A topping lift is a line running from the masthead, or from a fitting high on the mast, down to the outer end of the boom to hold the boom up when the mainsail is not supporting it. Without it, the boom would drop onto the deck or the cockpit the moment the main was lowered. The same term is used for the line that holds up the outboard end of a spinnaker pole, usually called the pole lift or pole topping lift to tell it apart. For a beginner, the topping lift is the thing that stops the boom hitting heads while the mainsail is being hoisted or flaked. For an experienced sailor it is also a sail-shape control to be got out of the way the instant the main is up, because a tight topping lift is one of the commonest reasons a mainsail sets badly.
How it is rigged
On most cruising yachts the topping lift is a length of low-stretch rope or a wire with a rope tail. It is either fixed at the masthead and adjusted at the boom end with a small purchase or a cleat, or fixed at the boom end and led down the mast to a cleat or winch at deck level, often through a sheave in the masthead crane. The adjustable end lets you take up slack or ease it off as required.
The common alternative is a rigid vang – a spring-loaded or gas strut kicker between the mast base and the boom – which holds the boom up by pushing rather than pulling. Boats fitted with one may dispense with a topping lift altogether or keep a light one as a backup.
Why it matters for sail shape
The topping lift’s effect on sail shape is entirely a matter of getting it out of the way. When the mainsail is set, the boom is supported by the leech of the sail through the clew. If the topping lift is still carrying weight, it holds the boom end higher than the sail wants it, which slackens the leech and lets it fall off to leeward. The result is a sail that is too twisted at the top, a mainsheet that seems to do nothing until it is very tight, and, at worst, a topping lift that flogs against the leech and chafes the cloth.
The correct setting is just slack: eased enough that it hangs in a gentle curve and takes no load with the main sheeted in any condition, but not so slack that it wraps around the leech or the backstay. Most sailors mark the topping lift at the cleat so it can be set by eye. On boats with a rigid vang the problem disappears, which is one reason so many racing and performance cruising boats fit one.
Cruising use
For a cruising sailor the topping lift is first a safety device and second a convenience. Take it up before dropping the main so the boom stays clear of the cockpit while you flake and tie the sail. Take it up when reefing on boats without a rigid vang, so that the boom does not drop as the halyard is eased and the new clew reef is set, and so that the boom end is high enough to clear the dodger and the heads of the crew. At anchor, the topping lift lets you raise the boom to make room under the cover or to rig a cockpit awning.
Racing use and the pole lift
Racers dislike topping lifts for the shape penalty and the chafe, and prefer a rigid vang. Where one is fitted, the trimmer’s first job after the hoist is to ease it until it is completely slack and confirm it is not touching the leech.
The pole topping lift, or pole lift, is a different animal. It runs from a point about two-thirds of the way up the mast to a bridle or fitting on the spinnaker pole and, together with the foreguy or downhaul, sets the pole’s height. Pole height controls the height of the spinnaker tack, and matching the tack to the clew height keeps the sail symmetrical and the luff breaking evenly. A racing trimmer adjusts the pole lift constantly as the wind changes and as the pole is squared or eased; a cruising sailor sets it once and leaves it.
Frequently Asked Questions about Topping Lift
How slack should the topping lift be when sailing?
Slack enough that it carries no load with the mainsail sheeted in any condition you expect to meet, but not so slack that it can wrap the leech or backstay. Mark the setting at the cleat once you find it.
What is the difference between a topping lift and a pole lift?
The topping lift supports the boom end; the pole lift supports the outboard end of the spinnaker pole and sets its height. They do similar jobs but are separate lines with separate controls.
The topping lift is easy to overlook and easy to misuse. Take it up before you drop or reef the main, ease it right off the moment the sail is set, and keep it clear of the leech, and you will have a safer cockpit and a mainsail that sets the way your sailmaker designed it.