Sail shapes. Sailing rig of a gaff schooner

Sailing rigs are used to create thrust to propel a ship using the wind. Consists of a spar and sails. Sailing weapons can be different. There are dozens of types of sailing weapons. We will not consider them now. For the most part you will be dealing with the very common type of "Bermuda sloop".

Sailing rig "Bermuda sloop".
Main and additional sails.

1. Head corner
2. Sorcerers
3. Luff
4. Tack angle
5. Main sheet
6. Staysail sheet
7. Clew angle
8. Sorcerers

Main sails - mainsail and staysail

Staysail

Bermuda rigged headsail. Genoa or genoa staysail, staysail, storm staysail are all names for the headsail.

Furling jib

One sail for any wind force. When the wind increases, its area can be reduced by twisting it partially around the forestay using a cable and a furling drum from the cockpit.

Furling the jib- a mechanism, a drum, that allows you to wind the jib onto the forestay. Furling the jib allows you not to set or remove the sail every time you leave or approach the anchorage, but simply wind it onto the forestay. Its disadvantage is that it is not optimal for all weather conditions.

Staysail on carabiners The replaceable staysail is attached to the forestay with carabiners (raks). This fastening is reliable and will not allow the sail to fall during ascent or descent. It can be quickly changed to a smaller or larger sail. This sail is convenient for long journeys, but not convenient for regattas.

Staysail on the forestay pier Replaceable sail, can be furled without furling the jib. A luff cable is sewn into the luff, which is held in the luff groove of the forestay pier. Stay-pier is a plastic or aluminum strip on the forestay. This type of jib provides better dynamic performance, but is difficult to furl on yachts over 35 feet. The jib is controlled (transferred from side to side) using jib sheets tied to the clew angle of the sail, and drawn along different sides of the yacht.

Grotto

The main sail is located behind the mast.
The classic mainsail is lowered and raised by a halyard through the top of the mast. For small yachts, a patent reef is sometimes used, a swivel design that allows the mainsail to be screwed onto the boom.
When the wind increases, the area of ​​the grotto is reduced - “they take reefs”. Screw the mainsail partially into the mast or onto the boom (with a patent reef). If the mainsail is a classic one, the sail is lowered on the halyard and the resulting “pocket” of reef is picked up with ropes.

The mainsail can be retracted onto a furler located inside the mast.

Main sheet- the tackle that controls the boom and, accordingly, the mainsail.
Mainsheet carriage and mainsheet - gear for sailing the mainsail.

Sail parts

Head corner- the top one, the sail is raised behind it.

Clew angle- the sheets that control the sail are tied into the clew eyelet of the jib

Tack angle- front, shows which tack the yacht is on

Skatorina- the edge of the sail, can be rear, front and bottom.

Additional sails

Spinnaker

Spinnaker- a light sail with a large area, made of nylon. Used for full courses - jibe and backstay.

Spinnaker carried on a special spar - spinnaker boom

Genaker

The gennaker is an asymmetrical spinnaker, a hybrid between a genoa and a spinnaker. It is similar to a spinnaker in that it is not attached to the forestay, it is just as light and has a large area. Like the genoa, it is attached to the bow of the yacht or to the bowsprit at the tack angle. He doesn't need a boom. It is much easier to control than a spinnaker

Storm sails

Trisail and storm staysail

They are sewn from very dense fabric of a smaller size compared to the main sails.

Trysail- a storm grotto, a small area made of very dense fabric. A trysail sail is used instead of a mainsail, but it is not attached to the boom, but is steered from the cockpit by two separate sheets.

In these times of dominance of Bermuda sloops, it is rare to see a gaff schooner at sea. Nevertheless, my “Chava” is equipped exactly like this. What is this, a reconstruction of a classic, desperate savings on an aluminum spar, or a tribute to romance?

The project allowed, among others, the option of arming the yacht as a Bermuda tender or a gaff schooner. Let's try to consider in detail and impartially the pros and cons of these sailing options for a specific project, as well as some features of the design and operation of a gaff schooner.

