ClassNK issues new guidelines on vehicle carrier structures

Its Guidelines for Vehicles Carrier Structures follows its earlier Guidelines for Racking Strength Assessment of Vehicle Carriers – Guidelines for Evaluation of Yielding Strength, issued in November 2016.
The latest guidelines, which are available to download free of charge at the classification society’s website, provide a set of technical requirements relating to strength assessments for bottom structures and fatigue strength assessments due to racking deformation.
This form of deformation can take place when a ship’s structure is subject to transverse forces in a seaway. The deck moves laterally relative to the bottom structure and the side shells move vertically relative to one another. Vehicle carriers are particularly susceptible to racking deformation because they are designed with a minimal number of transverse bulkheads to simplify loading and discharging, and to maximise cargo-carrying capacity. Ship sizes have continue to increase over recent years, and racking deformation has therefore become more important.
ClassNK ‘s research programme in this area is continuing with a focus on fatigue strength assessments relating to racking deformation and the latest guidelines will be updated when this research is completed.