backstay

backstay, a part of the standing rigging of a sailing vessel to support the upper part of a mast from aft, while forestays support it from forward. In square-rigged sailing ships, backstays are taken from the heads of all the component mastheads of each mast, or the equivalent in pole-masted vessels, and are brought back to each side of the ship. In antiquity they were set up with deadeyes and lanyards to chain-plates and in modern vessels with rigging screws that are made up to chain-plates. In fore-and-aft-rigged vessels backstays are fitted to the mast(s) to balance the forestay(s). In old-fashioned vessels these are usually running, that is, made up at the deck with a tackle or backstay lever. This allows the lee backstay to be released so that the sail and its boom, and gaff if fitted, are not constrained by it. Modern Bermudan-rigged yachts have permanent backstays from the masthead to the counter, called preventer backstays, inside which the mainsail and boom can move without hindrance. For illus. see rigging: standing rigging.