Ventilated diving equipment. "Remedies"

Diving equipment is a kit technical devices and products put on and secured to the diver, ensuring his life activity under the pressure of the surrounding water and gas environment for a long time.

Diving equipment creates the necessary physiological conditions for normal human activity, namely: it provides breathing air at a pressure corresponding to the pressure environment; insulates from water and prevents body hypothermia; creates the necessary stability under water; provides a stable connection with the surface.

IN composition of diving equipment usually include:

Ø breathing equipment (breathing apparatus, helmets, masks, hoses for supplying breathing gas mixtures)

Ø means of isolating the body from environmental influences (diving suits, diving suits, diving shirts)

Ø means of passive thermal protection (underwear and woolen underwear, insulation)

Ø means of active thermal protection (water and electrical heating suits, autonomous sources heat and electric current and so on.)

Ø means of regulating buoyancy and ensuring stability (inflatable vests, weights, galoshes, boots, etc.)

Ø communication means

Ø navigation aids (depth gauge, watch, compass, etc.)

Ø equipment (knife, fins, protective device for welding, etc.)

Diving equipment subdivided

Ø by depth of use - for equipment for small and medium depths and for deep-sea diving equipment

Ø according to the method of providing the breathing gas mixture to – autonomous and hose

Ø according to the method of thermal protection - electrically heated, water heated, unheated (with passive thermal protection)

Ø according to the method of protecting the body from environmental influences - with full insulation (wetsuits and wetsuits of the “dry” type - water- and gas-permeable) and with partial insulation (wetsuits and wetsuits of the “wet” type - water- and gas-permeable).

Diving equipment is divided into:

a) according to the method of gas supply - autonomous and non-autonomous:

b) according to the method of providing breathing - ventilated, injection-regenerative, regenerative with a closed breathing cycle.

c) equipment with open circuit breathing.

Diving equipment is divided into heavy and light.

In heavy equipment, the human body is isolated from the aquatic environment by a strong waterproof shirt, and the head is in a metal helmet, in which air, oxygen or a gas mixture is supplied through a hose from the surface,

To isolate the human body from the environment, light equipment is used various types wetsuits made of soft elastic rubberized fabrics. The diver's breathing is ensured by supplying compressed atmospheric air from the cylinders of the spinal apparatus or through a hose from the surface.

Ventilated equipment operates on the principle of continuous supply of compressed air from the surface through a hose, which in the space under the helmet is mixed with the air exhaled by a person and is removed into the water through special bleed valves of the helmet and diving shirt. This feature determined the name of the spacesuit used for work in the hydrolab as ventilated, although complete ventilation does not occur.

Three-bolt equipment is used when performing work at a depth of up to 60 m, and twelve-bolt equipment is used at a depth of up to 30 m.

Injection-regenerative equipment. The peculiarity of this equipment is that the breathing gas mixture is fully or partially restored in its regenerative system, while the breathing gas from the surface is supplied mainly to operate the injector and fill the spacesuit for the period of the diver’s immersion under water. If air is not supplied from the surface, then the breathing mixture is regenerated when it exits the injector window. The duration of a diver’s stay under water depends on the composition of the breathing mixtures and design features equipment.

Regenerative equipment, unlike ventilated and injection-regenerative equipment, does not have a gas volume. Breathing is ensured autonomously due to the reserves of artificial gases, oxygen, mixtures, etc., available in the device, and the continuous regeneration of the exhaled gas mixture, circulation in a closed cycle: device-lungs. During the circulation process, the gas mixture is cleared of carbon dioxide and becomes breathable. At the same time, the gas mixture is replenished with oxygen. Depending on the design of the device, additional oxygen can come from the device’s cylinder or be released from a special regenerative substance. According to their design features and scope of application, regenerative equipment is divided into oxygen, nitrogen-oxygen, etc.

Air balloon blocks

Elements of the air-cylinder block

The air-cylinder block is the main element of scuba gear.

The main components of the air-cylinder unit are:

· a cylinder or several cylinders of compressed air;

· shut-off valve with air reserve device (or without it);

· air pressure gauge in cylinders;

· suspension system for cylinders.

Air cylinders. Over the past decades, cylinders have not undergone such significant changes in their design as regulators. Some changes have occurred in the manufacturing technology of cylinder bodies, materials used, coatings, and additional accessories.

Balloon (tank) is a hollow cylinder, with a convex or straight (for aluminum) bottom at one end and an elongated neck with a neck at the other. The neck hole has a thread (conical or cylindrical), with which a shut-off valve is screwed onto the cylinder. The cylinder is designed for compact storage of high pressure (usually from 150 to 300 ati) compressed air consumed by the swimmer for breathing. To increase autonomy, cylinders can be connected into blocks of two or three cylinders together. Depending on the number of cylinders, such blocks are called one-, two-, or three-cylinder, respectively. Three-cylinder blocks are extremely rare.

The shape of the cylinders is quite standard, but allows for a number of variations with the same volume. For example, 12-liter cylinders are available in several modifications. The advantages of an elongated cylinder are better hydrodynamics and a closer location of its center of gravity to the swimmer’s center of gravity, which, as already mentioned, reduces the inertia of rotation in the water. True, such a cylinder can create inconvenience for people of short stature - cylinders of a more compact shape are better suited for them.

Thus, the choice of size, quantity and shape of cylinders is determined by the tasks you face and, in many respects, by your taste. The latter also applies to the colors of the cylinders, which are usually bright and clearly visible in the water.

