An athwartships steel member which can be either a ‘watertight floor’, ‘solid floor’, or a ‘bracket floor’. They act in way of the ship’s frames in the double bottom structure of the vessel and interconnect the ‘intercostal’ and ‘longitudinal’ members. Solid plate floors have lightening holes cut in and these serve to reduce the overall weight of the ship (and subsequent tonnage dues) as well as providing access for tank inspection personnel.
