The Type 814A (NATO codename: Dadie class) is the surveillance ship developed by 708 Institute for the PLA Navy. Equipped with electronic intelligence (ELINT), bow-mounted sonar, optical and acoustical surveillance systems, the ship was designed to collect foreign ship intelligence in offshore waters. Only one hull has been built and the ship is currently in service with the PLA Navy North Sea Fleet.
In 1979, the PLA Navy demanded a surveillance ship that can monitor foreign ships and collect electronic intelligence in offshore waters. The ship was to be based on the Type 635C coastal survey ship, with a displacement of 1,500 tonnes. Based on its studies, 708 Institute suggested to increase the standard displacement to 1,800 tonnes for improved performance.
The design work of the Type 814A was completed in 1982, and the ship was laid in December 1983 at Wuchang Shipyard in central China. Launched on 12 June 1986, the ship was named Xiangyanghong 28 for camouflage. The onboard surveillance systems passed their sea trial in early 1987.
A total of four hulls were originally planned, but only one built. The ship initially carried hull number V841, and this was later altered to Beidiao 841. Following its recent modernisation refit, the ship was renamed Beidiao 900. The ship is also known as Dadie class by Western intelligence.
