ClassNK has published new guidelines for the maritime transport of containers, aimed at improving stowage efficiency and ensuring safety measures such as the prevention of cargo collapse. These guidelines apply the latest knowledge in weather forecasting, ship motion, and digital twin technologies.
The recently published Weather Forecast-Based Cargo Safety Guidelines, Anti-Rolling Device Guidelines, and Container Stowage and Securing Mechanisms Guidelines enable safer and higher-capacity container shipping by optimizing stowage based on short-term voyage weather forecasts and by leveraging the roll-reduction effects of anti-rolling devices.
The Weather Forecast-Based Cargo Safety Guidelines detail that route selection based on weather and ocean information is one of the key factors for the safe transport of cargo. While forecasts are a valuable source of information when the forecast period is sufficiently short, it is necessary to consider their uncertainties to ensure safety. However, until now there were no specific standards, and each company managed it individually.
By clarifying the correlations between AIS records accumulated by ClassNK, over a million cases of historical weather and ocean data, and actual sea conditions through big data analysis, this guide specifies new technical requirements for qualifying the uncertainty of weather forecast values and cargo safety assessments, and describes the corresponding standard assessment methods.
Furthermore, this regulation also details a calculation method for a cargo correction factor based on short-duration voyage weather forecasts, related to container loading and the assessment of lashing strength for these ships.
By applying this guideline, safe and optimized stowage operations can be achieved on short-duration voyages based on weather forecasts.
In the case of the Anti-Rolling Device Guidelines, in recent years, more and more units, such as anti-rolling tanks, have been installed on cargo ships to improve safety, comfort, and work efficiency by reducing ship motion.
Faced with growing concern about accidents caused by cargo collapse, attention has increased on the system and while its installation on large merchant ships has become widespread, to date there are no common safety standards.
This standard specifies the technical and inspection requirements for anti-rolling devices, leveraging the experience on ship motions gained during the development of the Guidelines for parametric rolling countermeasures, and establishes a method for evaluating the effect of anti-rolling tanks in reducing rolling motion.
By applying this guideline, safe container stowage operations can be performed by considering the rolling reduction effects of anti-rolling devices.
Meanwhile, the Guidelines for container stowage and securing published in 2023, now revised, have contributed to balancing safety and economic efficiency by allowing optimized stowage operations that take into account the effects of routes and seasons, in response to the enlargement of container ships and advances in mooring technology.
With the publication of the guidelines on weather forecasts and anti-rolling devices, the related requirements have been revised to allow for container stowage that also reflects these factors.
