Förproofsbåde

Förproofsbåde is a term attested in Swedish maritime sources for a class of experimental vessels used in the early stages of ship design to test hull integrity and performance before full-scale construction. The exact meaning varies between sources, and the term is not standardized in major dictionaries. Etymologically, the name appears to combine elements implying "pre-" or "before" with "boat" (både), reflecting its function as a preliminary or preproof vessel, though precise origins are unclear.

Practically, förproofsbåde were typically small or scaled-down craft built to investigate structural strength, buoyancy, trim, and handling. They enabled shipyards to validate calculations, observe seakeeping behavior, and refine hull forms or construction methods without risking a full-size build. In historical contexts they appeared in both naval and merchant worlds, with variations tailored to the vessel class under development.

Today the term is rarely used, and explicit preproof boats are not common in modern practice. Contemporary equivalents include prototype ships, scale models, and virtual simulations that serve similar purposes in design verification and risk reduction. The concept survives in modern terminology as proof-of-concept testing and model testing within naval architecture and marine engineering.