Producing a Container Load Subset

It is to be noted that within this version of Calc, that the definition of the container loading subset is made as part of the General Particulars definition process.

Unlike compartment loading and fixed weight subsets, only one single container subset can be used in any one voyage specific deadweight loading condition. The container subset could represent a complete ship capacity of containers or it could represent, for example, only the maximum of a given type that could be carried externally on the hatch covers, as may be found on a multi-purpose vessel carrying dry bulk material in the hold. As such, a container subset must thus contain all the containers required by a particular operating condition. A full ship set of containers cannot be modelled as the combination of two or more subsets, that means, a single subset equals a full ship set.

The LCG and TCG are assumed to act at the mid-length and mid-breadth, respectively, of the container. The VCG is defined for a particular container type by you in the Container Types dialog, expressing it as a percentage of the height. The VCG can be set differently for an empty container from that set for a loaded container. (A partly loaded container is assumed to have the same VCG as a fully loaded one). Thus for each bay the overall weight and centres of gravity are calculated, and the resultant is treated as a fixed weight item with a uniformly distributed load over the length of the container.

A further and very important consideration is the change to the vessel's wind profile due to any containers on the deck. This has a large influence on the wind heeling stability and is specific to each container set. Calc automatically changes the wind profile by inserting extra points where container bays extend outside of the vessel's normal defined profile. This altered profile is then used for the calculation of the corresponding wind profile area and lever, both of which are quoted in the loading condition report.