Professional reading as the source and compass of your creativity If you want to be a writer, you first need to do two things: read a lot and write a lot. Every book you pick up teaches you a lesson or lessons, and very often a bad book can teach you more.

Who invented the compass? The simplest form of compass is a magnetic needle mounted on a rod so that it can rotate freely in all directions. The needle of such a primitive compass points to “north,” by which we mean the Earth’s North Magnetic Pole.

How to make a compass with your own hands If you are lost, expect trouble. Any sane gentleman would double check and double check his camping gear to make sure he has all the maps he could possibly need, as well as a compass to guide him.

Structurally, the MK is largely similar, so we will consider the design of its individual components using the example of the KMO-T compass.

Bowler compass (Fig. 1.) consists of a body, top and bottom covered with transparent glass covers 1 and 2. The internal cavity of the pot is divided by a glass disk 3 into two parts (chambers) - upper 6 and lower 9. In the upper part there is a card 10 and a pin 5. The magnetic system of the card consists of three pairs of bar magnets 3. Degree divisions, numbers and designations are made in the form of through holes (notches) in the scale of the card.

On the azimuthal ring 14 of the pot, which presses the top glass cover, the degree divisions of the azimuthal circle are marked. The kettle is filled with compass liquid, which is a 64% aqueous solution of hydrolytic industrial alcohol. On disk 3 there is a column 4, into which a pin is screwed, and the cartridge rests on its tip with a firebox. Along the perimeter of the pot chamber, an annular screen 11 is attached to the body. Air bubbles can be removed into the space between the body and the screen. To remove bubbles, you need to turn the pot on its side and fit the bubble to the hole at the bottom of the screen.

To calculate the heading on the card scale, an index attached to the inner wall of the screen is used, made in the form of a corner with a slot - a heading line.

At the bottom of the pot there is a diaphragm, which is located between the bottom and disk 3 and provides compensation for changes in the volume of liquid when the temperature changes. A hole with a screw plug for adding compass fluid to the pot is located on the side wall of the housing.

The pin is screwed through a bottom hole closed with a stopper into sleeve 8 in glass disk 3.

At the top of the compass are installed direction finders. They are used for direction finding of objects and celestial bodies in order to determine the position of the ship, estimate the compass correction and solve a number of other problems. Direction finders are also used to determine the heading angles of landmarks.

Direction finding can be carried out both directly from the magnetic compass bowl and from direction finding repeaters. In the first case, as a rule, the reverse bearing is taken, i.e. bearing from a landmark to the ship. This bearing differs from the direct one by 180 0. From repeaters for direction finding (common for gyrocompasses and MK), in the presence of an additional mirror scale, shifted relative to the main one by an angle of 180 0, the values ​​of the direct bearing to the reference point are taken.

Direction finders may differ from each other in size and design features, but they all have a base 7 (Fig. 2), ocular target 4 , subject target 2 , mirror 1 for direction finding of celestial bodies located at an altitude of more than 20 0, and a set of light filters 3 , used for direction finding of the Sun. The set of direction finders designed for direction finding from a compass bowl includes a jumper 6 with a cup 8 , on which instruments are installed during deviation work.

The eye target is a bar with a wide vertical slot. Through this slot you can observe objects in poor visibility. When taking direction during the day, the slot is covered with a folding curtain with a narrow slit.

A carriage carrying a triangular prism is placed on the bar 5 in a metal frame, which provides a slight increase in the image of the card divisions. The reverse magnetic bearing is read through the prism.

On the removable bridge there is a cup on which a deflector is installed - a device used when carrying out deviation work aimed at reducing compass errors. The bridge is secured to the compass with two hooks 9 . The cup is made in the form of a cylinder with a flange, in which three holes are machined for mounting screws. A horizontal guide pin is screwed into the cylindrical part of the cup, allowing the deflector to be correctly oriented relative to the sighting plane of the direction finder.

