Ship's salvage property. To eliminate water leakage of the hull and various damages, ships are provided with emergency equipment and materials.
The name and minimum quantity of salvage property are established by the standards of the Register of the Russian Federation, depending on the length and purpose of the vessel. The emergency supply includes: patches with rigging and equipment, plumbing and rigging tools, clamps, bolts, stops, staples, nuts, nails, canvas, felt, tow, cement, sand, wooden beams, wedges, plugs, etc. On passenger on ships and special-purpose vessels with a length of 70 m or more, as well as on ships made of fiberglass, the Rules of the Register of the Russian Federation provide for additional supplies. In addition, all modern large-capacity ships usually have light diving equipment and electric welding equipment.
Emergency supplies, other than diving equipment and bandages, must be painted blue: wooden crafts- fully; beams - from the ends and at the ends (at a length of 100-150 mm); metal objects - on non-working surfaces: plasters, mats, coils of wire - in transverse stripes.
Containers for storing emergency supplies must also be painted blue (either completely or in a stripe) and clearly labeled with the name of the material, its weight and permissible shelf life.
All specified supplies must be stored at emergency posts: in special rooms or in boxes. There must be at least two such posts on the ship, and one of them must be in the engine room (on ships with a length of 31 m or less, storage of emergency supplies is allowed only at one emergency post. Emergency posts must have clear inscriptions “Emergency post.” In addition In addition, signs for the location of emergency posts must be provided in the passages and on the decks.
Emergency equipment that has special markings is allowed to be used only for its intended purpose: when fighting water, as well as during drills and exercises. Any emergency equipment that has been used up or has become out of order must be written off according to the act and replenished to normal as soon as possible.
At least once a month, commanders of emergency parties (groups) with the participation of the boatswain must check the availability and serviceability of emergency equipment. The results of the inspection are reported to the chief mate. A similar check of emergency property (simultaneously with a check of fire-fighting equipment and life-saving equipment) is conducted by a senior assistant once every 3 months. Which he reports to the captain and takes measures to eliminate deficiencies. All this is recorded in the ship's log.
Soft patches are the main means of temporarily sealing holes; they can take the form of the hull contours anywhere on the ship. On sea vessels, four types of soft plasters are used: chainmail, lightweight, stuffed and training.
Plasters are made from waterproof canvas or other equivalent fabric; along the edge they are sheathed with lyktros (vegetable or synthetic) with four thimbles at the corners.
The sheets and guys of the chain mail patches are made from flexible steel cables, the control sheets are made from vegetable cables, and the undercut ends for all the patches are made from flexible steel cables or chains of the appropriate caliber.
The sheets and keel ends must be long enough to cover half of the ship's hull amidships and fasten on the upper deck, provided they are spaced from the vertical at an angle of 45
The control pin, designed to facilitate the installation of the patch on the hole, has, like a lotline, a breakdown every 0.5 m, counting from the center of the patch. The length of the control pin should be approximately equal to the length of the sheet.
Guys provided for chain mail and lightweight plasters serve as auxiliary equipment that facilitates a tighter fit of the patch to the hole. The length of each guy must be at least half the length of the vessel. The most durable of all soft patches is chain mail.
Plasters are applied to the hole as follows. First, using the numbering of the frames, mark the boundaries of the hole with chalk on the deck. Then the patch with the equipment is brought to the place of work. At the same time, they begin to wind the under-keel ends. At this point, the ship should not be moving. Depending on the location of the hole along the length of the vessel, the keel ends are brought in from the bow or stern and placed on both sides of the hole. If the under-keel ends are brought in from the stern, you should use weights attached to them, which will allow you to pass the under-keel end cleanly without touching the propellers and rudder.
Using staples, the heel ends are attached to the lower corners of the patch, and the sheets and control rod are attached to its upper luff. Then, on the opposite side, they begin to select the keel ends with hoists or winches, while simultaneously moving the sheets until the control rod shows that the patch has been lowered to the specified depth.
Stretched under the right angle and tightly selected sheets and keel ends are attached to bollards or cleats. The adherence of the patch to the damaged area is considered satisfactory if the ship's drainage systems are able to remove water from the flooded compartment.
A soft plaster allows you to quickly quickly seal cracks and small holes on ships, but it has a number of disadvantages:
Does not have the required strength;
Does not allow it to be started without the participation of a diver in cases where the hole is located near the zygomatic keel or has torn, bent outward edges;
Can be torn out of place when the ship moves.
At large sizes holes (more than 0.5 m2) as the damaged compartment is drained under the pressure of sea water, the patch will be drawn into the hole. In this case, before installing the patch, you have to resort to inserting several steel under-the-keel ends running along the hull through the hole. These ends, called false frames, are tightened on the deck with the help of turnbuckles; they play the role of a frame that prevents the patch from being pulled into the body.
Maneuvering a damaged ship
If a ship has received any damage on the high seas, skillful maneuvering is an important condition for preventing its destruction. As a result of damage, the ship may receive a large list, surface holes near the waterline, and as a result, as a rule, its stability decreases. Therefore, it is necessary to avoid, especially at high speed, sharp shifts of the steering wheel, which cause additional heeling moments.
If the bow is damaged, causing water leakage in the hull, the forward movement of the vessel will increase the flow of water, and therefore create extra pressure on the aft bulkhead of the damaged compartment. In this situation, going forward before filling the hole is risky, especially if the hole is significant. If it is impossible to repair the hole, you should significantly reduce speed or even go in reverse (for example, on multi-rotor ships).
