A vertical cylindrical trunk in a ship through which the suction pipes of the bilge pump pass, reaching right down into the lowest part of the hull. Its object is to prevent ballast or other objects from entering and choking the suction boxes of the pumps. In older wooden ships it was the trunk in which the ship's pump worked. It was the carpenter's duty, particularly in warships after battle, to sound the well continually to make sure that the ship was not making water through damage to its hull. As the trunk led to the lowest portion of the hull, water inside the ship would naturally flow there and thus give a maximum reading of the amount inboard.
Subjects: Maritime History.