Bermuda tender.

Bermuda rigging has long been the standard for sailing yachts. New materials and technologies used in the development of sails and spars have led to very effective and easy-to-control weapons that have no equal on sharp courses.

On full courses, a yacht so rigged can carry twin staysails or a gennaker instead of a spinnaker when sailing with a small crew or alone. The main problems of the Bermuda rig are the large amount of standing rigging and the serious loads transferred to the hull by the spars and rigging.

The relatively large cross-section mast is supported by two rows of spreaders. The sail area of ​​the project, armed with a Bermuda tender, is 78.2 m2.

Gaff schooner.

The gaff rig masts are relatively short and of large diameter, secured with shrouds and stays in the top area, since the gaff tendrils moving along them when setting the sails do not allow the placement of additional attachment points.

The mainmast is installed on the deck, the loads on the hull are distributed by the submast pilser. The foremast shrouds are located in the bow of the hull; the width of the hull here is much smaller than at the midships, where the mainsail shrouds are installed. In addition, the mast is additionally loaded with bow sails.

Therefore, the foremast passes through the deck in steps on the bottom, and is additionally braced at deck level.A special feature of the gaff rig is the absence of backstays. The shrouds of the standing rigging and boomsails take the entire load from the installed sails, and the booms of gaff sails, even at full courses, almost do not extend beyond the deck in plan.

This leads, on the one hand, to an elegant and swift silhouette - the masts have a noticeable design tilt towards the stern, on the other - long booms at full courses require mandatory block hoists, short drawn from their legs to suitable attachment points on the deck - as a rule, to the leeward side and slightly forward.

They rigidly fix the booms against involuntary jibes.The rather long bowsprit is another feature caused by the shape of the gaff mainsail and the need to balance its windage with forward bow sails, otherwise the yacht will be strongly driven to the wind.Main sail area –65.8 m 2 . Taking into account the additional windage, the yacht can carry about 100 m 2 sails.

Spar design.

The choice of a steel pipe in the project as the basis for the mast columns seems, at first glance, strange. There is an opinion among sailors that steel is not a suitable choice for a spar. They believe that such masts will be too heavy, the boat will lose stability, and corrosion will make them very short-lived.

However, the mass calculation tells a different story. A traditional timber spar requires an increase in mast diameter and will be heavier in weight. Aluminum alloy provides virtually no advantages over steel. If we introduce a couple more criteria - the cost of the material for making the mast and its availability, then steel certainly becomes the best choice.

The mast is assembled into a single unit by electric welding and sealed to prevent corrosion, after which it is protected with paint and varnish coatings in the same way as the steel body. All necessary electrical cables are routed externally, along the cables, as well as the running rigging.

Booms, gaffs, topmast.

These spar trees, according to the design, should be made of wood and hollow inside. The designer does not approve of their manufacture from solid pieces of wood due to excess weight and the risk of cracking.

The fittings and other useful things for the wood were already ready when, for reasons of durability, strength and reducing cost and labor, the decision was made to replace it with affordable aluminum alloy pipes.

In particular, this was prompted by correspondence with the owners of the American sistership schooner “Adventure”. They had to replace the booms after ten years of use of the boat, although the masts and sails were still in good condition. Just at this time, pipes made of aluminum alloys ceased to be in short supply, and the issue of spars was resolved in one fell swoop.

The blanks were thoroughly washed from grease and first coated with primer for aluminum, and then painted. The fittings, gaffs, and other hinged components and parts are made of stainless steel and installed on screws and threaded rods, as well as polyurethane sealant.

The mustaches of the gaffs are covered with technical leather, the “stainless steel” is polished with a felt wheel with GOI paste, clamped in a drill. The topmast is installed in its place in ezelgoft through insulating bushings machined from caprolon to prevent electrochemical corrosion.

The bowsprit is made of larch. I managed to select and purchase for this purpose dried boards 20 mm thick of the “zero” grade. The bowsprit is glued together from these larch boards using epoxy resin with the addition of dry wood dust.

