Section 3 Longitudinal strength
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Ships, July 2022 - Part 4 Ship Structures (Ship Types) - Chapter 8 Container Ships - Section 3 Longitudinal strength

Section 3 Longitudinal strength

Parent topic: Chapter 8 Container Ships

3.1 General

3.1.1 Longitudinal strength calculations are to be carried out in accordance with Pt 4, Ch 8, 3.2 Longitudinal strength and Pt 4, Ch 8, 3.3 Combined longitudinal and torsional strength 3.3.1

3.1.2 Alternatively the values and distributions of wave induced loads may be derived by direct calculation in accordance with LR’s ShipRight Procedure Guidance Notes on the Assessment of Global Design Loads of Large Container Ships and Other Ships Prone to Whipping and Springing.

3.1.3 For ships of abnormal hull form, or for ships of unusual structural configuration or complexity, the values and distributions of wave induced loads are to be agreed with LR. LR may decide to mandate the application of the ShipRight notations; SDA, FDA, FDA SPR or WDA.

3.2 Longitudinal strength

3.2.1 Longitudinal strength calculations are to be made in accordance with the requirements of Pt 4, Ch 8, 16 Longitudinal strength calculations and the additional notes contained in this Section and Pt 4, Ch 8, 14 Direct calculation.

3.2.2 The wave vertical bending moments and shear forces given in Pt 4, Ch 8, 16 Longitudinal strength calculations apply to mono-hull displacement ships in unrestricted service and are limited to ships meeting the following criteria:
  1. 65 m ≤ L ≤ 500 m
  2. 5 ≤ L/B ≤ 9
  3. 2 ≤ B/T ≤ 6
  4. 0,55 ≤ CB ≤ 0,9

For ships which do not meet the above criteria, the wave vertical bending moments and shear forces are to be specially considered.

3.2.3 In order to determine the local reduction factors, FD and FB, longitudinal strength calculations are to be made in accordance with the requirements of Pt 3, Ch 4 Longitudinal Strength where Mw is to be calculated in accordance with Pt 4, Ch 8, 16.6 Design vertical wave bending moments.

3.2.4 For operation in sheltered water or short voyages, see Pt 3, Ch 4, 5.2 Design vertical wave bending moments 5.2.3 and Pt 3, Ch 4, 5.4 Minimum hull section modulus 5.4.3 where Mw is to be calculated in accordance with Pt 4, Ch 8, 16.6 Design vertical wave bending moments.

3.3 Combined longitudinal and torsional strength

  1. The strength of the ship to resist a combination of longitudinal and torsional loads is to be determined in accordance with Pt 4, Ch 8, 15.1 Application.

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