Submarines: Chinese SSNs and SSBNs Mature


August 31, 2023: Since the 1970s, China has been trying to develop and build nuclear submarines competitive with Russian and Western boats. Their latest nuclear submarines, the Type 096 SSN and Type 094 SSBN, appear to have closed the quality and performance gap with similar Russian subs. The U.S. Navy confirmed the improvements, which makes the Chinese subs more formidable adversaries. Currently only six Type 093 SSNs and six Type 94 SSBNs are in service. The first (of six) 094 SSBN entered service in 2007 while the first (of six) 093 SSN entered service in 2006. Their replacements, the 095 SSN and 096 SSBN, are expected to enter service during the late 2020s.

This first Chinese Type 091 sub entered service in 1974 after being under construction for nearly a decade. It was retired in 2000 but three of the other four o91 SSNs remained in service, undergoing numerous upgrades. In 2013 Chinese media declared that in 42 years of operation no Chinese nuclear sub has ever suffered a nuclear reactor accident. This was an indirect dig at the Russians, who are the only nation with nuclear subs to have suffered nuclear accidents, in part because most nuclear subs ever built were Russian. During the first 60 years of existence several hundred billion dollars has been spent on developing and building nuclear powered submarines. Some 400 have been built so far, most of them Russian.

In 2000 China joined this club and retired its first nuclear submarine, the Type 091 Long March No. 1. This sub was demilitarized. That meant taking it apart to remove the nuclear reactor and then reassembling and cleaning it up for display. This is a very expensive process and so far only the United States and France have done this. The Americans demilitarized the Nautilus, the first SSN, in 1965, while France did the same in 2002 when their first SSBN, the Redoutable, in 2002. Nautilus was, in 1954, the first SSN in service and served until 1968 but was not decommissioned until 1980. In 1985 Nautilus was demilitarized and turned into a museum ship.

France did the same with its first SSBN, Redoutable, which entered service in 1971, was decommissioned in 1991 and demilitarized in 2002 and now serves as a museum ship.

The Chinese navy is modernizing and that means more nuclear subs and modern surface ships. Since 1949, when Communist China came to be, the navy has been organized into three fleets; Northern, Eastern and Southern. Back then the Chinese navy was a coastal defense force. For thousands of years China has been content to have little more than a coast guard, mainly to deal with pirates and smugglers. On only a few occasions was there a high seas (or "blue water") fleet.

Since the 1980s China has become a major importer and exporter and, to protect its growing overseas trade, something China has never had before, needs a blue water navy. Such a navy requires not just experienced sailors but also support ships. These are the tankers, supply, and maintenance ships that can keep warships operational when they are far from China. In the 1990s China began investing heavily in these ships, by 2021 had the largest fleet in the world in terms of numbers of warships, and expected to increase the size of their fleet nearly 30 percent by the end of the decade while the Americans were having problems maintaining the force that China just passed in terms of number of warships, but not yet in total tonnage.

China still has some more fundamental naval needs. For example, China has never demonstrated any talent or enthusiasm for anti-submarine warfare. Considering the number of nuclear and conventional subs arrayed against it, anti-submarine warfare should have higher priority in China. Another serious shortcoming is mine-clearing capability. The Chinese Navy is well equipped to plant mines off hostile shores and in defense of its own waters but there is not a lot of capability to clear enemy mines. Many navies share this shortcoming but for a major maritime trading nation like China, it would be sad to see all that trade shut down by a few hundred naval mines.

China is still addressing anti-submarine warfare (ASM)) and mine-clearing, but has a modern navy. The three fleets are equipped with modern ships and the composition of each of the three fleets reflect current needs, including dealing with ASM as well as the nearest naval threats. Each fleet has over a hundred aircraft for ASM, recon and fighters for air superiority and bombers carrying anti-ship missiles.

For example, the Northern Fleet faces Korea and southern Japan. It currently has 66 warships, including an aircraft carrier, 18 attack submarines (four of them nuclear powered SSNs and the rest diesel-electric), 13 destroyers (two of the larger ones are classified as cruisers), 12 frigates, 12 corvettes (small frigates) and 15 fast patrol boats armed with anti-ship missiles. There are also five amphibious ships that can carry and land tanks and other vehicles onto a beach.

The Eastern Fleet faces the East China Sea and Taiwan. It has over 140 ships including 18 diesel-electric submarines, 13 destroyers, 23 frigates, 24 corvettes and 38 fast patrol boats armed with anti-ship missiles. There are also 24 amphibious ships that can carry and land tanks and other vehicles onto a beach plus three larger amphibious ships with a flight deck.

The Southern Fleet faces Taiwan and the South China Sea. It has about 110 warships including an aircraft carrier and a new base for carriers and subs. There are 22 submarines including 14 diesel-electric and two SSNs. There are also six SSBN (nuclear powered ballistic missile) subs. There are ten destroyers, 14 frigates, 20 corvettes and 14 fast patrol boats armed with anti-ship missiles. There are also 15 amphibious ships that can carry and land tanks and other vehicles onto a beach and five larger amphibious ships with a flight deck.

