Abstract: The navigation condition of the water area near Xiangtan railway bridge across Xiangjiang River is very complicated. To investigate the safe speed in this water area, we carried out simulation on the navigation of typical vessels in secondary channel in the water area around the bridge through 1∶100 normal fix-bed hydraulic model and ship model test. We adopted the VDMS(Vehicle Dynamic Matlab Simulink) to rapidly detect the movement of ship models, and obtained the drift angles, drift distances and the corresponding speeds through the system's build-in program. According to the principle of safe navigation and the analysis on test results, we found that under the peak discharge for navigation Q=20 000 m³/s, the safe speeds of 2 000 DWT self-propelled ship, 2×2 000 DWT pushed barge train and 4×1 000 DWT pushed barge train are, respectively, 18.36-25.49 km/h, 14.40-19.40 km/h and 14.40-18.47 km/h. This research could serve as a basis for waterway administration departments and design departments.

Key words: water area around bridge, safe speed, ship model test