In the event of icing of a damaged ship, its stability and maneuverability are usually further deteriorated, so the crew must take measures to combat ice.
If the damaged ship has a significant list that cannot be reduced, then the captain is obliged to maneuver so that, in order to avoid capsizing, the elevated side of the ship is not to windward, especially when the wind reaches gale force or is squally. In stormy weather, changing the speed and course relative to the wave can significantly reduce the amplitude of rolling, avoid resonance, as well as possible loss of stability in following waves, most likely at wavelengths close to the length of the vessel.
If the damage sustained by the ship during navigation is so great that the crew cannot cope with the incoming water using the ship's means, it is most reasonable to ground the ship. If possible, you should choose a shore that has a gentle slope, sandy or other similar soil without stones. It is also desirable that there are no strong currents in the landing area. In general, it is better to run aground anywhere (if this does not threaten the obvious loss of the ship) than to attempt to reach a suitable shore and expose the ship to the risk of sinking at great depths.
When making a decision to ground a damaged ship, one must take into account the risk of reduced stability if the ship touches the ground with a small area of the bottom, especially on hard ground in an area where the depths increase sharply from the shore. The support reaction that appears at this moment, applied to the bottom of the vessel at the point of contact with the ground, is the reason for the decrease in stability. A dangerous roll may not occur if the slope of the ground is close to the angle of roll or trim of the ship, since the ship will land on the ground immediately with a significant part of the bottom, as well as when landing on soft ground: in this case, the tip of the ship does not rest on the ground, but crashes into him.
To prevent the ship from receiving further damage from impacts on the ground in stormy weather, it must be secured aground, for example, by bringing in anchors or additional flooding of compartments.
When all the damage has been repaired, they begin to pump out water from the flooded compartments. First of all, water must be completely removed from the compartments that have the greatest width. If this recommendation is neglected, as the vessel ascends, its stability may again deteriorate due to the presence of free surfaces.
Grounding is carried out, as a rule, by the bow, but in soft ground, landing by the stern with the release of both anchors at an angle to the coastline, possibly closer to straight, is not excluded. Despite the risk of damage to the rudder complex, this method is not without advantages: the bow of the ship, which is the most durable part of the hull, will absorb the shocks of the waves, and the minimum area will be exposed to the shocks; anchors can be used to secure a vessel aground, avoiding the very labor-intensive operation of delivering them. In addition, they can be used to facilitate the subsequent refloating of the vessel.
Self-test questions:
1. What applies to emergency equipment, materials and tools?
2. Marking of emergency equipment.
3. Plasters.
4. Sheets and guys.
Vessels navy, according to the Register Rules, are not supplied with rigid adhesives. If necessary, in ship conditions, the easiest and fastest way to make a hard patch is in the form of a single- or multi-layer wooden board with soft cushions of tow or felt around the perimeter.
The location of the boards in the patch depends on the shape and size of the hole. It is advisable to make a plaster with an aspect ratio of less than two in two layers, with mutually perpendicular arrangement of boards in the layers.
To close narrow and long holes, it is more advisable to use one- or two-layer patches with parallel arrangement of boards in layers. The boards should be located across the holes.
Hard patches It is most advisable to use it to close holes located above the waterline or near it, as well as in cases where the holes can be exposed by heeling and trimming of the vessel. This creates the most convenient conditions when placing a patch and allows you to do without the help of divers.
For narrow holes, the plaster is fastened using ordinary straight bolts passed through the plaster boards and metal strips placed from the inside of the vessel across the hole through its edges.
For wide holes, the patch is secured to the hole using hook bolts, taken from the inside - by the edges of the hole and also passed through the plaster. Additionally, in the center of the patch (along the axis of the hole), several butts or eyes can be installed for attaching guy ropes with lanyards from inside the vessel. 2.3. Sealing holes with concreting
Concreting is the most reliable way to repair damage to a ship's hull. With the help of concreting, it is possible not only to eliminate the water resistance of the hull, but also to partially restore its local strength in the area of damage.
Concreting can be done both in drained and in flooded compartments. The latter is a more difficult operation and less reliable. In this regard, underwater concreting is used only in cases where it is not possible to drain the compartment.
The components of a concrete solution are: binder (cement), aggregate (sand), fresh or sea water. When concreting damage in the above-water part of the hull, in addition to sand, gravel, crushed stone, etc. can be added as an inert filler if available (Table 2.2).
Table 2.2
Composition of concrete for repairing damage in the ship's hull (volume proportions)
|
Type and composition of concrete |
Inert aggregates (gravel, crushed stone, etc.) |
Volume proportions |
Notes |
|
|
Greasy concrete |
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|
For concreting in the underwater part of the hull. For concreting in underwater and above-water parts of the hull. For concreting in the above-water part of the hull |
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|
Skinny concrete |
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|
For upper layers concreting. |
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To prepare concrete mortar Ordinary Portland cement, pozzolanic Portland cement, aluminous (bauxite) cement, Baidalin cement and VVTs cement grades 400, 500, 600 can be used * (The grade of cement shows the tensile strength of concrete prepared from a 1:3 solution 28 days after hardening.).
Portland cement is the most widely used. However, in some cases it is advisable to use other cements. Thus, when underwater concreting, it is better to use pozzolanic Portland cement, which is resistant in an aquatic environment.