In terms of weight and dimensions, the cylinder is the most significant integral part scuba diver equipment. A breathing machine and other components of the air-breathing apparatus are attached to the cylinder.

Main technical characteristics air cylinders are:

capacity (volume);

· test and working pressure;

· body material.

Cylinder capacity. - Characterizes the capacity of the cylinder, i.e. the amount of internal volume filled with compressed air. It is usually measured in liters (dm 3), but on imported cylinders you can find capacity characteristics expressed in cubic feet (ft 3 or cu.ft). The relationship between these units of measurement is as follows: 1 ft 3 = 28.32 l, or 1 l = 0.0353 ft 3. Obviously, the larger the capacity of the cylinder, the greater the amount of compressed air that can be stored in it; the duration of a swimmer’s stay under water directly depends on this. However, large capacity cylinders are heavy and bulky. They create problems with buoyancy and stability at the beginning and end of a dive, and also require reinforced attachments to the harness.

To date, the most convenient relationships between the capacity of cylinders and their weight, as well as the proportions between the sizes of cylinders, have been determined. Cylinders with a capacity of 0.3 to 18 liters are produced, while cylinders with a volume of 8, 10, 12 and 15 liters are most often used as the main ones. Cylinders with a capacity of 6 and 7 liters are intended for teenagers and women. The smallest cylinders with a capacity of 0.3 to 2.0 liters are used as additional cylinders for backup sources of breathing, as well as for some special purposes.

Modern cylinders (compact series) have a reduced height and increased diameter compared to those produced previously. Such cylinders are most convenient when used in conjunction with a buoyancy compensator.

Test pressure- Hydraulic pressure to which the cylinder is tested during its manufacture and subsequent mandatory technical examinations, which in different countries are carried out at different intervals (in Russia - once every five years). The main purpose of the tests is to check the safety margin of the cylinder material against the effects of forces from compressed air pressure. The test pressure is set by the manufacturer and is usually 1.5 times the operating pressure.

Operating pressure- Also factory installed. This is the maximum permissible pressure that can be created in the cylinder when charging it with compressed air. Exceeding the operating pressure during its operation is unacceptable, since in addition to the body of the cylinder itself, the cylinder shut-off valve, reducer, and pressure gauge hose are subject to this pressure.

Obviously, what more pressure, the greater the volume of air that can be stored in the cylinder (in accordance with the Boyle-Mariotte law). But an increase in working pressure entails whole line problems, the main one being the problem of strength. Currently, cylinders with operating pressures of 200, 230 and 300 atm are most often used. On imported cylinders there are designations of working pressure in units of measurement such as bars (BAR) or PSI (Pounds per square inch, i.e. pounds per square inch). Let us recall the relationship between these units of measurement:

1 BAR = 1 atm = 1 kgf/cm 2 = 10 5 Pa = 14.65 PSI.

Housing material- the main factor determining the relative weight of the cylinder (the ratio of the weight of the cylinder in kilograms to the external volume in liters), operating pressure and service life of the cylinder. Basically, cylinders are made of alloy steel or aluminum.

Steel cylinders. They are quite technologically advanced, have good strength properties, and the material is not prone to aging. The main danger is the possibility of gradual failure associated with corrosive destruction of the metal when interacting with the environment or compressed air inside the cylinder, especially if the air contains water vapor. The main ways to combat corrosion of steel cylinders are:

· use of high-strength alloy steels containing elements such as chromium and molybdenum; electrochemical protection of carbon steels through the creation of protective passivating films that inhibit the corrosion process (for example, the use of electrolytic galvanized steels);

· protecting the surface from the access of an oxidizing agent from the environment (depolarizer) using paint and varnish coatings (surface painting);

· additional coating of the outer surface of the cylinder with synthetic materials (polyvinyl chloride, polyurethane);

· charging cylinders only with drained and cleaned high-pressure fluid and not completely consuming high-pressure fluid during dives;

· timely technical examination with maintenance of the internal cavity of the cylinder.

All these measures can be used individually or in various combinations, significantly increasing corrosion resistance.

Aluminum cylinders. Cylinders made of aluminum or its alloys appeared on the diving equipment market relatively recently. This is explained by the fact that the mechanical characteristics of aluminum (strength and yield limits, impact resistance, ductility) are significantly lower than those of steel. Considering this, most divers approach the choice of aluminum cylinders very carefully. However, aluminum cylinders also have a number of advantages over steel ones. Firstly, metal corrosion is almost completely absent. Aluminum, although it is a more electronegative metal than iron, has the unique property of forming a protective passivating film on the surface, consisting of aluminum oxide, which completely isolates the metal from corrosive destruction. At the same time, the problem of protection against corrosion, both external and inner surface balloon.

Secondly, the problem of equal strength with steel can be solved by increasing the thickness of the cylinder walls, especially considering that specific gravity aluminum is almost three times less than iron. True, this will lead to a decrease in capacity or an increase external dimensions aluminum cylinder compared to a similar steel cylinder. A smaller capacity will shorten the duration of the dive, and a larger external volume of the cylinder will require an increase in the weight of the swimmer’s weight belt to compensate for the excess buoyancy of the cylinder.

Finally, an aluminum cylinder is more sensitive to various types of mechanical damage, is prone to dents during transportation or accidental impacts with hard objects.