Larch has a high resin content in the wood, so before gluing, the surface must be thoroughly cleaned of it with acetone to ensure adhesion. In order to smear this amount of resin (more than 2 kg) on ​​the surface of the boards and assemble the package, I needed to make five batches.

To prevent the resin from setting up prematurely, I worked in the shade in the morning. The next day, the bowsprit was already processed with an electric plane. Then, when the extra piece of the workpiece was sawed off, it became possible to test the tensile strength of the resulting adhesive seam. When the board was torn off, it tore to the quick, and did not burst anywhere along the adhesive seam.

Standing rigging.

The shrouds and stays are made of stainless steel cable and 619 galvanized steel cable, with thimbles and hand-made stops. The fires were sealed according to the classical scheme - through one strand under two against the lay.

After manufacturing, each fire was painted for anti-corrosion protection and capped. Standing rigging turnbuckles and mounting brackets must be at least as strong as the cables attached to them.

The shrouds of the foresail and mainsail, installed on the bulwark gunwale, were strengthened during construction, and therefore are used not only for their intended purpose, but also for lifting the boat with standard 6-meter slings.

Galvanized wire rope for standing rigging is much less expensive than stainless steel wire rope, but requires periodic maintenance. According to classical technology, at the beginning and end of each season it must be removed from its regular place, boiled in drying oil and rubbed with paraffin.

Often they also use coatings based on varnish, paint, or coated with modern compounds designed specifically to protect the rigging. In addition to being cheap, there is another important advantage of galvanized cable - it always warns of corrosion with rust spots, which makes it easier to control the condition of the rigging.

Such a cable does not break unexpectedly, like a stainless steel cable. Therefore, the use of galvanized cable for standing rigging is quite justified.For the forestay and jib rail, as well as the waterstay and waterbackstays, it is advisable to use a stainless steel cable.

The bow sail carabiners quickly wear away the galvanizing, exposing the steel, and the waterstay and waterbackstays are constantly bathed in sea water.Marine galvanized lanyards and connecting brackets have a rather unsightly appearance, are huge in size and have questionable durability due to corrosion; those purchased from import catalogs cause justified mistrust due to poor quality and manufacturing technology.

In addition, their price is unreasonably high. Therefore, the turnbuckles and shackles for the standing rigging were made to order: the turnbuckle body and locknuts were made of bronze, and the tips and pins were made of stainless steel. Lanyards must be attached to the pins through hinges, giving the joints a second degree of freedom.

The traditional scheme for protecting sails and spars from abrasion on the rigging includes installing bear protectors on it in the right places. Such protectors can be made from scraps of worn-out gear using the technology of making printed mats.

Attaching sails to the spar, setting and steering.

Gaff sails are tied with the luff to the gaff, the luff to the mast and the luff to the boom. They are placed with a gaff-hardel tied to the heel of the gaff, and a dirik-halyard tied to its end. Gaff sails are controlled using gear tied to the boom and called a boom sheet.

There are many options for attaching the boom sheet to the hull, the simplest is a block attached to a butt (U-bolt) welded to the deck. This option is provided for by the project and was originally implemented on the Chava for the mainsail and foresail.

A slightly more complex option involves installing a boom-sheet shoulder strap and, thanks to the shift of the thrust point to the leeward side, allows you to increase the tension of the luff and reduce the “twist” - the twisting of the upper luff into the wind relative to the lower one.

This should increase the efficiency of the sail on sharp courses. This design combines well with the installation of a stern stop to support the main boom when the mainsail is in full swing. The foresail gaff on a schooner is equipped with additional tackle, called the foresail backstay, which goes to the top of the mainmast.

Each mast has cable strips installed on the shrouds, which also turned out to be convenient and safe supports for the back when working with sails near the mast. There are four dowels on each floor plank, three cleats on each mast, and four cleats are installed on the deck.

Nevertheless, this is the necessary minimum for such a weapon scheme. Efficiency of weapons during ocean cruising It is quite clear that in the conditions of the Olympic Triangle race, a yacht armed with a Bermuda tender will come first.

