The first function(stiffening the hull's structure) is accomplished primarily by the main transverse bulkheads that extend continuously through the watertight volume of the ship from keel to main deck. Figure 11-28 shows a main transverse bulkhead at the forward end of the machinery spaces in a destroyer. These bulkheads resist the longitudinal twists and transverse stresses in the structure since they are stiffened both vertically and horizontally by stiffeners supported at the bottom, sides, and deck by brackets