China appears to have built significant point-defense capabilities, in the form of large anti-aircraft guns and probable close-in weapons systems (CIWS), at each of its outposts in the Spratly Islands. AMTI began tracking the construction of identical, hexagon-shaped structures at Fiery Cross, Mischief, and Subi Reefs in June and July. It now seems that these structures are an evolution of point-defense fortifications already constructed at China’s smaller facilities on Gaven, Hughes, Johnson, and Cuarteron Reefs.

Gaven Reef

Hughes Reef

China has built nearly identical headquarters buildings at each of its four smaller artificial islands. The two smallest of the islets, Hughes and Gaven Reefs, feature four arms built off of these central structures. The end of each of these arms sports a hexagonal platform, approximately 30 feet wide. The northeastern and southwestern arms host what are most likely anti-aircraft guns (roughly 20 feet long when measured from the back of the housing to the tip of the barrel). The other two platforms hold smaller (roughly 10-foot-wide) objects without clearly visible barrels. These cannot be definitively identified, but are likely CIWS to protect against cruise missile strikes, according to the Center for Naval Analyses’ Admiral Michael McDevitt (Ret.) and RAND’s Cortez Cooper in a new podcast.

Johnson Reef

China modified this blueprint for its facility on Johnson Reef. There the central facility has only two arms, with the southern one sporting the same anti-aircraft gun (which is covered by a tarp in recent imagery but was previously visible) and the northern one an apparent CIWS. Another gun and probable CIWS, along with a radar, were constructed on a separate structure, consisting of three hexagonal towers on the eastern side of the artificial island. This structure seems to be a less complex precursor to those built more recently at Fiery Cross, Mischief, and Subi Reefs.

Cuarteron Reef

At Cuarteron Reef, the last of the four smaller artificial islands completed, the point-defense systems have been completely separated from the central headquarters building. The northeastern and southwestern ends of the islet each host a structure identical to the one built at Johnson, including an anti-aircraft gun, probable CIWS, and radar.

This model has gone through another evolution at China’s much-larger bases on Fiery Cross, Subi, and Mischief Reefs. Each of these sports four structures, consisting of tiered hexagonal towers oriented toward the sea. They are positioned so that any anti-aircraft guns and CIWS installations placed on them would cover all approaches to the base with overlapping fields of fire. Earlier AMTI imagery of the construction of these buildings showed that each included six hexagonal structures in a ring around a central tower. Since then, three of the outer hexagons have been buried, while the others have been built in a tiered pattern, with those in the front (facing outward), built lower than those behind. All of the structures except one at Fiery Cross are also backed by an even taller tower consisting of several terraces. These towers likely contain targeting radar and other systems necessary for the operation of advanced point defenses. The structure at Fiery Cross lacking this tower is built alongside the base’s runway and may be connected to radar and communications systems at the airport.

Fiery Cross Reef

Construction of all four structures has been completed at Fiery Cross Reef, where covers have been placed over the point defenses installed on the central hexagonal tower and the two in front of it. But the size of the platforms (which matches those at the four smaller artificial islands) and covers suggests they boast systems similar to those at Gaven, Hughes, Johnson, and Cuarteron Reefs.

Mischief Reef

At Mischief Reef, two of the four structures have been completed, with covers already placed over the systems installed there. Two others are still being finished, with disturbed soil showing where the three buried chambers were placed. One of those has covers over the front two platforms, while the other has space for a system that has not been installed yet. All three platforms at the fourth structure are empty, but it is clear from the spaces left empty on the platforms that the systems to be installed on the front two will be smaller than the one placed on the central platform. This is consistent with the pattern of larger anti-aircraft guns and probable CIWS seen on the smaller islets.

Subi Reef

At Subi Reef, only one of the four structures seems to have its point defenses already installed, while the others sport empty spaces waiting for guns.

These gun and probable CIWS emplacements show that Beijing is serious about defense of its artificial islands in case of an armed contingency in the South China Sea. Among other things, they would be the last line of defense against cruise missiles launched by the United States or others against these soon-to-be-operational air bases. They would back up the defensive umbrella provided by a future deployment to the Spratlys of mobile surface-to-air missile (SAM) platforms, such as the HQ-9 deployed to Woody Island in the Paracel Islands. Such a deployment could happen at any time, and Fox News has reported that components for SAM systems have been spotted at the southeastern Chinese port of Jieyang, possibly destined for the South China Sea.