This type of sail is by far the best on sharp courses, and when the wind moves to the stern corners, there is always the option of setting a spinnaker or gennaker. However, the specifics of a long-distance voyage impose slightly different requirements on a sailing vessel.

Two more important aspects that are worth considering are the increased stability of a gaff schooner and a lower tendency to broach due to the low center of sail.

Sturdy and securely braced steel masts provide confidence in stormy conditions, and the low center sail allows more sail to be carried in fresh weather, making the boat a true storm bird.

The sail distributed along the length with a long bowsprit and main boom to the transom allows the boat to be accurately centered in different weather conditions, facilitating the helmsman's watch and simplifying the adjustment of the thrusters.

The schooner successfully maneuvers and gains altitude even in very fresh weather, but this cannot be considered decisive when deciding on the choice of armament for a cruising yacht.

Drive with a family crew or alone.

To work with the sails of a Bermuda tender with an area of ​​about 100 m2 in such conditions, serious mechanization will be required. Bow sails are furled, the mainsail is mechanized (for example, retractable into the mast), powerful clew winches.

At the same time, the expenditure of muscular strength becomes minimal, the boat is perfectly controlled by two people and even alone thanks to the efficiency of the sailing armament.However, there are also problems here. In order for all this to work reliably, you will need to invest a lot of money in purchasing high-quality equipment with an appropriate margin of safety.

In addition, this modern equipment operating in marine conditions will require constant ongoing maintenance. Do-it-yourself repairs of high-tech components during a long voyage are excluded or very limited, so it is necessary to provide for the possibility of duplicating equipment or other options for restoring the functionality of weapons.

When rigged with a gaff schooner, the total sail area is divided into several fairly small sails, each of which can be set by a single person.

There is no mechanization, and in order to select the sheets of the bow sails, a pair of small winches on the cockpit coamings is sufficient. You only need one more small winch on the main boom for reefing.

The foresail and mainsail gaffs are lifted manually through pulley systems. The absence of lip openings on the masts eliminates many problems when setting and cleaning the mainsail and foresail, which are typical for Bermuda sails.

At the same time, the use of new materials - relatively light gaffs made of aluminum pipes, sails made of Dacron - gives this type of weapon new useful qualities. As a result of such innovations, a modern gaff schooner tacks much better than its traditional counterpart. As the weather cools, the fisherman is removed successively, then the topsail, leaving only the main sails. As the wind picks up, the mainsail begins to reef as the boat begins to “beg”, showing a tendency to drift.

The time to remove the jib usually comes when the mainsail is already reefed to a couple of shelves. By the way, the gaff schooner is drifting steadily. To do this, it is enough to leave the bow sails on the windward side during the tack and put the rudder slightly into the wind.

The problems with servicing gaff weapons are traditional and well known. There are much more different types of gear than on a Bermuda boat, and they require special wiring and fastening points, for example, cleats on the shrouds, so working with sails is generally more difficult and takes more time.

As a safety measure, a net is stretched between the water backstays and runs under the bowsprit, which also adds to the charm of the boat. Routine maintenance and repairs boil down to timely replacement of running rigging gear, leather on the gaffs and restoration of worn out protectors.

A traditional wooden spar also requires constant attention, but in our case we were able to get rid of this, since the masts and all other spar trees are metal. The most they need is periodic restoration of paintwork in areas of wear.

It’s clear - you can justify anything, and there is some subjectivity here. Nevertheless, the choice was made, the boat was built with a gaff version of the armament, it passed sea trials on the open sea with access to the ocean and so far fully justifies the design decisions laid down.

Andrey Popovich. Vladivostok.

The word "Bermudian" refers to the design of the sails and the way they are attached to the spar on ship. Characteristic features of Bermuda sails are:

• side view close to triangular;
• attachment to the ship and its mast along the luff of the sail;
• To control the sail, one angle is used - the clew and (or) the luff.

