Det Norske Veritas - Germanischer Lloyd

Strength Analysis of Hull Structure in Bulk Carriers
 N DNV CLASSIFICATION NOTES 31.1

Annotation

Introduction

This Classification Note covers only the strength analysis of hull structure in non CSR bulk carriers. For bulk carriers with CSR notation, the strength analysis of hull structure is covered in Rules Pt.8 Ch.2. This Classification Note is applicable for ships with class notation HC-A, HC-B, HC-C and HC-B.

For ships with class notationHC-M, design load cases are given in Rules Pt.5 Ch.2 Sec.5 Table C1 based on the ships’ loading manual. For application of sea pressure load, cargo load and hold mass diagrams, relevant parts of this Classification Note may be applied.

The “Rules for Classification of Ships” require a direct structural analysis to be carried out in order to cope with the complexity in the loading of bulk carriers and the many possible loading conditions. The scope for the analysis is to verify that stresses in the girder structure are within specified limits when the structure is loaded in accordance with the specified design load conditions.

The structural analysis is generally related to primary strength members of the midship region of bulk carriers arranged with double bottom and single or double side. However, additional calculations may have to be carried out for fore- and aftmost holds as the hopper/top wing tank construction normally is changed significantly compared to the midship construction.

Where in the text it is referred to the Rules, the references refer to the July 2011 edition of “Rules for Classification of Ships”.

Any recognised calculation method or computer program may be applied provided the effects of bending, shear axial and torsion deformations are considered when relevant.