For concreting at low temperatures, aluminous cement is the best, since, firstly, the hardening of concrete prepared from it is accompanied by an increase in temperature, and secondly, the strength of the concrete rapidly increases immediately after the mortar sets.
Such quick-setting cement is VVC (waterproof, quick-setting), concrete from which acquires half its strength after about 6 hours. An even faster setting cement is Baydalin cement. However, concrete prepared from it begins to crack after 2-3 months. This type of cement is advantageous for short-term concreting*.
The physical and mechanical properties of some types of concrete prepared from grade 400 cement at a ratio of 1:3 with filler are given in Table. 2.3.
Table 2.3
Information about concrete
|
Name |
Setting time, h |
Mechanical strength (1x98066.6 Pa) |
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|
not later |
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|
1 . Portland cement-400 2. Pozzolanic Portland cement-400 3. Aluminous cement-400 4. Baidalin cement |
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Note. In the numerator - upon hardening in air, in the denominator - in water.
Acceleration of the concrete hardening process can be achieved by adding special hardening accelerators to it, which can be used:
liquid glass, which is added to water during the preparation of concrete in an amount of 10-12% of its volume;
calcium chloride, which is introduced directly into the cement in an amount of 2 - 10% of its mass and mixed thoroughly with it;
technical soda in an amount of 5-6% by weight of cement, which dissolves in water during the preparation of concrete;
technical hydrochloric acid added to water in an amount of 1.0 - 1.5% by weight of cement.
These hardening accelerators speed up the setting process of concrete by approximately two times, but at the same time reduce its strength. The best of these accelerators are technical soda and technical hydrochloric acid.
To seal small damage, it is better to use fine sand as a filler. For large volumes of concreting, in addition to sand, gravel and crushed stone are used as fillers. In their absence, you can use finely broken bricks and, as a last resort, slag, but not more than 25-30% of the total volume of filler.
All fillers used for preparing concrete should, if possible, be washed in clean water and not have fatty impurities that impair the strength of concrete. Both fresh and sea water can be used to prepare concrete. The use of sea water reduces the strength of concrete by approximately 10%. The water must be clean, not contaminated with oil, oils and fats.
The preparation of the concrete solution is carried out on a clean deck or in a special box, as close as possible to the place of its use, and includes the following sequence of operations:
filler is poured in an even layer on the deck or along the entire platform of the box;
a uniform layer of cement is poured over the aggregate layer;
a second layer of aggregate is poured on top of the cement layer;
all three layers are thoroughly mixed and then raked to the sides, forming a thicket;
fresh or sea water is poured into the bowl in an amount equal to approximately half or slightly less than the volume of cement; In practice, water is added to the mixture of cement and sand in small portions as they are mixed;
the resulting concrete solution is mixed with shovels until a completely homogeneous mass is obtained and the solution takes the form of a thick dough.
In the place designated for concreting, formwork is installed, a so-called cement box with two open sides, one open side of which is adjacent to the perimeter of the damage site, and the other side is filled with concrete.
To ensure a tight fit, gaskets made of felt or resin tow can be used. At small sizes damage (cracks, etc.), the box can be directly filled with concrete.
If the hole is of significant size, it must first be covered with reinforcement made of steel tubes or rods, arranged in the form of a grid with cells from 10 to 25 cm and tied at crosshairs with wire. The reinforcement is attached to the body, and after that the box is filled with concrete (Fig. 2.12).
For tight concrete connection with the body, it is necessary that at the place of concreting it is thoroughly cleaned of rust and dirt and washed with soap and caustic soda. Concrete must be supplied continuously to the laying site so that each subsequent layer of mortar is applied to a layer that has not yet hardened. If for some reason there is a break in the supply of concrete and the solution in the cement box hardens, then before further supply of fresh concrete it is necessary to put metal mesh or steel sheet or strips.
Rice. 2.12. Schematic diagram concreting the hole:
1 - concrete; 2 - cement box made of sandbags; 3 - sand; 4 - sandbags, 5 - reinforcing steel mesh; 6 – grid
To protect fresh concrete to prevent erosion by water that can seep through the hole, special outlet pipes are installed in the cement box. The cross-section of the outlet pipe must ensure the flow of filtration water without creating pressure.
The method of installing the tube depends on the nature and location of the hole (Fig. 2.13). However, in all cases it must come from the bottom point of the hole, and its outer end (the surface of the drained water) must be below the concrete level.
After the concrete has hardened the tube is plugged. Fastening a wooden shield or a rigid wooden plaster with soft sides to the hole is carried out using hook bolts, for which special holes are drilled in the plaster (shield).
Rice. 2.13. Placement of the cement box on board the vessel:
1 - soft patch; 2 - internal formwork; 3 - concrete; 4 - external formwork; 5 - spacers; b - spacers of the internal formwork; 7 - shield; 8 - outlet tube; 9 - supports; 10 - thrust bars
B.2.2.1: Water flow into the compartment. Actions to take when water ingress is detected.A: Under normal operating conditions, the flow of water into the compartment is controlled by measurements of the water level in the bilges of the cargo rooms - every watch, which is reported to the watch officer and an entry is made in the measurement log; In MKO, water flow is monitored visually. In emergency situations, when a hole is received, the location of the hole is visually determined: between which frames it is located, its size, height from the main deck. All of the above is reported to the bridge. On the bridge, calculations are carried out on the stability and unsinkability of the vessel.
Q.2.2.2: What means are used to seal the hole?