The Northern Fleet must deal with the two largest and most formidable fleets in the region; South Korea and Japan.

The Eastern Fleet has the longest coastline to defend and the new coast guard comes in handy to help, often using retired and repurposed corvettes. The Eastern Fleet also must assist the Northern Fleet against South Korea and Japan as well as any attack on Taiwan.

The Southern Fleet is currently concentrating on the South China Sea, as well as contributing forces for any attack on Taiwan.

In addition to new nuclear sub designs, the Chinese Navy has innovated in other ways. For example, during 2022 China introduced the Zhu Hai Yun, a 2,000-ton ship that carries up to fifty unmanned submarine, surface and airborne vehicles. Zhu Hai Yun is operated remotely to get it out to the high seas, where the ship operates autonomously to carry out a variety of missions it is capable of. China is depending on its AI (Artificial Intelligence) software to effectively carry out its mission and then signal that it is returning. The U.S. Navy has similar but smaller (145-ton) unmanned surface ships that do not carry and operate other autonomous vehicles, but can stay at sea for up to sixty days carrying out ASW (Anti-submarine warfare) missions. The navy has also developed larger autonomous cargo ships to move supplies long distances. Smaller armed and unarmed autonomous vessels have been in service for decades to patrol ports and coastal areas. China believes it has a lead in AI control software and the Zhu Hai Yun is an effort to test that. The Americans are depending on less ambitious technologies that have produced impressive results so far, while a new Orca autonomous submarine takes those proven concepts further than ever before.

A month before China presented the Zhu Hai Yun, the Americans received the first of 24 Orca 80-ton XLUUV (extra-large UUVs) that can carry and deploy a variety of naval mines and evade enemy detection due to their small size.

Orca was the U.S. Navy solution to the difficulties with deploying offensive mobile naval mines and a robotic submarine in enemy controlled waters, like the South China Sea. Orca could even operate as an offensive weapon against Chinese submarines seeking to block access to the South China Sea and Taiwan. China is considered the major submarine threat in the Pacific and the South China Sea is seen as a major future battleground.

Currently China has about 55 diesel-electric subs of recent design in service versus 42 operated by Japan and South Korea, each with 21. Malaysia and Indonesia each have two and Australia has six. The United States has about 30 nuclear attack subs in the Pacific versus a dozen Chinese SSNs and SSBNs. The anti-China coalition also has a large array of surface and aerial ASW forces.

To even the odds China has built a network of underwater sensors in the South China Sea that is complemented by ASW aircraft and surface ships. South Korea and Japan have similar technology monitoring their coastal waters. The only nation capable of blocking Chinese subs from moving out of the South China Sea is the United States, which has underwater sensors and a large fleet of ASW aircraft. The problem is defeating the Chinese diesel-electric submarine force. China has been trying to build effective SSNs for decades and that is still a work-in-progress. Chinese non-nuclear subs are another matter and they have become world-class.

The U.S. Navy believes robotic subs carrying mobile mines would be an effective new ASW asset because the U.S. is already developing some of the new ASW technology needed for this. This includes UUVs (Unmanned Underwater Vessels) and mobile mines. Over a decade ago the navy adopted civilian underwater UUVs used for monitoring the oceans and has been using them to do that as well as collect data useful for wartime submarine operations. With a growing number of civilian and military customers, American UUV developers and manufacturers have been coming up with new ocean research UUVs that also have military applications. The latest example of this is the new class of XLUUVs with the ability to go deeper, carry a cargo bay for other research gear to be stored and deployed from, and operate autonomously for up to six months. The first of these XLUUVs was the Echo Voyager, which Boeing developed from a research project and had the first one ready for testing in 2016. The tests were successful and have involved more complex and completely autonomous operations. In 2019 the navy ordered four militarized “Orca” versions of the Echo Voyager for $11 million each.

Both models are diesel-electric powered autonomous subs that are 16 meters (51 feet) long with a payload compartment 9.1 meters long, 2.6 meters (8.5 feet) in diameter and is wholly inside the pressure hull. Propulsion is by battery powered electric motors and diesel generators to recharge the batteries when on or near the surface. This XLUUV has no topside sail and can stay underwater for days at a time because there is no crew on board to sustain. While submerged these UUVs can move at 14 kilometers an hour and have sufficient generator fuel to travel 12,000 kilometers.

The main difference between Echo Voyager and Orca is that Echo Voyager is built to dive to extreme (3,400 meters/11,000 feet) depths. Orca does without that but adds additional passive sensors and signal processing computers to detect other submarines or surface ships. There is also an underwater communications system for arming the dozen Hammerhead mobile mines Orca is designed to carry and place on the ocean floor in areas like the South China Sea. These Hammerhead bottom mines carry a Mk 54 lightweight torpedo, which is normally carried by ASW helicopters and aircraft. Mk 54 has a range of ten kilometers and a guidance system that is regularly updated. Hammerhead is being used in a similar fashion to a larger version of this used during the Cold War that deployed a larger Mk 48 torpedo. Hammerhead is an encapsulated system equipped with passive sensors to detect and identify submarines and surface ships and attack specific types of targets, like diesel-electric subs larger than Orca.




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