On a sailing vessel, a backstay is a piece of standing rigging which runs from the mast to the transom of the boat, counteracting the forestay and jib. Sailing is the art of controlling a Sailing vessel. By changing the Rigging, Rudder and dagger or centre board a Sailor manages the force On a Sailing boat standing rigging generally refers to lines wires or rods which are more or less fixed in position while the boat is under sail The mast of a sailing ship is a tall vertical or near vertical Spar, or arrangement of Spars which supports the Sails Large ships have several masts On a Sailing vessel a forestay, sometimes just called a stay is a piece of Standing rigging which keeps a mast from falling backwards A jib (also spelled jibb) is a triangular Staysail set ahead of the foremost mast of a sailing boat The backstay is an important sail trim control and has a direct effect on the shape of the mainsail and the headsail. A mainsail is the most important sail raised from the main (or only mast of a sailing vessel A headsail of a Sailing vessel is any Sail set forward of the foremost mast.

Types of backstays

Sailboat diagram. The backstay is identified by the number 15.

There are two general categories of backstay: The permanent backstay is attached to the top of the mast. The running backstay is attached about two-thirds of the way up the mast (sometimes at multiple locations along the length of the mast). In general, most modern sailboats will have a permanent backstay and some will have a permanent backstay combined with a running backstay. Backstays are not always found on all vessels, especially smaller ones.

A permanent backstay is attached at the top of the mast and may or may not be readily adjustable. In a mast head rig, tensioning the permanent backstay will directly tension the forestay. A fractional rig on a sailing vessel consists of a Foresail, such as a Jib or genoa sail, that does not reach all the way to the top of the mast This control is used to adjust the amount of "sag" in the headsail. In a fractional rig, tensioning the permanent backstay will have two effects: First, the forestay is tensioned (controls sag in headsail) and second, the mast bend is increased, particularly in the upper one-half to one-third of the mast. A fractional rig on a sailing vessel consists of a Foresail, such as a Jib or genoa sail, that does not reach all the way to the top of the mast Increased mast bend tends to reduce the draft (camber) of the mainsail.

A running backstay always attaches to the mast at a point below the top of the mast and is generally used in conjunction with a permanent backstay. Running backstays are found on both masthead rigs and fractional rigs. There are some rigs for which running backstays may be used without a permanent backstay. This occurs most often where the mainsail has significant roach; here, a permanent backstay would interfere with the operation of the mainsail. In Sailing the parts of a Sail have common terminology for each corner and edge of the sail As a direct consequence of its attachment point (below the top of the mast) a running backstay is always adjustable because it must be manually engaged and disengaged during every tack or jibe. A jibe or gybe is a sailing maneuver where a Sailing vessel turns its Stern through the wind such that the wind direction changes from one side of the Adjusting the tension on the running backstay has two effects: First, the forestay is tensioned (controls sag in headsail) and Second, mast bend is reduced (the mast becomes straighter). The overall effect of tensioning the running backstay is a deeper mainsail (more camber) combined with a reduction in headsail sag. If the running backstays leads to the mast where the forestay attaches, the effect of tensioning them will be as follows. Again the forestay is tensioned reducing sag in the headsail and second, mast bend is increased with flattening of the mainsail as a result. Both effects are desirable as the wind increases.

Backstays are generally adjusted by means of "block and tackle", hydraulic adjusters or by lines leading to winches. A block and tackle is a system of two or more Pulleys with a Rope or Cable threaded between them usually used to lift or pull heavy loads For the mechanical technology see Hydraulic machinery and Hydraulic cylinder Hydraulics is a topic of science and Engineering

Backstays as Antennae

On modern oceangoing yachts, the backstay is also commonly used as an antenna for Marine SSB radios and/or an amateur radio. Amateur radio, often called ham radio, is both a Hobby and a service in which participants called "hams" use various types of Radio communications Now this is accomplished by placing structural backstay insulators at either end of the backstay. Backstay Insulators, when used as a pair are devices which allow for the Electrical Isolation of a section of wire on a Yacht so that it can