Despite the noted disadvantages, aluminum cylinders are used by divers all over the world. Due to their lower relative weight compared to steel cylinders, they can be recommended for recreational diving for teenagers, women, and also for sports competitions. For example, for underwater navigation, since these cylinders are low-magnetic and do not affect navigation devices. When planning dives with aluminum cylinders, it is necessary to take into account a slight increase in positive buoyancy as compressed air is consumed. A special feature of the body shape of aluminum cylinders is the presence of a flat bottom, which allows them to be used without “shoes”. An important factor is that the cost of such cylinders is lower than steel ones. Manufactured aluminum cylinders are usually designed for operating pressures of 150, 200 and 230 atm.

In addition to steel and aluminum cylinders, there are composite cylinders made of polymer materials. Such cylinders have found use in emergency breathing equipment, but have not become widespread in diving.

Passport stamp. The only source by which you can find out the characteristics of the cylinder and draw a conclusion about its suitability for use is the passport stamp stamped on the neck of the cylinder and containing the following information:

· manufacturer;

· type of cylinder;

· operating pressure;

· capacity;

· test pressure;

date of manufacture;

· brand;

· factory number.

After hydraulic testing, the date of the test and the date of the subsequent next test are marked on the passport stamp ( technical examination) balloon.

Shut-off valve. A shut-off valve is screwed into the threaded hole in the neck of the cylinder neck. The valve is unscrewed from the cylinder only during a hydraulic test (inspection) or if it is necessary to inspect the inside of the cylinder.

Structurally, the valve can be connected to a reserve device. The number and type of shut-off valves depends on the number of cylinders in the scuba gear and on the degree to which the diver is provided with a reserve supply of air.

Hanging system. There are two ways to attach an air tank to a swimmer's back: with the valves down or up. In the first case, the swimmer can switch cylinders with his hands, in the second - not. But the first case requires longer hoses and more careful operation. The second method is more convenient to use and can be used with any breathing apparatus, but does not allow the swimmer to reach the reserve valve.

In the vast majority of cases, scuba gear is worn on the back, like a backpack. In this case, three types of design are possible:

One or two cylinders are attached using a strap(s) to a buoyancy compensator vest.

One or two cylinders are attached in the same way to a special anatomical backrest equipped with shoulder and waist straps.

The straps are attached to metal clamps covering the cylinder block (this method is used in most domestic scuba gear). They usually have additional breaststroke straps that go between the diver's legs. Modern amateur equipment of international standard does not provide for its presence.

MASK

Main function

The human eye is not capable of clearly reproducing information about objects in a more dense, from an optical point of view, medium, such as water. There needs to be air space between the eye and the water.

The simplest device for this is swimming goggles. However, you should not dive with goggles to a depth of more than 1-2 meters. The pressure under the goggles at this depth becomes significantly less than the surrounding environment, and the goggles begin to act like suction cups. The result is a network of hemorrhages in the eyes (and this is in the best case!).

Therefore, for swimming underwater, it is necessary to use a mask that allows, by exhaling through the nose, to equalize the pressure in the space under the mask with the ambient pressure. According to generally accepted opinion, a mask is the main item in a submariner’s equipment.

Let us remind you that according to the international codes of all underwater federations, swimming without a mask is a distress signal.

Mask elements

Any mask consists of a soft body, a hard rim into which one or more portholes are inserted and a fastening strap

Most modern masks have a silicone body (however, rubber masks are still available). Silicone is softer and more elastic than rubber (although it is inferior in strength), it is more durable and less susceptible to the destructive effects of water and sunlight. Silicone can be either transparent in all the colors of the rainbow or transparent. The choice here is a matter of taste. However, please note that the clear silicone housing increases the field of view but may create a slight glare on the viewing glass.

The rim is made of metal or impact-resistant plastic.

The porthole must be mechanically strong, not form fragments with sharp edges when broken, and withstand the chemical effects of sea water. Some types of plastics satisfy these requirements (but they are expensive, so they are used mainly by professionals) and strained glass. The porthole must be marked “TEMPERED” for glass and “SAFETY” for plastic.

The mask strap can be made of either rubber or silicone (the latter, of course, is preferable).

Selecting a Mask

The choice of masks is wide. The best masks provide maximum visibility with a minimum amount of under-mask space.

The space bounded by the mask on one side and the submariner's face on the other is called the under-mask space. This space is filled with air. Naturally, the larger it is, the greater the lifting force and the more difficult it is to keep the body horizontal or head down. Therefore, it is better to choose a mask with a small volume (about 200 mm).

The wider the angle of view, the better. The viewing angle depends on the size and shape of the porthole.

The hydrodynamic resistance depends on the size and shape of the mask. The smaller this value, the more comfortable the mask.

To blow your ears under water, you need to hold your nose. When snorkeling, this can be done with one hand. If you have a breathing apparatus mouthpiece in your mouth, then it is difficult to perform this procedure with one hand. This is where a mask with a separate protrusion for the nose comes to the rescue. This design allows you to blow with one hand; in addition, the under-mask space is reduced and the field of view is increased by bringing the porthole closer to the eyes, and the hydrodynamic resistance is also reduced.

To compensate for human vision deficiencies, two-lens masks with replaceable lenses have been developed and produced. Diopter glasses are selected for each eye separately. At the factory, all masks are equipped with regular glasses, which can be replaced within a few minutes with diopter glasses selected for your eyes. Now there is no need to look for special contact lenses with micro holes to compensate for pressure.

For masks with replaceable lenses, lenses with anti-fog coating are available. Applied with inside Glass layer of material prevents the loss of individual drops of moisture, but does not affect the clarity of the image.

Masks are available with valves built into the bottom. To clear the water from the mask, you can do without using your hands; just exhale through your nose.