The direction finder has an index 10 for its orientation relative to the compass azimuthal scale. This index is shifted, like the azimuthal scale, by 30 0 relative to the sighting plane of the direction finder.

compass binnacle(Fig. 3), made of a non-magnetic alloy, consists of a base 1 and a body 2. A pot is placed in the binnacle under the cap 3, and its body houses a deviation device, a deviation pipe, special iron and elements of the optical system. The binnacle has two rectangular windows 5 and 6 on the aft side, closed with covers: the upper one for access to the deviation device, the lower one for access to the power cable connectors and elements of the optical system. The window on the bow side (not shown in the figure) serves to access the upper lens of the optical system.

At the top of the cap 3 there is a protective glass, which has a removable safety cover. Four windows 15 with hinged covers in the cap are used to operate the direction finder during precipitation.

There is a deviation device inside the binnacle. This includes magnets for eliminating semicircular deviation and a roll magnet with devices for changing their position.

Magnets that create longitudinal and transverse forces are mounted on gears 12 (Fig. 4) with a manual drive. Two gears with two magnets to create longitudinal force are located in the DP of the vessel. They simultaneously rotate at equal angles in counter directions around a horizontal axis using a handle on which the letter is printed IN..

In exactly the same way, a device is designed for rotating around the horizontal axis of those two magnets that are designed to compensate for the transverse ship force that causes semicircular deviation. These magnets, as well as the gears that support them, are located perpendicular to the DP. The handle for their rotation is indicated by the letter WITH. In some cases, additional magnets 9 are installed in the binnacle in the ship's DP and perpendicular to the DP. They are fixed in a horizontal position in sockets near the main magnets.

Magnet 6, with the help of which the roll deviation is destroyed, is located in the pipe 7 of the deviation device in a brass frame. To ensure the movement of the tilt magnet in the vertical direction, a threaded rod 14 is placed inside the pipe. By rotating the head of the rod by handle 10, you can move the magnet up or down and install it at the required distance from the card. After installation, the position of the magnet is fixed with locknut 11.

The quarter deviation of the KMO-T compass is eliminated using four longitudinal bars 3 and one or two transverse induction plates 15. The bars are installed on brackets 4 and in the clamp sockets slightly below the level of the card arrows. Two bars have a rectangular cross-section, and the other two have a round cross-section. The clamp with bars can be rotated at a certain angle relative to the DP, which ensures the simultaneous destruction of both components of the quarter deviation. In the binnacle under the pot there is space 13 for the electromagnetic deviation compensator.

Optical system(Fig. 3) conveys the image of the card’s scale, so the helmsman sees light divisions on a dark background. At night, the card is illuminated from below with lamps, and the helmsman sees a dark image of the card’s divisions against a light background.

The optical path pipe consists of three sections: fixed 7 and two retractable. The fixed section is bolted to the base of the binnacle. The upper retractable section 9 can move up and down, and the lower 11 can also rotate around its axis.

When installing a compass on a ship, the binnacle is located on the upper bridge. The optical system pipe is passed into the wheelhouse through a hole in the deck flooring and ceiling. The compass has a power supply for lighting and heating.

The optical diagram of the system is shown in Fig. 5.It consists of 2 lighting lamp, safety glass 3, two lenses (upper 4, lower 6 ) heated glass 7 and mirrors 9. Some of the listed parts are located in the binnacle 5, and some in a metal pipe underneath.

As shown in the figure, a light beam from the sector of the bottom side of the card illuminated by the light bulb is projected onto the mirror 1 . Therefore, the image of the scale in the mirror is reflected in the most convenient form for the observer - the values ​​of degree divisions and digitization are read from left to right.

As an example of the design of the device in Fig. Figure 6 shows the upper part of the binnacle of the Sector MK. Here, the bowler 1 installed in the binnacle together with the gimbal suspension 2 using springs 6 , protecting it from the influence of vibration and shock. The boiler is equipped with a direction finder 3 . Using scales 4 And 5 The ship's heading and heading angles of landmarks are measured, respectively. As mentioned above, the bars 7 And 8 are used to compensate for MC deviation.

