Any skipper, both in antiquity and now, once in the open sea beyond the sight of the coast, first of all wants to know in which direction his ship is heading. The device by which you can determine the course of the ship is well known - it is a compass. According to most historians, the magnetic needle - the ancestor of the modern compass - appeared about three thousand years ago. Communication between the peoples in those days was difficult, and while a wonderful direction indicator reached the shores of the Mediterranean Sea, many centuries passed. As a result, this invention came to Europe only at the beginning of the second millennium BC. e., and then it spread widely.
Once in Europe, the device underwent a number of improvements and was called a compass, playing a huge role in the development of civilization. Only a magnetic compass instilled confidence in the sea in people, helped them overcome their fear of the ocean. Great geographical discoveries would have been unthinkable without a compass.
History has not preserved the name of the inventor of the compass. And even the country that presented this wonderful device to humanity, people of science cannot name for sure. Some attribute his invention to the Phoenicians, others claim that the first who drew attention to the wonderful property of the magnet to be mounted on the plane of the magnetic meridian were the Chinese, the third preferred the Arabs, the fourth mentioned the French, Italians, Normans, and even the ancient Mayans, the latter on the ground that once in Ecuador a magnetic rod was found, which (with a passionate imagination) could be considered the prototype of the magnetic needle.
At first, the device for determining the countries of the world was very simple: a magnetic needle was stuck in a piece of cork and lowered into a cup of water, which later became known as a compass kettle. Sometimes, instead of corks, they took a piece of reed or simply inserted a needle into a straw. Even this simple device brought the sailors invaluable amenities, with it you could go out on the open sea and not be afraid that you would not find a way back to your native coast. But the sailors wanted more. They vaguely felt that the wonderful floating arrow, the accuracy of which was obviously very low, had not yet revealed all its magnificent capabilities. And the water often spilled out of the pot, sometimes even with the arrow. Only in the 13th century did a compass appear with a dry bowler, and most importantly, with a card attached to the arrow. The potato was a simple at first glance, but truly remarkable invention: a small circle of non-magnetic material, together with a magnetic arrow rigidly attached to it, is freely suspended on the tip of a vertical needle. Four main rumbas were applied on top of the cartouche: Nord, Ost, Zuid and West, so that Nord would exactly coincide with the northern end of the arrow. The arcs between the main points were divided into several equal parts.
It seems to be nothing special? But before that, the old compass with a fixed card was each time turned in a horizontal plane until the northern end of the arrow coincided with Nord. Only then could it be possible to determine the course at which the ship was heading. This, of course, was very inconvenient. But if the card itself rotated with the arrow and itself was installed in the plane of the meridian, it was enough just to glance at it briefly to determine any direction.
And yet, despite the improvements introduced, the compass has long remained a fairly primitive device. In Russia in the XVII - early XVIII centuries the most skillfully made it pomors in the cities and villages of our North. It was a round box of walrus bone with a diameter of 4-5 centimeters, which the Pomors kept at the waist in a leather bag. In the center of the box on a bone hairpin was a card with magnetized metal needle-arrows fixed from below. If you did not use a compass (or a mark, as its pomors called it), a blank cover was put on top of it. A similar instrument is written in the Maritime Charter of Peter I: “Compasses must make and watch with good skill so that the needles, on which the compass spins, are sharp and strong and would not be easily broken off. Also, so that the wire (referring to the arrow. - V.D) on the compass to Nord and Zuyd was firmly rubbed with a magnet, so that the compass could be true, which should have a good look, because the course and integrity of the ship depends on it. ”
Nowadays, the compass kettle is tightly closed with a thick glass lid tightly pressed to it by a copper ring. On top of the ring, divisions from O to 360 ° are applied - clockwise from Nord. Two black vertical copper wires are pulled inside the pot, so that one of them falls exactly at 0 °, and the other at 180 °. These delays are called course features.
The compass on the ship is set so that the line drawn between the course lines, exactly coincides with the bow - the middle of the stern (or, as they say in the Navy, with the diametrical plane of the ship).
History also does not give an answer about who invented the compass with the rotating card. True, there is a widespread version that in 1302 the Italian Flavio Joya (according to other sources, Zhiyoya) strengthened a card on a magnetic arrow, divided into 32 rumba, and placed the arrow on the tip of a hairpin. Grateful countrymen even erected a bronze monument to Joya in his homeland - in the city of Amalfi. But if someone really should have erected a monument, this is our compatriot Peter Peregrin. In his work “Message on Magnets”, dated 1269 and devoted to the description of the properties of a magnet, contains reliable information about his improvement of the compass. This compass did not have a card. A magnetic needle was fixed on the vertical hairpin, and the azimuthal circle on the top of the pot was divided into four parts, each of which was broken down in degrees from 0 to 90. A movable direction-finding sight was put on the azimuthal circle, using which it was possible to determine directions to coastal objects and luminaries that are not high above the horizon. This vizier was very similar to a modern direction finder, which still serves the Navy.
About a century and a half passed before a new invention appeared after Peregrine, which made it even easier to work with the compass.
The sea is very rarely calm, and any ship experiences pitching, and it, of course, negatively affects the compass. Sometimes the sea waves are so intense that they generally disable the compass. Therefore, there was a need for a device that would allow the compass bowler to remain calm with any pitching.
Like most brilliant inventions, the new compass suspension was extremely simple. The compass bowler, somewhat heavier from below, was suspended on two horizontal axles, supported by a ring. This ring, in turn, was mounted on two horizontal axles, perpendicular to the first, and hung inside the second ring, motionlessly fastened to the vessel. Thus, no matter how steeply and often the ship tilted, and in any direction, the card remained always horizontal. By the name of the Italian mathematician D. Cardano, who proposed this remarkable device, the suspension was called cardan.
The Portuguese also suggested dividing the compass rose into 32 rumba. They remained on the compass cards until our time. Each got its own name, and relatively recently, about fifty years ago, one could find somewhere in the cockpit of a sailor who crammed a compass with shadows: “Nord Nord shadow Ost, Nord Nord Ost, Nord Ost shadow Ost, Nord Ost, Nord Ost shadow Zuyd ”and so on. Shadow in this case in Russian means: aside. Now, although all 32 rumba remained on many modern compasses, divisions in degrees (and sometimes in fractions of a degree) were added to them. And nowadays, when reporting the course that the helmsman needs to keep, they prefer to say, for example: “Course 327 °!” (instead of the previous “Nord West shadow Nord”, which is essentially the same thing - the difference of 1/4 ° is rounded).
Since the magnetic compass acquired its modern design in the 19th century, it has improved very little. But then the idea of \u200b\u200bterrestrial magnetism and of magnetism in general has advanced far. This led to a number of new discoveries and inventions, which, if the compass itself is not touched, are directly related to navigation.
The more complicated the tasks that fell on the military and merchant (commercial) fleets, the greater the requirements for compass readings made by sailors. The observations became more precise, and suddenly, completely unexpectedly for themselves, the sailors noticed that their main assistant, a compass, which they had trusted for so many centuries, very rarely gives the correct testimony. Any magnetic compass for two or three degrees, and sometimes much more, to put it mildly, lies. We noticed that in different places on Earth the compass errors are not the same, that over the years they increase at some points, decrease at others, and that the closer to the pole, the greater these errors.
But at the beginning of the 19th century, science came to the aid of sailors and in the middle of it coped with this disaster. The German scientist Karl Gauss created the general theory of terrestrial magnetism. Hundreds of thousands of accurate measurements were taken, and now on all navigational charts, the deviation of the compass needle from the true meridian (the so-called declination) is indicated directly on the map with an accuracy of a quarter of a degree. It also indicates to which year the declination, sign and magnitude of its annual change are given.
Navigators increased their work - now it became necessary to calculate the correction for the change in declination. This was true only for mid-latitudes. At high latitudes, that is, in areas from 70 ° north and south latitudes to the poles, the magnetic compass could not be trusted at all. The fact is that in these latitudes there are very large anomalies of magnetic declination, since the proximity of the magnetic poles, which do not coincide with the geographical ones, affects. The magnetic needle tends to occupy a vertical position here. In this case, science does not help, and the compass lies without a twinge of conscience, and sometimes it starts to change its testimony all the time. Not without reason, going to the North Pole on airplanes (1925), the famous Amundsen did not dare to trust the magnetic compass and came up with a special device, which was called the solar course indicator. In it, the exact clock turned a small mirror after the sun, and while the plane flew above the clouds without deviating from the course, the “bunny” did not change its position.