Many manufacturers produce masks with a convenient mechanism for quickly adjusting the fastening straps and with swivel buckles. This mechanism allows you to tighten or loosen the belt without removing the mask and quickly select the optimal angle of the belt position.

To check the mask for tightness, place it on your face without a belt and take a light breath through your nose. If the mask “sucks” and stays on your face, then its shape suits you. By the way, if you wear a mustache, you should either get rid of it or accept the slow but inevitable leakage of water. There's nothing terrible about that.

Instructions for using the mask

A. How to remove water from under the mask.

During swimming, water can enter the space under the mask. This can be caused by hair caught under the flange of the mask, or if you laugh, talk or yawn.

To remove water, tilt your head back, press the top of the mask (if your mask has a valve, there is no need to press the top edge) and exhale through your nose. Water must be removed through the lower flange of the mask. This procedure can be repeated until the water is completely removed from under the mask.

When immersed in water, the glass of the mask may fog up. To prevent fogging, simply wipe the inside of the glass with saliva and rinse with water. This procedure reliably prevents fogging.

After diving, rinse the mask clean fresh water. Try not to leave the mask in direct sunlight for a long time. Protect the glass from contact with hard objects, and the body from excessive and prolonged deformation. For storage and transportation, it is better to use special plastic boxes.

B. The effect of water pressure on the mask during diving.

When diving, you may experience discomfort as a result of increased water pressure on the mask. This occurs due to the difference in pressure between the outside and inside of the mask. These pressures need to be equalized by slowly exhaling through the nose into the mask.

C. Pressure on the eardrums.

Another unpleasant result of increased pressure can be discomfort in your ears. This occurs due to the difference in pressure on the eardrum of water on one side and air on the other. To equalize these pressures it is necessary to “blow out”, i.e. pinch your nose with your fingers and exhale through your nose (it is very convenient to blow through a mask with a protrusion for the nose).

WETSUITS

Main function

Everyone understands the need to use insulating wetsuits when diving in cold water. But what is “cold” water for a submariner? A scuba diver begins to freeze before a swimmer without scuba gear, since the swimmer’s movements are usually less active. It's safe to say that for most people, an hour-long immersion in water with a temperature of 30 0 C requires the use of a thermally insulating wetsuit. Of course, they are used perfectly in warm and ice water. different models suits, which can belong to one of three groups: wet, dry or semi-dry.

Wetsuits

Wet suits are made of neoprene, a porous rubber that contains air bubbles and therefore has good thermal insulation properties. Neoprene, like regular rubber, does not allow water to pass through. The wetsuit fits tightly to the body and reduces the rate of exchange of the small volume of water under the suit with the surrounding water: the internal water heats up quickly, and heat loss through the neoprene is very limited. For the manufacture of modern suits, neoprene with a thickness of 3 - 7.5 mm is usually used, covered on both sides with nylon or jersey fabric; The inner covering can also be made of synthetic plush. Some suits have an additional layer of metallized thermo-titanium fabric placed between the neoprene and the outer covering. The heat-reflecting properties of this material improve the thermal insulation characteristics of the suit. The second layer of thermotitanium on the inside of the neoprene makes the suit even warmer.

There are different types of wetsuits: monosuits and separate wetsuits. Suits with short sleeves and legs are very popular in warm, tropical climates or for pool activities.

Separate wetsuits consist of pants, in the vast majority of cases combined with a sleeveless vest, and a jacket, usually with a hood. This suit covers the submariner’s torso with a double layer of neoprene and has better thermal insulation properties than a monosuit of equal thickness. To make dressing easier, one or both shoulder straps of the pants are sometimes made with Velcro fasteners.

For ease of putting on, wet suits are equipped with zippers. Since the latter allow water to pass through, the more of them, the lower the thermal insulation characteristics of the suit, but the easier it is to put on.

Monosuits have one zipper at the front. The pants of separate suits can be either with or without zippers; jackets are almost always equipped with vertical zippers, either straight or oblique, detachable or permanent, fastened from top to bottom or from bottom to top.

Another version of a wetsuit is a monosuit and a sleeveless jacket worn over it. IN warm water You can use only a monosuit, enjoying its advantages, and in cool water you can additionally insulate yourself with a jacket.

Desirable elements of a wetsuit are neoprene socks or boots. In addition to their thermal insulation function, they increase comfort when swimming with fins, preventing foot rubbing. Boots differ from socks in the presence of a dense rubber sole, which allows you to move in them on land (in preparation for or after a dive) without damaging the neoprene. If you use socks, then when walking along the shore or deck, wear slippers or sandals over them - otherwise the neoprene sole will not last long. The most common thickness of socks is 3 - 3.5 mm, boots - 3, 3.5 and 5 mm. Boots can be with or without zipper - the first option is more convenient and durable.

At water temperatures below 22 - 24 0 C, the use of neoprene gloves becomes relevant; the most common are 3 and 5 mm. For cold water, gloves with a thickness of 7 mm are suitable. Three-fingered models have the best heat-insulating properties. The thicker the gloves, the more difficult it is to perform the usual manipulations with your fingers - to inflate and deflate the compensator, to correct a displaced mask, to remove hair that has gotten under it. On the other hand, frozen fingers lose sensitivity and mobility, which makes correct execution much more difficult. Choosing the optimal gloves for given diving conditions is a very important matter, since your safety under water largely depends on the performance of your hands. If you are about to dive into cold water, and your suit does not have a hood, you can use a separately made hood, tucking its shirtfront under the collar of the suit.