The considered version of the MK boiler design is typical. However, other design options are also used along with it. Thus, in order to reduce the influence of the ship's pitching on the operation of the compass in a number of products, for example, in the KM-145 compass (Fig. 7), the float 1 supplied with additional casing 2 , communicating with the working chamber of the boiler, as a result of which it is filled with supporting liquid 3 . The presence of this casing leads to an increase in the period of natural oscillations of the moving compass system, which has a positive effect on its operation.

In compasses for small boats “Gals” (Fig. 8) there is a card 2 , including two magnets 1 , does not have a float. Scales with division values ​​5 0 are marked on its outer horizontal 3 and lateral cylindrical 4 surfaces. The elements of the support device included in the cartridge include a corundum bearing and a conical part that protects it from lateral movements. An indicator stop is inserted into the card body 5 , with a ball at the free end, serving to prevent its vertical movement and at the same time playing the role of an indicator of the list and trim of the vessel. The latter is possible because the card has the properties of a physical pendulum.

The magnetic compass KMS 160 (magnetic spherical compass) is designed for installation on the console table in the pilothouse of the vessel and this determines the features of its design. The magnetic system of the card (Fig. 9) contains 4 rod magnets with a diameter of 3 mm, made of alloy 52 KFTM. The two middle magnets are 75 mm long, and the two outer ones are 55 mm long. The diameter of the card scale is 125 mm, its division value is 1 0. The residual weight of the cartridge in the PMS-5 liquid is 0.035 N.

The card is installed on a pin (Fig. 10), which is screwed into the inner frame 1 gimbal suspension. Outer ring supports 3 gimbal are installed in the housing 4 compass pot. Cargo 5 ensures the verticality of the pin axis during the rocking process of the vessel.

The working chamber of the pot is closed on top with a transparent hemispherical lid 6 and is completely filled with PMS-5 liquid. As a result, the scale image increases and its apparent diameter increases to 160 mm.

There is a hole in the bottom wall of the case 7 connecting the working chamber with the compensation chamber. In the compensation chamber, the air volume is separated from the liquid by an elastic diaphragm 8 . Liquid vibrations caused by mechanical influences on the compass are damped by the cup 9 and screen 10 . There is a hole in the center of the bottom of the pot, closed with a stopper. 11 , to fill the pot with liquid. A deviation device can be attached to the bottom of the pot.

Not all compasses are mounted in the binnacle. This most often occurs with compasses intended for use on small boats. These include the above-mentioned compass - horizon "Tals" (Fig. 11), installed directly in the wheelhouse console and the KMS-160 compass. The first does not have devices to compensate for the influence of the ship's magnetic field, the second has the indicated compensators.

Recently, ring magnets, rather than rod magnets, have begun to be used in MK cards. One of the design options for such a card is shown in Fig. 12.

The sensitive element consists of a housing 1 with a ring magnet 2 having an outer diameter of 52 mm, a hole diameter of 20 mm and a thickness of 1 mm. The magnet is made of a special alloy and is magnetized in a uniform magnetic field. The sensitive element includes a float 3, consisting of a base and a cover. The float has a sleeve 4 connected to a cone. The bushing contains a thrust bearing 6, secured with a screw 7. On the annular shelf of the housing there is a disk 8 with a scale divided into 360 divisions.

The SE has a weight of (5.6±03)10 -2 N in the compass liquid (70% ethyl alcohol, 10% glycerin, 20% distilled water). The period of oscillations of the SE at its initial deviation from the magnetic meridian by 40° at H=12 A∙m -1 is (20±4) s.