But the misadventures of the magnetic compass did not end there. Shipbuilding developed rapidly. At the beginning of the 19th century, steamboats appeared, followed by metal ships. Iron ships quickly began to displace wooden ones, and suddenly ... One after another, under mysterious circumstances, several large steamers drowned. Analyzing the circumstances of the collapse of one of them, on which about 300 people died, experts found that the accident was caused by incorrect readings of magnetic compasses.
Scientists and sailors gathered in England to figure out what was going on. And they came to the conclusion that ship iron affects the compass so much that errors in its readings are simply inevitable. The doctor of theology Scorsby, who was once a well-known captain, who spoke at this meeting, showed the experience of the effect of iron on the needle of the magnetic compass and concluded: the greater the mass of iron, the more it deflects the needle of the compass from the meridian. “We,” said Scorsby, “are sailing in the old fashioned way, as on wooden ships, that is, without taking into account the influence of ship iron on the compass. I’m afraid that it will never be possible to get the compass on the steel ship ... ”The deviation of the needle of the magnetic compass under the influence of ship iron was called deviation.
Opponents of iron shipbuilding cheered up. But this time, science came to the aid of the magnetic compass. Scientists have found a way to minimize this deviation by placing special annihilating magnets next to the magnetic compass. The leadership in this, of course, belongs to Captain Matthew Flinders, by whose name the first destroyer - the Flindersbar is named. They began to place them in binnacles next to the compass pot.
Formerly, a wooden box was called binnacle, in which a compass was placed with a lantern at night. English sailors called him that: a night house - night house. Nowadays, binnacle is a wooden four- or six-sided cabinet, on which a compass bowler is installed. To the left and right of it on the binnacle are massive iron balls the size of a small melon. They can be moved and secured closer and away from the compass. A whole set of magnets is hidden inside the cabinet, which can also be moved and secured. Changing the mutual arrangement of these balls and magnets almost completely destroys the deviation.
Now, before embarking on a flight, when the cargo has already been loaded and secured, the deviator rises to the ship and in the designated area of \u200b\u200bthe sea, an hour and a half carries out the destruction of the deviation. According to his commands, the ship moves at different speeds, and the deviator moves balls and magnets, reducing the effect of ship iron on the compass. Departing, he leaves a small table of residual deviation, which navigators have to consider every time the ship changes course, as a correction for deviation. Recall Jules Verne’s novel “The Fifteen Years Captain,” where the villain Negoro planted an ax under the binnacle of the compass, dramatically changing his testimony. As a result, the ship instead of America sailed to Africa.
The need to periodically destroy and determine the residual deviation made me think about the problem of creating a non-magnetic compass. By the beginning of the 20th century, the properties of the gyroscope were well studied, and on this basis a gyroscopic compass was constructed. The principle of operation of the gyrocompass created by the German scientist Anschutz consists in the fact that the axis of a rapidly rotating top maintains its position in space unchanged and can be installed along the north-south line. Modern gyrocompasses are enclosed in a hermetically sealed sphere (hydrosphere), which, in turn, is placed in an external housing. The hydrosphere floats in suspension in a liquid. Its position is regulated using an electromagnetic blast coil. The electric motor brings the speed of rotation of the gyroscopes to 20 thousand revolutions per minute.
To ensure comfortable working conditions, the gyrocompass (the main device) is placed in the most peaceful place of the ship (closer to its center of gravity). With the help of electric cables, the gyrocompass readings are transmitted to repeaters located on the wings of the bridge, in the central post, in the navigational cabin and other rooms where necessary.
Today, the industry produces various types of these devices. Using them is not particularly difficult. Corrections to their indications are usually instrumental. They are small and permanent. But the devices themselves are complex and require qualified specialists for their service. There are other difficulties in operation. The gyrocompass must be turned on in advance, before going out to sea, so that he can, as the sailors say, "come to the meridian." Needless to say, the gyrocompass provides an incomparably higher accuracy of heading and stability at high latitudes, but the credibility of the magnetic compass has not decreased at all. The fighting of the fleet during the Great Patriotic War showed that it is still necessary on ships. In July 1943, during a military operation, the gyrocompass on the destroyer Soobrazitelny was out of order. The navigator switched to a magnetic compass and at night, in stormy weather, out of sight of the coasts, having traveled about 180 miles (333 kilometers), he reached the base with a residual of 55 cable (10.2 kilometers). The Kharkov destroyer leader who participated in the same operation, under the same conditions, but with a working gyrocompass, had a misclosure of 35 cable (6.5 kilometers). In August of the same year, due to a fire on board, the gyrocompass on the gunboat Krasny Adzharistan was out of order. The navigator of the ship during the war successfully conducted accurate laying, using only magnetic compasses.
That is why even today, even on the most modern ships equipped with navigation systems, radio engineering and space systems, incorporating several direction indicators, which are independent of either deviation or declination, there is always a magnetic compass.
But no matter how accurately we measure the course, you can graphically plot it only on the map. The map is a planar model of the globe. Sailors use only specially made, so-called navigational charts, the distances at which are measured in miles. To understand how such maps were created, you will have to look into the 15th century, in those distant times when people just learned how to put land and sea on them and swim using them. There were, of course, cards before. But they were more like inept drawings made by eye, from memory. There were also maps based on the scientific ideas of their time, pretty accurately depicting the shores and the sea known to sailors. Of course, there were a lot of mistakes in these maps, and they were not built in the same way as maps are built in our time, but nevertheless they were of help to sailors who set sail on seas and oceans.
It was a time full of contradictions. On the one hand, “experienced people” vowed that they had met horrible monsters in the ocean, huge sea snakes, beautiful sirens and other wonders, and on the other, great geographical discoveries were made one after another. On the one hand, the Holy Inquisition choked every living thought, and on the other, many enlightened people already knew about the spherical shape of the Earth, argued about what the size of the globe was, had an idea of \u200b\u200blatitude and longitude. Moreover, it is known that in the very year 1492, when Christopher Columbus discovered America, the German geographer and traveler Martin Beheim already built a globe. Of course, he was not at all like modern globes. On the Beheim globe and later, more perfect models of the Earth, there were more white spots than the continents accurately shown, many lands and shores were depicted according to the stories of "experienced people" who it was dangerous to take a word. Some continents were absent on the first globes. But the main thing was already - in a large circle perpendicular to the axis of rotation, the Earth was surrounded by the equator, which in Latin means the equalizer.
The plane in which it lies, as it were, divides the globe in half and equalizes its halves. The equatorial circumference from the point taken as zero was divided into 360 ° longitudes - 180 ° east and west. To the south and north of the equator on the globe to the poles, small circles were drawn parallel to the equator. They were called parallels, and the equator began to serve as a reference point of geographical latitude. The meridian arcs perpendicular to the equator in the Northern and Southern hemispheres converged at an angle to each other at the poles. In Latin, the meridian means "midday". This name, of course, is not accidental, it shows that on the entire line of the meridian, from pole to pole, noon (however, as at any other moment) occurs simultaneously. From the equator to the north and south, the meridian arcs were divided into degrees - from 0 to 90, calling degrees north and south latitude, respectively.
Now, to find a point on a map or globe, it was enough to indicate its latitude and longitude in degrees.
A geographic coordinate grid was finally built.
But it’s one thing to find a point on the map and quite another to find it in the open sea. Imperfect maps, a magnetic compass, and a primitive goniometer for determining vertical angles - that’s all that a sailor had to go on a long voyage. With an arsenal of even such navigational instruments, coming to a point that is within sight or even beyond the horizon is a simple matter. Unless, of course, the peaks of the distant mountains located at this point were visible above the horizon. But as soon as the sailor retreated to the sea further away, the coast disappeared from sight and uniform waves surrounded the vessel from all sides. Even if the seafarer knew the exact direction that should lead him to the goal, then it was difficult to count on success, since capricious winds and unexplored currents always take the ship off the intended course. This deviation from the course, sailors call drift.
But even in the absence of drift, it is almost impossible to select the desired direction using a regular map and navigate the vessel along it. And that's why. Suppose that, armed with an ordinary map and a compass, we planned to sail out of sight of the coast from point A to point B. Connect these points with a straight line. Suppose now that this line at point A lies exactly at the 45 ° course. In other words, the AB line at point A will be located at an angle of 45 ° to the plane of the meridian passing through point A. This direction is easy to keep with the compass. And we would come to point B, but on one condition: if the meridians were parallel and our course line at point B would correspond to the direction of 45 °, as at point A. But the thing is that the meridians are not parallel, but gradually converge at an angle to each other. So, the course at point B will not be 45 °, but somewhat less. Thus, in order to come from point A to point B, we would have to turn right all the time.
