Tuesday, February 13, 2018

Behind the Scenes / How advanced are Chinese nuclear subs?


8:58 pm, February 13, 2018

By Kojiro Tanikawa and Tatsuya Fukumoto / Yomiuri Shimbun Staff WritersIn mid-January, a submarine of the Chinese Navy entered the contiguous zone around the Senkaku Islands in Okinawa Prefecture. The Japanese government released a photograph and concluded that the submarine was a Shang-class nuclear-powered attack submarine. Chinese submarines are becoming more active in waters near Japan, but how advanced are their capabilities? We examined the submarines’ current state and strategy, as well as the challenges they pose for Japan.

A veil of secrecy 

“What is this?”

A Japanese security expert was surprised when he saw a photo of the Chinese submarine, which was taken by the Maritime Self-Defense Force and released by the Defense Ministry on Jan. 12. The shape of the vessel was unlike any Chinese submarine they had encountered before.

Between the protruding superstructure called the “sail” and the vertical rudder at the stern of the submarine was a bulging deck.

Retired Vice Adm. Masao Kobayashi, former commander of the Maritime Self-Defense Force’s Fleet Submarine Force, analyzed the photo and said: “This is probably an improved variant of the Shang-class submarine that is equipped with vertical launching tubes. Such launching tubes would allow the submarine to fire a dozen anti-ship cruise missiles at once. This is an invaluable picture.”

Both the United States and Russia have already commissioned a large number of nuclear-powered submarines equipped with vertical launching tubes.

However, while the existence of the improved Shang-class Chinese submarines equipped with vertical launching tubes had been reported in some overseas media over the past few years, the vessels had been shrouded in a veil of secrecy until now.

The improved submarine has finally made an appearance before the MSDF, which had been tracking it.

Submarines equipped with horizontal launching tubes can fire only a limited number of torpedoes at a time. Chinese submarines equipped with vertical launching tubes like the ones on U.S. and Russian submarines would be capable of launching a large number of missiles from the deck simultaneously, thus gaining the ability to make a concentrated attack on a target.

The Defense Ministry has refrained from confirming whether the Shang-class vessel that was caught on camera is an improved variant.

However, Defense Minister Itsunori Onodera said, “Cruise missiles loaded onto a submarine of this class are long-range.” The cruise missiles carried by Shang-class submarines are thought to have a maximum range of 540 kilometers.

Sound detected

Chinese submarines’ largest targets would be U.S. carrier strike groups. China is aiming to become a great maritime power capable of opposing the U.S. military, and values its submarines as a pillar of its “A2/AD” (see below) strategy.

For U.S. aircraft carriers, the question of how to protect themselves from attacks by Chinese submarines is becoming crucial.

The widest of the routes through the “First Island Chain” that the Chinese Navy can use to leave the East China Sea is a more than 250-kilometer stretch between Okinawa Island and Miyakojima island, both in Okinawa Prefecture.

It is an area of great strategic importance, where vessels of the Chinese military have actively come and gone in recent years. The MSDF keeps Chinese submarines under surveillance in seas around the area.

On the night of Jan. 10, sonar from the MSDF destroyer Onami and an acoustic detector dropped from a P-3C patrol plane detected the sound of the Chinese nuclear-powered submarine. Although the Onami repeatedly issued warnings, the nuclear submarine ignored them and entered the contiguous zone around Taishojima island.

A nuclear-powered submarine can stay submerged for longer periods than a regular diesel-powered submarine. It can also move faster and can carry more weapons in its larger hull. However, its weakness is that it produces a loud noise. China’s nuclear submarines are still thought to be significantly louder than those of the United States. If the submarine that appeared this time was an improved Shang-class vessel, the MSDF could have confirmed that fact by comparing the new sound data it collected over an extended period of time against the physical appearance of the submarine when it appeared on the surface.

What did China intend by deploying its latest nuclear-powered submarine regardless of the risk of being detected?

“There is a possibility that China was attempting to discover Japan’s detection capabilities. The Chinese side also likely obtained valuable data, just like the MSDF. China now knows where and how their submarine was detected,” Kobayashi pointed out.

Japan-U.S. alliance vital

Submarines traveling underwater in the contiguous zone do not violate international law. However, since China continues to unilaterally assert territorial rights over the Senkaku Islands, such navigation increases tensions between China and Japan.

What will happen in the future if Chinese submarines intrude into Japan’s territorial waters around the Senkaku Islands?

Under international law, submarines are obliged to surface when crossing through the territorial waters of another country. If a submerged submarine belonging to another country traverses Japan’s territorial waters, the government will issue maritime security operations and demand that the submarine surface with its flag displayed. If the submarine does not comply with the demand, the government will order it to leave Japan’s territorial waters.

When a Chinese submarine was discovered navigating underwater in territorial waters around Taramajima island in Okinawa Prefecture in 2004, the Self-Defense Forces undertook maritime security operations, tracking the submarine using a P-3C patrol plane and other means until the sub returned to the high seas.

Such incidents near the Senkaku Islands pose the risk of an accidental confrontation between the SDF and the Chinese military. In order to prevent a contingency from occurring in the area, it is vital that the Japanese government check its guidelines for emergency response while maintaining its close alliance with the United States.

(From The Yomiuri Shimbun, Jan. 20, 2018)

■ A2/AD

A2/AD is a Chinese military strategy aimed at preventing intervention by the United States. It is an abbreviation of “Anti-Access” and “Area Denial.” It comprises two stages: preventing the U.S. military from operating in and deploying reinforcements to the area called the “Second Island Chain,” which stretches from the Izu Islands to Guam, followed by preventing the U.S. military from entering the area, called the “First Island Chain,” which stretches from the Nansei 

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