Photos posted by a Chinese People’s Liberation Army Navy (PLAN) observer show what appears to be an electromagnetic railgun being affixed to a PLAN tank landing ship, the Haiyang Shan. The LST is being used to test the weapon because its tank deck can accommodate the containers for the gun’s control system and power supply, according to comments from a former PLAN officer translated by “Dafeng Cao,” the Twitter handle of the anonymous analyst.

For nearly a decade, the US Navy’s Office of Naval Research (ONR) and various contractors worked to develop a railgun system for US ships. A prototype weapon was built by BAE Systems. Testing at the US Navy’s Naval Surface Warfare Center in Dahlgren, Virginia was deemed so successful that the Navy was planning to conduct more testing of the gun at sea aboard a Spearhead-class Joint High Speed Vessel (JHSV).  The program promised to deliver a gun that could fire projectiles at speeds over Mach 7 with a range exceeding 100 miles. The 23-pound hypervelocity projectile designed for the railgun flying at Mach 7 has 32 megajoules of energy—roughly equivalent to the energy required to accelerate an object weighing 1,000 kilograms (1.1 US tons) to 252 meters per second (566 miles an hour).