PhotogaleriesTYPE-091 HAN class gallery 2018-05-252020-10-09 Javier (Chang Zheng 2 boat). The Chinese nuclear submarine program has always been at low speed for Western standards, but at last China achieved technological autonomy for its own designs. (Chang Zheng 4 boat). The Han class has undergone constant and major modernizations since its construction, which does not leave in a good place the capabilities achieved. (Chang Zheng 4 boat). There is evidence of Han submarines following foreign naval groups during maneuvers or operational movements, which is a leap forward in China’s strategic policy. (Chang Zheng 4 boat). The hydrodynamic design was very advanced when they were put into service, with a highly streamlined hull, completely different from previous Chinese designs. (Chang Zheng 5 boat). The active Han class submarines fitted new sonars and anechoic tiles to reduce their acoustic signature and make detection more difficult for anti submarine systems.