Lloyd’s Register Increases Container Stowage with BoxMax
Lloyd’s Register’s BoxMax service, and accompanying notations, aims to enable operators to load more cargo more flexiblyvby increasing and optimizing container stack weights, taking into account voyage (V) and weather (W) specific conditions.
This approach, pioneered by Lloyd’s Register (LR) last year, has now been further improved by voyage and weather dependent criteria being incorporated into the modeling. The result is that the right stow and lashing requirements can be planned for any voyage at any time of year. Following on industry feedback since the announcement last year of new container securing arrangement rules, Lloyd’s Register has now created the BoxMax notation.
Providing container ship operators with guidance for different weather and voyages is a breakthrough, building on the same principles behind summer and winter load lines and freeboard requirements.
“No investment is required,” said Luis Benito, Global Marine Marketing Manager, Lloyd’s Register. “BoxMax is a smart solution to the needs of operators. Significant improvements in container stack weights can now be identified. Forces in a stack vary widely and vary between stacks at different locations in a ship. Our rules provide the greatest stowage planning flexibility in the market, enabling operators to achieve the most cost effective container transportation.”
LR addresses the interaction between the complex, multi-degree of freedom motions experienced by a container ship and the consequential load paths through container stacks and their support arrangements. LR said this is not just mathematics – real containers have been load tested at full scale and ships have been instrumented; new insight for the larger 16-18,000 teu designs now emerging and for next generation 22,000+ teu ship designs.
Lloyd’s Register is now ready to assess ships’ lashings for any voyage and season. Building on its experience in other ship type sectors, including naval ships, Lloyd’s is able to offer a service can assess the stowage requirements in specific sea areas and in specific seasons.
The BoxMax method uses ship specific factors, supplied by LR, which define the key ship motion parameters of heave acceleration, roll and pitch angles and whipping accelerations in specific sea areas and for the required season. All the other ship motion acceleration values are dependent on these four parameters.
David Tozer, Business Manager, Container Ships, Lloyd’s Register, said, “Consider a container ship trading with ‘unrestricted service’, all year round, between Asia and Europe. For this trade the maximum container stack weight is 100%, i.e. the voyage dependent feature is of no benefit for stacks which are travelling the full distance. However, for stacks which are only travelling in the SE China or Mediterranean Sea areas for example, the stack weights can be greater. The assignment of the BoxMax (V) notation will denote the ship has access to this capability.”
“Similarly, if the containers being shipped within these areas are being carried during the summer months the stack weights can be increased, in some cases by up to 25%. The BoxMax (W) notation will demonstrate this capability,” he added.
For container stacks which are travelling the entire Asia-Europe voyage, the benefits of summer sailing may be relatively small, of the order 2%, as Biscay may be challenging even during the summer months.
The Lloyd’s Register Voyage and Weather Dependent method is applicable to any voyage, anywhere, during any season, LR said. The voyage dependent factors are calculated for each specific ship, and each ship will benefit, depending on where it is trading, whether it be long haul or short sea.