Communication and navigation systems serve as the “eyes and ears” of safe vessel navigation. On modern vessels, equipment such as navigation radar, GPS/BeiDou receivers, AIS, VHF, gyrocompasses, and wind sensors are densely installed, creating increasingly complex electromagnetic environments. Jiangsu Haizhongzhou Shipping Industry Co., Ltd. has established standardized procedures for system integration testing and electromagnetic compatibility (EMC) design, ensuring that all equipment operates cooperatively without mutual interference.
Integration testing is divided into three phases. The first phase is laboratory bench testing: before equipment is installed on board, all communication and navigation devices are connected in a simulated environment to complete protocol matching, data format verification, and basic functional testing. The second phase is quayside static testing: equipment is powered on in its actual installed positions to test transmission power, reception sensitivity, and mutual interference between devices, such as the impact of radar pulses on VHF receivers. The third phase is underway dynamic validation: during sea trials, positioning continuity, communication reliability, and gyro follow-up accuracy are verified under dynamic conditions.
Anti-interference design is embedded throughout the system integration process. First, at the cable routing level, coaxial cables and power cables are routed in separate layers with a minimum spacing of 300 mm, and signal cables avoid long parallel runs with power cables. Second, at the signal interface level, critical signal lines use twisted shielded cables, with the shield grounded at a single point to avoid ground loops. Third, at the RF equipment level, bandpass filters are installed between radar transmitters and receivers to suppress harmonic interference. For co-located VHF and AIS installations, cavity filters are used for frequency isolation to prevent transmitter blocking of receivers.
Additionally, Haizhongzhou Shipbuilding has established a complete grounding system. A dedicated communication grounding copper busbar is installed, separate from the power grounding. The enclosures and cable shields of all communication and navigation equipment are connected to the communication grounding busbar via the shortest path. Test data show that after systematic integration testing and anti-interference design, the first-time power-on success rate of communication and navigation systems exceeds 98%, with no equipment anomalies or data loss caused by electromagnetic interference observed during sea trials. This methodology has been extended to all newbuild vessels as a standardized operating procedure.