Railgun uses electromagnets to propelmetallicc objects up to 4,500 mph.
United States rail gun ambitions have begun to wane, our development has proof of use but fitting rail guns on existing designs especially non-nuclear surface combatants has proven to ineffective and has not moved forward from land-based testing. These weapons take a huge amount of electricity, forcing redesigns of existing combatant designs such as the AEGIS destroyer only the Zumwalt in the US fleet has the power grid to currently support a railgun system at sea while not fitted.
The railgun could make modern naval guns obsolete due to the ability of the railgun to fire projectiles without the use of propellant. This ability to make storing munitions much safer and increase survivability if the ship is hit by enemy fire.
Has the Peoples Liberation Army Navy developed a seagoing prototype?
Pictures would suggest that the PLAN has fitted naval gun for testing on a landing ship. The LST 936, Haiyang Shan, a ship over twenty years old. This old brown water ship would have little use for such a large cannon for combat purposes. Clearly, this is not an operational fitting of a new gun for the ship, rather the ship has been conscripted into a research ship.
With ample room on its tank deck, the ship has the ability to house generators, fire control systems and instrumentation for technicians to record the results.
The PLAN guarded view of the fitting of such systems but has no choice but to remove them to get the ship underway, look at the pictures below to see the new cannon.