A: Depending on the size of the hole, the following are used: wooden wedges, hammered and manually inside housings; shuminator plugs, thrust emergency bars available in emergency supplies, sliding mechanical stops; placing a patch on the hole and pumping water out of the compartment, placing a cement box (installation, wedging the formwork, pouring cement mortar using liquid glass). If there are holes larger than the size of the patch, they are sealed by special emergency rescue services (ASTR) using caissons.
B.2.2.3: Types of patches used to seal a small hole. Equipment of the patch.
A: Plasters are divided into chain mail, stuffed and lightweight types. For crew training, a training patch is provided. The patches are made in the form of a square from several layers of tarpaulin coated with lyctros. At the corners of the square and in the middle of each side, metal thimbles are inserted into the lyktros, to which the appropriate gear is attached for applying the plaster to the hole site.
B.2.2.4: The procedure for applying a patch to a hole. A: The patch is brought to the hole on the deck and unrolled. The keel ends are inserted under the hull of the vessel; steel sheets and guy ropes are spread across the deck. The under-keel ends on the side of the hole are fastened with staples to the thimbles of the lower luff of the plaster, and the ends of the opposite side are driven through rosin blocks onto winches or onto grab hoists spaced along the deck. Steel sheets are attached to the luff thimbles of the patch and laid on bollards, cleats, dowels, and other parts of the hull on the deck for etching them, using rosin blocks if necessary. Guys are attached to the side luffs of the patch by thimbles and carried to the bow and stern to move the patch along the side. A control line with markings is attached to the middle of the luff to determine the immersion of the patch from the main deck. The patch is dumped overboard, and the slack in the keel ends is removed manually by pulling the sheets. Having selected the slack of the under-keel ends, they are placed on the winch drums (or grab hooks), and the patch is applied to the hole using guy ropes. The correct installation of the patch is controlled from inside the ship's hull, the sheets, jack ends, guys are tightened and everything is secured. The patch is on.
B.2.2.5: Setting up the cement box. Preparation of the solution
A: The most common way to seal a hole is to place a cement box on the damaged area, which allows you to seal the hole and partially restore the damaged strength of the hull in the area of damage. The solution for filling a cement box consists of cement and aggregate - sand, taken in a one to one proportion. To prepare concrete, gravel, crushed stone, and broken crushed brick can be used as aggregates. The composition is made in the following proportion: cement - 1 part; gravel, crushed stone - 1 part (by volume); sand - 1 part. All aggregates, for example, sand, gravel, must be washed in clean water and free from fatty impurities, since the presence of the latter impairs the strength of concrete. It is best to choose a place for preparation, as close as possible to the area of the hole. The solution is prepared on a clean deck or in a special box - tvoril. To do this, filler is poured into the gvoril over the entire area in an even layer, on top of which a layer of cement is poured, and then filler again. All three layers are thoroughly mixed and raked along the edges of the mortar, forming a funnel in the center for water (fresh or sea) in an amount equal to approximately half the weight of the cement. The resulting solution is mixed with shovels until a homogeneous mixture is obtained. Then a cement box, prepared in advance and placed on the damaged area, is filled with this mixture. The design of the cement box is such that it has neither a bottom nor a lid. One open side fits tightly to the site of damage, and through the second open side it is filled with concrete. To ensure that the box fits tightly to the damaged area, pads made of felt or resin tow can be used. For small damage (cracks, etc.), the box can be immediately filled with concrete. For a hole of significant size, it must first be covered with reinforcement made of steel tubes and rods arranged in a grid with cells (from 0 to 25 cm) tied at intersections wire To avoid erosion of the concrete by water seeping through the hole, before it finally hardens, special drainage tubes for water drainage. After the concrete has hardened, they are closed with plugs.
B.2.2.6: Reinforcement of watertight bulkheads of compartments adjacent to the flooded one.
A: A column of water in a flooded compartment creates pressure on the bulkheads of adjacent empty compartments, which become deflected: a rupture may occur steel sheets along welding joints and flooding of the adjacent compartment and, as a consequence, deterioration of the vessel's stability, and, possibly, loss of buoyancy. To reinforce the bulkheads, timber from emergency supplies is used: boards, beams, wedges. Approximately 1/3 of the water column in the flooded compartment on the adjacent bulkhead, boards are installed across the vessel and propped up with beams at an angle to the deck, which are attached to it and the boards. The support is ready.
Currently, small vessels with fiberglass hulls are becoming increasingly widespread, so it is advisable to summarize some experience in repairing such vessels by amateurs.
During the operation of ships, damage to the hulls from invisible underwater obstacles (sinks, stones, piles, etc.) poses a great danger. If the plastic housing hits an obstacle, the following main types of damage are possible:
1) holes in the casing;
2) separation of the set from the skin;
3) deep (more than half the thickness of the skin) scratches.
Let's look at the repair of these three main types of damage to the plastic case separately.
Holes in the casing
Holes in the casing usually occur when the hull hits a fairly sharp obstacle located near the surface of the water at high speed. The damaged vessel must be lifted out of the water and placed on the shore (on keel blocks, etc.) so that it is convenient to work in the area of the hole. Then a thorough inspection of the damage is carried out and the boundaries of the hole are established (holes can be drilled at its ends).The entire damaged section of the skin is cut out from the body along with the kit. The cutout should be rectangular, but with obligatory rounding of the corners (Fig. 1). The set that falls into the damaged area must be cut off at a distance of 100-150 mm outward from the contour of the cutout in the casing, cut down and also removed. You can cut fiberglass of small thicknesses (2-5 mm) manually - with a hacksaw with hacksaw blade made of R-9 steel.
