lugsail

lugsail, a four-sided sail set on a yard or lug, used almost exclusively in small craft. The sail is very similar to the one used in a gaff rig, but has a wider throat, and depends on its luff for stability. The yard by which the sail is hoisted is normally two-thirds the length of the foot of the sail and carries a strop one-quarter of the way from throat to peak. This strop is hooked to a traveller on the mast and is hoisted in the normal way until the luff is as taut as possible.

The earliest known drawing, by a Dutch artist, of what may have been a lugsail is dated 1584, but the name itself does not appear for another century. Suggestions that it is of much more ancient origin and first appeared in the Mediterranean in Egyptian and Phoenician craft around the 1st century bc are not borne out by any evidence and probably arose through confusing the lateen rig with the true lug rig. The original lugsails were set on dipping lugs and later on the standing lug, of which the gunter rig is the most modern and the most efficient type.

The balanced lugsail, which became popular in the west around the end of the 19th century, is laced to a boom which extends a short way forward of the mast, and set flat by a tack tackle. It is almost certainly a western adaptation of the short-boomed Chinese balanced lugsail, which itself developed during the 3rd century from the canted square sails of Indonesia.