QUESTIONS FOR SELF-CONTROL:

1. What is the difference between the magnetic compasses KM-145-3 and KM-145-4? KM-145-4 and KM-145-6?

2. How many magnets does the Sector compass card contain?

3. What role does the diaphragm play in the compass bowl?

4. For what purpose do compasses use an additional chamber filled with a supporting liquid?

5. What is the procedure for installing and removing the direction finder?

6. What is located in the compass binnacle?

A, m. compas (de mer), goal. kompas, it. compasso. 1. A device with a magnetized needle for determining the cardinal points. Sl. 18. A compass has an arrow anointed with a magnet that turns around at midnight. Lex. new vocabulary. // Smorgon Terms 77.… … Historical Dictionary of Gallicisms of the Russian Language

compass- (compass (sea compass); Italian compasso, compassare – adymdap olsheu) bagytty bagdarlap, anyktauga arnalgan aspap. K. kome zhane uzhak zhurgizude, artillery and topography, geodesy zhumystardy zhurgizu ushin, zhergiliktі zherde askerlerdin bagdar... ... Kazakh explanatory terminological dictionary on military affairs

Compass- Seeing a compass in a dream means that you will be forced to fight with limited means, with your hands tied, thus making your success more difficult, but also more honorable. Seeing an ordinary or nautical compass in a dream portends... Miller's Dream Book

- (Compass) a nautical instrument used to continuously indicate the ship’s compass course at sea and, if necessary, to determine directions to various earthly objects or celestial bodies visible from the ship. K. for a navigator... ... Marine Dictionary

Compass (in maritime affairs ≈ compass) (German: Kompass, Italian: compasso, from compassare ≈ to measure in steps), a device for orienteering on the ground. According to the principle of operation, magnets are divided into: magnetic, which uses the property of a direct permanent magnet... Great Soviet Encyclopedia

Compass- People who are waging a desperate struggle with very limited means dream of a compass. It is quite difficult to achieve success in such a struggle, but it is honorable. Whether you dream of a sea or an ordinary compass is not important. In any case, this dream foreshadows... Large universal dream book

A compass installed in the conning tower of a ship. During the battle, the CB serves at the same time as the main one if the main CBs are moved down behind cover for safety or knocked down by enemy fire. Samoilov K.I. Marine dictionary. M.L.: State Military... ... Naval 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) a compass by which the ship’s course is assigned and its position is determined. On large ships, two main ships are usually installed, the main bow and the 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) the compass by which the helmsman steers, i.e., keeps the ship on a given course. K.P. is installed on a ship as many as there are control posts. Samoilov K.I. Marine dictionary. M.L.: State Naval... ... Naval Dictionary

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• Ocean Marine dictionary with stories and tasks, Enriques R., The waters of the World Ocean cover more than two-thirds of our planet. But man has explored only 5 percent of this vast kingdom. But this is not such sad news - after all, it means both us and... Category:

Along with the development of the theory of deviation, the device itself was improved. MKs were developed for various types of ships, which differed from each other in the type of sensitive element, accuracy characteristics, deviation compensators and information display devices. Historically, MKs have become predominant in the navy. with a movable sensitive element (card) which are often called arrow. Their undoubted advantage is that the presence of a card, which is independently installed in the meridian, allows you to read the value of the ship's course directly from the scale of this card, which ensures the possibility of orientation even in the absence of power. The relative simplicity of the design of such a MC increases the reliability of heading guidance.

Recently, ships have begun to use induction MK, which do not have a card. Instead, special sensors are used that measure the parameters of the ship's magnetic field. These sensors are oriented in a certain way relative to the centerline plane of the vessel and are stationary relative to it. These compasses are remote, have smaller dimensions of the sensitive element, and allow greater freedom in choosing their installation location. However, they require power supply and special heading indicators called repeaters.

Modern pointer compasses intended for use on long-distance vessels are also equipped with devices for remote transmission of information. These devices can be optical, electromechanical or electronic (digital). Heading information can be displayed in either analogue or digital form and typically on multiple heading indicators (repeaters). Distinguish main And travel MK. The main magnetic compass is installed on the upper bridge in the center plane of the ship or, as an exception, near it and can be used for bearing finding of various landmarks. Information from the main microcontroller can be taken directly from its card or, if there is a system for remote information transmission, in the wheelhouse. If the main compass does not have a remote transmission, then a track MK is installed in the wheelhouse.

When placing any type of MC on a ship, it is necessary to ensure easy access to their information, minimal influence on their operation of the ship's pitching and the ship's magnetic field, and care for strict orientation of the MC body relative to the center plane.