If, having left point A, we will constantly keep the course on our map 45 °, then point B will remain to our right, we, continuing along this course, will cross all the meridians at the same angle and approach the end in a complex spiral ends to the pole.
This spiral is called loxodrome. In Greek, it means "oblique path." You can always pick up such a loxodrome that will lead us anywhere. 14, using an ordinary map, would have to do a lot of complex calculations and constructions. This is what the sailors did not like. For decades, they have been waiting for such a map, according to which it will be convenient to lay any courses and sail across any seas.
And in 1589, the famous mathematician and cartographer, the Flemish Gerard Merkator, came up with a map that finally satisfied the sailors and turned out to be so successful that so far no one has offered anything better. Sailors all over the world today use this card. This is what it is called: a Mercator map, or a map of an equiangular cylindrical Mercator projection.
The grounds laid in the construction of this map are brilliantly simple. It is impossible, of course, to restore the course of reasoning of G. Mercator, but suppose that he reasoned like this.
Suppose that all the meridians on the globe (which quite accurately conveys the relative position of the oceans, seas and land on Earth) are made of wire, and the parallels are made of elastic threads that are easily stretched (rubber did not know at that time). Bend the meridians so that they from arcs turn into parallel lines attached to the equator. The surface of the globe will turn into a cylinder of straight meridians crossed by stretched parallels. We cut this cylinder along one of the meridians and spread it on a plane. This will result in a geographical grid, but the meridians on this grid will not converge, like on a globe, at the points of the poles. In straight parallel lines they will go up and down from the equator, and parallels will cross them everywhere at the same right angle.
A round island at the equator, as it was round on the globe, will remain round on this map, in the middle latitudes the same island will significantly stretch in latitude, and in the region of the pole it will generally look like a long straight line. Mutual location of land, sea, configuration of continents, seas, oceans on such a map will change beyond recognition. After all, the meridians remained as they were, and the parallels stretched.
Swimming, guided by such a card, of course, was impossible, but it turned out to be fixable - it was only necessary to increase the distance between the parallels. But, of course, it’s not just to increase, but in exact accordance with how much the parallels were stretched during the transition, the expansion card. On a map constructed with the help of such a grid, the round island at the equator and in any other part of the map remained round. That's just, the closer it was to the pole, the more space it occupied on the map. In other words, the scale on such a map increased from the equator to the poles, but the outlines of the objects plotted on the map were obtained almost unchanged.
But how to take into account the change of scale to the poles? Of course, you can calculate the scale separately for each latitude. Only a very troublesome thing will be such a voyage, in which, after each movement to the north or south, you will have to make rather complicated calculations. But it turns out that one does not have to do such calculations on the Mercator map. The map is enclosed in a frame, on the vertical sides of which degrees and minutes of the meridian are plotted. At the equator they are shorter, and the closer to the pole, the longer. They use the frame like this: they take the distance to be measured, take it off with a pair of compasses, bring it to the part of the frame that is at the latitude of the measured section and look at how many minutes it fit into it. And since the minute and degree on such a map vary in magnitude depending on latitude, but in fact remain always the same, it was they who became the basis for choosing the linear measures by which sailors measured their way.
In France, there was a measure of its own - equal to 1/20 degrees of the meridian, which is 5537 meters. The British measured their sea roads with leagues, which also represent a fraction of a degree and are 4828 meters in size. But gradually, sailors all over the world agreed that it is most convenient to use for measuring distances at sea the magnitude of the arc corresponding to one angular minute of the meridian. So until now, sailors measure their paths and distances precisely with the minutes of the arc of the meridian. And in order to give this measure a name similar to the names of other travel measures, they dubbed the meridian minute a mile. Its length is 1852 meters.
The word "mile" is non-Russian, so let's look at the "Dictionary of foreign words." It says that the word is English. Then it is reported that the miles are different: a geographical mile (7420 m), land miles are different in size in different states, and finally, a nautical mile is 1852.3 meters.
Everything is correctly said about the mile, except for the English origin of the word; it is actually Latin. In ancient books, the mile was met quite often and meant a thousand double steps. From Rome, and not from England, this word first came to us. So there is a mistake in the dictionary. But this mistake can be understood and forgiven, since the compiler of the dictionary article had, of course, in mind the international sea, or, as the English call it, the Admiralty mile. In Peter's times, she came to us from England. We called it that - the English mile. Sometimes today it is called the same.
Using a mile is very convenient. Therefore, the sailors are not going to replace the mile with any other measure.
Having made his way on the line on the Mercator map, having calculated and remembering which course should be followed, a sailor can safely sail without thinking that his way, straight as an arrow, is not a straight line on the map, but just the same curve that was mentioned a little earlier is loxodrome.
This, of course, is not the shortest path between two points. But if these points are not very far from each other, then the sailors are not upset and put up with the fact that they will burn up excess fuel and spend extra time on the transition. But on this map, the loxodrome looks direct, which does not cost anything to build, and you can be sure that it will lead exactly where you need it. And if you have a big voyage, such as, for example, crossing over the ocean, in which the additional cost of the curvature of the path will result in a significant amount and time? In this case, the sailors learned to build another curve on the Mercator map — the orthodrome, which in Greek means the “direct path”. The orthodrome on the map coincides with the so-called large circle arc, which is the shortest distance between two points on the sea.
These two concepts poorly fit into the mind: the shortest distance and the arc standing nearby. With this, it is all the more difficult to reconcile if you look at the mercantile map: the orthodromy looks much longer than the loxodrome. If both curves are laid between two points on the Mercator map, the orthodromy will bend like a bow, and the loxodromia will stretch like a bowstring that pulls its ends together. But one must not forget that ships sail not on a flat map, but on the surface of the ball. And on the surface of the ball, the segment of the arc of the big circle will be the shortest distance.
The unit of speed adopted in navigation is closely related to the unit of measurement of distances in the sea — a mile — a knot, which we will discuss later.
If on the course line laid on the map, periodically postpone the distance traveled by the ship, the skipper will always know where his ship is, that is, the coordinates of its place in the sea. This method of determining coordinates is called dead reckoning and is widely used in navigational laying. But a prerequisite for this is the ability to determine the speed of the ship and measure the time, only then can you calculate the distance traveled.
Ship speed indicators. 2. Vials. 2. The log is manual. 3. Log mechanical
We have already said that on the ships of the sailing fleet an hourglass was used for measuring time, designed for half an hour (bottles), one hour and four hours (shift). But there were also another hourglass on the ships - phials. In total, this watch was designed for half a minute, and in some cases even for fifteen seconds. One can only be surprised at the art of glassblowers, who managed to make such instruments, exact at that time. No matter how small this watch is, no matter how short the time interval that they measured, the service that the watch rendered to sailors at one time is invaluable, and they, like the bottles, are remembered every time they talk about determining the speed of a ship , as well as when measuring the distance traveled.
The problem of determining the distance traveled and the upcoming path has always stood and is facing seamen.
The first methods of measuring speed were perhaps the most primitive of the navigational definitions: they simply threw a piece of wood, bark, a bird's feather, or other floating object from the bow of the ship and simultaneously noticed the time. Walking along the side from the bow to the stern of the ship, the floating object was not let out of the eyes, and when he passed through the stern section, they again noticed the time. Knowing the length of the ship and the time during which the subject passed it, the speed was calculated. And knowing the total travel time, they made an approximate idea of \u200b\u200bthe distance traveled.
On sailing ships with very weak winds, this ancient method determines the speed of the ship today. But already in the XVI century the first lag appeared. From a thick board, a sector of degrees was made in 65-70, with a radius of about 60-70 centimeters. As a rule, the lead load in the form of a strip was designed along the arc that bounds the sector, so that the sector thrown into the water would sink two-thirds and a small corner remained visible above the water. A thin, sturdy cable called the laglin was attached to the top of this corner. In a sector close to the geometric center of the submerged part, a conic hole of 1.5-2 centimeters in diameter was drilled and a wooden cork was tightly fitted to it, to which the laglin was firmly tied eight to ten centimeters from the end attached to the corner of the lag. This cork was fairly firmly held in the hole of the submerged lag, but it could be pulled out with a sharp jerk.
Why is it so difficult to attach the laglin to the lag sector? The fact is that a plane body moving in a liquid medium is perpendicular to the direction of motion if the force moving this body is applied to its center of sail (similar to a kite). However, it is necessary to transfer the point of application of forces to the edge of this body or to its corner, and it, like a flag, will be located parallel to the direction of movement.
