US-built submarines traditionally last up to 35 years, versus fewer than 30 for lower-quality, Chinese-built boats. With similar pre-existing force levels and identical production rates, the US undersea fleet will level off at a higher level than the Chinese fleet will.
‘Excluding the 12 Kilos purchased from Russia, the total number of domestically produced submarines placed into service between 1995 and 2007 is 30, or an average of about 1.9 per year,’ wrote Ronald O’Rourke from the US Congressional Research Service. ‘This average rate of domestic production, if sustained indefinitely, would eventually result in a steady-state force of domestically produced submarines of about 38 to 56 boats of all kinds, again assuming an average submarine life of 20 to 30 years.’
And that’s being optimistic. ‘It’s possible that the greater resources required to produce nuclear-powered boats might result in a reduction in the overall submarine production rate,’ O’Rourke wrote. ‘If so, and if such a reduced overall rate were sustained indefinitely, it would eventually result in a smaller steady-state submarine force of all kinds.’
According to current Pentagon projections through 2040, the US submarine fleet should never dip below 51 boats, with a peak of 73 in 2013 and 2014. And all of those boats are nukes – a not insignificant distinction.
Sub versus Sub
Even under the most favourable projections, the PLAN will possess just a handful of nuclear-powered attack submarines at a time over coming decades. China’s SSN fleet could actually decline in the short term, as the three ancient Type 091s are likely to leave service before an equal number of Type 095s are ready.
That matters because only nuclear-powered submarines, with their high endurance, are capable of true ‘blue-water’ operations far from shore bases. It’s for that reason that all of the US Navy’s submarines are nuclear-powered: Washington’s global military presence demands it.
To project power beyond its own coastal waters, Beijing needs nuke boats. The fact that China isn't building large numbers of SSNs reflects either a lack of serious interest in a true, global naval presence – or an inability to back up grand military ambitions with working hardware.
China is left with an undersea fleet composed mostly of diesel attack submarines, which by virtue of their short range tend to be defensive in nature. ‘Current Chinese diesel submarines rarely deploy outside the first island chain (west of the Philippines) and essentially never deploy beyond the second (east of the Philippines),’ Cote wrote. ‘Nor would these submarines be well-suited for extended deployments into the Pacific or Indian Oceans because of range and crew habitability constraints.’
Even as defensive weapons, China’s diesel submarines lack flexibility. For one, ‘the PLA has only a limited capacity to communicate with submarines at sea,’ according to the Pentagon’s annual China report. Moreover, the PLAN’s subs are optimized for attacking surface targets such as US aircraft carriers. Lacking the most sophisticated sensors and weapons, they’re far less useful for hunting US submarines. ‘China has very limited (Anti-Submarine Warfare) capabilities and US submarines are the most difficult ASW target in the world,’ Cote wrote.
‘Thus, China would have difficulty preventing US submarines from operating in its shallow coastal waters,’ Cote continued. That’s important because one of the American subs’ main tasks is to destroy enemy submarines. China’s undersea fleet cannot prevent the United States’ undersea fleet from hunting it down in its own home waters.
Considering the imbalance between large, sophisticated, ASW-optimized US submarines and their smaller, less flexible, surface-attack-focused Chinese rivals, a census of the two nations’ undersea boats can create a false impression of near parity: 60 Chinese subs versus 70 US ones. But if the American vessels can hunt the Chinese vessels almost with impunity, it almost doesn’t matter how many submarines Beijing possesses.
Even if numbers really did matter, the trends aren’t in China’s favour. Beijing might match the United States in submarine production rates, but it can’t possibly keep up with the combined sub acquisitions of Washington and its closest Pacific allies. Japan is in the process of adding six diesel attack boats to its current force of 16. Australia aims to double its fleet of six diesel boats. South Korea is also doubling its six-strong undersea fleet. Two years ago, Vietnam purchased six Kilos from Russia.
The Song submarine’s surprise appearance alongside the USS Kitty Hawk helped stoke fears of Chinese undersea dominance that were further fuelled by a brief surge in PLAN sub acquisition. Today, with more US and allied submarines entering service and fewer Chinese boats on the slipways, those fears – and the policies and assumptions they produced – warrant reconsideration. China isn’t building a world-class, globally-deploying submarine force. It’s building a mostly defensive, regional undersea force – and a smaller one than once predicted.