To be able to seal the cutout, it is necessary to make a bevel of the edges with a width of at least 10-12 times the thickness of the skin along the entire perimeter of the cutout (Fig. 2). It is best to use a pneumatic machine with an elastic lacing circle for this purpose (Fig. 3), but with a certain skill you can bevel the edges sharp knife and a hammer (Fig. 4) or even a file.
The surface of the edges on both sides of the cutout must be dried (for example, with a 300-500 W lamp with a tinplate reflector or an electroreflective oven of the Neva type) and before molding the hole, it must be degreased with acetone or gasoline for 20 minutes. to evaporate the degreaser. The hole must be sealed with plywood, which should follow the contour of the body at the cutout (Fig. 5). For this purpose, you can use plywood 3-4 mm thick, bending it along special patterns taken locally from the other side (Fig. 6), and securing it to the same patterns.
Applied to plywood separation layer, after drying, the hole is molded from the inside with fiberglass impregnated with a binder (inner lining of the hole). The area of each layer of fabric gradually increases, and the bevel of the edges is completely filled. It is necessary to lay layers of fiberglass until the surface of the inner lining and skin is leveled (Fig. 7).
After the inner trim has polymerized, the plywood seal is removed, and the surface of the trim that was in contact with the plywood is cleaned to remove the separating layer and also degreased. Then the outer lining of the hole is molded, but not along the plywood seal, but directly along the inner lining. The cross-section of the sealed hole is shown in Fig. 8.
To polymerize the overlays, heating is necessary with a lamp with a reflector or an electroreflective oven. When working in rainy weather, it is necessary to make an awning over the repair site to prevent water from entering directly into the molding area.
Before installing a new set in place of the removed one, thoroughly clean and degrease inner surface sheathing.
Then carefully adjusted pieces of the new decorative material (“strength filler”, “core”), most often wooden, are glued in (using BF glue or K-153 compound). The decorator is joined at the end or with a miter bevel. After this, the new sections of the decorator are molded to the skin and the ends of the old set with layers of fiberglass impregnated with a binder. The molding of the joints of the set should overlap the ends of the old set by 120-150 mm (Fig. 9).
Both sides of the hole seal are cleaned for painting and painted.
Separating the set from the casing
The detachment of the set from the casing occurs when the hull hits a large underwater obstacle (rock, pile, etc.). Sometimes tearing off of the molded set (especially in the bow) occurs during a long course of the vessel in planing mode in waves, when strong impacts of the hull on the water are observed.The part of the kit that has fallen away from the casing must be cut out and removed, and the casing must be thoroughly cleaned and degreased before installing a new kit. The installation and design of the new decorator is carried out in the same way as when installing a kit when sealing a hole. After polymerization of the moldings, they must be cleaned and painted.
Repairing deep scratches
Deep scratches occur when the body touches sharp objects (for example, sharp stones).It is necessary to repair deep scratches immediately upon their discovery, since in places of such damage the strength of the skin is significantly reduced. Deep scratches in the plastic casing are the spots from which delamination of the casing begins.
Sealing deep scratches is done as follows. The sheathing around the scratch is cleaned in the manner described above in such a way that an oval-shaped depression is obtained for the entire depth of the scratch, with a bevel along the perimeter (Fig. 10). This recess is then molded in the usual way with layers of glass cloth impregnated with resin until it is level with the surface of the skin (Fig. 11). After cleaning, the molded surface must be painted over.
The main types of damage described above most often occur when the body hits an obstacle. But damage to the casing can also be caused by other reasons. For example, during long-term operation of the vessel in shallow water or frequent approaches to the shore in shallow places, frequent contact with the bottom (especially when it is rocky or sandy) causes abrasion of the bottom hull plating, primarily in the bow. Therefore, it is recommended to reinforce the skin in this area with additional layers of fiberglass even during the construction of the hull (especially in the area of the keel in the bow). During long-term use, the worn surface must be renewed. To do this, it is necessary to dry, clean and degrease the worn area of the casing, and then mold it onto it. required amount layers of fiberglass.
Vibration during operation of an outboard motor (especially two motors) can damage the transom. There were cases when, when operating a boat with two Moskva outboard motors, cracks appeared in the corners of the under-engine cutout in the transom, which could lead to complete destruction of the transom (Fig. 12).
Repair of this unit must be carried out as follows. The ends of the cracks should be drilled to prevent them from spreading further. Then the area of the cracks must be cleaned on both sides and a rounded wooden booklet must be inserted into each corner of the cutout. The thickness of the bracket should be equal to the thickness of the transom (Fig. 13).
The bracket is glued to the transom with epoxy compound or BF glue. Then chopped fiberglass cloth on resin is hammered into the crack, and the entire area of the crack, together with the knuckle, is molded with fiberglass cloth impregnated with resin (Fig. 14). The thickness of the molding should be equal to half the thickness of the transom. The transom repaired in this way no longer shows any signs of new destruction during further operation.
During the operation of the vessel, damage such as eyelashes, cleats, and bollards being torn out of the deck is also possible. In this case, it is necessary to cut out the place where the torn part is attached to the deck, then round the corners of the cutout and make a bevel of the edge (Fig. 15). Then plywood is installed underneath and the cutout is molded (Fig. 16), as discussed above.