So the lag, when thrown overboard a moving vessel, is held perpendicular to the direction of its movement, since the laglin is attached to the cork, standing in the center of the sail plane of the sector. When the vessel moves, the sector experiences a lot of water resistance. But it’s worth jerking the laglin sharply, as the cork pops out of the nest, the point of application of force is transferred to the corner of the sector, and it begins to plan to glide over the surface of the water. He practically does not feel resistance, and in this form it was not difficult to pull the sector out of the water.
Short skerts (thin tips) were woven into the laglin at a distance of about 15 meters from each other (more precisely, 14.4 m), on which one, two, three, four and so on knots were tied. Sometimes the segments between two adjacent skers were also called nodes. Laglin, along with the skerts, wound around a small view (such as a coil), which was convenient to hold in hands.
Two sailors stood at the stern of the ship. One of them threw a lag sector overboard and held a view in his hands. Lag, falling into the water, rested and reeled up the laglin from the view after the going ship. The sailor, having lifted the view above his head, carefully watched the laglin sliding from the view and, as soon as the first skitter came close to the edge of the stern section, he shouted: “Tovs!” (it means "Get ready!"). And almost after that: “Vertie!” ("Flip!").
The second sailor held in his hands bottles for 30 seconds, but the team of the first turned them over and, when all the sand was poured into the lower tank, shouted: “Stop!”
The first sailor jerked the laglin sharply, a wooden cork popped out of the hole, the lag sector lay flat on the water and stopped wrapping the laglin.
Noticing how many little nodules went overboard while winding the laglin, the sailor determined the speed of the ship in miles per hour. It was not difficult to do this: the Skerts were woven into the laglin at a distance of 1/120 miles, and the clock showed 30 seconds, that is, 1/120 hours. Consequently, how many knots of the laglin wound from the view in half a minute, so many miles the ship passed in an hour. From here came the expression: “The ship is sailing at the speed of so many knots” or “The ship is making so many knots.” Thus, a knot at sea is not a linear track measure, but a measure of speed. This must be firmly grasped, because, speaking of speed, we are so used to adding “per hour”, which happens to be read in the most authoritative editions of “knots per hour”. This, of course, is wrong, for the knot is the mile / hour.
Now nobody uses the manual lag. More M.V. Lomonosov in his work "On the greater accuracy of the sea route" proposed a mechanical lag. Described by M.V. The Lomonosov log consisted of a turntable similar to a large cigar along which wings-blades were located at an angle to the axis, as on the rotor of a modern hydraulic turbine. A pinwheel tied into a laglin made of a cable that barely twisted, M.V. Lomonosov suggested lowering the stern of a marching vessel. Naturally, it rotated faster, the faster the course of this ship was. The front end of the laglin was proposed to be tied to the shaft of a mechanical counter, which was supposed to be mounted at the stern of the ship and count the miles passed.
Lomonosov suggested, described, but did not have time to build and test his mechanical lag. Already after him several inventors of the mechanical lag appeared: Walker, Messon, Clintock and others. Their lags are somewhat different from each other, but the principle of their work is the same as that proposed by M.V. Lomonosov.
More recently, as soon as a ship or ship went to sea, a navigator and a sailor carried a lag spinner, laglin and counter, which was usually called a typewriter, onto the upper deck. The turntable with the laglin was thrown overboard, and the typewriter was mounted on the feed slider, and the navigator wrote off the indications that appeared on her dial at the time the work started. At any moment, looking at the dial of such a lag, one could find out quite accurately about the path traveled by the ship. There are lags that simultaneously show speed in nodes.
Nowadays, many ships have more advanced and accurate lags. Their action is based on the property of water and any other liquid to exert pressure on an object moving in it, increasing as the speed of movement of this object increases. A not-so-complicated electronic device transfers this pressure (dynamic water pressure) to a device installed on a bridge or at the navigational command post of the ship, first, of course, converting this value into miles and knots.
These are the so-called hydrodynamic logs. There are more advanced lags for determining the speed of the vessel relative to the seabed, that is, the absolute speed. Such a lag works on the principle of a sonar station and is called sonar.
In conclusion, we say that the word lag comes from the Dutch log, which means distance.
So, having got a compass, a navigation map and units of distance and speed — a mile and a knot at your disposal, the navigator can safely conduct a navigation pad, periodically marking on the map the distances traveled by the ship. But the presence of the countable coordinates of their place in the sea does not at all reject the observables, that is, determined by the instrumental method according to celestial bodies, radio beacons, or along coastal landmarks mapped, but, on the contrary, necessarily means them. The difference between the numbered coordinates and the observed ones is called a residual by the sailors. The smaller the residual, the more skillful the navigator. When swimming in coastal visibility, it is best to determine the observable place by lighthouses, which are clearly visible during the day and emit light at night.
There are few in the world of engineering structures, about which there are so many legends and legends, as about lighthouses. Already in the poem "Odyssey" by the ancient Greek poet Homer, dating from the VIII-VII centuries BC, it is said that the inhabitants of Ithaki lit fires so that the expected home Odysseus could recognize its native harbor.
Suddenly on the tenth day appeared to us
coast of the homeland.
Howling he is already close; there are all the lights on it
so we could discern.
This is, in fact, the first mention of the use by sailors of the fires of ordinary bonfires for navigational purposes when sailing near the coast at night.
Centuries have passed since those days before the lighthouses acquired a familiar look for everyone - a high tower crowned with a lantern. And once the resin barrels or braziers with coal, which served as the first lighthouses, glowed directly on the ground or. on high poles. Over time, to increase the range of visibility of light sources, they were installed on artificial structures, which sometimes reached enormous sizes. The most venerable age are the lighthouses of the Mediterranean Sea.
One of the seven wonders of the ancient world is the Lighthouse of Alexandria, or Faros, a height of 143 meters, built of white marble in 283 BC. The construction of this highest building of antiquity lasted 20 years. A huge and massive lighthouse, surrounded by a spiraling staircase, served as a guiding light for sailors, showing them the way during the day with smoke from the oil burned at its top, and at night with the help of fire, as the ancients said, "more brilliant and unquenchable than stars." Thanks to a special light reflection system, the range of visibility of the fire on a clear night reached 20 miles. The lighthouse was built on the island of Faros at the entrance to the Egyptian port of Alexandria and served as both an observation post, a fortress and a weather station.
Equally famous in antiquity was the famous Colossus of Rhodes - a giant bronze figure of Helios, the god of the Sun, established on the island of Rhodes in the Aegean Sea in 280 BC. Its construction lasted 12 years. This statue, also considered one of the seven wonders of the world, 32 meters high, stood in the Rhodes harbor and served as a beacon until it was destroyed by an earthquake in 224 BC. e.
In addition to these lighthouses, about 20 were known at that time. Today, only one of them has survived - the lighthouse tower near the Spanish port city of A Coruña. It is possible that this lighthouse was built by the Phoenicians. During his long life, he was repeatedly updated by the Romans, but on the whole he retained his original appearance.
The construction of lighthouses developed extremely slowly, and by the beginning of the 19th century there were no more than a hundred of them on all the seas and oceans of the globe. This is due primarily to the fact that it was in those places where the lighthouses were most needed, their construction turned out to be very expensive and time-consuming.
The light sources of the lighthouses were continuously improved. In the XVII-XVIII centuries, several dozen candles weighing 2-3 pounds each (about 0.9-1.4 kg) burned in the lanterns of the lighthouses. In 1784, Argand oil lamps appeared, in which the wick received oil under constant pressure, the flame stopped smoking and became brighter. At the beginning of the 19th century, gas lighting was installed on the lighthouses. At the end of 1858, electric lighting equipment appeared on the Upperford Lighthouse (English Channel).
In Russia, the first lighthouses were built in 1,702 at the mouth of the Don and in 1704 at the Peter and Paul Fortress in St. Petersburg. The construction of the oldest lighthouse in the Baltic - Tolbukhin near Kronstadt - lasted almost 100 years. The building began to be built on the orders of Peter I. His own sketch was preserved, indicating the main dimensions of the tower and the postscript: "The rest will be given to the will of the architect." The construction of a stone building required significant funds and a large number of skilled masons. The construction was delayed, and the king ordered the urgent construction of a temporary wooden tower. His order was creeped out young, and in 1719 on the Kotlin lighthouse (the name comes from the spit on which it was installed), a light flashed. In 1736, another attempt was made to erect a stone building, but it was only possible to finish it in 1810. The project was developed with the participation of a talented Russian architect AD. Zakharov, the creator of the building of the Main Admiralty in St. Petersburg. Since 1736, the lighthouse bears the name of Colonel Fedor Semenovich Tolbukhin, who defeated the Swedish naval assault on the Kotlinskaya Spit in 1705, and then the military commandant of Kronstadt
The oldest lighthouses of the world. 1, 2. Ancient lighthouses with open fire. 3. Faros (Alexandria) lighthouse. 4. La Coruña Lighthouse
Dozens of generations of Russian sailors know the round, low, thick-set tower of the Tolbukhin lighthouse. In the early 70s of the XX century, the lighthouse was reconstructed. The coast around the artificial island was reinforced with reinforced concrete slabs. The tower is now equipped with modern optical equipment, which allows to increase the range of visibility of fire, and the country's first automatic wind power station, ensuring its uninterrupted operation.
