Bulkhead
A Bulkhead is a vertical partition (wall) inside a ship's hull that divides it into separate compartments. Bulkheads contribute to the vessel's structural strength and, crucially, provide watertight subdivision: watertight bulkheads confine any flooding to one compartment, so that damage or a leak need not sink the ship.
This subdivision is a fundamental safety principle — SOLAS requires ships to be divided by watertight bulkheads so they can survive specified flooding (the collision bulkhead near the bow is a key example). Other bulkheads provide fire boundaries (fire-rated bulkheads) or simply divide spaces (accommodation, holds, tanks). The failure of adequate subdivision is a classic cause of ships foundering (as the Titanic's bulkheads not reaching high enough famously showed). Bulkheads are essential structural and life-saving elements of ship design, central to damage stability and survivability. They are a core part of how ships are built to stay afloat.
Bulkheads are why a holed ship doesn't simply sink — by dividing the hull into watertight compartments, they confine flooding and keep the vessel afloat. Required by SOLAS and central to damage stability, they are one of the most important safety features in ship design, as famous casualties have shown when subdivision failed.
What is a watertight bulkhead for?
To confine flooding to one compartment so damage or a leak in one part of the ship does not sink the whole vessel.
What is a collision bulkhead?
A strong watertight bulkhead near the bow designed to contain flooding if the ship is struck or grounds forward.