Word " sloop" means that the ship is single-masted, but with two sails:

• mainsail (attached to the mast along the entire luff)
• a jib connected by the upper i.e. halyard corner to the mast, the lower (called tack) corner to the bow of the deck, and the entire luff or to a cable (this can be a cable sewn into the luff of the sail, or a stay - a cable holding the mast in front, or stay-pier, i.e. rigid tackle instead of a cable in the form of a pipe or rod).

The stay-pier is undoubtedly the best option, but is used less frequently due to its high cost and (or) large mass.

Bermuda sloop looks like shown in Figure 4.1.

In the figure, instead of dimensions, letter designations are indicated:

s p - fin area.
s r - rudder area.
s k is the area of ​​the underwater part of the hull.
B max - the maximum width of the yacht hull.
B kvl - width according to kvl.
B stern - width of the stern.
V is the displacement of the yacht.
m pl - fin mass.

Explanations

1. Cool to the wind- when the yacht moves towards the wind at some acute angle. Modern cruising yachts this angle is about 45°, but the fastest large yachts can have 30°!
2. Tacking- a method (technology) of moving a yacht towards the wind, consisting of alternating movement: first on the left, then on the right tack (Tack - the position of the yacht relative to the direction of the wind. Right tack - the wind blows to the starboard side, from the right half of the yacht, left tack - to the left board, from the left half.
3. Get out into the wind- move towards the wind;
4. Bermuda sails have three angles and three luffs, each with its own name:
   - the upper angle at which the sail is lifted up the mast using a halyard (i.e. cable, rope) is called the halyard angle;
   - the lower corner of the sail facing the headwind is called the tack angle;
   - the rear angle of the sail, facing the direction downwind, is called the clew angle and is used to control the sail using a sheet (rope);
   - luffs are the edges of the sail;
   - the luff in the working position is facing the wind and a cable is sewn into it (it’s called a lyktros);
   - luff - at the back. The waste stream of wind flows from it;
   - the lower luff faces the deck.
5. Seaworthiness- the ability of a yacht to successfully withstand the elements of wind and waves of a certain strength. The stronger the wind and waves, the more seaworthy the yacht should be. A yacht that is more durable and better able to withstand unexpected weather conditions is considered more seaworthy.
6. Genoa- a wide jib, with its clew angle extending behind the mast towards the stern.

Proportions of a Bermuda cruising sloop

Proportions of modern cruising yachts can be expressed through the main dimension L kvl. Actually L kvl usually lies within the range of 2.5 ÷ 20 m.

L max ≥ L kvl. L max can reach 1.3 L qvl however there is a tendency to L max = L kvl.
H = (1 ÷ 1.5)Lkvl, most often H ≈ 1.3 L kvl.
h st = (0.75 ÷ 1)H; it is better when h st = H, however, problems arise with the strength of the mast.
h b = (0.07 ÷ 0.2) L kvl; the larger h b, the more seaworthy the yacht.
∆ ≈ 0,1L kvl - displacement of the CP to the nose from the central nervous system. A very important quantity that affects the handling of the yacht.
T total = (0.2 ÷ 0.3) L kvl; Tk ≈ 0.05 L kvl.
The fin, like the rudder feather, is hydrofoils. They act like a glider wing, only they are positioned vertically.
s k ≈ 0.6 L kvl × T k;
s p ≈ 0.6Sк = 0.036 L kvl × T k.
Much depends on the shape of the hydrofoil, i.e. on t, 1, b.
In cross section, the fin and rudder blade have the shape of a drop with a blunt end forward. t ≈ (1.8 ÷ 2.5)l = (0.18 ÷ 0.25) L kvl, where l ≈ 0.1 L kvl; b ≈ (0.012 ÷ 0.015) L kvl.
For the rudder blade, the relationship between t, 1 and b is similar, but for the rudder s p ≈ 0.25s p.
mpl ≤ (0.2 ÷ 0.4)V for cruising and keel yachts;
mpl ≈ 0 for light boats, dinghies, sailing boards and catamarans (in general for multihull yachts),
V = (0.0046 ÷ 0.007)L 3 kvl; S = (0.5 ÷ 0.75)L 2 kvl;
S st ≈ S gr, it is better when S st = 1.25S gr.
Bmax ≈ (0.3 ÷ 0.45) L kvl. V kvl ≈ (0.27 ÷ 0.4) L kvl.
B k ≈ B kvl.