In 1724, the Kern lighthouse (Koksher) on the island of the same name began to operate in the Gulf of Finland. By the beginning of the 19th century, 15 lighthouses operated on the Baltic Sea. These are the oldest lighthouses in Russia. Their service life exceeds 260 and more years, and the Kypu lighthouse on the island of Dago has existed for more than 445 years.
At some of these facilities for the first time a new lighthouse technique was introduced. So, on Keri, who turned 250 in 1974, in 1803 an octagonal lamp was installed with oil lamps and copper reflectors -? Russia's first light-optical system. In 1858, this lighthouse was equipped (also the first in Russia) with a Fresnel lighting system (named after the inventor of the French physicist Augustin Jean Fresnel). This system was an optical device, consisting of two flat mirrors (bizzerkals) located at a small (in a few angular minutes) angle to each other.
Thus, Keri twice became the ancestor of various lighting systems: the capric - mirror reflective system, and the diopter - a system based on the refraction of light when passing through separate refractive surfaces. The transition to these optical systems has greatly improved the quality characteristics of the lighthouse and increased the efficiency of ensuring navigation safety.
The role of lighthouses was also played by the famous 34-m Rostra columns, built in 1806 to commemorate Russia's glorious victories at sea. They indicated the branching of the Neva into the Big and Small Neva and were installed on both sides of the Spit of Vasilyevsky Island.
One of the oldest lighthouses on the Black Sea is Tarkhankutsky with a tower 30 meters high. It went into operation on June 16, 1817. On one of the buildings of the lighthouse the words are inscribed: “Lighthouses - the shrine of the seas. They belong to everyone and are inviolable, like ambassadors of powers. ” Today its white fire is visible for 17 miles. In addition, it is equipped with a beacon and an audible alarm.
In 1843, at the very end of the Quarantine pier in the Odessa Gulf, a firehouse with a mast was set up, on which two oil lamps were lifted using a winch. Thus, this year should be considered the year of birth of the Vorontsov lighthouse. However, the real lighthouse on the Quarantine jetty was opened only in 1863. This is a 30-foot (over 9 m) cast-iron tower crowned with a special lantern.
In 1867, the Odessa lighthouse became the first in Russia and the fourth in the world, converted to electric lighting. In general, the transition to a new source of energy was extremely slow. In 1883, of the five thousand lighthouses of the globe, only 14 were with electric light sources. The rest also worked on kerosene, acetylene and gas lamps and burners.
After the raid pier was significantly extended, in 1888 a new Vorontsov lighthouse was built, which stood until 1941. It was a cast-iron tower 17 meters high. In the days of the defense of Odessa, the lighthouse had to explode. But it is he who is depicted on the medal "For the Defense of Odessa". The new lighthouse, the one that we see today, was built in early 1954. The tower, which has a cylindrical shape, has become much higher - 30 meters, not counting the 12-meter base. In a small house, on the second pier, a remote control for all mechanisms is mounted. A strict white tower, standing on the very edge of the raid breakwater, is depicted on stamps and postcards and has become one of the symbols of the city.
By 1917, 163 light beacons were built on all the seas of Russia. The most underdeveloped network of lighthouses was the seas of the Far East (only 24 with a coast length of several thousand kilometers). On the Sea of \u200b\u200bOkhotsk, for example, there was only one lighthouse - Elizabeth (on Sakhalin Island), on the Pacific coast as well, one - Peter and Paul on the approach to the port of Petropavlovsk-Kamchatsky.
During the war, a significant part of the lighthouses was destroyed. Of the 69 lighthouses on the Black and Azov Seas, 42 were completely destroyed, of 45 on the Baltic Sea - 16. In total, 69 lighthouse towers, 12 radio beacons, 20 sound-signal installations and more than a hundred luminous navigation signs were destroyed. Almost all the preserved objects of the navigation equipment were in unsatisfactory condition. Therefore, after the end of the war, the Navy's Hydrographic Service began restoration work. According to data as of January 1, 1987, 527 light beacons operated on the seas of our country, 174 of them on the seas of the Far East, 83 on the Barents and White Seas, 30 on the coast of the Arctic Ocean and 240 on other seas.
In early 1982, the lights of another Far Eastern lighthouse - Eastern Dum - lit up on the coast of the Sea of \u200b\u200bOkhotsk. In a desert area between Okhotsk and Magadan, a 34-meter red cast-iron tower rose on the hillside.
In 1970, the construction of a stationary lighthouse in the Gulf of Tallinn ended 26 kilometers northwest of the port of Tallinn (Estonia).
Modern decoys. 1. Sandy Lighthouse (Caspian Sea). 2. Chibuyiy Lighthouse (Shumshu Island). 3. Lighthouse Front Sivers (Black Sea). 4. Lighthouse Piltun (Sakhalin Island). 5. Lighthouse Šventoj (Baltic Sea). 6. Tallia Lighthouse
Lighthouse Tallinn was the first automatic lighthouse in the USSR, all of which systems are powered by atomic isotopes. The lighthouse is installed at a depth of 7.5-10.5 meters in the area of \u200b\u200bthe Tallinmadal Bank on a hydraulic base (a stone bed with a diameter of 64 meters and a reinforced concrete conical giant with a base diameter of 26 meters). The conical shape of the base (45 °) significantly reduces ice loads on the structure. A lighthouse guards the bank and provides access to the port. A reinforced concrete monolithic cylindrical lighthouse tower with a height of 24.4 meters ends with a glazed circular steel lantern structure. The total height of the lighthouse from sea level is 31.2 meters, from the bottom - 41 meters. The tower is lined with cast-iron tubing, painted in black (lower broadened part), orange (middle part) and white (upper part). It has eight floors, in which technical and service rooms are located (isotope power plant - on the ground floor). The light-optical apparatus provides a range of white light for 28 kilometers. The Tallinn lighthouse is equipped with a radio beacon with a range of 55 kilometers, a transponder radar beacon and telecontrol system equipment with all the lighthouse navigation aids. At a height of 24.2 meters, a heavy bronze memorial plaque was installed on which the names of destroyers, patrol ships, submarines and auxiliary vessels were cast — a total of 72 ships that died during the Great Patriotic War in the Tallinn area.
Lighthouses like Tallinn do not need maintenance personnel. Therefore, at present, a course has been taken on the construction of just such lighthouses.
Among the lighthouses built and put into operation in recent years, a special place belongs to the automatic lighthouse Irbensky. It is built on the high seas on a hydraulic basis. All technical means of the lighthouse work automatically. The lighthouse is equipped with a helipad.
A significant place in navigation equipment, especially recently, was taken up by pulsed lighting equipment, with the introduction of which there is no need for complex optical systems. Impulse lighting systems with tremendous luminous intensity are especially effective on highly lit backgrounds of ports and cities.
To warn of dangerous places located offshore, or as reception rooms when approaching the ports, floating beacons are used, which are ships of a special design, anchored and equipped with lighthouse equipment.
To confidently identify lighthouses during the day, they are given a different architectural form and color. At night, and in conditions of poor visibility, ship crews are helped by the fact that each of the lighthouses is assigned radio and acoustic signals of a certain nature, as well as lights of various colors - all these are code elements by which sailors determine the "name" of the lighthouse.
Each ship or vessel has a guide “Lights and Signs”, which contains information about the type of construction of each lighthouse and its color, the height of its tower, the height of the fire above sea level, the nature (constant, flashing, dimming) and the color of the lighthouse. In addition, data on all means of navigational equipment of the seas are entered in the corresponding directions and indicated on the navigation charts at their locations.
The range of luminous beacons is 20-50 kilometers, radio beacons are 30-500 or more, lighthouses with airborne acoustic signals - from 5 to 15, with hydroacoustic signals - up to 25 kilometers. Acoustic air signals are now given by nautophones - howlers, and earlier on the lighthouses a bell buzzed, warning about a dangerous place - about shallows, reefs and other navigational dangers.