Dry and semi-dry suits

Dry suits insulate the submariner's body from the water. For amateur purposes, dry suits with open faces and hands are typically used in combination with half- or full-face masks and wet gloves. For better sealing, there are neck seals and double cuffs on the sleeves. The edges of the gloves are tucked between the inner and outer cuffs.

How does a dry suit seal after being put on? The vesting occurs through the “appendix” (a rubber tube glued into the front part), after which it is tightly tied with a rubber band. This method of sealing has proven itself well in practice. The domestic industry continues to produce dry suits of this type. The vast majority of foreign-made dry suits are equipped with sealed zippers, making the dressing process easier and faster.

Under a rubber-based dry suit, additional insulation is placed: woolen underwear or special foam overalls. It must be remembered that in the event of partial or complete depressurization of such a suit, water will displace the air in the insulation layer, thereby reducing the buoyancy of the submariner. Neoprene suits themselves have thermal insulating properties and require less additional insulation. Quite often, like wet ones, they are worn on a naked body. In any case, the loss of buoyancy when depressurizing a neoprene suit is significantly less than a rubber one.

How to choose a suit?

The vast majority of amateur divers around the world use wet suits. A wet suit is more maintainable and practical than a dry suit. Swimming in a dry suit requires more professionalism, since air bubbles moving in the space under the suit change your stability. Perhaps the only advantage of a dry suit is its better thermal insulation properties. If you have little experience in scuba diving, start with the “wet” option. A separate wetsuit made of neoprene with a thickness of 7 mm is quite suitable for a dive lasting 30 - 40 minutes in water with a temperature of 5 - 10 0 C. We add that dry suits are much more expensive than wet suits of similar quality.

Costume care instructions

1. Rinse with fresh water after use in salt water. For daily use in salt water, you can do without desalination, but then you should not allow the suit to dry completely between dives, since it is the salt crystals that form that destroy the rubber.

2. Rinse the suit clean water after diving in contaminated water.

3. Do not dry it in direct sunlight or near heating devices.

4. Avoid severe kinks and permanent folds or stretching during storage and transportation.

3.5 Flippers

Main function

Is it possible to swim without fins? Without a doubt. You can dive with a mask or without fins, enjoying the beauty of the underwater world. But everything changes when we put on scuba gear. The weight of the cylinders under water is small, but the mass, i.e. the inertial force remains the same as on land - about 20 kg. In addition, rigid cylinders restrict freedom of movement. The use of fins compensates for the difficulties encountered. Properly selected, comfortable and effective fins largely determine a scuba diver’s comfort underwater. Choosing the most suitable fin model depends on the tasks you face and your individual characteristics.

Elements of fins

To assess the suitability of fins, we highlight two parameters:

· ease of attachment to the leg;

· efficiency when swimming. The first is determined by the design of the overshoe, the second by the design of the blade and the general shape of the fin.

The variety of designs of galoshes comes down to two basic options: with closed and open heels. The first ones are very comfortable when put on bare feet and provide the tightest connection between the fins and the foot. To put a wetsuit on your boots, it is more convenient to use fins with an open heel, equipped with a strap. They are also called adjustable. Modern models Adjustable fins allow you to tighten and loosen the strap right on your foot.

The variety of designs of fin blades is very large. For fins, as for any engine, the efficiency factor is extremely important, i.e. the ratio of useful work to energy expended. Underwater, everything is measured by air: the more energetic the physical work, the greater the air consumption. The more efficient the fins, the less air is needed to cover a certain distance. All other things being equal, the effectiveness of the fins and their suitability for your individual characteristics can change the air flow rate by 20 - 30%. Accordingly, the time spent under water will change by the same amount.

Long fins with blades made of thin, elastic and fairly hard plastic and rubber galoshes have excellent hydrodynamic properties. In terms of speed, such fins are superior to the vast majority of other models and are optimal for swimming without scuba gear. It is no coincidence that underwater hunters around the world prefer fins of this particular design. Scuba divers, on the contrary, rarely use them, since they are inferior to smaller fins in maneuverability. For swimming with the apparatus, fins with shorter blades made of similar material are available.

Another way to increase efficiency is fins with windows. What is their meaning? During a stroke, a zone of high pressure is created on one side of the rowing surface, and a zone of low pressure on the other. The resulting vortex flows along the edges of the fins create additional resistance. Slots at the base of the blade allow water to pass through, reduce the pressure difference and thereby weaken the vortex flows. This design does not increase the speed imparted by the fins, but reduces the effort during the stroke.

The efficiency of fins increases significantly when using the tunnel effect. During the stroke, a certain amount of water inevitably rolls off to the sides, without participating in creating the forward movement of the submariner. If inner part The blades of the fins are made from more soft material than the side parts, then when the fin is stroked, it bends, forming a groove that orients the flow of water in the desired direction, thereby reducing the amount of water rolling down idle. Another way to create a tunnel effect is to separate plastic blade 2 - 4 longitudinal rubber grooves allowing transverse bending. A variation of the tunnel effect is the spoon or ladle effect, achieved by a wedge-shaped insert of softer material or rubber grooves of different lengths. Today fins with tunnel effect most popular among submariners - scuba divers.

Choice of fins

How to choose fins? First, you need to choose between closed-toe and open-toe fins. For activities in the pool, high-speed swimming or spearfishing, it makes sense to go with the first option. If you plan to seriously engage in scuba diving, we recommend purchasing fins with an open heel and adjustable straps and getting neoprene socks or boots, since without them, swimming in adjustable fins is extremely uncomfortable and often leads to the formation of calluses.

