Nangong 681 class series ships in PLAN service are designated by a combination of two Chinese characters followed by three-digit number. The second Chinese character is Gong (工), short for Gong-Cheng (工程), meaning engineering in Chinese, because these ships are ships built for engineering projects. The first Chinese character denotes which fleet the ship is service with, with East (Dong, 东) for East Sea Fleet, North (Bei, 北) for North Sea Fleet, and South (Nan, 南) for South Sea Fleet. However, the pennant numbers may have changed due to the change of Chinese naval ships naming convention. Nangong 681 class floating pile driver can also be used as a crane ship.[1]