Now it’s hard to imagine sailing without lighthouses. To turn off their light is like somehow removing the stars from the horizon, used by sailors to determine the ship’s position in an astronomical way.
The choice of places, installation, and provision of continuous operation of the lighthouse are carried out by people of a specialty - hydrographs. In wartime, their work is of particular importance. When the ships of the Black Sea Fleet and the ships that were part of the Azov Flotilla and the Kerch Naval Base started landing on the north-eastern coast of the Kerch Peninsula on the morning of December 26, 1941, well-organized hydrographic support contributed to the successful operations. On the eve of the landing, the targets were equipped with two luminous portable buoys near the coast on the approaches to Feodosia, as well as landmark lights, including on the rock of Elchan Kaya.
In the dead of night on December 26, lieutenants Dmitry Vyzhull and Vladimir Mospan secretly landed from the Shch-203 submarine, reached a icy cliff on a rubber boat, with great difficulty climbed up to the top with equipment and installed an acetylene lamp there. This fire reliably ensured the approach of our ships with landing to the shore, and was also a good guide for landing ships approaching Feodosia. The submarine from which the daredevils landed was forced to move away from the cliff and dive due to the appearance of an enemy aircraft. At the appointed time, the boat did not approach the meeting point with the hydrographs, and their search, made a little later, ended in failure. The names of Lieutenants Dmitry Gerasimovich Vyzhull and Vladimir Efimovich Mospan are listed on the memorial plaque of the dead, installed in the building of the Hydrographic Department of the Black Sea Fleet, their photos are placed on the stand of hydrographs who died during the Great Patriotic War, in the Main Directorate of Navigation and Oceanography.
During the heroic defense of Sevastopol, the Kherson lighthouse under continuous bombardment and shelling continued to operate, providing entry and exit of ships.
During the third assault on the city, June 2 - July 4, 1942, attacks on Chersonese were attacked by more than 60 enemy bombers. All residential and office premises of the lighthouse were destroyed, the optics were broken.
The head of the lighthouse, who gave the fleet more than 50 years of his life, Andrei Ilyich Dudar, despite being seriously wounded, remained at the military post until the end. Here are the lines from the application for assigning the name of the passenger ship “Andrey Dudar”: “... the hereditary sailor of the Black Sea Fleet - his grandfather was a member of the first defense of Sevastopol, his father served as a keeper of the Kherson lighthouse for 30 years. Andrey Ilyich was born at the lighthouse, served as a sailor on the destroyer destroyer Kerch. At the end of the Civil War, he worked to restore the fleet. He began the Great Patriotic War as the head of the lighthouse ... ”Work on the lighthouse requires special hardening of people. The life of lighthouses cannot be called arranged, especially in winter. For the most part, this people is harsh, not spoiled.
The lighthouses have a surprisingly sharpened sense of duty and responsibility. Once, Alexander Blok wrote to his mother from the small port of Aberwrack in Brittany: “Recently, a guard died on one of the rotating lighthouses, before he had time to prepare the car for the evening. Then his wife made the children turn the car with their hands all night. For this she was given the Legion of Honor. ” The romantic American poet G. Longfellow, the author of a wonderful epic about the Indian folk hero “Song of Hiawatha”, wrote about the eternal connection of the lighthouse with the ship:
Like Prometheus, chained to a rock, Holding the light stolen from Zeus, Encountering a storm in the roaring darkness, He sends the sailors a hello: "Sail, majestic vessels!"
The ocean forced hydrographs to create a whole system of protection against marine dangers, which was improved along with navigation. It will develop and improve as long as the ocean and ships exist.
Thus, when sailing near the coast, lighthouses, mountain peaks, and some distinctive places on the coast have long served as reference points for sailors. Having determined the directions (bearings) for two or three such objects by compass, the sailors get a point on the map — the place where their ship is. But what if there are no conspicuous places or the shore has disappeared beyond the horizon? This circumstance has long been an insurmountable obstacle to the development of navigation. Even the invention of the compass - because it shows only the direction of movement of the vessel - did not solve the problem.
When it became known that it is possible to determine longitude by the chronometer, and latitude by the heights of the bodies, a reliable goniometer was needed to determine the heights.
Before the goniometer device, which suits sailors, sextants, and many other devices, its predecessors, appeared and confirmed its superiority, it was on ships. Perhaps the very first among them was the Sea Astrolabe - a bronze ring with divisions by degrees. Alidad (ruler) passed through the center, both halves of which were offset from each other. At the same time, the edge of one was a continuation of the opposite edge of the other, so that the ruler possibly more accurately passed through the center. There were two openings on the alidade: a large one for searching for a star, and a small one for fixing it. During measurements, she was held or hung by the ring.
Goniometer and chronometer. 1. Astrolabe. 2. The quadrant. 3. The chronometer. 4. Sextant
Such an instrument was suitable only for rough observations: it fluctuated not only during pitching and in windy weather, but also from a simple touch of the hands. Nevertheless, the very first distant voyages were made with a similar device.
Subsequently, the astronomical ring came into use. The ring also had to be suspended, but during measurements there was no need to touch it with his hands. A tiny sunbeam, penetrating through the hole on the inner surface of the ring, fell on a scale with divisions. But the astronomical ring was a primitive device.
Until the 18th century, Jacob’s staff, also known as the astronomical beam, arrow, golden rod, but most of all as a town rod, served as a navigation tool for measuring angles. It consisted of two rails. A movable transverse was mounted on a long rail perpendicular to it. On a long rail marked by degrees.
To measure the height of the star, the observer placed the long bar at one end near the eye, and moved the short one so that it touched the star with one end and the horizon line with the other. The same short bar could not serve to measure any stellar heights, therefore, several were attached to the device. Despite its imperfection, the town stock lasted about a hundred years, until the end of the 17th century, the famous English navigator John Davis offered his own quadrant. It consisted of two sectors with an arc of 65 and 25 ° with two movable diopters and one motionless in the common apex of the sectors. The observer, looking into the narrow slit of the eye diopter, designed the thread of the subject diopter on the object being sighted. After that, the counting was completed along the arcs of both sectors. But the quadrant was far from perfect. Standing on a swinging deck, combining the thread, the horizon and the bunny was not easy. In calm weather, it was possible, but on a wave of excitement, heights were measured very roughly. If the sun shone through the mist, its image on the diopter blurred, and the stars were completely invisible.
To measure the heights, a device was needed that would allow the luminosity to be combined with the horizon once and regardless of the motion of the ship and the position of the observer. The idea of \u200b\u200bconstructing such an instrument belongs to I. Newton (1699), but it was designed by J. Hadley in England and T. Godfrey in America (1730-1731) independently of each other. This marine goniometer had a scale (limb), which was one eighth of a circle, and therefore was called octane. In 1757, Captain Campell improved this navigation instrument, making a limb in one sixth of a circle, the device was called the sextant. They can measure angles up to 120 °. Sextan, like its predecessor, octane, belongs to a large group of instruments that use the principle of double reflection. By turning the large mirror of the device, it is possible to send the reflection of the star to a small mirror, to combine the edge of the reflected star, such as the sun, with the horizon line and at this moment take a count.
Over time, the sextant improved: an optical tube was put in, a number of color filters were introduced to protect the eyes from the bright sun during observations. But, despite the emergence of this perfect goniometric device and the fact that by the middle of the 19th century, naval astronomy had already become an independent science, the methods for determining coordinates were limited and inconvenient. The sailors were not able to determine latitude and longitude at any time of the day, although scientists have proposed a number of bulky and difficult mathematical formulas. These formulas have not received practical distribution. Latitude was usually determined only once a day - at true noon; in this case, the formulas were simplified, and the calculations themselves were minimized. The chronometer made it possible to determine longitude at any time of the day, but it was necessary to know the latitude of its place and the height of the sun. It was only in 1837 that the English captain Thomas Somner, thanks to a lucky accident, made a discovery that had a significant impact on the development of practical astronomy, he developed the rules for obtaining a line of equal heights, the laying of which on the map of the Mercator projection made it possible to get the observable place. These lines were called somner in honor of the captain who discovered them.
Having a sextant, a chronometer and a compass, the navigator can lead any ship, regardless of whether there are other, even the most modern navigation electronic systems on it. With these time-tested instruments, the sailor is free and independent of any vicissitudes in the open sea. The navigator, dismissive of the sextant, runs the risk of being in a difficult situation.
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Marine magnetic compass and other types of marine compasses
Magnetic compass - an indispensable component of navigation equipment
Magnetic compass - This is a navigation device that implements the physical principle of the ability of a magnetic needle to navigate along the Earth's magnetic lines, with which the ship's course is determined, as well as directions to objects directly observed by the skipper. Ideal magnetic compass indicates the north direction along the Earth’s magnetic meridian passing through the magnetic poles. Accuracy magnetic compasses decreases as you approach the magnetic poles.