Now about choosing a specific model. Overall design and color variations are important, but the hydrodynamic properties of the fins are much more important. Depending on your build and physical capabilities, certain fins will be most comfortable for you. We offer the following test to help you make an informed choice. All you need is a swimming pool or an open pond. Put on your mask and fins, calm your breathing and dive in one breath for a fixed distance close to your limit. For some it will be 25 m, for others it will be 50 or more. Rest and repeat the experience with other fins. Choose those with which this exercise is easiest for you. They do not necessarily develop maximum speed, thereby reducing diving time, but they most efficiently convert your energy into forward motion, which means they will best save air when diving.

Instructions for using fins

If the fins do not have metal parts, it is not necessary to rinse them with fresh water after each sea dive, but it is advisable to do this before a long break in use.

Do not leave them in direct sunlight for a long time, do not dry them on a stove or other heating device, and avoid deformation during transportation and storage. For the latter, do not neglect the use of plastic inserts in the galoshes included in the delivery kit.

Subject to these simple rules The fins will last for many years.

3.6 UNDERWATER DEVICES

Purpose

When underwater, it is advisable for a diver to monitor many parameters, namely to know: dive time, current depth, maximum depth reached, direction of movement. The diver's instruments help obtain such information.

Watch. - (watch) help control dive time. Mechanical or quartz watches are made in a sealed and durable case. To determine the start of the dive time, there is a movable ring (dial) around the dial, with a large scale marked out. A design feature of diving watches is the use of a rubber strap of increased length to secure the watch over a wetsuit. The dial of a diving watch has larger diameter than regular watch. The dial itself or just the numbers must be made of reflective materials.

Compasses. Underwater magnetic compass ( compass) also has increased symbol sizes on the scales. The moving element is usually a card, as in marine compasses. The card moves in a cavity filled with an alcohol-glycerin mixture. This ensures smooth running of the cartridge. Most often only the north-south arrow is marked on the card. The scale is graduated from 0 to 360 0, every 5 degrees. On top of the scale, as a rule, there is a movable dial with a sighting line, which is used to measure the course and take bearing.

Underwater compasses are produced in wrist versions; they are combined with watches and built into the diver's instrument console.

Depth gauges -(depth gauges) are the easiest to use devices. They are available in both wrist-mounted versions and integrated into the instrument console. Almost all modern depth gauges are membrane type. Their design is almost the same.

Instrument console. As a rule, it includes a high-pressure gauge (indicates the pressure in the cylinders of air-breathing apparatus), a depth gauge and a compass. All these devices are located linearly in a common sealed housing made of impact-resistant plastic or hard rubber.

3.7 BULOCATION COMPENSATOR

Diving underwater. There a person comes into contact with unusual world full of secrets and mysteries. Everything is “wrong” here: light and color, sounds and sensations of your own body, ease of movement in any direction, “victory” over gravity. But, unfortunately, it is simply the force of gravity, so familiar up there, here in the world of liquid and swarming bubbles that has entered into a “union” with the Archimedean, or buoyant force. It is this “union” that sometimes causes a lot of trouble for those who decide to go under water. The imbalance of forces of the “union” either prevents them from going under water or drags them to the bottom. A certain (necessary) part of a modern scuba diver's equipment - the so-called buoyancy compensator - allows the position of forces to be balanced and the diving process to be controlled in the "up-to-down" direction.

Without going into the historical details of the emergence of buoyancy compensators, we will consider the design principles of this type of equipment, the basic principles of operation of devices and mechanisms, and also try to determine the trends in their development. The first models of buoyancy compensators had a double shell. The external one was forceful. Made from durable synthetic material, it protected the inner shell from mechanical stress. Load-bearing belts and power elements for attaching other equipment and pockets were sewn onto it. The inner shell was made of gas-tight material - it was this that was the working fluid of the compensator. Currently, expansion joints consist of a single shell, the outer layer of which is reinforced with synthetic fiber, and the inner layer is covered with a gas-tight layer to ensure tightness. Almost any company that produces underwater technical equipment includes a buoyancy compensator in its “gentleman’s” set. Currently, the following division of the great variety of models and types of compensators is unofficially accepted:

· stabilizing vest;

· adjustable vest;

· professional compensators.

Stabilization vest it really looks like a vest. Its internal volume consists of 3 interconnected air chambers: dorsal and 2 lateral. The swimmer inserts his arms into the inner armholes of the side chambers. The load-bearing strength element is the shell itself. There are also models with duplicate shoulder straps. The advantages of this type of buoyancy compensator are its large working volume and comfortable position on the swimmer’s body. The disadvantages include high hydrodynamic resistance and some stiffness of movement with the full volume involved.

Adjustable Vests. As a rule, this type of buoyancy compensator has a well-developed dorsal chamber; the side chambers pass under the swimmer's arms or are absent altogether. Only shoulder straps with adjustable buckles go over the shoulders. The advantages of this design are the following: the vest perfectly fits any swimmer’s body type, is easy to use both in the air and under water, has low hydrodynamics, and does not restrict movement. The disadvantage is perhaps the small working volume.

Professional expansion joints. These are single-volume compensators. Externally they have the shape of a torus or an inverted Latin letter "U". Torus-shaped ones have a head bolster and a developed chest part, which is why they are sometimes called “bibs.” "U"-shaped ones are located between the swimmer's back and the tank. The advantages of these compensators: they have good stability in the filled position on the surface of the water, do not interfere or restrict movements when filled, are compact and easy to use, and have low hydrodynamics.

