block model

A block model is a solid wooden form carved or assembled to represent the three-dimensional shape of a ship's hull in simplified form. It serves as a tangible design tool and communication aid before detailed plans are drawn or the actual vessel is built. The model captures the essential underwater profile and side elevation of the hull, allowing designers and builders to evaluate proportions, curves, and overall character without committing to full-scale timber or steel.

Block models are typically made from softwood blocks, laminated in horizontal layers and then carved or planed to shape. Each layer represents a cross-section at a particular station along the hull's length. Traditional models were sometimes built by stacking and shaping separate planks, while others were sculptured from a solid piece. The grain and color variations in the wood are deliberate, marking the station lines; this allows a craftsperson or designer to see the hull's shape at any point along its length by looking at the edge grain.

Use in design and communication

Shipbuilders and naval architects use block models to refine the form before investing in the full lofting process, where lines are scaled up to full size on the mould loft floor. The model can be rotated and viewed from all angles, making it easier to spot aesthetic or functional flaws than drawings alone permit. In yards working without computer modeling, a block model also served as a reference object for loftsmen and framers, ensuring consistency between the designer's intent and the timber being shaped.

Block models vary greatly in size and finish. A designer's rough study model might be two feet long and carved from a single piece of pine, while a builder's presentation model could be several feet in length, painted, and mounted on a stand. Some models include a notched or stepped base that shows the depth and shape of the keel and stem, important structural features that affect both performance and construction.

Though replaced in modern yards by CAD and digital hull-form databases, block models remain valuable teaching tools in naval architecture and are still occasionally built for historical reconstruction or as design aids in small-craft building. The method teaches form-making by hand and makes the relationship between cross-sections and the continuous hull surface physically obvious in a way that drawings do not.