When determining the direction of movement of the vessel, it is taken into account that the magnetic and geographical poles do not coincide, and the angle between the corresponding magnetic and true meridians, called magnetic declination, is nonzero. In addition, oscillations of the Earth’s magnetosphere and the intrinsic magnetic field of ships, in the construction of which magnets are present, contribute to the readings magnetic compass interference called deviation magnetic compass. Direction indicated magnetic compasscorresponds to the compass meridian, therefore the deviation of the magnetic compass is defined as the angle between the magnetic meridian and the compass. Magnetic declination and deviation are taken into account to determine the true course. magnetic compass.
The composition of the ship's magnetic compass:
- Cooking pot
- Binnacle
- Direction finder
- Deviation device
Bowler hat magnetic compass It is a cylindrical container of two parts located one below the other. The top one contains a card freely moving in a solution of ethyl alcohol - a non-magnetic disk with a scale and magnetic arrows, and the bottom one - compensates for changes in the volume of the compass liquid, depending on external causes, for example, ambient temperature. A gimbal compensates for ship roll.
Binnacle magnetic compass - in fact, a case with a protective cap, shock-absorbing suspension and backlight, there is also a deviation device inside it, the purpose of which is to “destroy” the deviation magnetic compass. However, even taking into account "destruction" in the calculation of the direction, the residual deviation, which changes as the vessel moves, is taken into account.
Direction finder magnetic compass defines angular directions to visible objects. Simplified direction finder consists of targets fixed on the base (eye and subject) and a deflector cup. The direction finder rotates relative to the azimuth circle. The target target has a hinged mirror to obtain the bearing of celestial objects.
Types of ship compasses:
Magnetic compass - not the only design option ship compass. Also manufacturers are offered gyro compasses (based on a gyroscope), indicating the direction of the true pole, not the magnetic one, and guaranteeing the accuracy of readings at high latitudes, but sensitive to the acceleration of the vessel; electronic compassesworking through data transfer interfaces, transferring information to a compatible ship equipment; satellite compasses - devices based on satellite positioning information - a common view ship compasses, offered by a large number of manufacturers and providing accuracy of measurements. Design type selection ship compass depends on the type of vessel and equipment, economic feasibility and welfare of the shipowner.
To choose and buy ship compass, you must either understand the industry, or contact the company "", whose engineers have implemented dozens of projects to equip ships of any type with all types of ship equipment, including magnetic compassestypical for small fleet.
On the pages of the catalog of the online store "" presented magnetic compasses world-class manufacturers, as well as Russian devices not inferior in quality. The company accepts orders to equip ships magnetic compasses global brands such as:
- Magnetic compasses purchased at Marinek», Tested by practice and time.
Market ship compasses wide, so when choosing a specific model it will be useful to listen to the opinion of engineers. When equipping your own vessel with equipment, remember that comfort on board is the result of the failure-free operation of all ship systems, including magnetic compass and other "little things", without which it is impossible to imagine a modern ship.
Marine compass
The marine compass works on the same principle as a regular tourist compass, where the needle always goes north-south.
The main difference between the two compasses is that in the marine compass there are several arrows attached to the bottom of the card so that when the arrows are tipped, the card is tilted with them, with the north mark coinciding with the north magnetic pole. This is done for the convenience of taking readings, since in the sea the card rotates more slowly than the arrow. In order to slow down the rotation even more, the compass case is filled with a liquid, usually a non-freezing alcohol mixture.
The globe is surrounded by a magnetic field. Since magnetic north and geographic north do not coincide, the magnetic compass does not indicate geographic north. The difference between geographic and magnetic north is called declination.
Internal compass with compass
Earth's magnetic field is best illustrated by an old school experience in which a magnet is placed under a sheet of metal filings. Sawdust lines up along magnetic lines emerging from the poles of a magnet.
If the arrow is placed in the Earth’s magnetic field, it will likewise occupy a position along the magnetic lines emerging from the poles. So, at any point on the globe, an unsecured arrow will occupy a position along the north-south line. The vessel can turn in any direction, but the card will always indicate the same direction.
On the compass hull there is a mark indicating the diametral (longitudinal) line of the vessel; the direction on the compass card that matches this mark indicates the compass direction in which the boat is moving. To control the compass, you need to turn the yacht until the desired direction on the compass card coincides with the diametric line.
Variation
The geographic north and south poles do not coincide with the magnetic poles, therefore, since all objects correspond to geographic poles on the maps, there is an error in all readings of magnetic compasses. It is called declination. This value changes when moving around the globe. The declination is a tabular quantity, its value for a particular area is indicated in the center of the compass image on the map of this place. Declination is defined as the difference between compass reading and geographic north due to terrestrial magnetism; it is eastern and western.
Deviation
There is another factor affecting the compass on board and causing errors. We are talking about the influence of the magnetic properties of the equipment of the boat itself on the compass needle, for example, steel parts of the motor and some electrical appliances. On wooden and fiberglass yachts this error is relatively small, but on a metal vessel it can be significant.
Small boat deviation map example
Deviation is defined as the deviation of the compass from the geographical north under the influence of the magnetic field of the ship itself; it also happens to be eastern and western.
Deviation varies depending on the direction of the boat, therefore it should be taken into account each time you change course. To determine the deviation, the yacht must be taken to an open place, then go in a circle through all points of the compass. The compass readings taken in each direction are compared with the true bearings indicated on the sea chart, the difference between them is recorded in a table called a deviation map (for an example of such a map, see the figure on the left). The data on this map indicate the deviation of any course that the vessel can follow, they are taken into account when taking all compass readings.
Head compass
To reduce the oscillations of the card and to facilitate the management of the vessel, most of the main compasses are covered with a convex glass filled with liquid, which softens any vibrations. It also keeps the level of the card unchanged when the yacht rolls.
Sometimes a professional tuner can reduce the deviation or reduce it to nothing, for this, correction magnets are placed around the compass in the cockpit. The main compass on the ship is regularly checked to make sure that the deviation remains constant. Typically, a boat is driven on the basis of its evidence. This compass is placed in the cockpit near the steering wheel or tiller.
Bearing compass
This is a small compass used to take bearings of coastal objects when determining the location of a boat. There are many varieties of such devices, but they all have one thing in common - portability, which makes it possible to determine bearings from anywhere on board where the coastal object is clearly visible. In the compass readings for bearings, the deviation is not taken into account, therefore, the results should be compared with the readings of the main compass at the point where the bearing is determined, because the deviation values \u200b\u200bcan vary at different places on board. Typically, the compass is held at eye level, while simultaneously using the sight to line up coastal objects in a single line before taking readings.
Compass error
Since each compass reading contains an error (magnetic declination and deviation), it must be adjusted before use for navigation. Two errors are combined and, after addition or subtraction, form the compass error:
East declination 5 ° + east deviation 2 ° \u003d compass error east 7 °
East declination 5 ° - west deviation 2 ° \u003d compass error east 3 °
This means that when the names of different parts of the world (north and south, west and east) correspond to navigation concepts, values \u200b\u200bwith the same names must be added, and subtracted with different names.
If the error is eastern, the compass reading will be less than true. If the error is western, the compass reading will be more than true.
Each compass reading contains an error, so it must be corrected to work with a map where only true values \u200b\u200bare used.
The course of the vessel plotted on the map is true (does not contain errors), therefore, before using it to control the vessel, it is necessary to move from it to a compass one.
Similarly, the bearing of a coastal object, taken with the help of a hand-held compass, must be converted to true before marking the map. You can get confused during the transition, so you need to perform it carefully.
The two examples below will facilitate understanding.
1. On the map, the course is plotted from point A to point B, its value (true) is 266 ° according to the compass’s card. The compass error is eastern and is 5 °. (Since the error is eastern, the compass reading will be less than true.) The steering wheel must be turned at the 26 G course (compass reading) to follow the 266 ° (true) course on the map.
2. The bearing of the coastal object, taken using a hand-held compass, is 266 °. Compass error east 5 °. The error is eastern, which means that the true bearing for laying on the map should be less than the compass. Bearing laid on the map will be equal to 261 °.
Electronic compasses
Most yacht owners still use traditional magnetic compasses, and on large ocean-going ships they prefer electronic compasses.
Various modifications are produced. There are gyro compasses, digital, laser compasses. Laser and gyrocompasses are very expensive, they are rarely found on cruisers. They are distinguished by one advantage: they have no error, that is, the compass reading is true, as on the map.
