DNV DNV-RU-SHIPS PART 3 CHAPTER 10 PDF

Application

The requirements given in this section apply to all ships, and cover the strengthening requirements for local impact pressure that may occur in the bow area.

The bow impact pressure given in [2.1] applies to areas away from knuckles, anchor bolster etc. that may obstruct the water flow during wave impacts. In way of such obstructions, additional reinforcement of the shell plating by fitting carlings or similar shall generally be considered.

Extent of strengthening

The strengthening shall extend forward of 0.1 L from the F.E. and vertically from the minimum design ballast draught, TBAL, defined in Ch.1 Sec.4 [3.1.6] and to forecastle deck if any. See Figure 1.

If the flare angle, α as defined in [2.1.1], is greater than 40° at 0.10 L from F.E., the bow impact area shall be extended to 0.15 L from F.E.

Further, if the flare angle, α as defined in [2.1.1], is greater than 40° at 0.15 L from F.E., the bow impact area shall be extended to 0.2 L from F.E.

Aft of 0.1 L from F.E. the bow impact strengthening is only applicable for areas where the flare angle is greater than 5°.

Additional bow impact load assessment and direct strength analysis may be required for ships with a high flare angle or if considered necessary for actual structural arrangement.