Since the deck at the site where the hole is sealed will be somewhat weakened compared to the whole area, it is advisable to place the eye or bollard in a different place. If this is not possible and the part has to be put in its original place, then a reinforcing plate with a thickness equal to half the thickness of the deck must be placed to seal the hole in the deck (Fig. 17).
On small ships with stationary power plants, when the bottom hits, sometimes the seawater seam molding breaks off, and therefore water begins to flow into the engine compartment. To temporarily stop the leak, you can use raw rubber and a metal yoke 50-60 mm wide. The rubber should be laid around the kingston, overlapping the vertical flange of the molding square by 20-30 mm, and compressed with a yoke (Fig. 18). The flow of water into the boat will either sharply decrease or stop.
Upon returning the vessel to its mooring site, it is necessary to lift it onto the wall or hang the stern over the boom or over a flat bank (in case of minor damage) and repair the damaged molding. Repairs must be made as follows. Completely cut off the inner and outer Kingston molding angles. Thoroughly clean the surface of the kingston, as well as the surface of the bottom (inside and outside) in the area of damage. Kingston is installed in place and secured. First, the kingstone is molded from the inside. The first layer of molding square, impregnated with epoxy compound, is placed on the kingston and bottom and carefully smoothed so that there are no air bubbles underneath. Then the remaining layers of the molding square are laid, impregnated with ordinary resin.
After polymerization of the internal molding square, it is necessary to check it for tightness. The internal molding square is coated with a soap solution, and compressed air is supplied from the outside with a hose at a pressure of 3-3.5 kg/cm 2 (if there is no compressed air line or compressor, you can use a car cylinder).
If there is no air leak, an external molding square is formed, after polymerization of which the repair can be considered complete. If air passages are found along the edges of the molding square, these places must be repaired again.
Only the main types of damage to fiberglass hulls are considered. Repair of any other damage is similar to the cases listed above.
When repairing a ship's hull made of fiberglass, you can use any reinforcing materials - fiberglass, glass mat, glass matting, etc., as well as resins of any brand. The temperature conditions for the polymerization of fiberglass (i.e., a temperature not lower than 18-20 ° C) can be created either by 300 or 500 W lighting lamps with tinplate reflectors, or by reflective furnaces of the “Neva” type.
When going on a long journey on a ship with a fiberglass hull, you need to take with you a small amount of resins (1-1.5 kg) with hardening additives and fiberglass. Resin and fabric are needed to repair hull damage that can occur when sailing through various water systems. If it is not possible to take resins and fiberglass with you, you must have an epoxy compound, which can also be used to repair minor damage to the body.
Unsinkability of the ship— its ability to withstand emergency damage leading to flooding of one or more compartments, while maintaining a sufficient reserve of buoyancy and stability.
The set of actions of the crew aimed at maintaining and restoring the buoyancy and stability of the vessel is understood as a struggle for its unsinkability.
The main document that must be followed to ensure the unsinkability of an undamaged ship is the Ship Stability Information for the captain. This document contains requirements for stability criteria, the maximum quantity and placement of cargo specifically for a given vessel, information about the vessel necessary for, and recommendations for maintaining stability.
Emergency landing information and stability of the vessel is the main document containing information about the emergency condition of the vessel in various cases of flooding.
At the beginning of the Information are given:
- general information about the vessel;
- layout diagrams of all watertight bulkheads;
- diagrams of the location of all holes and drives for closing them;
- systems used in the fight to make a ship unsinkable;
- instructions necessary to maintain intact ship stability sufficient to withstand the most severe design damage.
The main part of the Information contains in tabular form the results of calculations of emergency landing and stability of the vessel with symmetrical and asymmetrical flooding of compartments for typical vessel loading options. For each option, the possible consequences of flooding and the necessary measures to preserve the vessel are indicated.
Floating workshop Antea
Preventing a ship from sinking
Timely detection of sea water entering the ship's hull is one of the main factors influencing success in the fight for unsinkability.
The death of a vessel from loss of buoyancy occurs over a long period (several hours, and sometimes even days), which makes it possible to carry out work to rescue the crew and passengers. If stability is lost, the vessel capsizes in a matter of minutes, which entails big number victims.
The reasons for the entry of water into the hull of a ship can be various: holes, fatigue cracks, rupture of skin seams, fistulas, violation of the tightness of outboard closures of ship systems and devices, pipeline leaks, etc.
The basis for control over the flow of water into the hull is regular measurements of the water level in the bilge wells of the compartments. On ships not equipped with water level sensors, the water level in the compartments is determined manually using a folding foot rod (or other manual measuring instrument, rice. 1) through special measuring tubes leading from the upper deck to the bilge wells.
Rice. 1 Tape measure for measuring liquid level
Bilge wells- These are recesses in the corners of the compartment for collecting water. The bilge wells contain water intakes for the drainage system.
If it is not possible to take measurements, control pumping of water from the bilge wells is carried out.
IN normal conditions During navigation, the water level in the compartments is monitored at least once per shift. When sailing in stormy conditions, in ice and other special conditions When it is possible for water to enter the ship’s hull, measurements of water in the compartments should be made at least once an hour. The measurement results must be recorded in the ship's logbook.
Indirect signs of water entering the compartment may be:
- the noise of water entering the compartment;
- water filtration through leaks at the junction of the bulkhead with the longitudinal elements of the hull, pipelines, at places where cables are laid, etc.;
- the noise of air squeezed out by water escaping through ventilation and measuring pipes, necks and other openings on the main deck;
- sweating of the surfaces of the flooded compartment;
- dull sound on impact metal object along the surface of the flooded compartment.