The more affordable digital compass is popular with many sailors, especially when crossing the ocean. It eliminates, or at least reduces deviation, the readings in numbers on its screen are read much easier than on an oscillating card of the magnetic compass. Conveniently, it can be combined with an autopilot device and instruments for measuring the strength and direction of the wind.
From the book All About Everything. Volume 1 author Likum ArkadyWho invented the compass? The simplest form of the compass is a magnetic needle mounted on a rod so that it can rotate freely in all directions. The arrow of such a so-called compass points to the "north", by which we mean the North magnetic pole
From the book of 100 great inventions the author Ryzhov Konstantin Vladislavovich21. COMPASS Compass, like paper, was invented by the Chinese in ancient times. In the III century BC Chinese philosopher Hen Fei-tzu described the device of a modern compass in this way: it looked like a pouring spoon from magnetite with a thin handle and a spherical, carefully
From the book Great Soviet Encyclopedia (AS) of the author TSB From the book Great Soviet Encyclopedia (AB) of the author TSB From the book Great Soviet Encyclopedia (GI) of the author TSB From the book Great Soviet Encyclopedia (GO) of the author TSB From the book Great Soviet Encyclopedia (KO) of the author TSB From the book The latest book of facts. Volume 1 [Astronomy and astrophysics. Geography and other earth sciences. Biology and medicine] the author From the book Chinese Art of Possession of the Sword. Tai chi jian guide by Yun Zhang From the book 3333 tricky questions and answers the author Kondrashov Anatoly Pavlovich31. The golden compass points to the south (jinzhen jinan) Compass is a device that indicates the right direction. This position indicates how to correctly complete the form; at the same time, this is an important part of practice. 31.1. Clasped hands, Sequence of movements, Bend your elbows,
From the book of 100 famous inventions the author Pristinsky Vladislav LeonidovichWhich ship belonged to the feed, keel, sails and compass, which became the constellations of the same name? The constellations of Korm, Kiel, Sail and Compass were formed in the XVIII century as a result of the "dismemberment" of the constellation of the Ship Argo by Abbe Lacaille. Described by Claudius Ptolemy in 150
From the book The latest book of facts. Volume 1. Astronomy and astrophysics. Geography and other earth sciences. Biology and medicine the author Kondrashov Anatoly Pavlovich From the book How to write in the XXI century? author Garber Natalia From the book Who is Who in the World of Discoveries and Inventions the author Sitnikov Vitaliy PavlovichProfessional reading as a source and compass of your work. If you want to be a writer, you first need to do two things: read a lot and write a lot. Each book you take in your hands gives a lesson or lessons, and very often a bad book can teach you more,
From the book Always ready! [The course of survival in extreme conditions for modern men] by Green RodWho invented the compass? The simplest form of the compass is a magnetic needle mounted on a rod so that it can rotate freely in all directions. The arrow of such a primitive compass points to the "north", by which we mean the North magnetic pole of the Earth.
From the author’s bookHow to make a compass with your own hands If you are lost, expect trouble. Any sane gentleman will double-check and double-check his camping equipment to make sure that he has taken all the cards that he may need, as well as a compass for orientation
The technical tools used to determine the main directions in the sea also include magnetic compasses. Magnetic compasses use the property of the magnetized arrow to be located along the magnetic lines of force of the Earth’s magnetic field in the north-south direction. In a ship, a magnetic needle, in addition to the Earth’s magnetic field, is affected by magnetic fields created by ship's iron and electrical installations. Therefore, the magnetic needle of the compass mounted on the ship will be located in the so-called compass meridian.
The simplicity of the device, autonomy, constant readiness for action and small size are the advantages of a magnetic compass compared to a gyroscopic one.
But the readings of the magnetic compass must be corrected by an amendment, the magnitude and sign of which varies depending on the course of the vessel, its location on the earth's surface and other reasons. At high latitudes, the accuracy of the magnetic compass readings decreases, and in the region of the Earth’s magnetic and geographical poles it ceases to function at all.
All ships of the navy are equipped with marine magnetic 127-mm (5-inch) compasses (Fig. 131).
The main parts of the compass are: kettle 1 with a card, binnacle 2, direction finder 3 and deviation device 4.
Bowler hat (Fig. 132) is a brass cylindrical tank, divided into two chambers that communicate with each other. The compass card is placed in the upper chamber 1, the lower 2 serves to compensate for changes in the volume of the compass fluid during fluctuations in ambient temperature.
As a compass liquid, a solution of ethyl alcohol (43% by volume) in distilled water freezing at a temperature of -26 ° C is used. To reduce the fluctuations of the pot during pitching, a brass cup with a lead load 3 is attached to the lower part of its body.
The pot is equipped with a cardan ring, which allows you to keep the azimuthal ring of the pot in a horizontal position.
Potato (Fig. 133) - the main part of the compass, consists of a system of magnetic arrows 1, a float 2, an agate firebox 3, a screw for attaching the firebox 4, six brackets 6 supporting the mica disk 5, onto which a paper disk is divided, divided into rumba and degrees .
Fig. 131.
Fig. 132.
Direction finder - a special device for determining directions to visible objects and celestial bodies. It consists of a base, objective and ocular targets and a cup for the deflector.
Binnacle made from silumin. The main parts of the binnacle: body, upper and lower bases, shock-absorbing suspension, deviation device and protective cap.
Fig. 133.
Deviation device It is placed inside the binnacle and is a brass pipe with two movable carriages for installing exterminating magnets. A set of magnets to destroy the semicircular deviation is attached in a special wooden case.
All manufactured 127-mm compasses have bottom lighting card. The lighting system includes: an umformer, a power supply and a cartridge with a bulb (in the case of power from a ship's DC network).
The lighting system can operate on ship's alternating current, but in this case, instead of the umformer, a transformer is included in the power circuit, which reduces the voltage to 6.12 or 24 V.
compass - a, m. compas (de mer), goal. kompas, it. compasso. 1. A device with a magnetized arrow to determine the countries of the world. Words 18. The compass is an arrow anointed with a magnet that turns around at midnight. Lex new vocabulum. // Smorgonsky Terms 77. ... ... Historical Dictionary of Gallicisms of the Russian Language
compass - (compass (marine compass); Italian. compasso, compassare - adymdap шеlsheu) baғytti baғdarlap, anyқtauғa arnalғan aspap. K. Keme zhne ұshaқ zhargizude, artillery of topography, geodesy қ zhmystardy zhurgizu үshіn, zhergіlіktі zherde әskerlerdің baғdar ... ... Kazakh explanatory terminological dictionary on military affairs
Compass - To see a compass in a dream means that you will be forced to fight with limited means, with your hands tied, making your success more difficult, but also more honorable. To dream of a regular or marine compass - portends ... Miller's Dream Book
- (Compass) a seaworthy instrument used to continuously indicate in the sea the compass course of the ship and to determine, if necessary, directions to various earthly objects or celestial bodies visible from the ship. K. for the mariner ... ... Marine vocabulary
Compass (in maritime business ≈ compass) (German Kompass, Italian compasso, from compassare ≈ measured in steps), a device for orienting on the ground. According to the principle of action, K. is divided into: magnetic, which use the property of a direct permanent magnet ... Great Soviet Encyclopedia
Compass “The compass is a dream for people who are fighting a desperate struggle with very limited means.” To succeed in such a struggle is difficult enough, but honorable. Do you dream of a marine or ordinary compass - it doesn’t matter. In any case, this dream portends, ... ... Large versatile dream book
Compass installed in the conning tower of the ship. During the battle, K. B serves at the same time as the main one, if the main K., for safety, are put down for cover or shot down by enemy fire. Samoilov K.I. Marine Dictionary. M. L.: State Military ... ... Maritime Dictionary
- (Gyroscopic compass) see Compass. Samoilov K.I. Marine Dictionary. M. L.: State Naval Publishing House of the NKVMF of the USSR, 1941 ... Marine Dictionary
- (Standard compass) compass, according to which the ship's course is assigned and its position is determined. On large vessels usually set two main K. main bow and main stern on the front and rear bridges. Samoilov K. I. Marine ... ... Marine Dictionary
- (Magnetic compass) see Compass. Samoilov K.I. Marine Dictionary. M. L.: State Naval Publishing House of the NKVMF of the USSR, 1941 ... Marine Dictionary
- (Steering compass) compass, which controls the helmsman, that is, holds the ship at a given course. KP is installed on the ship as many as control posts. Samoilov K.I. Marine Dictionary. M. L.: State Naval ... ... Maritime Dictionary
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