Behind the diversity of designations, terms and numerical ratios, it is not easy to guess the charm of a classic cruising yacht. Therefore, we will formulate its advantages in a brief verbal form.

Firstly, and this is the main thing, a cruising Bermuda sloop of good proportions is a good tackler. The “dead zone”, where the helmsman cannot immediately and directly (except under the engine) steer the yacht, is only about 90° out of 360° (45° each to the right and left sides from the direction towards the wind). With sails of high aerodynamic quality and high similar characteristics of the fin and the underwater part of the yacht as a whole, this figure can be reduced to 80°.

Racing large superyachts even reach 60°. However, every degree into the wind costs more and more, which requires extremely expensive sailing fabric and, even more so, ready-made sails. The most modern masts, rigging, controls and equipment also cost more than conventional ones. The hydrodynamic qualities of the underwater part of the yacht are no less expensive: complex fin shapes, ultra-clean surfaces that do not allow the slightest adhesion of algae and other dirt, “narrow” gates of sailing modes: strict adherence to the angles of attack of the sails in relation to the variable wind, ultra-precise accounting of destabilizing factors ( waves, currents, etc., etc., etc.) require the use of expensive instruments and computers during navigation.

Secondly, a cruising Bermuda sloop of good proportions is easy to operate and does not require a large crew due to the well-organized wiring of the sheets and the mechanization of the controls: winches, blocks, stoppers, steering gear - are extremely simple.

Third, on passing courses, where triangular (Bermuda) sails are not the most effective, it is possible to install an additional sail made of light fabric - a spinnaker or gennaker (a gennaker is an asymmetrical spinnaker, a spinnaker resembles a parachute and is comparable in area to the total area of ​​tacking sails). This gives a noticeable increase in speed and the maximum possible is achieved. The use of a spinnaker or gennaker requires good coordination from the crew in control. Fairness requires saying that on a Bermuda sloop, the sails set “butterfly” on a jibe course allow you to go on a cruise without any hassle.

Fourth, a wide and flat bottom of the stern in combination with a high power-to-weight ratio (i.e. S/V = 24 ÷ 30 m2/ton of displacement) allows the yacht to exit the displacement sailing mode into the surfing mode and reach a speed higher than what Froude’s law limits it in displacement mode (according to Froude or taking into account 1 knot = 1853 m/hour, or 0.514 m/s, 1 foot = 0.3048 m. ). A reliable Bermuda sloop-type cruising yacht can be built relatively cheaply.

To the direct question: “What is the speed of the yacht?” The answer is: “It is always different.”

When the wind speed is zero (complete calm), the yacht will stand or float with the current or row with sails due to the oncoming waves and move slightly. In this case, a motor or oars come to the rescue. But this is a rare situation when there is no wind at all.

With a low wave (for each size of yacht this is its own value) with a wind of 3 ÷ 4 points (3.4 ÷ 7.9 m/s), a medium-sized yacht (≈ 6 ÷ 7 m by waterline) develops a speed according to the Froude formula of about 10 ÷ 13 km/h. For the same yacht, with a wind speed of 12 m/s, you can reach a speed of 25 km/h. Larger yachts go faster, smaller ones - slower.

In conditions of strong wind and storm (over 20 m/s), the fastest course is a gulfwind course along the wave or slightly obliquely. Courses counter to the wave at an acute angle to the wind slow down the speed greatly, and small yachts can no longer fight the elements and drift with the wind or stop at anchors.

Riding on a following wave puts the yacht into surfing and planing mode. The speed increases to wind speed and more!

The helmsman (captain) of the yacht has a large selection of different options: try to move in the chosen direction, hide in a shelter, anchor, try to use the motor, despite the fact that a cruising yacht is a self-righting yacht, even if it turns out to be with the mast down - this is for counting the mass of the fin.

