How Thick Were Sailing Ship Keels?

A full keel is the most traditional and conservative type of keel, extending the entire length of a ship and providing excellent stability. In shipbuilding, a keel is the main structural member and backbone of a ship or boat, running longitudinally along the center of the ship. The keel decreases lateral drift and improves the efficiency of the vessel sailing, especially while sailing against the wind by producing hydrodynamic lift.

A keel is a plate that runs longitudinally from stem to stern of the ship, with slightly more thickness than adjoining plates. When encountering waves or gusts of wind, the keel’s weight and form assist in stabilizing the vessel, preventing excessive rolling and pitching. It serves as the spinal column of a vessel, running longitudinally along the hull’s centerline, extending from the bow (front) to the stern (rear). Smaller vessels such as kayaks or inflatable boats may not have keels due to their design and purpose differing from larger boats and ships.

The ship structure described by Sutherland includes the keel, stem, sternpost, transverse framing of the bottom, and transverse framing of the bottom. For example, a typical wooden ship’s keel is made of four to two inches of Malabar Teak and American Elm. Keel dimensions are given as sided dim. = 1314 to 10, molded dim. = 14, and keel depth is the distance from the waterline down to the level of the keel.

In summary, keels play a crucial role in the stability and efficiency of a ship, particularly when sailing against the wind.