There are other classification features that will be discussed below.

.Composition of the magnetic compass kit

As noted above, magnetic compasses with a card are currently the most widely used in the navy. The main element of such a compass is the bowler 1 (Fig. 2.1), in which its measuring system is assembled. To determine bearings and heading angles, a direction finder is installed on the compass bowl 2 . The pot itself is placed in a special stand (binnacle) 7 , which also houses devices 6 to compensate for MK deviation caused by the influence of the ship's magnetic field. Compensators are installed on the outside of the binnacle 3 deviation of the magnetic compass generated by the field created by the ship's soft magnetic materials, as well as the box 5 , containing a toggle switch for turning on the device backlight and a regulator for its brightness. Compensators are installed directly under the boiler 4 deviations from induction. Along with the above, latitudinal deviation compensators and elements of remote information transmission systems can be installed on the binnacle.

In Fig. 2.2 shows as an example the appearance of the binnacle of the remote MK “Sector”, on which the above-mentioned compensators are visible 3 , backlight brightness control 5 and cap 1 , which covers the pot to protect it from bad weather. Hinged lids 2 allow measurements to be taken without removing the cap. Removable covers 4 close the windows that provide access to the elements installed inside the binnacle.

In the boat or yacht version, the boiler is equipped with lighting devices designed to operate in the absence of an on-board power supply. Such devices can be oil lamps and illuminators that consume direct current from dry cells or batteries.

These compasses are usually used without

The next day, the frigate "Ringing" was again carelessly running under sail in the open ocean, and classes continued on its deck.

– First of all, I want to tell you that sailors do not speak “to O mpas", and "comp A s,” said Yakov Platonovich, because it was his turn to get acquainted with this nautical instrument.

Proof of this is another sea song by the writer Alexander Green, I really like it.

The Southern Cross is shining in the distance,

With the first wind the computer will wake up A With.

God protects the ships

May he have mercy on us...

In order for God to truly preserve the ship on a long voyage, the sailors themselves must skillfully manage their ship. And the compass in this matter is their main and reliable assistant.

Of course, a sea compass differs from a land compass not only in the emphasis in the name...

- Also big, right? – asked Vasya.

– The size is a given. – But there is a fundamental difference in design.

In an ordinary tourist or school compass, a magnetic needle runs on the needle. Walks with its end over a round scale with divisions and letters.

And in a marine compass, the scale itself sits on a needle.

It's called KART U SHKA. Similar to the word "card". This is a round card with degree divisions, made of waterproof cardboard or plastic.

– Is the compass flooded with waves? – Anton was surprised.

- Of course not. It is closed on top with waterproof glass with a rubber gasket. The card needs waterproofing for something else... Let's look at the structure of the marine compass in more detail, then you will understand everything.

Yakov Platonovich opened the cabinet and took out a small black vessel. Instead of handles, the vessel had a ring around the top.

- Bowler hat! – Anton was surprised. - I got smoked at the fire...

- You are right. This body of the ship's magnetic compass is called a bowler hat. His bottom is heavy. Therefore, when the bowler is suspended in this ring (it is called a cardan ring), the compass maintains an even horizontal position during any motion.

But, of course, the pot is not smoked, but painted black. It's actually brass. It cannot be made of iron; the magnetic needles would immediately become confused.

At the bottom of the pot there is a pin with a point made of very durable metal. The card sits on a stiletto heel.

The compass card is designed like this. In its center there is a hollow float made of thin brass. It looks like a flattened ball. At the bottom there is a small inverted cup made of hard stone (usually agate). It's called topka (similar to the word "top", isn't it?). Fire the float and put it on the tip of the stud. It fits on the stiletto heels very easily. A special liquid is poured into the pot, and a float in the liquid makes the card almost weightless...

- So that’s why the card is waterproof! Because in liquid! - Anton guessed.

“A weightless card, of course, spins easier on the needle,” Slava noted.

“And besides,” said Yakov Platonovich, “the liquid serves as a brake for the card: it prevents it from spinning aimlessly and dangling too much...

