Prevention of Progressive Flooding through Watertight Bulkheads

Hull damage in way of a watertight bulkhead may result in flooding of a single compartment; however, the principal hazard arises when water spreads uncontrollably into adjacent spaces, leading to progressive flooding. Progressive flooding may occur through piping systems, drainage arrangements or other penetrations connecting watertight compartments, thereby defeating the primary function of the bulkheads and significantly compromising the vessel’s stability.

To prevent the spread of water following damage, all penetrations through watertight bulkheads should be fitted with effective means of closure, and drainage and sanitary piping systems should be designed and maintained so as not to create open paths between compartments. In the event of seawater ingress, the timely closure of such openings and the use of available sealing arrangements are essential to maintain buoyancy. Certain closing arrangements should also be fitted as a preventive measure, particularly during periods of reduced vessel operation.

Shipowners should ensure that damage control plans and manuals are complete, clearly presented and aligned with the vessel’s actual condition. The means provided for closing openings should be of an appropriate type and quantity, clearly marked, and readily accessible to the crew at all times.

It is equally important to conduct regular inspections, verify the integrity of installations passing through watertight bulkheads, and ensure that the crew are familiar with procedures to prevent progressive flooding. The timely implementation of these measures is critical to preserving vessel stability and preventing more severe consequences following damage.

Recipients: This safety lesson is addressed to shipowners and operators, shipbuilders, maritime administrations, classification societies, and seafarers.