Tree (sailing)

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The tree is part of a sailboat or a sailing yacht and is used to stretch and adjust ( trim ) the sail attached to it . It is named after the sail that is attached to it. For example, the tree of the main sail is called the large tree , the tree of the mizzen sail is called the mizzen tree . In very rare cases, even find Fockbäume for clamping the jib , the most common headsail on yachts that is normally driven without a tree. The spinnaker is also driven on a tree.

Big tree

Large boom of a sailing yacht:
(1) Tree
(2) Mast
(3) Lümmel fitting
(4) Sails
(5) Dirk
(6) Boom cam with pulleys for luff tensioners and reefing lines
(7) Main sheet
(8) Boom vang
(9) Luff

The main boom (1) for the main sail on the main mast, or the mizzen tree for the mizzen sail on the mizzen mast, is connected to the mast (2) at one end, usually via the lounger bearing (3), and can therefore be used both vertically and horizontally swiveled and moved in a vertical direction. The sail (4) is attached to the tree with its lower edge (the leech ). These may be "mounted side" (that is by means of thin line in a special manner tethered) or with sliders or a sewn into the sail luff rope to be in a groove (the Keep) fed the tree top.

To stretch and trim the sail, two pulley blocks ( tackles ) can be attached to the tree, with which the tree is pulled down. One tackle (9) serves as a luff stretcher, i.e. tensions the sail in the front area, the second tackle, the downhaul or hold-down device (8), tightens the sail in the middle and rear area. A line that is attached (attached) to the rear (right in the picture), lower corner of the sail (the clew ) and is guided around a pulley (6) in the tree - not visible in the picture - allows the bottom leech of the sail - If the luff extension is missing, the tension of the luff can be adjusted with the help of the main halyard. Smaller boats often do not have a luff extender, then the luff tension can be adjusted by the position of the boom, the luff bearing of which can snap into different positions on a rail on the mast.

In order to bring the sail at the correct angle to the wind, the sheet (7) is attached to the tree , usually via another tackle.

On traditional sailing ships, the trees were initially made of solid wood, at the end of the 19th and in the 20th century mostly of steel or aluminum tubing. On sailing yachts and dinghies they are usually made of aluminum , on high-performance vehicles they are also made of carbon fiber reinforced plastic .

In addition to the above, other lines or devices can be attached to the tree: Bullenstander , Dirk (5), tree kicking instead of the vang , lazy jacks or lazy bags (main drop), mainsail recovery system with tree cover, tree brake . In addition, in or on the main boom - if there is no furling system - the reefing lines are usually guided, which fix the respective clew of the reefed sail and in some cases also serve as a downhaul.

Jib boom

Jib boom

The jib boom extends the rigging in front of the bow. He is tired mostly down with a bobstay the stem at the bow back and carries up at Klüverstag one or more jib sail or serves as a stop point for a Blistersegel .

Spinnaker pole


The rear end of the spinnaker pole or spinnaker pole is attached to the mast, suspended from the top nant and braced downwards with the vang. The front end lies between the forestay and the shrouds and holds the spinnaker's neck via the stern hauler .

When the trade sail is on a downwind course , two trees are used, one for each sail.

A tree is enough for the Parasail .

The gennaker is operated on the bowsprit and without a boom.

The blister is driven at the bow and without a tree.



With surfboards , the sail is attached to a boom . Two curved rods surround the sail horizontally so that it can be operated from both sides. The boom is attached to the surf mast at about chest height.

Jib boom

The jib boom is used to stiffen the lower leech of the jib . This controls the tension on the leech via the outhaul, often in conjunction with a self-tacking jib .