Square Rig Sailing

What Is Square Rig Sailing?

The lines and rigging on a square-rig ship can be confusing.

Square rig sailing refers to sailing ships that use square sails — or rather, the sails were more in the shape of a trapezoid. The 4 corners of a square sail distinguish it from the 3 corners of the fore-and-aft sail. Square sails are the oldest type of sail in the history of sailing. In square rig sailing ships, one or more masts support horizontal spars, to which the four-cornered sails are attached. The spars are perpendicular to the ship's keel — in contrast to fore-and-aft rigging, in which the sails are rigged so that they run along the line of the boat's keel. The square rig sailing configuration is believed to have originated with the Vikings of the 9th and 10th Centuries, and was the dominant sailing ship rigging in use for many centuries.

While the term square rig sailing is often used to refer exclusively to the traditional square rig ships of earlier centuries, square rig refers to any sail and rigging configuration in which one or more four-cornered sails are supported by horizontal spars, including sailboats with gaff-rigged mainsails, even if other sails on the vessel are fore-and-aft rigged.

Gaff Rigs

A gaff rig is a sail rig in which a four-cornered sail is suspended from a gaff, which is a spar attached to the mast at one end.

A spar that supports the top of the sail and is attached to the mast at one end is a gaff. A spar that crosses the mast is a yard. A spar that is attached to the bottom of the sail and anchored to the mast at one end is a boom.

A sailing vessel with two masts, both carrying square rig sails, is known as a full rigged brig. The foremast typically has 3 spars supporting square sails. The mainmast also supports square sails on yards, but includes a small fore-and-aft sail attached to a standing gaff.

Full-Rig Ships and Barques

The traditional full rig ship (or full rigged ship, or fully rigged ship) includes 3 or more masts — lower mast, top mast, and topgallant mast. Each mast supports multiple square sails hanging from yards. A full rig ship is sometimes simply referred to as a ship.

A barque has 3 or more masts, with square sails on all masts except the aftermast, which carries fore-and-aft sails. A barquentine also has 3 or more masts, and has square sails on the foremast only, with fore-and-aft sails on the other masts.

Other square rig sailing ships include the brigantine, the topsail schooner, the hermaphrodite brig, and the unusual jack-ass barque.

In contrast to the more modern fore-and-aft sail rigging, a square sail always takes the wind from the same side of the sail. The sailboat can sail downwind well, but cannot sail across the wind or upwind nearly as well as a fore-and-aft rigged sailboat.