DNV Classification Note 32.2 Container Securing ?? The calculation procedures for mixed stowage of 20' containers stowed in 40 ... evaluation of securing arrangements for cargo containers

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  • CLASSIFICATION NOTES

    The content of thiaccepts that it is verification servicpursuant to this dconsequences aris

    The electronic

    No. 32.2

    Container SecuringJULY 2013

    DET NORSKE VERITAS AS

    s service document is the subject of intellectual property rights reserved by Det Norske Veritas AS (DNV). The userprohibited by anyone else but DNV and/or its licensees to offer and/or perform classification, certification and/ores, including the issuance of certificates and/or declarations of conformity, wholly or partly, on the basis of and/or

    ocument whether free of charge or chargeable, without DNV's prior written consent. DNV is not responsible for theing from any use of this document by others.

    pdf version of this document found through http://www.dnv.com is the officially binding version

  • FOREWORD

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    Classification Notes

    Classification Notes are publications that give practical information on classification of ships and other objects. Examplesof design solutions, calculation methods, specifications of test procedures, as well as acceptable repair methods for somecomponents are given as interpretations of the more general rule requirements.

    Det Norske Veritas AS July 2013

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  • Classification Notes - No. 32.2, July 2013

    Changes Page 3

    CHANGES CURRENT

    General

    This document supersedes Classification Notes No. 32.2, July 2011.

    Text affected by the main changes in this edition is highlighted in red colour. However, if the changes involvea whole chapter, section or sub-section, normally only the title will be in red colour.

    Main changes

    General

    New requirements in Rules for Classification of Ships Pt.5 Ch.2 Sec.6 have been elaborated in this Class Note.

    Sec.2 Design loads

    Wind loads and accelerations have been updated according to Rules for Classification of Ships Pt.5 Ch.2Sec.6

    Sec.4 Acceptance criteria

    Acceptance criteria for containers have been updated

    Sec.8 Additional container arrangements

    Table with reduction in MSL for lashings attached to lashing bridge has been updated The calculation procedures for mixed stowage of 20' containers stowed in 40' container cell guides have

    been made clear. Acceptable methods on how to take into account vertical twistlock clearances for vertical lashing and

    external lashing have been introduced.

    Introduced new Appendix C Individual Accelerations for Lashing Calculations

    A new procedure has been included in Appendix C specifying how to obtain individual accelerations forlashing calculations based on wave load analysis.

    Introduced new Appendix D Alteration of Container Securing Arrangements

    A table has been introduced in Appendix D specifying document requirements and Class approval scopefor typical alterations of container stowage.

    In addition to the above stated main changes, editorial corrections may have been made.

    Editorial Corrections

    DET NORSKE VERITAS AS

  • Classification Notes - No. 32.2, July 2013

    Contents Page 4

    CONTENTS

    CHANGES CURRENT ................................................................................................................... 3

    1. General.................................................................................................................................................... 61.1 Introduction...............................................................................................................................................61.2 Procedure ..................................................................................................................................................61.3 Definitions.................................................................................................................................................71.4 Assumptions..............................................................................................................................................8

    2. Design Loads........................................................................................................................................... 82.1 General......................................................................................................................................................82.2 Wind load..................................................................................................................................................82.3 Accelerations.............................................................................................................................................9

    3. Loading Conditions................................................................................................................................ 93.1 General......................................................................................................................................................93.2 LC1: Transverse loading I ........................................................................................................................93.3 LC2: Vertical loading ...............................................................................................................................93.4 LC3: Transverse loading II .....................................................................................................................103.5 LC4: Longitudinal loading......................................................................................................................10

    4. Acceptance Criteria ............................................................................................................................. 114.1 General....................................................................................................................................................114.2 Containers ...............................................................................................................................................114.3 Container securing devices .....................................................................................................................124.4 Ship local supporting structures..............................................................................................................14

    5. Direct Calculation using Beam Analysis............................................................................................ 145.1 General....................................................................................................................................................145.2 Modelling of geometry ...........................................................................................................................145.3 Boundary conditions ...............................................................................................................................165.4 Loading conditions..................................................................................................................................165.5 Results.....................................................................................................................................................16

    6. Formula based Analysis, Basic Formulae.......................................................................................... 166.1 Rigid container securing arrangements (cell guides and similar) ...........................................................166.2 Non-rigid securing arrangements (lashings and similar) ........................................................................176.3 Container stack with four flexible horizontal supports...........................................................................196.4 Container stack with combined rigid and flexible horizontal supports ..................................................206.5 Container blocks .....................................................................................................................................20

    7. Formula based Analysis, Derived Formulae ..................................................................................... 227.1 General....................................................................................................................................................227.2 Container stack with single rigid support ...............................................................................................237.3 Contai