As per SOLAS Chapter XII, Regulation 4:

• Bulk carriers of 150 m and above, with single-side skin construction, designed to carry solid bulk cargoes of density ≥ 1000 kg/m³, constructed on or after 1 July 1999, must, when loaded to the summer load line, be able to withstand flooding of any one cargo hold under all loading conditions and remain afloat in a satisfactory equilibrium condition, as specified in paragraph 4.
• Bulk carriers of 150 m and above, with double-side skin construction, where any part of the longitudinal bulkhead lies within B/5 or 11.5 m (whichever is less) inboard from the ship's side (measured at a right angle from the centerline at summer load line), designed to carry solid bulk cargoes of ≥ 1000 kg/m³, constructed on or after 1 July 2006, must also be able to withstand flooding of any one cargo hold and maintain satisfactory equilibrium as per paragraph 4.
• Bulk carriers of 150 m and above, with single-side skin construction, carrying solid bulk cargoes of ≥ 1780 kg/m³, constructed before 1 July 1999, must be able to withstand flooding of the foremost cargo hold and remain afloat in equilibrium in all loading conditions.
• The equilibrium condition after flooding must comply with the annex to IMO Resolution A.320(IX), equivalent to Regulation 27 of the International Load Line Convention, 1966, as amended by Resolution A.514(13).
• Flooding assumptions:
  • Flooding is assumed to the external water level.
  • Permeability values:
    • Loaded hold: 0.2
    • Empty hold: 0.35
    • For a hold partially loaded with cargo:
      • Cargo volume: permeability relevant to the cargo
      • Remaining empty volume: permeability 0.25
  • Bulk carriers constructed before 1 July 1999 and assigned a reduced freeboard in compliance with Regulation 27(7) of the Load Line Convention (adopted on 5 April 1996) may be considered as compliant with paragraph 3 of this regulation.
  • Bulk carriers assigned reduced freeboard in accordance with paragraph 8 of Regulation 27 may be considered as complying with paragraph 1 or 2, as applicable.
  • For such vessels, the condition of equilibrium after flooding must meet the relevant provisions of the 1996 Protocol to the Load Line Convention.
  Part (b)

  Structural Requirements for Bulk Carriers

  • Bulk carriers of 150 m and above, with single-skin construction, designed to carry solid bulk cargoes with density ≥ 1000 kg/m³, constructed on or after 1 July 1999, must be structurally capable of withstanding flooding of any one cargo hold to the external water level. This requirement applies for all loading and ballast conditions, and must consider dynamic effects from the pressure of water in the flooded hold.
  • Bulk carriers of 150 m and above, with double-skin construction, where any part of the longitudinal bulkhead lies within B/5 or 11.5 m (whichever is less) from the ship’s side, designed to carry bulk cargoes with density ≥ 1000 kg/m³, constructed on or after 1 July 2006, must comply with the same structural strength provisions as above.
  Part (c)

  Water Ingress Alarms

  Bulk carriers shall be equipped with water level detection systems providing audible and visual alarms on the bridge in the following spaces:

  • Each cargo hold:
    • One alarm when water reaches a height of 0.5 m above the inner bottom
    • Another alarm when water reaches not less than 15% of the cargo hold’s depth but not more than 2 m
  • Any ballast tank forward of the collision bulkhead:
    • Alarm activates when the water level reaches 10% of tank capacity
  • Any dry or void space (excluding chain lockers):
    • Alarm activates when the water level reaches 0.1 m above the deck

    The alarms must be both audible and visual, and located on the navigating bridge.