Controlling the spread of water throughout the vessel
Each crew member, upon detecting signs of water ingress, is obliged to:
- Immediately inform the officer of the watch or the engineer on watch. The sooner a general ship alarm is declared, the sooner the crew will begin to fight for survivability, the greater the chances of minimizing damage from the accident.
- Without waiting for further instructions, clarify the location, size, and nature of the damage. If the damage is significant and the compartment is flooded, then this information is important for calculating the rate of flooding and selecting means to restore the watertightness of the hull.
- If possible, de-energize the compartment.
Gullkronan medical ship Source: fleetphoto.ru
If possible, then proceed to repair the damage to the housing, and if this is not possible, then leave the flooded compartment, sealing all its closures.
Water will flow into the damaged compartment until the pressures of the water columns inside and outside are equalized. If there are open holes in the main deck, the water level in the flooded compartment will eventually become equal to the emergency waterline.
Sealing all openings leading into the compartment allows you to limit the exit of air, which will create an air cushion and limit the flow of water.
Search for damage can be carried out different ways. The most complete picture of the damage can be obtained by lowering the diver. But this is not always possible, mainly due to weather conditions. You can feel the hole in the side with a long pole, making a cross bar. The hole in the area of the cheekbone and bottom can be felt using the under-keel end, attaching some object to it in the middle part that would cling to the edges of the hole when dragged along the skin.
Removing water from adjacent compartments must be carried out, at a minimum, for two reasons:
- The minimum buoyancy reserve of most ships is designed to flood one compartment. Additional water mass in adjacent compartments can lead to loss of buoyancy;
- when a compartment is flooded, the ship partially loses stability due to the presence large area free surface of liquid cargo. If there is freely moving water in adjacent compartments, the ship may completely lose stability and capsize.
Container ship Sonderborg Strait Source: fleetphoto.ru
Bulkhead reinforcement must be done based on considerations that during operation the strength of structures weakens both due to rusting of the metal and due to “fatigue.” When reinforcing bulkheads, the following rules must be observed:
- reinforcements should be made to the elements of the set, and not to the sheathing;
- To avoid damage to water tightness, it is prohibited to use jacks or supports to correct residual deformation when the bulkhead bulges.
Emergency supplies and materials
An emergency supply kit is a set of equipment and materials that is in constant readiness and is designed to combat the emergency flow of water into the vessel. Kit includes: patches different types, emergency equipment, emergency materials and tools. All items included in the emergency kit are marked in blue. The locations of emergency supplies are indicated on the deck and in the passages.
Damage to the ship's hull varies in size: small - up to 0.05 m2, medium up to 0.2 m2 and large - from 0.2 to 2 m2. Cracks, loose seams and small holes are usually repaired using wooden wedges and plugs.
Consists of sliding stops, emergency clamps, hook bolts, swivel head bolts, tow cushions and spigot mats. The design of the devices makes it possible to speed up work on eliminating emergency damage to the ship’s hull with high reliability (Fig. 2).
Rice. 2 Emergency equipment: 1 - emergency stop; 2 - emergency clamp; 3 - hook bolts; 4 - bolt with swivel head Emergency materials:
- pine boards - for making shields and plasters;
- pine beams - for reinforcing decks, bulkheads and pressing panels;
- pine and birch wedges - for sealing small cracks, crevices and wedging stops and panels;
- pine plugs different diameters for sealing holes and portholes;
- sand, cement and cement hardener - for installing cement boxes;
- coarse wool felt, resin tow, canvas, rubber - for sealing shields and plasters;
- construction staples, bolts and nuts different sizes, nails;
- red lead and technical fat, etc.
Emergency tool— sets of rigging and metalworking tools: sledgehammer, hammer, rigging apron, punching chisel, pile, chisel, pliers, notches, rod drill.
Emergency patch— a device for temporarily sealing holes in the underwater part of a ship’s hull. Based on their design, plasters are divided into soft, hard and semi-rigid. The patch consists of several layers of canvas trimmed around steel mesh, wooden or steel frame.
Chain patch 3x3 or 4.5x4.5 m in size is included in the emergency supply of ships of an unlimited navigation area with a length of more than 150 m, except for tankers. It consists of a chainmail mesh made of galvanized metal rope with square cells and serves as the base of the plaster. The net-ka-chain mail is edged with a steel rope connected by benzels to the lyctros of the plaster. Two layers of waterproof canvas are applied to the base on each side, stitched right through the entire patch. The lyctros of the plaster is made of resin hemp rope with four drop-shaped thimbles embedded in the corners and four round thimbles in the middle of each side. The keel ends, sheets, guys and a control pin are attached to the thimbles. The patch has high strength and allows you to close large holes, providing high density fit.
Timber carrier Stepan Geyts Source: fleetphoto.ru
Lightweight patch 3x3 m in size, included in the emergency supply of vessels of unlimited navigation area with a length of 70-150 m or tankers, regardless of their length. Consists of two layers of waterproof canvas and a coarse felt pad between them (1). Diagonal through stitching is made along the entire plane of the patch at a distance of 200 mm from each other. The edges of the patch are trimmed with lyctros made of hemp resin rope (2). At the corners of the lyktros, thimbles are embedded with benzels (3) for fastening the heel ends and guy ropes (4). In the middle of the luff there is a krengel (5), to which a marked control pin is attached to determine the position of the patch along the side of the vessel. On one side of the plaster, at a distance of 0.5 m from each other, pockets are sewn for metal rods or pipes that give rigidity to the plaster.
