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Section 2 Vessel Registered with Coastal Service
201. Application
The requirements are to apply to the dredger which is intended to register with coastal service.
202. Reduction of scantling
1. For the scantling of structural members, the values obtained from the formulas in relevant Chapters may be reduced with the ratios given in Table 12.1. However, those are not to be less than the minimum scantlings given in Table 12.1.
2. The reduction of structural members other than that given in Table 12.1 is to comply with at the discretion of this Society.
3. The deck beams, inner bottom platings and inner bottom longitudinals and structural members of deep tanks which are subject to heavy cargoes or concentrated loads are not to be less than that
obtained from the requirements of relevant Chapters regardless of the requirements of
Par 2.
Par 1
and
Table 12.1 Reduction ratio and minimum scantlings of structural member
Items | coastal service | smooth water area | Min. scantling |
Longitudinal strength | 5 % | 10 % | - |
Shell plating(incl. keel plate) | 5 % | 10 % | 6 mm , (excluding superstructure) |
Min. thickness of deck | 1 mm | 1 mm | 5 mm |
Section modulus of frame (incl. bottom longitudinal) | 10 % | 20 % | 30 cm Ë |
Section modulus of beam | 15 % | 15 % | - |
Section modulus of deck girder | 15 % | 15 % | - |
Plate thickness of double bottom structure | 1 mm | 1 mm | 5.5 mm |
Plate thickness of single bottom structure | 0.5 mm | 10 % or 1 mm , whichever is the smaller | - |
Plate thickness of super structure end bulkhead and stiffeners | 10 % | 10 % | - |
Ch 1 2
203. Equipment
1. The dredger, according to its equipment number specified in Ch 11, is to be provided with equip-
ment of Table 11.1. given in Table 11.1.
However, the weight of one anchor between two may be of 85 % of that