Sail components include the features that define a sail's shape and function, plus its constituent parts from which it is manufactured. A sail may be classified in a variety of ways, including by its orientation to the vessel and its shape. Sails are constructed out of flexible material, shaped by various means, while in use, to offer an appropriate airfoil, according to the strength and apparent direction of the wind. A variety of features and fittings allow the sail to be attached to spars. Whereas conventional sails form an airfoil with one layer of fabric, wingsails comprise a structure that has material on both sides to form an airfoil—much like a wing placed vertically on the vessel—and are beyond the scope of this article. Sails may be classified as either triangular, which describes sails that either come to one point of suspension at the top or where the sail comes to a point at the forward end, or quadrilateral, which includes sails that are attached to a spar at the top and have three other sides, or as square.
They may be classified as symmetrical or asymmetrical. Asymmetrical sails perform better on points of sail closer to the wind than symmetrical sails and are designed for fore-and-aft rigs. Symmetrical sails perform best on points of sail. Triangular sails have names for each of three corners. Rigs with such sails include Bermuda, cutter and vessels with mixed sail plans that include jibs and other staysails. Most triangular sails are classified as fore and aft. Gaff, lug and some sprit sails have four sides and are set fore and aft so that one edge is leading into the wind, forming an asymmetric quadrilateral shape. Naming conventions are consistent with triangular sails, except for corners. A square rig is a type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular, or square, to the keel of the vessel and to the masts—the sails themselves are not square but are symmetrically quadrilateral; these spars are called yards and their tips, beyond the last stay, are called the yardarms.
A ship so rigged is called a square-rigger. The shape of a sail is defined by its edges and corners in the plane of the sail, laid out on a flat surface; the edges may be curved, either to extend the sail's shape as an airfoil or to define its shape in use. In use, the sail becomes a curved shape, adding the dimension of draft; the top of all sails is called the head, the leading edge is called the luff, the trailing edge is the leech, the bottom edge is the foot. Head – The head is the upper edge of the sail, is attached at the throat and peak to a gaff, yard, or sprit. For a triangular sail the head refers to the topmost corner. Leech – The aft edge of a fore-and-aft sail is called the leech; the leech is either side edge of a symmetrical sail -- square. However, once a symmetrical sail has wind blowing along its surface, whether on a reach or close-hauled, the windward leech may be called a luff. Luff – The forward edge of a fore-and-aft sail is called the luff, may be attached along a mast or a stay.
When on a reach, the windward leech of a spinnaker is called the luff and, when on a reach or close-hauled, the windward leech of a square sail may be called the luff or the weather leech. Foot – The foot of a sail is its bottom edge. On a fore-and-aft mainsail, the foot is attached, at the tack and clew, to a boom. A fore-and-aft triangular mainsail achieves a better approximation of a wing form by extending the leech aft, beyond the line between the head and clew in an arc called the roach, rather than having a triangular shape; this added area would flutter in the wind and not contribute to the efficient airfoil shape of the sail without the presence of battens. Offshore cruising mainsails sometimes have a hollow leech to obviate the need for battens and their ensuing likelihood of chafing the sail. Roach is a term applied to square sail design—it is the arc of a circle above a straight line from clew to clew at the foot of a square sail, from which sail material is omitted; the roach allows the foot of the sail to clear stays coming up the mast, as the sails are rotated from side to side.
The names of corners of sails vary, depending on symmetry. Head – In a triangular sail, the corner where the luff and the leech connect is called the head. On a square sail, the top corners are head cringles. Peak – On a quadrilateral sail, the peak is the upper aft corner of the sail, at the top end of a gaff, a sprit or other spar. Throat – On a quadrilateral sail, the throat is the upper forward corner of the sail, at the bottom end of a gaff or other spar. Gaff-rigged sails, certain similar rigs, employ two halyards to raise the sails: the throat halyard raises the forward, throat end of the gaff, while the peak halyard raises the aft, peak end. Clew – The corner where the leech and foot connect is called the clew on a fore-and-aft sail. On a jib, the sheet is connected to the clew. Clews are the lower two corners of a square sail. Square sails have sheets attached to their clews like triangular sails, but the sheets are used to pull the sail down to the yard
José Ángel Rojo Arroitia is a Spanish former professional footballer who played as a midfielder. He played 192 La Liga matches over nine seasons, scoring a combined 14 goals for Athletic Bilbao and Racing de Santander. Born in Bilbao, Rojo joined the youth system of hometown club Athletic Bilbao in his last year as a junior, he made his senior debut with neighbouring SD Indautxu, being loaned twice to the Segunda División team and being relegated as many times. Aged 22, Rojo was promoted to the first team before the start of the following campaign. By that time his elder brother José Francisco was an established member of the line-up, therefore the younger sibling was referred to administratively as Rojo II. José Ángel made his debut in La Liga on 24 January 1971 when he came on as a late substitute in a 2–1 away victory against Real Zaragoza, he went on to start six further league games for Ronnie Allen's team, adding four appearances in the Copa del Generalísimo. In 1971–72 Rojo began to feature for Athletic, made his European debut against Southampton, featuring the full 90 minutes in the 1–2 away loss in the UEFA Cup.
The following season he contributed with 37 appearances in all competitions, helping the side to ninth place in the league and victory in the domestic cup, with the player appearing in the final in Madrid, a 2–0 defeat of CD Castellón. Over the next four campaigns, Rojo was a frequent presence in the midfield for Athletic. In 1976, he was in the side and scored in both legs of a Spanish Cup tie against Sporting de Gijón in which the opponents overturned a 2–0 first leg deficit to win 5–2 at San Mamés. Although the result itself was an embarrassment, it did prompt the club to pursue the opposition's star player Iñaki Churruca, who would play an important role for the team in the coming years. Rojo missed the first half of 1976–77 due to injury, scoring what was to be his final goal for the side in a 3–0 home win over Hércules CF as they ended the league in third place. Athletic reached the final of the UEFA Cup, losing on the away goals rule to Juventus F. C. and with him appearing in the first leg, one of his five games in the run.
After signing with Racing de Santander in the summer of 1977, Rojo was a regular in his three seasons in Cantabria, narrowly avoiding top flight relegation in the first but finishing second from bottom in the second. After nearly dropping down another level in 1979–80, he retired at 32. Having never featured at any youth level for Spain, Rojo came to the attention of the selectors due to his form for Athletic, his first and only cap arrived on 17 October 1973, when he played the entirety of a 0–0 friendly draw in Turkey – his brother took part in the match. Rojo featured for the unofficial Basque Country team in 1971 in a match against Catalonia. Athletic Bilbao Copa del Generalísimo: 1972–73.