Stuffed patch 2x2 m in size is included in the emergency supply of ships of an unlimited navigation area with a length of 24-70 m. It consists of two layers of waterproof canvas and a stuffed mat applied over the entire plane with the pile facing out, edged with resin hemp lycrop with thimbles. The entire plane has end-to-end stitching with square dimensions of 400x400 mm.
Training patch 2x2 m in size is available on ships for training in patching. It differs from the stitched plaster in the absence of a stitched mat - only two layers of waterproof stitched canvas, edged with a lashing rope with thimbles. If necessary, it can be used as an additional combat patch.
Wooden hard plaster of two wooden shields with a mutually perpendicular arrangement of boards, between which a layer of canvas is laid. Along the perimeter of the inner shield there are cushions made of resin tow and canvas. The size does not exceed the size of one spatula.
Sealing a hole by placing a soft plaster is a reliable way to eliminate it, since the plaster is pressed by the hydrostatic pressure of water. Disadvantages of this method:
- stopping the ship;
- loss of controllability;
- turning the vessel with its log facing the wave, leading to flooding of the work area.
The emergency supplies necessary to apply a plaster to the hole are stored next to it in an emergency post or a special box.
Lighter carrier Castoro Otto Source: fleetphoto.ru
Under-knee ends. They are made from steel cables or rigging chain with a strength 10% higher than the strength of the lycrop plaster. The under-keel ends are attached to the lower corners of the patch, pass under the bottom of the vessel and go out onto the deck of the opposite side, and have thimbles at the ends.
Sheets. They are made from plant rope for all sheets, except for chain mail, for which the sheets are made from steel rope. There are thimbles woven into both ends of the sheet. The keel ends and sheets are attached to the plaster using rigging brackets.
Guys. They are made from vegetable and also from flexible steel cable. At the ends of the guys there should be thimbles for attaching with staples to the side luffs of the patch. The length of each guy is taken equal to twice the length of the sheet, but not less than half the length of the vessel. Guys are intended for stretching and aiming chainmail and lightweight patches at the hole.
Control line from vegetable tench is placed in the middle thimble of the lyktros using quick release coupling(hook-snore) and its length is equal to the length of the sheet. The control line is broken every 0.5 m from the center of the patch and marked like a lotline. For chainmail patches, the middle sheet with the indicated marking is used as a control pin. Hoists for patches have swivel hooks.
Caniface blocks. They are manufactured with swivel grips for fastening on the deck, eliminating the possibility of spontaneous laying out.
Placing the patch
Before applying the plaster, mark with chalk on the deck the boundaries of damage to the ship's hull that must be covered with the plaster. At the same time, they begin to insert the keel ends from the bow of the vessel (Fig. 3). Winding up the heel ends is one of the most labor-intensive operations and requires a lot of time. During winding, the keel ends are given some slack to avoid snagging on the underwater part of the hull. To reduce the likelihood of the keel ends getting caught on the side keels, it is recommended to fasten two rigging shackles in their middle part at a distance greater than the width of the vessel. Around the superstructures, the pedestal ends are surrounded with the help of auxiliary conductors supplied in advance. After this, the undercut ends are drawn along the sides to the hole and placed on both sides of it.
If necessary (when installing soft patches on large holes, especially if they are at great depth), along with the keel ends, false frames are installed from the steel cables available on the ship (mooring lines, spare pendants, etc.), laid over the hole and tightly wrapped. The ends of the false frames on the deck are connected with screw lanyards and tightly wrapped.
Rice. 3 Installation of a soft plaster: 1 - pull; 2 - hoist; 3 - sheet; 4 — rope to the hoist (winch); 5 - undercut ends; 6 - patch; 7 - control pin; 8 — false frames Simultaneously with the insertion of the under-keel ends, a plaster with all its equipment is brought to the site of damage. By the time the patch is installed, the vessel should not be moving. Using staples, the under-the-knee ends are attached to the thimbles in the lower corners of the patch (there are three on the chain mail patch, and two under-the-knuckle ends on all other types of plasters). The patch is unrolled and gradually lowered overboard, attaching the sheets and control pin to the luff. On the side luffs of the chainmail and lightweight patches, guy ropes are additionally attached. As the plaster is lowered, the underside ends are tightened from the opposite side. When the patch, according to the indications of the control pin, is lowered to a given depth, the sheets are secured, and the keel ends on the opposite side are tightly tightened with grip hoists or through rosin blocks, placed on closely spaced winches and tightened with their help. To protect the heel ends from damage when covering, it is recommended to place logs or boards under them at sharp bends.
For reliable fastening, the sheets must be stretched at an angle to the vertical of approximately 45°, the keel ends must be tightly wrapped perpendicular to the keel of the vessel. When setting chain mail and lightweight patches, the guys should be spread as far as possible from the patch to the bow and stern in order to bring the angle between the guy and the luff as close as possible to 90°, at which the luff will be most tightly pressed to on board the ship.
To close large holes, it is most advisable to use stronger chainmail or lightweight patches, and when using a chainmail patch, first install false frames, and when placing a lightweight patch on a hole in an area where the side of the ship does not have a longitudinal curvature, spacer tubes should be installed.
Ro-roller Hvítanes
