectedly mediocre performance following the beginning of Russia’s full-scale invasion of Ukraine in February 2022, combined with the Ukrainian military’s increasingly potent capabilities, necessitated both redeployments and increased defensive operations, heightening Balaklava’s value as opposed to Sevastopol’s open roadstead. Despite being mothballed for nearly three decades, the Balaklava facility has received renewed interest.

Prior to the full-scale invasion of Ukraine, the BSF had seven submarines in service. Shortly before the war began, the BSF’s Project 636.3 Varshavianka-class (NATO designation Improved Kilo-class), B-265 Krasnodar, and B-261 Novorossiisk boats were deployed to the Russian Navy’s Mediterranean squadron based in Tartus, Syria (Investigator.org.ua, February 9, 2022; Ukrainska Pravda, June 30, 2022). Four days after the full-scale invasion, Türkiye invoked its restrictions on warships transiting the Turkish Straits under the 1936 Montreux Convention, effectively marooning the two submarines in the Mediterranean until the war ended (see Black Sea Battleground, May 10, 2022; 24 Kanal, January 21, 2023). The BSF’s five boats remaining in the Black Sea were the 877В Paltus-class Alrosa (NATO designation: Kilo-II class)—undergoing repairs—and the Project 636.3 Varshavianka-class B-237 Rostov-na-Donu, B-262 Staryi Oskol, B-265 Velikii Novgorod, and B-271 Kolpino—all equipped with Kalibr land-attack cruise missiles (RIA Novosti, May 13, 2021; Ukrainska Pravda, May 13, 2022).

Ukrainian naval operations in the Black Sea were remarkably successful. This was especially notable as the Ukrainian Navy had virtually ceased to exist. In its greatest accomplishment, on April 13, 2022, the Ukrainian military launched two Neptun cruise missiles at the BSF’s flagship, the missile cruiser Moskva, which sank the next day (Interfaks-Ukraina, April 13, 2022).

Ukrainian cruise missiles would also target docked ships as well as the BSF headquarters in Sevastopol. On August 2, 2024, Ukraine launched 10 British-supplied Storm Shadow/SCALP cruise missiles, sinking the B-237 Rostov-na-Donu attack submarine in drydock, previously attacked Crimea in September 2023, the first combat loss of a Soviet or Russian submarine since World War II (Interfaks-Ukraina, August 7, 2023; see EDM, August 13, 2024). For Ukraine, the destruction of even one Russian cruise-missile submarine was a substantial victory. The BSF was left with three combat-ready submarines, including the Staryi Oskol, Velikii Novgorod, and Kolpino. Following the assault, the BSF transferred their submarines from Sevastopol to Novorossiisk (Defense Express, August 21, 2024).

Unfortunately for the BSF, the beam of both the Alrosa and the Kalibr-armed Varshaviankas (width of 32.4 feet [9.9 meters]) precluded their passing into the Balaklava facility with its 19.6–27.8 feet (6–8.5 meter) width. It seems evident that Balaklava, unless expanded, can currently only house smaller surface ships (24 Kanal, January 22). During World War II, after the Nazis captured Sevastopol, the Black Sea Fleet was transferred to Novorossiisk. In an example of history repeating itself, in September 2022, seven months after the beginning of Putin’s full-scale invasion of Ukraine, the BSF’s Kilo-class submarines were withdrawn to the relative safety of Novorossiisk, a secondary naval base where they currently operate (The Moscow Times, November 19, 2022).

While the new U.S. administration proposes peace initiatives, the closure of the Turkish Straits, a consequence of Russian President Vladimir Putin’s war, has severed the link between the Mediterranean squadron and the Black Sea Fleet, leaving Russia’s warships isolated and vulnerable to Ukrainian attack. As Russia is determined to hold Crimea and has been reinforcing the peninsula’s defenses, reworking Balaklava makes sense, as its size restrictions presently render it unsuitable for its original purpose. In any event, the war has shown the BSF’s shortcomings in an unfavorable light, which will necessitate substantial reforms following the cessation of hostilities.