Let's consider the main devices and mechanisms that allow you to control the internal volume of the compensator. In general, they are the same for everyone existing models and use the same principles. These devices include a bleed valve and an air filling system. On some models there are up to 4 bleed valves. The compensator is filled with air in two ways: through the mouth filling valve system or from the second stage of the scuba gear. The buoyancy control device has two push-on inlet valves located in one ergonomically shaped molded plastic housing. A long corrugated tube with a large bore area communicates at one end with the internal volume of the compensator (sometimes there is another exhaust-type bleed valve in this place, and the tube itself is also a valve rod), the other end is attached to the body of the filling device, where there is a mouthpiece to hold it in a swimmer's mouth. A durite air supply hose from the gearbox to the valves of the filling mechanism is located parallel to the corrugated tube. The system was called "inflator", which is now officially used in all technical descriptions and instructions for use and maintenance of expansion joints. The bleed valves have a sufficient flow area, which allows, if necessary, to quickly release the air present in the compensator. By pressing the button protruding on the inflator body, the swimmer opens the valve, and air enters the internal volume of the compensator through a corrugated tube. Some expensive models of compensators are equipped with an emergency breathing machine built into the inflator body. An important component of the compensator is the system for attaching it to the scuba diver’s body. The compensator must be easy to put on and take off, securely attached to the swimmer’s body and withstand significant loads (the weight of the scuba diver and his equipment). Modern compensators have a number of devices that meet operational and ergonomic requirements. These are: built-in pockets for soft goods, swivel attachment points for shoulder straps, attachment points additional equipment, built-in adjustable cradle for attaching a scuba cylinder, large spacious side pockets with drainage meshes, a system for releasing embedded loads.

Concluding the review, we list some trends in the development of buoyancy compensators: the use of double independent air chambers, the use of a three-dimensional cut of air chambers (which leads to a significant increase in working volume with virtually no change in the external dimensions of the compensator), increased ergonomics and further “anatomization” of compensators, as well as improvement of the filling system and transition to pneumatic control of release valves.

Diving equipment

Training using normobaric diving equipment.

Diving equipment- set technical means, used by a diver to ensure his life and work under water. Diving equipment is often divided into two types: heavy (for diving to great depths) and light (for diving to shallow depths, and also used for sports purposes). Diving equipment is also distinguished by the method of air supply: hose and autonomous. However, the reference classification of diving equipment involves division both by design features and by the type of air supply system and the composition of the breathing mixtures used in these systems.

History of diving equipment

In ancient times, when attempting to dive under water (for example, for hunting purposes), a person could only rely on his endurance and courage. Moreover, the first mentions of technical devices for diving under water are found in the works of Aristotle in the 4th century BC. In his writings, he writes that in the time of Alexander the Great, divers could breathe underwater by lowering an inverted cauldron into it, in which air remained. In fact, this inverted cauldron was a prototype of a diving bell invented only in the 16th century.

Diving bell

Diving bell

The history of diving equipment dates back to the Middle Ages, when a technical device called a diving bell came to the aid of sea explorers. Its essence was that when immersed, air remained inside this bell, which was enough for a person to work under water for some time. Around the same time, a technical device called a caisson was invented, which was used to form a water-free chamber underwater.

Around the same time they came up with diving helmet, essentially a bell in miniature, into which air was supplied through a flexible hose using a pump located on the surface. In 1690-1691, Edmund Halley proposed his own version of diving equipment, which was later named after him. Since the change of air in new versions of equipment occurred continuously, providing constant ventilation, the equipment began to be called ventilated.

Despite the fact that these methods were quite primitive and severely limited divers, they were widespread until the mid-19th century.

Diving suit

The first suit suitable for underwater work dates back to the year. It is believed that its author was the Englishman August Siebe. The suit included a helmet with a porthole, hermetically connected to a waterproof shirt. Air was supplied through the hose into the helmet, and from under the shirt the already used air quietly came out. The main disadvantage of this suit was the possibility of water penetrating under the shirt when the diver tilted. The shirt was later replaced by a completely sealed suit. In addition to the suit, galoshes and chest weights were included to compensate for the buoyancy of air. In this case, the helmet was supplemented with an exhaust valve designed to remove excess air, which allowed the diver to regulate buoyancy.

However, back in 1839, English diving suits, invented by John Dean, began to appear in Russia. This diving equipment was a combination of Siebe's diving suit with a powerful pump. This equipment developed quite quickly, and by the middle of the 19th century it was in fact the prototype of modern twelve-bolt ventilated equipment. A little later, an analogue of modern three-bolt equipment appears in Russia, invented by the Frenchman Auguste Deineruz (French) Russian .

Since the 1860s, the production of twelve-bolt equipment has been established at Russian factories. From about this time, ship divers were introduced into the crew of large ships.

Helmet from Three-Bolt Diving Suit

Ventilated diving equipment ensures the diver's breathing by continuously supplying compressed air from the surface through a flexible hose into the inside of the equipment, usually into the space under the helmet. Inside the equipment, the air is mixed with used air and periodically released into the water (ventilated).

A classic representative of ventilated diving equipment is a diving suit. Depending on the type of connection between the helmet and the diving suit itself, the equipment is divided into three-bolt and twelve-bolt.

Three-bolt diving equipment finds its application mainly in marine conditions at medium depths. Most often used for various rescue and ship-lifting diving operations. Usually found in operation on rescue ships, diving stations of sea diving boats.

Twelve-bolt diving equipment Finds application at shallow depths, mainly in rivers and lakes. Most often used for underwater technical work in ports and harbors. The advantage of this equipment is that it is easy to put on, but the connection between the helmet and the suit is less airtight than in a three-bolt version, so the depth of immersion is limited. It is in operation at coastal diving posts, diving stations of river diving boats and technical watercraft.

