Dhelian Cog

A cog is a type of ship that first appeared about 200 years ago in Anvil, and was widely used since that time. Cogs are clinker-built, generally of oak. These vessels are fitted with a single mast and a square-rigged single sail. They are mostly associated with seagoing trade in rivers and seas east of the Great Sand Sea, especially by the Dhelians. Typical seagoing cogs ranged from about 15 to 25 meters in length, with a beam of 5 to 8 meters and were 30–200 tons burthen. Cogs are rarely as large as 300 tons although a few are considerably larger, over 1,000 tons.

Although the name cog is recorded as early as 4600, the seagoing vessel of that name seems to have evolved on the Imperial coast around 400 years ago. Cogs progressively replaced longboats and triremes ships in bodies of water during the last century. Cogs can carry more cargo than longships of a similar size. Their flat bottoms allow them to settle on a level in harbour, making them easier to load and unload. Their high sides make them more difficult to board in a sea fight, which may have make them safer from pirates.

Construction

Cogs are typically constructed largely of oak, and have full lapstrake, or clinker, planking covering their sides, generally starting from the bilge strakes, with double-clenched iron nails for plank fastenings. At the stem, chases are formed; that is, in each case, the land of the lower strake is tapered to a feather edge at the end of the strake where it meets the stem or stern-post. This allows the end of the strake to be fastened to the apron with the outside of the planking mutually flush at that point and flush with the stem. This means that the boat's passage through the water will not tend to lift the ends of the planking away from the stem. Before the next plank is fitted, the face of the land on the lower strake is bevelled to suit the angle at which the next strake will lie in relation with it. This varies all along the land. The new strake is held in position on the preceding one before the fastening is done