Drawing on practical information from equipment makers and its own guidelines, Korean Register (KR) has released the latest version of SeaTrust-LS, its container securing strength assessment software. SeaTrust-LS has been significantly enhanced by incorporating KR's new 2018 guidance for container securing assessment and reflects practical insights and feedback from world-class lashing makers, SEC Bremen and German Lashing Robert Böck.
Achieving optimum container stowage and arrangement is crucial to the safe operation of a vessel as it dramatically affects the trim, stability and longitudinal strength of the ship. Optimum stowage will also maximise the economy of container handling. If the container stowage arrangements do not provide the required secured strength, then the loading and safety of containers can be significantly compromised. Optimal container stowage and arrangement is more critical than ever as the trend for ever-larger containerships persists – with ULCS now carrying stacks of 10 or more container tiers on deck.
This year KR has revised its guidance for container stowage and lashing by conducting ship motion analysis for different sizes of containerships from 1,000TEU up to 23,000TEU. Analysis has included optimising accelerations, nonlinear analysis for calculating accurate external lashing forces, and CFD (Computational Fluid Dynamics) analysis under various possible scenarios relating to the application of reasonable wind forces.
The latest version of SeaTrust-LS contains all revisions of this latest guidance. The new SeaTrust-LS applies the semi-nonlinear calculation method to consider the twistlock separation effect of external lashing. This ensures the safe securing of external lashing as well as faster computing time for lashing strength assessment. The new software provides a range of useful features, including the calculation of optimal acceleration and wind force, together with 13 route reduction factors enabling containerships to maximise their cargo capacities while ensuring the safety of the ships themselves.
It also includes a feature to identify maximum cargo capacity automatically. This function can assist users to easily optimise design stack weight, the lashing bridge design and the container stowage arrangement. This allows the operator to select the best stowage arrangements under specified allowable targets. SeaTrust-LS incorporates an auto-update feature to enable users to work to the latest software and KR's rules; it also includes a Software Development Kit allowing it to integrate easily with customer's own software.