Injection-regenerative equipment used for diving work at great depths and ensures the diver’s breathing due to the gas volume of the equipment, in which the respiratory mixture is fully or partially restored in the regenerative system of the equipment. The energy intensity of the regenerative system directly affects the length of time a diver remains underwater. In this case, the maximum immersion depth depends not only on the design features, but also on the composition of the breathing mixtures.

Injection-regenerative equipment is divided into two types:

• helio-oxygen equipment.

Air oxygen equipment

Air oxygen equipment- This is a three-bolt equipment equipped with an injection-regenerative device. The main elements of this device are an injector, a regenerative box and a removable switch tap. It is possible to remove the injection-regenerative device, thus obtaining conventional three-bolt equipment.

Air-oxygen equipment allows a diver to dive to a depth of up to 100 m. This equipment is mainly used in the operation of deep-sea diving stations of sea diving boats and is used to perform rescue and ship-lifting diving operations.

Helium-oxygen equipment

Helium-oxygen equipment also equipped with an injection-regenerative device. But in this type of equipment, the injection-regenerative device makes it possible to restore the gas composition in the suit at all stages of the dive. The injector of this device operates in two modes, and the regenerative box is equipped with two cartridges, which are included in the air recovery system in parallel. The front load body contains a valve for switching operating modes and an emergency gas reserve device.

When working at depth or when lifting, the injector operates in economical mode. This mode is called main mode. The auxiliary mode of operation of the injector provides for an increased supply of gas to the operation of the injector. The second mode is used only during a dive or a quick change of gas mixture in a spacesuit at depth. The operating modes of the injector, as well as the emergency gas reserve device, are under the control of the diver. The emergency gas reserve device is intended for emergency situation to replenish gas when leaks occur from the suit, or gas supply from the surface is interrupted, for example, due to a ruptured hose.

Helium-oxygen equipment is used in the operation of deep-sea diving stations of rescue, rescue-ship-lifting and other vessels. The main name of this equipment is rescue, ship-lifting work.

Regenerative Gear

Regenerative Gear, or equipment with a closed breathing circuit, unlike the ventilated and injection-regenerative ones, it is equipped with an autonomous gas supply system and is much lighter, so it is classified as light equipment. This equipment does not use gas volume, and breathing is provided closed system breathing apparatus. Air regeneration occurs during the breathing process in a special apparatus included in the equipment.

The following types of regenerative equipment are distinguished: oxygen, nitric-oxygen, rescue, etc.

Oxygen equipment usually consists of a chest or back breathing apparatus and a diving suit. Typically allows diving to a depth of about 20 m and is used for ship diving. There is also a low-magnetic version of this equipment, used for diving work in the presence of a mine danger.

Equipment with an open breathing pattern- this is light diving equipment in which the diver’s breathing is provided by a flow of air aimed only at inhalation, and the exhalation of the used air is carried out directly into the water. Mainly used for sporting purposes, less often for ship diving. It is divided into 3 main types: hose, air balloon and universal. Breathing in all three types occurs through a mouthpiece or half mask of a helmet.

Hose equipment consists of a hose apparatus, wetsuit, galoshes, chest and waist weights.

Air balloon equipment consists of an air bladder, a wetsuit, a weight belt and fins. The equipment is completely autonomous and allows you to move freely underwater. used most often for sporting purposes. Breathing in the equipment is carried out through the helmet-mask mouthpiece or half-mask of the helmet.

Universal equipment consists of an air balloon or hose apparatus, wetsuits, weights, boots, galoshes and fins. This equipment is mainly used for ship diving. Besides autonomous system air supply, it is possible to supply air from the surface through a hose.

Air supply means

• Diving pump- a mechanism for supplying air from the surface, through a hose, into a diver’s suit (in particular, into three-bolt diving equipment), for work at a depth of up to 20 meters.
. Mandatory disinfection is carried out during the annual inspection of diving equipment, as well as upon receipt of it from the warehouse. During operation, disinfection is usually done in rare cases and is mainly associated with the suspicion or appearance of a diver infectious diseases.

Before disinfection, preparatory cleaning of contaminants and washing with boiled water, cooled to 40-50 °C, is carried out. After cleaning, wipe dry with a rag. Then the disinfection itself is carried out using rectified ethyl alcohol.

Corrugated tubes, breathing bags, diving hoses and gas pressure lines are washed hot water, sometimes steamed, and then poured with a certain amount of alcohol for 10-15 minutes. Later, the alcohol is drained, and its remains are removed with strong air pressure. Disinfection of such parts of equipment as a helmet, mask, half mask, mouthpieces, flanges and other rubber products is simply wiped with an alcohol-soaked gauze swab.

To degrease and disinfect the fittings of oxygen and helium cylinders, they are wiped with an alcohol-soaked rag, the remaining alcohol is removed with a stream of air - a set of items put on the diver and connecting him to the equipment supplying the breathing mixture, depending on the depth of immersion and the method of supplying the breathing mixtures, heavy diving equipment is distinguished and lung. Heavy... ...Nautical Dictionary

diving equipment- A set of devices and protective clothing worn by a diver that ensures his life activity at high pressure in the surrounding water or gas environment. Note Diving equipment is distinguished according to the following characteristics: depth of use... Technical Translator's Guide

Diving equipment- Diving equipment: A set of devices and protective clothing worn by a diver, ensuring his vital functions under high pressure in the surrounding water or gas environment...