But, to be precise, the card inside the compass does not rotate. Almost. At least she always tries to stay still. And the compass pot revolves around her. Along with the ship. Yes, yes!.. The fact is that arrows are attached to the bottom of the float - magnetized steel strips in lead pencil cases. There are several of them. Some compasses have two, but this Russian-style one has six...

– For balance? – Slava asked.

- Not only. Several arrows maintain the north-south direction more accurately than one.

While maintaining this position, the arrows also hold the float with the card. Therefore, the card with its northern mark (there is the number 0 and the letter N) always faces north, no matter which direction the ship is sailing.

Do you see what happens? The ship changes course, its hull turns, and with it the compass bowl with a black wire stretched in it—the course thread—turns. And thanks to the arrows, the card is always in the same position. The course thread runs in front of its edge and shows the course. Because on the card there are indications of the cardinal points and all 360 degrees. Zero degrees is exactly north.

Compass device

When it is necessary to determine where the ship is going, they look at the compass and report what the course line shows. For example: “Course forty-five degrees” or “heading north-east”...

– What is “Nord-East”? – asked Ksenya.

- Northeast. But more on that later. Let's finish the question about the design of the compass.

Look, a bubble is floating in the liquid under the glass. The fact is that this compass is old; it was given to me when it had already served its useful life. In general, there should be no bubbles in the liquid. To do this, at the bottom of the compass there is a special elastic plate - a membrane, and under it there is a small chamber with air. The membrane, due to the elasticity of the air, props up the liquid and squeezes out the bubbles.

Compasses come in different sizes. They differ in the diameter (that is, the transverse width) of the card. This one here is big, 127 mm. It is installed on large ships. There are smaller ones - 100 mm. And there are boat compasses, they have a 75-mm card.

“Just like the caliber of shells,” Vasya noted.

- Yes. But a compass is a peaceful thing, it serves for safe navigation. Without it, no captain will go to the open sea.

-What kind of liquid is in the pot? – asked the inquisitive Slava. – She won’t freeze if the ship floats among the ice, near the pole?

“It doesn’t freeze even in severe frost.” Sometimes it is a mixture of glycerin and alcohol. And in the compasses of this system there is simply a solution of ethyl alcohol, in other words, wine alcohol...

Vasya giggled. Yakov Platonovich also grinned:

– Yes, there are many anecdotes about this: about navigators who poured the contents of a cauldron into themselves and confused north with south... Remember, I talked about the Neptune festival, which was organized by trainees on the Barquentine? There was also such an episode in their performance: during the exam, Neptune asks a question:

Well, who will tell me now,

what is l and s e l - s p i r t?

You, of course, remember that this is a part of the spar for an additional sail. But in the play, the “stupid” cadets do not know this. And one bravely answers:

But this is, of course, just for fun. I have met all sorts of sailors in my life, including those who loved to take a sip. But I have never seen such idiots who would try to use the contents of a compass pot for this... Well, we laughed and moved on.

On a large ship there are usually several compasses. The main one is called the main one. It is installed on the upper bridge, the ship's course is assigned to it and the readings of other compasses are checked. The routing compass stands in front of the helm - the helmsman guides the ship along it. There may be several more compasses in different places on the ship - spare ones and for additional control.

In one maritime museum I saw an antique compass especially for the captain. He is upside down. Instead of a bottom, there is glass in the pot, and you can see the card through it. Such a compass was screwed to the ceiling of the cabin. The captain could follow the course without leaving his bunk. I slept, opened my eyes slightly, made sure that everything was in order and - you can continue to dream while experienced assistants are on watch...

But usually compasses are mounted not on the ceiling, but on special bedside tables - wooden or made of a non-magnetic alloy.

This bedside table is called a binnacle. Translated from Dutch - “night house”. Because on such a bedside table the compass is always under a special cover or cap - like in a house under a roof. And at night there is a light on there. In calm weather it looks cozy - like a light in a forest hut. I remember in one book I read the following verses:

We are floating in the darkness without lights,

Having escaped all pursuits.

