engine, with a speed of 38 knots. However, technical constraints forced the Chinese to settle for a diesel engine, powering two screws for a maximum speed of 30 knots. The Type 053Ks were armed with HQ-61 surface-to-air missiles, launched from two twin-armed launchers; these did not enter service until the mid-1980s. The 100 mm. gun armament was also delayed. This class received NATO reporting name as Jiangdong class. Only two Type 053Ks were completed, possibly due to unsatisfactory performance and the long development time for their intended armament. Yingtan (531) was laid down in 1970 and commissioned in 1977, and followed by Zhongdong (532). Both ships were withdrawn from service in 1992, with one scrapped in 1994 and the other preserved as a museum ship. Type 053H surface-warfare frigate The PLAN retired many older frigates in the 1970s, and the No. 701 Institute developed the Type 053H (Hai for anti-ship) as a replacement. The initial design was armed with four SY-1 anti-ship missiles in two twin-missile box launchers, two single 100 mm. guns, six twin 37mm guns, depth charges and short-range ASW rockets. The Type 053H received the NATO codename Jianghu-I. The first was constructed by the Hudong Shipyard and entered service in the mid-1970s. At least a dozen were built and entered service with the PLAN East Sea Fleet. The Type 053H was improved in four successive subclasses, receiving NATO codenames Jianghu-II through Jianghu-V. The Type 053Hs were succeeded by the PLAN's first multirole frigates, the Type 053H2G and Type 053H3 frigates. Type 053H2 surface-warfare frigate The Type 053H2, NATO codename Jianghu-III, is an improved version of Type 053H1 frigates. Hudong Shipyard built seven hulls for the People's Liberation Army Navy (three ships) and Royal Thai Navy (four ships) between 1985 and 1992. In 2013,two of PLAN Type 053H2 frigates were transferred to Bangladesh Navy. Basically, Type 053H2 is an anti-surface warfare (ASuW) frigate for the littoral environment featuring a sophisticated combat management system and enhanced electronic warfare and countermeasures capabilities. Foreign sales The Chinese sold the Type 053H, and derivatives to foreign navies. One refurbished Type 053H1 and two Type 053H2 was sold to the Bangladesh Navy, with two refurbished Type 053Hs going to the Egyptian Navy. Sonars for these ships are Echo Type 5, a development of EH-5 sonar used on Jianghu-III's, adopting LSIC technology. PLAN also added Type 343 fire control radar for gun. They mounted