Following news of the latest successful tests of hypersonic missiles by the United States, and apparently North Korea, it may have escaped people's attention that the U.S.'s aging, yet venerable, guided missile-armed Ohio-class submarines have been earmarked to be among the first platforms to get them. Already among the most heavily armed ocean-going vessels on the planet, an arsenal of hypersonic missiles would cement their future in the navy for years to come.
The Ohio-class of submarines were first commissioned in the early-1980s, with 18 built between 1981 and 1997. Designed as nuclear-powered ballistic missile submarines (SSBN), they were commissioned to replace the aging 41 for Freedom-class of submarines. At the time of construction, they were the largest submarines ever built.
In the early-2000s, four of the original fleet of SSGNs were converted to guided missile submarines following the 1994 Nuclear Posture Review. This review recommended that the U.S. only needed around 14 SSBN submarines to meet its strategic needs at the time.
Since then, the Department of Defense has permanently reduced the Ohio-class submarines’ submarine-launched ballistic missile (SLBM) capacity from 24 SLBMs to 20 in compliance with U.S.-Russia strategic nuclear arms control limits established by the New Strategic Arms Reduction Treaty.
The Ohio-class submarine is one tough cookie
Each of the four SSGNs can carry a complement of no less than 154 Tomahawk missiles, as well as, a complement of torpedoes too. Soon enough, its already impressive capability to deliver destruction from afar will include some hypersonic missiles currently under development under the Conventional Prompt Strike (CPS) program.
Such missiles will be able to hit targets with equal precision and range as existing guided missiles, but with incredible speed. In fact, such missiles should be able to speed towards their designated targets at close to 5 times the speed of sound. More importantly, this incredible speed will make intercepting and countering such missiles a very tricky task indeed.
At present, the U.S. Navy expects to deploy the new hypersonic strike weapons by 2025. No information is yet available on how many of these new missiles will be able to fit in each Ohio-class submarine silo, but it would not be unreasonable to assume two or three.
If all 20, or so, silos of each submarine were equipped in this way, this could mean a maximum payload of between 44 and 66 missiles per submarine. To this end, the Tomahawk will still remain relevant, may be preferable in many scenarios, so a mixed load is likely to be carried. If true, this would mean that the new missile would not increase or decrease the current firepower of the Ohio-class submarine, but rather increase its potency and versatility.
Other nations are also developing their own hypersonic missiles, like Russia and China, for their own submarine fleets. Russia, for example, is currently testing its new 3M22 Zircon missile (also Romanized Tsirkon) that can travel at Mach 8.
These missiles will likely be supplied to Russia's existing Pr. 855M Severodvinsk-II Class submarines and possibly upgraded Oscar-II class boats.
From the U.S.'s point of view, such a new missile payload will mean that the remaining Ohio-class submarines will stay a major platform until they are retired.