And only furtively at the stern

Burns like a candle on the window,

Binnacle fire...

Binnacles come in different shapes. On the Meridian we had a wooden one at the helm, and the cap over the compass looked like a copper diver's helmet with cylindrical attachments on the sides. These were spare oil lamps for illuminating the map - in case the engine deteriorated, there was no electricity and the light in the bottom of the compass pot went out...

And inside any binnacle there is a special device with magnets to eliminate compass errors.

– Are there any errors in a compass? – Vasya was surprised.

- Certainly. Every ship, even a wooden one, has a lot of all kinds of iron. It greatly influences the magnetic needles under the card... Those who have read the book “The Fifteen-Year-Old Captain” remember how the villain Negoro put an iron bar under the compass. The card went astray, and the brigantine "Pilgrim" sailed past America... Well, now there cannot be such huge mistakes, but there are as many small annoying errors as you like.

By the way, the deflection of the compass card under the influence of the ship's iron is called d e v i a c i i . To reduce it, there are magnet regulators in the binnacle.

But it is rarely possible to completely eliminate deviation. Therefore, the navigator must always take it into account when plotting a course - add or subtract degrees of correction.

It is also necessary to take into account magnetic declination.

The fact is that the geographic poles of the Earth - North and South - do not coincide with the magnetic poles that control compass needles. For example, the North Magnetic Pole is located in Greenland. Magnetic poles tilt needles away from true north and south. Far from the poles this is not very noticeable, but in polar waters the difference is great. This difference between the directions to the magnetic and geographic poles is called magnetic declination. It is measured in degrees and can be eastern or western - depending on where the magnetic force pulls card from the geographic pole. More precisely, from the meridian that passes through this pole.

It must be said that meridians can also be drawn through magnetic poles. They are called magnetic. And the meridians running through the geographic poles are called true.

Magnetic declination is the angle between the true and magnetic meridian.

To make the work of navigators easier, compass cards are printed on nautical charts and they indicate what the declination is in this area of ​​the sea.

There is always a lot of fuss with declination and deviation, and to avoid it, engineers came up with compasses without magnetic needles, said Yakov Platonovich.

– How do these compasses work? – Slava was amazed.

– I’ll explain now... Ksenya, yesterday I was repairing your bicycle and removed the front wheel. Please bring it from the hallway.

Of course, Vasya got ahead of Ksenya and brought the wheel himself.

“Slava, hold it by the axle, on both sides,” Yakov Platonovich ordered. – And try to unwind the rest... Be careful... Be careful, but stronger... That's it. Now, Slava, try to quickly turn the axle, change the inclination of the wheel...

Slava tried it. Did not work out! The wheel rustling rapidly in the air did not obey the boy! It and its axis wanted to remain in the same position.

- You see! – Yakov Platonovich said joyfully. – This is called the e f f e c t g i r o s k o p a.

A gyroscope is a rapidly rotating disk or top. It always tries to maintain the position of its axis in space.

- Like a children's spinning top! – Anton exclaimed. – She doesn’t fall when she spins either!

- Right! Yula is also a gyroscope... Now imagine that one end of the axis is directed to the north, and the other, thus, faces south. We spin the disk... The axis is instead of an arrow. And no magnetization is needed.

- How simple! – Ksenya exclaimed.

- No, friends. I try to explain this more simply. In fact, the axis will not look at the poles for a long time: after all, the Earth changes its position in space - unlike the gyroscope. Therefore, the compass, which is called a gyroscopic compass, is a very complex device. It contains a whole system of gyroscope tops, they are hidden inside a hollow ball - a gyro sphere. The gyrosphere has an amazing property. When gyroscopes are launched in it with the help of electricity, under their action, as well as under the influence of the rotation of the Earth, it rises to the desired position - with the northern mark of its ring exactly at the North Geographic Pole.

True, the gyrosphere does not do this right away, but gradually. And there is no need to rush her. Therefore, the gyrocompass is turned on in advance before swimming.