When the wind force is excessive for your yacht, when a dangerous (large and jerky) list and strong drift occur, reduce the sail area, in nautical language: “take reefs”. This operation is greatly facilitated and accelerated if the yacht has devices for furling the sails: furling the jib around the luff, reefing the mainsail for furling it along the lower luff while simultaneously releasing the halyard.

The passion for speed-squeezing yachts in all possible ways, already at the design stage, leads to a deterioration in their habitability (i.e. living conditions) and, most importantly, to a decrease in reliability, since ultra-lightweight yachts often find themselves in conditions on the verge of their strength. Operating such yachts requires the highest qualifications of the crew.

The drawing resistance is determined by stretching the fabric with your hands diagonally, as well as along the threads - along the warp and weft. It is necessary to pay attention to the uniformity of the warp and weft threads, since if they have different densities, for example, like calico, the stretching in different directions will be uneven. From this point of view, for example, fabrics with lavsan are unsuitable for sails. Nylon fabrics, which have very large elastic deformations, cannot be used for almost all main sails.

The first chapter talked about the basic requirements that a sail must meet from an aerodynamic point of view. The simplest way to give a sail the required shape is to cut its luffs with a given curvature - sickles. Sickle sizes for various types of sails designed for medium winds are shown in Fig. 79. For a Bermuda mainsail, the values ​​of the sickles are taken at the upper limit if the mast is not rigid enough, since when it bends the sail becomes flatter.

Rice. 79. Cut the sails to ensure the correct shape of the belly: a - Bermuda mainsail; b - staysail; c - mainsail-guari and gaff; d - rack (the dashed line shows the sickle on the luff in the absence of a boom)

The “belly” obtained by the sickles is located close to the mast - such a sail works well only in fresh winds. For medium winds, it is advisable to move the belly back by 1/3, and for weak winds even 1/2 the width of the sail from the mast. This is achieved by using wedge-shaped tabs (darts) along the seams from the luff. On a sail for medium winds, the tabs are made equal to 1/4 of the length of the seam from the mast, and for light winds - 1/3. The length of the bookmarks is reduced in height, gradually reducing them to nothing. In total, 1-1.5% of the length of the luff should go into bookmarks.

The luff of the mainsail is drawn with a hump, which can increase the sail area from 10 to 30%. A hump of considerable size must be supported by armor, otherwise the luff will twist and create additional resistance.

Staysails that are hoisted on the forestay, or simply stretched at the halyard, clew and tack angles, are subject to distortion of their profile under the influence of the wind. With the luff slack and the luff taut, the belly at the top becomes disproportionately large, and the flow of air flowing off the jib interferes with the efficient operation of the mainsail. Taking this feature into account, the luff of the jib is cut with two sickles - in the upper part with a concavity there is a negative sickle), in the lower part with a convexity (a positive sickle). The concavity prevents the jib from becoming too “bellied” in the upper part, and prevents the luff from bending to windward and from blowing out the mainsail. A small sickle is made along the lower luff of the jib (sometimes in combination with tabs along the panels), the luff is usually straight or slightly concave.

To improve the aerodynamics of the mainsail, a fairing pocket is used, which is used to attach the sail to the mast. When changing tacks, the shape of the pocket is automatically rebuilt and the sail always takes on the desired concave-convex profile.

Even more advanced is a double-layer sail. Between its panels it is possible to place not only the mast, but also battens, bows, seams - everything that disrupts the smoothness of the surface, and it is also easier to sew than a sail with a mast pocket.

Staysails with high clews and Swifts with straight masts, reinforced with spreaders and diamond shanks, are cut completely flat, without bookmarks. The belly of the sail is set by bringing the clew angle closer to the mast, while it will gradually decrease as it moves away from its middle part towards the tack and halyard angles. At the ends of the sail, the pressure difference on its sides will be small, and the inductive resistance will correspondingly decrease. The lifting force of such a sail is somewhat less than the maximum possible, but on sharp courses this loss is compensated by a decrease in drag. The yacht will go against the wind not only faster, but also with less drift and roll.

