What does backstay mean?
A backstay is a strong rope, wire, or cable that runs from the top of a mast down to the stern of a boat or ship, providing essential support that keeps the mast upright and prevents it from pitching forward under the strain of the sails. Working together with the forestay, which performs the same function at the bow, the backstay forms part of the standing rigging — the network of fixed lines that holds a vessel's spars in place. Some boats carry running backstays, which can be adjusted or released during manoeuvres such as tacking. The term belongs chiefly to the vocabulary of sailing, shipbuilding, and marine engineering, though it extends by analogy to similar support lines on cranes, tents, and other masted structures. For anyone interested in how tall ships and modern yachts withstand the enormous forces of wind at sea, the backstay is a small but indispensable piece of engineering.
nounA rope or cable running from the top of a mast to the stern of a ship, used to support the mast and prevent it from falling forward.
- A rope or cable from the masthead to the stern of a vessel that supports the mast against forward pull.
- (By extension) A similar supporting line on other rigging structures, such as masts of cranes or tents.
"The rigger replaced the frayed backstay before the yacht set out across the Atlantic."
"The crew eased the running backstay as the boat came about through the wind."
"Inspectors found corrosion in the crane's backstay and ordered it taken out of service."
Used when referring to multiple support lines, e.g. both port and starboard running backstays.
"Both backstays were renewed during the winter refit."
Without its backstay, a tall ship's mast would simply topple forward — one humble rope holds up the entire sail plan.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of backstay
The word backstay combines 'back', indicating the rearward direction of the line toward the stern, with 'stay', a term for a supporting rope that English borrowed from Old French 'estai' in the medieval period; the French word itself derives from a Germanic root related to holding fast. Backstay arose as part of the specialised nautical vocabulary of the age of sail, alongside companion terms such as forestay and staysail. Its cognates are therefore chiefly the other rigging terms built on the same root 'stay'.
Related word forms
How backstay is actually used
A technical term used mainly in sailing, shipbuilding, and marine engineering; rarely encountered outside nautical contexts. In sailing usage, 'running backstays' are adjustable and can be released when tacking, unlike fixed permanent backstays.
Easily confused with backstay
A forestay runs from the masthead to the bow of the ship, while a backstay runs from the masthead to the stern.