Where did the saying?
It’s a sailor’s expression, from the days of sailing ships. We ignorant landlubbers might think that a sheet is a sail, but it’s actually a rope (always called a line in sailing terminology), or sometimes on really big ships a chain, which is attached to the bottom corner of a sail. The word actually comes from an Old English term for the corner of a sail. The sheets were as vital in the days of three-masted square-rigged sea-going ships as they are today, since they trim the sail to the wind. If they run loose, the sail flutters about in the wind and the ship wallows off its course out of control. Extend this idea to sailors on shore leave, staggering back to the ship after a good night on the town, well tanked up. The irregular and uncertain locomotion of these jolly tars must have reminded onlookers of the way a ship moved in which the sheets were loose. Perhaps one loose sheet might not have been enough to get the image across, so the speakers borrowed the idea of a three-masted sa
