Main Image Credit A nuclear-powered submarine in the Russian Northern Fleet, pictured in July 2020. Courtesy of Sergey Yakovlev/Alamy Stock Photo
Projections indicate that the coming decade will see more Russian submarines capable of carrying more cruise missiles, while NATO's corresponding capacity will be constricted.
The Russian Navy has a tradition emphasising cruise missile submarines which goes back to the early days of the Cold War. But this capability is now being transformed in three major ways which could reshape the submarine threat facing NATO. Firstly, the cruise missiles are increasingly intended for land-attack, whereas they were mostly anti-ship missiles in the past. Secondly, they are being carried by more diverse, and flexible, submarine platforms. And thirdly, there will be a massive increase in the number of missiles which can be carried to sea.
The Russian Navy launched its latest Severodvinsk-class cruise missile submarine, K-571 Krasnoyarsk, on 30 July 2021. This type, the Project-885A, can carry three different types of cruise missile in 32 vertical launch tubes. The missile options are versatile and modern and represent a wider trend in the Russian Navy: cruise missiles are in.
Based on analysis of open sources, we estimate that the number of cruise missile ‘slots’ available aboard Russian submarines will more than double from 2020 to 2030. This is due to a combination of new submarines and modifications to older boats. Meanwhile, the US Navy’s total ‘slots’ will decrease markedly over the same timeframe. This could lead to a significant change in the balance for this strategic capability between Russia and NATO.
The projection uses the number of cruise missiles expected to be carried in a ‘full load’ aboard all commissioned submarines. We estimate that the Russian Navy’s capacity will increase from fewer than 300 missiles in 2020 to nearly 650 by 2030. At the same time, the US capacity will decrease from around 1,000 in 2020 to around 775 in 2030 – still more than Russia, but with the gap substantially closing. Caveats need to be applied to these estimates: not all submarines will be available at the same time and not all missile tubes will be loaded. But based on the current submarine building plans, the direction is clear.
The Russian increase is tied to the adoption of new weapons. The headline-grabbing new missile, Zircon, is a hypersonic anti-ship missile. It has been tested extensively in recent years and is being adopted by both surface vessels and submarines.
Zircon is part of the wider trend of adopting hypersonic missiles. They reduce reaction times on time-sensitive targets and will be harder to intercept. Thanks to Zircon, Russia appears to be ahead in this area.
Zircon will be carried by the new Severodvinsk-class submarines like Krasnoyarsk. These are more popularly known by the Russian name Yasen-class, or the Yasen-M variant for all but the lead boat. They are larger and more heavily armed than equivalent submarines under construction in the West. By 2030, nine of these are expected to be in service. There are plans for the US Navy to adopt its own hypersonic weapon – a boost-glide system – but this is still in development and has yet to go to sea.
The ‘Zirconisation’ of the Russian Navy is similar to the previous round of ‘Kalibrisation’, where the Kalibr cruise missile was rapidly rolled out to multiple platforms. In the submarine context, Kalibr (NATO: SS-N-27 Sizzler) is principally a long-range subsonic land-attack cruise missile, broadly equivalent to the Tomahawk. Aboard Russian submarines it is again native to the Severodvinsk class, and can be carried by smaller submarines. The payload aboard the conventionally powered Kilo and Lada-class boats is very limited, however – it is likely to be around four rounds only. Small numbers have been launched against targets in Syria, providing valuable combat testing for the system.
The other Russian submarine cruise missile is the Onik (NATO: SS-N-26 Strobile). This is a large supersonic weapon which is capable of hitting both ships and land targets. Because of its size and the need for a vertical launch tube, it is currently limited to Severodvinsk-class submarines. It can be thought of as a smaller and more modern evolution of the Cold War-era Granit (NATO: SS-N-19 Shipwreck). That missile, until the advent of Zircon, represented the pinnacle of anti-ship missile threats.
Currently, a large part of the Russian Navy’s cruise missile capacity aboard submarines is tied up in the Granit system. This system was designed to overwhelm high-value targets such as aircraft carriers. While it is still considered formidable, only the Oscar-II-class submarines can carry these massive weapons. Moreover, as a dedicated anti-ship weapon it has limited versatility. There are, however, reports that the Oscar-II-class boats are to be modified to carry the same array of new missiles as the Severodvinsk class.
Because the new missiles are smaller, more can be carried. It is thought that each of the Oscar-II's 24 Granit missiles will be replaced by three Kalibr, Onik or even Zircon missiles. This will increase the cruise missile load to 72 missiles per boat. Exactly how many Oscar-II boats will be modernised, and when, remains to be seen. The first boat brought up to 949AM standard appears to retain the Granit, so there is some uncertainty – but again, the direction is clear. The first boat expected to carry the new missile fit, Irkutsk, is already being modified.
The last major cruise missile upgrade will be to the Akula-class attack submarines. These are the current backbone of Russia's nuclear-powered attack submarine fleet. They are being modernised to carry Kalibr cruise missiles in their torpedo room. The exact load-out is not reported, but it provides a similar capability to the Royal Navy’s nuclear-powered attack submarines which carry Tomahawks in this way.
The diversification of launch platforms could multiply the complexity of countering the threat. And while a non-nuclear submarine with four cruise missiles seems small compared to the 32 missiles aboard a Severodvinsk-class boat, it does represent a serious ‘first night’ strike capability. This will concern NATO planners, and it introduces submarine-launched cruise missiles to the Baltic and Black Sea fleets. These fleets previously lacked cruise missiles, so the submarine threat will be reshaped.
The decrease in US Navy capacity will primarily be due to the retirement of the four Ohio-class cruise missile submarines. These can each carry 154 Tomahawk cruise missiles, by far the most missiles of any submarine. The Ohio boats will be partially replaced by enlarged Virginia Block V submarines. These will carry 76% more weapons than earlier boats in the class. However, with only 40 vertical launch tubes per boat, there will still be a decrease in overall fleet capacity.
The US Navy’s Tomahawk fleet will become more versatile, however, as the new Block V missile is adopted. This will provide a long-range anti-ship capability to the missile which, until now, was solely a land-attack weapon.
Beyond the US, only two NATO navies currently field cruise missiles. The Royal Navy’s nuclear-powered attack submarines can carry the Tomahawk, and the French Navy is introducing the NCM (Naval Cruise Missile) weapon. In both cases these are carried in the torpedo room instead of vertical launch tubes. This has some advantages, being more versatile and easier to reload in some circumstances, but is also likely to represent a smaller load-out. This is because every cruise missile carried means fewer of other types of weapons. US Navy submarines could also be loaded with additional Tomahawks in the torpedo room, but this scenario is not counted in the calculations as it is not thought to be standard practice. Additionally, some NATO submarines carry anti-ship missiles such as Exocet and Harpoon, but these are short-range systems.
Projecting the cruise missile capacities beyond 2030 becomes harder, as new classes will start to enter service. The leading NATO navies and Russia will continue to build new submarines capable of carrying cruise missiles. But cruise missile slots will be competing with an increasing number of other capabilities, such as uncrewed underwater vehicles. It therefore seems less likely that either the US Navy’s future SSN(X) or the Royal Navy’s SSN(R) will emphasise cruise missiles to the extent of the Severodvinsk class. And even if they do, Russia’s next Laika/Husky-class attack submarine to replace the Akula class is expected to have a bank of cruise missile tubes.
The direction is clearly towards a shift in cruise missile capacities. Over the coming decade we will see more Russian submarines capable of carrying more cruise missiles. NATO's corresponding capacity will be constricted.
The views expressed in this Commentary are the author’s, and do not represent those of RUSI or any other institution.
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