A Winch is a geared drum used to haul in and hold lines under load – sheets, halyards, control lines and reefing pennants. The line is wrapped around the drum, a handle or motor turns it through internal gearing, and pawls stop it from running back. For a beginner, the winch is what lets one person trim a genoa that would otherwise need three. The experienced sailor adds two things: winches always turn clockwise, so the wraps go on clockwise; and the power ratio stamped on the winch is theoretical – friction takes a good bite out of it before the load reaches your arm.
Anatomy of a Winch
- Drum: the surface the line grips, usually textured for better hold.
- Pawls and springs: spring-loaded ratchet teeth that allow the drum to turn one way and lock it the other. The click you hear is the pawls.
- Gears: one, two or three speeds. Turn the handle one way for fast, low-power hauling and the other for slow, high-power grinding.
- Self-tailing jaws: a sprung, toothed ring on top that grips the tail so the line can be trimmed single-handed. The stripper arm peels the tail out as the drum turns.
- Handle socket: the drive at the top, taking a standard handle, usually 250 mm (10 in) long, with a lock to stop it flying overboard.
A winch’s size number – 16, 40, 48 and so on – approximates its power ratio in its most powerful gear: handle length divided by drum radius, multiplied by the gear ratio. A size 48 in theory lets you pull 48 times harder than you turn; in practice, expect to lose a fifth or more to friction.
Using a Winch Properly
- Wrap clockwise: two turns for light loads, three or four as the load builds. Too few turns and the line slips; too many before the load comes on and you risk a riding turn.
- Tail before you grind: keep tension on the tail with one hand, or feed it into the self-tailer, before you start turning the handle.
- Grind smoothly: use the fast gear while the sail is flogging and change to low gear as it fills. Body weight over the handle, not arm strength, does the work.
- Ease with care: keep a hand flat on the wraps and let them slip around the drum in a controlled way. Never let fingers get between the line and the drum.
- Clear a riding turn: take the load off with a second line rolling-hitched to the sheet, then unwind the override.
Winches and Sail Trim
For the sailmaker, the winch is the trimmer’s tool for putting the designed shape into the sail. Sheet tension sets leech tension and twist on a headsail; halyard tension controls where the draft sits along the luff; the cunningham and outhaul flatten the main. Undersized winches lead to under-trimmed sails, because the crew stop grinding when it gets hard rather than when the sail is right. A common rule of thumb for genoa sheet load in pounds is sail area in square feet times the square of the apparent wind in knots times 0.00431 – a 400 sq ft genoa in 20 knots pulls around 690 lb – and the winch needs to be sized for that.
Cruising Versus Racing
Cruisers favour self-tailing winches, sized generously so one person can trim in a breeze, and increasingly fit electric primaries. A racing boat runs its primaries with a dedicated tailer and adds pedestal grinders (“coffee grinders”) on bigger yachts, but the lesson is the same on both: a winch you can actually grind the last few inches on is worth more than a lighter one you cannot.
Maintenance
Strip each winch at least once a season. Clean the gears and bearings in solvent, apply a light film of winch grease to gears and bearings, and oil the pawls and springs – never grease them, or they will stick and the winch will free-spin under load. Replace tired pawl springs; the alternative is a runaway sheet.
Winch, Windlass and Capstan
A windlass is the anchor machine on the foredeck with a gypsy for chain. A capstan is a vertical rope drum. A winch is neither: it is the geared drum for rope around the cockpit and mast, and it should never be asked to handle chain.
Frequently Asked Questions about Winches
Which way do the wraps go on a winch?
Clockwise, on every winch in the world, looking down from above. Put a wrap on anticlockwise and the pawls will not hold.
What does the size number mean?
It is roughly the power ratio in the winch’s most powerful gear – the theoretical multiplication of your effort on a standard handle. Friction reduces the real figure.
Why does my sheet slip on the drum?
Too few wraps for the load, a polished drum that has lost its texture, or a line that is too small or too slick for the self-tailing jaws. Add a wrap first.
A winch is the crew’s strength multiplied, and how well it is used decides whether the sails ever reach the shape they were designed to hold. Wrap it right, grind smoothly, size it generously and keep it greased, and the last few clicks of trim that make a boat come alive will always be within reach.