However, there is evidence of the use of sails in land transport - for example, the sail was widely used to provide auxiliary motive power on carts in China.

The simplest sail is a piece of material made from threads of natural or synthetic materials. Larger sails are sewn from several pieces. Before stitching, the panels are shaped in such a way that the finished sail, installed in its place and filled with wind, has a well-streamlined convex-concave shape, resembling a bird’s wing in cross-section, and develops the greatest useful force.

Synthetic fabrics are used to make modern sails. In some cases (for example, to make sails for windsurfers), not fabric, but a durable film is used. There are also more complex and expensive sail manufacturing technologies, in which the entire sail is made not from pieces of fabric or film, but from high-strength synthetic threads placed between two layers of film along the lines of action on the sail of the greatest loads.

There are also structures that are completely different from an ordinary sail, which are a wing placed vertically and use the power of the wind for the same purposes as a sail. Such structures are sometimes installed, for example, on sports boats (also, by the way, quite different from the ordinary boats familiar to most) in order to achieve speed records on the water. Having very little in common with a stretched piece of material, these wings are nevertheless called, due to their inertia, either a “rigid sail” or a “wing sail”.

Types of sails

Straight sails - sail, which are placed across the ship and attached to yards that rise to masts and topmasts. They look like an isosceles trapezoid. They are used to arm large sailing vessels: ships, barques, barquentines, brigs and brigantines.

It has the shape of a right triangle. The upper side (hypotenuse) is attached to the rail, tilted forward. The forward end of the rake extends to the deck; tack is taken over it.

Bermuda sail

Bermuda sail- a triangular sail stretched between the mast and the horizontal boom.

At the moment it is the most common type of sail. In terms of ease of control, installation and traction characteristics, it is the undisputed leader.

Luger (raik) sail- a type of oblique sail.

Sail most often in the shape of an irregular trapezoid, the upper luff is attached to the rake, the lower luff is attached to the boom.

Other

Sail parts

A drawing showing the names of the parts of a sail.

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See what "Bermuda sail" is in other dictionaries:

This term has other meanings, see Sail (meanings). Sailing vessel A sail is a fabric or plate attached to a vehicle that converts wind energy into forward motion ... Wikipedia

SAIL- A propulsion device designed to convert wind energy into useful thrust of the vessel. It is a panel of linen, cotton or synthetic fabric, mounted on the parts of the spar, which is placed across the vessel (straight P.) ... ... Marine encyclopedic reference book

Sailing vessel A sail is a fabric (see canvas) or plate attached to an object that is stretched relative to the wind so that its pressure creates a force that sets the object in motion. As a rule, a sail is used for... ... Wikipedia

Sailing vessel A sail is a fabric (see canvas) or plate attached to an object that is stretched relative to the wind so that its pressure creates a force that sets the object in motion. As a rule, a sail is used for... ... Wikipedia

Sailing vessel A sail is a fabric (see canvas) or plate attached to an object that is stretched relative to the wind so that its pressure creates a force that sets the object in motion. As a rule, a sail is used for... ... Wikipedia

Oblique sails are sails that are placed in the center plane along the ship. They have many varieties. Unlike straight sails, they allow the ship to sail steeper to the wind, at an angle of up to 20°. Oblique sails also include triangular sails.... ... Wikipedia

Sailing vessel A sail is a fabric (see canvas) or plate attached to an object that is stretched relative to the wind so that its pressure creates a force that sets the object in motion. As a rule, a sail is used for... ... Wikipedia

Sailing vessel A sail is a fabric (see canvas) or plate attached to an object that is stretched relative to the wind so that its pressure creates a force that sets the object in motion. As a rule, a sail is used for... ... Wikipedia

Bermuda: Bermuda is a group of islands in the Atlantic Ocean Bermuda name shorts. See also Bermuda Triangle Bermuda sail Bermuda sloop Bermuda schooner Bermuda petrel Bermuda juniper Bermuda grass Bermuda stock ... ... Wikipedia