A bulkhead is a vertical wall-like structure dividing a ship’s interior into separate compartments, serving both structural and safety purposes.
Types by Orientation
- Transverse bulkheads — run side-to-side across the ship’s width, dividing it into sections along its length (forepeak, cargo holds, engine room, aft peak)
- Longitudinal bulkheads — run bow-to-stern, dividing the ship’s width (common in tankers, separating cargo tanks)
The Collision Bulkhead
A mandatory, specially reinforced transverse bulkhead positioned near the bow, specifically designed to contain flooding if the vessel suffers a bow collision — its position and strength are governed by SOLAS requirements.
Watertight vs Non-Watertight
Not all bulkheads are watertight — some are purely structural or for space division, while watertight bulkheads are specifically designed and certified to prevent water passing between compartments, critical to a ship’s damage stability in case of hull breach.
Why Bulkheads Matter for Survivability
A ship’s watertight subdivision — how many compartments it’s divided into and how well those divisions hold — directly determines how much flooding the vessel can survive without sinking, a core principle tested in damage stability calculations.
Exam Relevance
Bulkhead types, watertight subdivision principles, and damage stability calculations involving bulkhead-defined compartments are core Ship Construction and Stability topics in deck officer competency exams.