“I’d like to see,” said Slava, who finally lowered the wheel (his hands were tired).

– Unfortunately, I don’t have a gyrocompass. This is a very expensive thing and, moreover, bulky. The size of a barrel... The gyrocompass is installed deep in the hull of the ship so that there are fewer mechanical influences.

– And there, in the depths, does the navigator climb every time to check the course? – Slava was upset.

- Not at all! From this compass, which is called the uterus, electrical cables stretch to special devices - repeaters, translated into Russian, “repeater” means “repeating”.

Repeaters are similar to magnetic compasses. Only their cards are controlled not by magnetic needles, but by electrical signals coming from the gyrocompass. And all repeaters have the same readings.

The convenience is that there can be as many repeaters as you like and you can place them throughout the ship.

- But that means there is some inconvenience? – Slava asked shrewdly.

- Unfortunately, there is. The gyrocompass is a capricious device... We had a navigator on the Barquentine who loved to tell an anecdote with a kind of Odessa humor.

"Two ships are sailing along the Black Sea. One watchman shouts from the side to the other:

- Hey, brothers-sailors, where are you going?!

- What is it, you don’t see it yourself, right? It’s clear that it’s for Odessa-mother!

- No, listen to what this man is telling me! We are going to Odessa, and you are doing the opposite!

– What are you telling me, young man! Where is Odessa here? In the north! Where is our sunshine? Back to Pivden, because now it’s neatly twelve o’clock. It shines in our stern. So we are moving north!

- What do you want to say? Why is the sun always in the south every noon?

- Ha! Don’t you know such simple astronomy? How then, excuse me, do you drive your trough across the sea?

- Yes, we have a gyrocompass!

- And with us! It is he who seems to be heading north!

- So it is with us to the north!.. Guys, call the captain to the bridge, geography is a complete mess!..”

It turned out that on one ship the gyrosphere in the womb took its own whim and turned one hundred and eighty degrees. That is, backwards. Sometimes they can pull out such tricks. Therefore, you need an eye and an eye...

When they finished laughing, Yakov Platonovich continued:

- Well, besides, the gyrocompass depends on the power supply. What if there’s a car accident and there’s no electricity? Once such a story happened to us near the Azores - the engine went out. Okay, let's go sailing. Where to go if the gyrocompass is turned off? This is where the magnetic compass came to the rescue. Old, well-deserved, but reliable - it never turns off.

On most modern ships, magnetic compasses are required. You never know what happens at sea. The vessel should not lose its ability to sail if the power is lost. Especially a sailboat. Therefore, there should always be tools on board that do not rely on electricity.

“The law of the gramophone,” said Ksenya.

-What kind of law? – Vasya was surprised.

- Grandfather came up with it. When we celebrated the New Year, the lights suddenly went out and there was an accident in the transformer booth. There are screams and complaints throughout the house: the chandeliers don’t light up, the garlands on the Christmas trees have gone out, the TVs don’t work. And grandfather lit the candles and pulled out an old gramophone. Well, you know, such a suitcase with a spring inside and a handle for winding, and he put on the record:

Why are you, friends, depressed?

Or have you forgotten the songs of the sea?

And we celebrated well. It was even a little annoying when the electricity turned on.

- Since we don’t have a gyrocompass, maybe we can look at the gramophone? – suggested the simple-minded first-grader Anton. - And let's listen to records?

Yakov Platonovich said that this is possible.

And soon the worn gramophone, which boatswain Peryshkin had kept since childhood, was playing a record with a song from the same old film “The Children of Captain Grant”:

There lived a brave captain

He traveled to many countries...

The cats sat by the gramophone and listened with their heads bowed. Syntax wanted to touch the shiny head of the membrane, but Yakov Platonovich said: “I you...” And Sinka’s outstretched paw froze in the air.

“And the disk of the gramophone is also almost like a gyroscope,” Vasya noted, “That’s how it spins!”

The record is over. And, before turning it over, Yakov Platonovich said:

– We are not finished with the compass yet. Tomorrow I will tell you about the divisions on his card.