Container Terminal Wind System
Wind system design to assess the risk of wind blowing containers off a stack in real time.
When the wind speed gets too high, the container handling equipment needs to be shutdown. Real-time monitoring of critical wind speeds based on actual stacking configurations has much better potential to provide realistic warnings and shutdown wind speeds. During our research, we found that the wind speed which causes containers to fall is sensitive to the stacking configuration and the laden weight of the containers. Another sensitive variable is the wind direction. Any attempt to find a single shutdown speed results in assuming a worst-case scenario. This approach will be overly conservative when the analyzed stack condition is the least favorable. It may be less safe if a standard stack configuration was used as the basis for the policy. To get the most efficient and realistic wind policy, active calculation of critical wind speed for all the containers in the pod based on their stacking arrangement is recommended.
Because container stability is sensitive to the sliding coefficient of friction between containers, a test of the container friction under various weather and site conditions was performed. The friction factor between the containers does change with wet conditions and when dust is present. These factors will be integrated into the critical wind speed calculations, where the user can enter the weather conditions so an appropriate shutdown windspeed can be determined. The systems integrator can link this input to a weather forcasting service so the conditions automatically update reflect the weather. The stacking configuration, container dimensions, and container weights will be determined from data output by the Terminal Operator's existing container tracking software.
This benefits terminal operations by determining critical wind speeds for the as-stacked containers instead of using worse-case scenarios. When this information is combined with wind monitoring and forecast data, a shut-down decisions can be made with more confidence. Operation personnel will be able to determine which containers are adversely influencing the critical wind speed, thus allowing restacking operations to improve the critical wind speed while maintaining the same level of safety. Integration of a weather forecasting system from a nearby University will help operation personnel with planning, scheduling and decision-making involving container operations in windy conditions.