Hull construction precision is fundamental to ship quality. In traditional shipbuilding, precision management has often been concentrated on post-assembly measurement, where problems are already difficult to correct. Jiangsu Haizhongzhou Shipping Industry Co., Ltd. has fully introduced a digital closed-loop control system, achieving controllable, measurable, and traceable precision throughout the entire process from cutting, forming, sub-assembly, and block assembly to final erection.
The system centers on 3D measurement equipment and precision analysis software. During block fabrication, high-precision total stations collect 3D coordinates of key control points—such as reference lines, mating lines, and allowance lines—with sub-millimeter accuracy. Data are uploaded in real time to a precision database, where the software automatically compares them against the theoretical model, generating color-coded deviation maps. The system triggers an immediate alarm when deviations exceed preset thresholds.
The core of closed-loop control lies in the “feedforward–feedback” linkage mechanism. In the feedforward stage, the system predicts weld shrinkage and angular deformation for each weld based on historical data, automatically compensating part dimensions during CNC cutting and beveling. In the feedback stage, measured deviation data drive dynamic adjustments to subsequent processes, such as repositioning jig supports, modifying assembly sequences, or optimizing welding parameters. This mechanism prevents deviation accumulation in downstream processes.
Haizhongzhou Shipbuilding has achieved full digitalization of precision control on its main vessel types. On the 85,000 DWT bulk carrier, for example, the first-time positioning success rate for block assembly has increased from 78% to over 95%, and berth rework man-hours have been reduced by approximately 60%. The complete record of precision data also provides valuable historical reference for future vessel construction. Digital closed-loop precision control has become a key technical safeguard for Haizhongzhou Shipbuilding in producing high-quality hulls.
