What is the inner bottom of a ship primarily comprised of?

The inner bottom of a ship is primarily comprised of the engine room tank top plating. This area serves as the structural foundation and is crucial for supporting machinery and other components located in the engine room. The tank top plating is designed to withstand the stresses imposed by the weight of the equipment, machinery, and any potential impacts during operation. Additionally, it provides a surface that can support tanks or other fixtures that may contain liquids.

While hull plating relates to the external structure of the ship and is important for the overall integrity of the vessel, it is not specifically what defines the inner bottom. Scantlings refer to the dimensions and sizes of structural components in shipbuilding, but they do not specifically denote the materials used for the inner bottom. Double bottom compartments provide space for ballast and help improve stability but are distinct from the definition of the inner bottom itself. Thus, the focus on the engine room tank top plating highlights its primary function and significance in the context of the ship's inner bottom.