Galley - Design

Design

Galleys have since their first appearance in ancient times been intended as highly maneuverable vessels, independent of winds by being rowed, and usually with a focus on speed under oars. The profile has therefore been that of a markedly elongated hull with a ratio of breadth to length at the waterline of at least 1:5, and in the case of ancient Mediterranean galleys as much as 1:10 with a small draught, the measurement of how much of a ship's structure that is submerged under water. To make it possible to efficiently row the vessels, the freeboard, the height of the railing to the surface of the water, was by necessity kept low. This gave oarsmen enough leverage to row efficiently, but at the expense of seaworthiness. These design characteristics made the galley fast and maneuverable, but more vulnerable to rough weather.

On the funerary monument of the Egyptian king Sahure (2487–2475 BC) in Abusir, there are relief images of vessels with a marked sheer (the curvature along its length) and seven pairs of oars along its side, a number that was likely to have been merely symbolical, and steering oars in the stern. They have one mast, all lowered and vertical posts at stem and stern, with the front decorated with an Eye of Horus, the first example of such a decoration. It was later used by other Mediterranean cultures to decorate sea going craft in the belief that it helped to guide the ship safely to its destination. These early galleys apparently lacked a keel meaning they lacked stiffness along their length. Therefore they had large cables connecting stem and stern resting on massive crutches on deck. They were held in tension to avoid hogging, or bending the ship's construction upwards in the middle, while at sea. In the 15th century BC, Egyptian galleys were still depicted with the distinctive extreme sheer, but had by then developed the distinctive forward-curving stern decorations with ornaments in the shape of lotus flowers. They had possibly developed a primitive type of keel, but still retained the large cables intended to prevent hogging.

The design of the earliest oared vessels is mostly unknown and highly conjectural. They likely used a mortise construction, but were sewn together rather than pinned together with nails and dowels. Being completely open, they were rowed (or even paddled) from the open deck, and likely had "ram entries", projections from the bow lowered the resistance of moving through water, making them slightly more hydrodynamic. The first true galleys, the triaconters ("thirty-oarers") and penteconters ("fifty-oarers") were developed from these early designs and set the standard for the larger designs that would come later. They were rowed on only one level, which made them fairly slow, likely only 5-5.5 knots. By the 8th century BC the first galleys rowed at two levels had been developed, among the earliest being the two-level penteconters which were considerably shorter than the one-level equivalents, and therefore more maneuverable. They were an estimated 25 m in length and displaced 15 tonnes with 25 pairs of oars. These could have reached an estimated top speed of up to 7.5 knots, making them the first genuine warships when fitted with bow rams. They were equipped with a single square sail on mast set roughly halfway along the length of the hull.