What is the definition of frames in hull construction?

• A. Frames are attached to the keel and extend athwartships from side to side; they help strengthen the hull.
• B. Frames are vertical members inside the hull only.
• C. Frames are used only for deck support.
• D. Frames are decorative trim.

Answer: (A)

Frames in hull construction are the transverse framing members that form the hull’s skeleton. They are attached to the keel and span from one side of the vessel to the other, giving the hull its cross-sectional shape and providing a backbone that distributes stresses from the plating, deck, and loads along the length of the boat. This crosswise arrangement keeps the hull from flexing or deforming under water pressure and waves, while offering secure points to attach planking and other structural elements.

That’s why the description focusing on frames as crosswise members attached to the keel is correct. The idea that frames are only vertical interior members, or that they’re only for deck support, or simply decorative trim, doesn’t match how the hull is built and reinforced.