Ship models are made for many different purposes. Before computer technology became standard for ship design, wooden models were made. The models here represent those used for framework, plating, and showing-off! But why build only half a hull? The answer lies in symmetry. If you design one half to perfection and reverse it, when it comes to the build you will have a symmetrical hull.
The small models are scale replicas of yacht hulls and are inscribed with a series of lines to indicate the position of the framework. The lines would then be traced or “laid down” on the floor and used as an outline for the shape of the hull. The larger models depict the hulls of cargo vessels. They were used to determine the best size and layout for the steel plates which formed the hull.