File:Bulkheads and longitudinals.png

English: A schematic showing the make-up of a ship with its longitudinals, bulkheads and compartments. The schematic was based on the image at http://www.encyclopedia-titanica.org/titanic-hidden-deck.html. As mentioned there and at http://www.titanic-titanic.com/titanic_watertight_compartments.shtml, the bulkheads do not reach up to the top hull; instead the bulkheads can reach only until the first deck; this eg allows quick evacuation of personnel in an emergency, and also allows easier passage for everyday use. If this is done however, the first deck should be kept watertight at all times, meaning that no hatches, ... can remain open at the first deck (ideally, this is also done troughout other ship sections). This first deck could eg be used to house the sleeping quarters (placement of these more below in the ship increases the response time and is also less safe as sections between the top and the sleeping quarters may flood in the event of a collision, hereby then prohibiting escape ...) Also visible at the drawing are cross-cut sections; these show that as the ship gets thicker (at the center), there are more compartments.