Shanghai waterway bureau ( swb ) is a large nationalizes enterprise , with the major business for dredging waterway . in the ages of planned economy , as she belonged to constitution , all of the working vessels and equipments depended on national investment to build . since liberation she has developed gradually to own a dredgers flotilla 上海航道局是一个以航道疏浚为主业的国有大型企业，在计划经济的年代属事业性单位，所有的生产船舶机具都是依靠国家投资建造，建国以来已经逐步发展成为国内最大且在世界疏浚业中排名第七位的疏浚船队。
The beyond is the simple notation of serial number of pricker , totaled 7 digits of codes , in which the first digit represents the diameter of needle - bar of pricker , the second digit represents the siding of triangle side on functional section of pricker , the third digit represent the length of functional section of pricker , whereas in standard notation , it represents the distance from needlepoint to gradual deflating small port ( lower port ) , the fourth digit represents the total length of pricker , which is the distance from the inside of bending helve to the needlepoint , the fifth digit represents the total quantity of dents on the cording of functional section , and the sixth digit represents the model of barb on functional section , while the seventh digit represents the distance between barbs on functional section 以上为刺针编号的简单写法，共7位代码，第一位是刺针针杆的直径；第二位是刺针工作段三角面的边宽；第三位是刺针工作段的长度，同标准写法所不一样的是针尖到渐缩锥小口(下口)的距离；第四位是刺针的总长度，按弯柄内侧至针尖的距离；第五位是工作段棱上的总齿数；第六位是工作段上钩刺的型号；第七位是工作段上钩刺与钩刺之间的距离。
