1 Objective and Scope

1.1 General

1.1.1 The cargo hold structural strength analysis is used for the assessment of scantlings of longitudinal hull girder structural members, primary supporting members and bulkheads within the cargo hold region. This section gives the requirements for cargo hold structural strength analysis.

1.1.2 Cargo hold structural strength analysis is mandatory within the cargo hold region including the aft bulkhead of the aftmost cargo hold and the collision bulkhead. The evaluation areas are defined in [5.1].

1.1.3 For the purpose of FE structural assessment and load application, the cargo hold region contains the following cargo hold regions, which may vary depending on the ship length and cargo hold arrangement, as defined in Figure 1:

Midship cargo hold region,
Forward cargo hold region,
After cargo hold region,
Foremost cargo hold(s),
Aftmost cargo hold(s).

Figure 1 : Definition of cargo hold regions for FE structural assessment

Holds in the forward cargo hold region are defined as holds with their longitudinal centre of gravity position forward of 0.7 L from AE, except foremost cargo hold.

Holds in the midship cargo hold region are defined as holds with their longitudinal centre of gravity position at or forward of 0.3 L from AE and at or aft of 0.7 L from AE.

Holds in the after cargo hold region are defined as holds with their longitudinal centre of gravity position aft of 0.3 L from AE, except aftmost cargo hold.

Foremost cargo hold(s) is (are) defined as hold(s) in the foremost location of the cargo hold region.

Aftmost cargo hold(s) is (are) defined as hold(s) in the aftmost location of the cargo hold region.

1.2 Cargo hold structural strength analysis procedure

1.2.1 Procedure description

The structural FE analysis is to be performed in accordance with the following:

Model: Three cargo hold model with:
- Extent as given in [2.2]
- Finite element types as given in [2.3]
- Structural modelling as defined in [2.4]
Boundary conditions as defined in [2.5]
FE load combinations as defined in [3]
Load application as defined in [4]
Evaluation area as defined in [5.1]
Strength assessment as defined in [5.2] and [5.3]

1.2.2 Mid-hold definition

For the purpose of the FE analysis, the mid-hold is defined as the middle hold(s) of the three cargo hold length FE model.

In case of foremost and aftmost cargo hold assessment, the mid-hold represents the foremost and aftmost cargo hold including the slop tank if any, respectively.

1.2.3 Scantling assessment

The scantling assessment is carried out according to Ch 7, Sec 1 for each individual cargo hold using the FE load combinations defined in Ch 4, Sec 8 applicable to the considered cargo hold. The FE analysis results are applicable to the evaluation area as defined in [5.1.1], of the considered cargo hold.

The individual transverse bulkhead structural elements, inclusive plating, stiffeners and horizontal stringers, are to be assessed considering two cargo hold finite element analyses, i.e. the analysis for the hold forward and the one for the hold aft of the considered transverse bulkhead.