Repairing holes in the hull. Elimination of emergency damage to the vessel. Hole, steering accident, rollover. Emergency supplies and materials
Setting up a cement box
Sealing damaged areas of a ship's hull with concrete is reliable, durable and airtight. Concreting also makes it possible to seal damaged areas that would simply be impossible to do by other means. Practice has shown that it is only possible to restore the tightness of flooded compartments after landing a ship on rocky ground using concrete. Concreting also makes it possible to repair damage in hard-to-reach places of the ship, for example, under the foundations of machinery and mechanisms, in the forepeaks and afterpeaks, and on the ship’s cheekbones. Concreting can achieve absolute impermeability of damaged areas, whereas other temporary seals cannot provide this. Concreting can be carried out both in drained and in flooded compartments, although the latter is a rather difficult operation and is carried out only if it is impossible to drain the compartment.
The components of a concrete solution are cement, aggregates and water.
To repair damage to ship hulls, cement grades 400, 500, 600, and Portland cement are used.
For underwater concreting, it is better to use pozzolanic Portland cement, which is resistant to aquatic environment. For concreting at low temperatures Alumina cement is the best. During the setting process, heat is released in alumina cement, accompanied by an increase in temperature to +100 ° C, which allows this cement to be used even in severe frosts.
Do not use damp or soaked cement. Acceleration of the concrete hardening process can be achieved by adding special hardening accelerators to it:
Liquid glass - added to water in an amount of 10-15% of the water volume before preparing concrete. To further accelerate hardening, the dosage of liquid glass can be increased to 50%, but after a month the strength of this concrete is reduced by almost half;
Calcium chloride is added to cement in an amount of 2-10% of its volume and mixed thoroughly with it. Hardening accelerates almost 2 times;
Technical soda - dissolves in water in an amount of 5-6% of the mass of cement during the preparation of concrete;
Technical hydrochloric acid- added to water in an amount of 1-1.5% of the mass of cement when preparing concrete, it accelerates the setting process of concrete by almost 2 times.
Repairing minor damage (if the hole does not have torn edges protruding inwards) is carried out with emergency equipment specially designed for this purpose. Methods for eliminating water leakage in these cases are as follows.
Repairing broken seams. Open seams and cracks, small narrow gaps in the sheathing can be sealed with wedges, tow cushions, and filled with special mastics and putties.
Sealing damage using wedges begins with the widest part of the crack, where the thickest wedge is driven. As the crack narrows, the size of the wedges should also be reduced. The wedges, previously wrapped in tarred tow, are driven in approximately 2/3 of their length. The space between the wedges and the narrow spots at the ends of the split section of the seam are clogged with strands of tow. When sealing cracks, it is recommended to drill at the ends of the cracks to prevent the crack from continuing.
Water leakage through thin cracks - “tearing” seams - can be eliminated by filling with mastic. The mastic is heated to a dough-like state.
Seal small holes. The sealing is carried out from the inside of the vessel using wooden shields with a cushion along the edges, hard plasters or tow cushions; if the hole does not have torn edges protruding inward, the shield or patch on the hole is secured with tension. or hook bolts, for which special holes are drilled in the patch (shield).
The most difficult part of the operation is placing the patch on the hole, as it is wrung out by the incoming water. To facilitate the work, the patch is installed above the hole, lightly supported by a temporary stop and then moved along the casing onto the hole. The patch is held on the hole with a stop until the bolts are secured. Special clamps greatly facilitate the installation of a rigid plaster. A patch with a clamp hooked to the frames is installed above the hole. After this, the entire structure gradually lowers onto the hole. If there is a lot of water pressure, before you start sealing the hole from the inside, you need to apply a soft patch on the outside.
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 ships and vessels special purpose 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 products- 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 report and, as soon as possible, replenished to normal levels.
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 length 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 keel ends are brought in from the stern, you should use weights attached to them, which will allow you to pass the 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.
The sheets and keel ends, stretched at the required angle and selected tightly, 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 vessel
If the ship receives any damage on the high seas, an important condition preventing his death is skillful maneuvering. 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 the hull to leak, the forward movement of the vessel will increase the flow of water, and therefore create additional 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 voyage is so great that ship's means the crew cannot cope with the incoming water, the smartest thing to do is 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 deciding whether to ground a damaged ship, one must take into account the risk of reduced stability if the ship touches the ground small area 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 it is possible to land by the stern with the release of both anchors at an angle to the coastline, possibly closer to straight. 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 shock will be exposed to minimum area; 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.
On every warship, the emergency team of the survivability division should always have at its disposal required material and tools for sealing holes from the inside.
Rice. 3. Emergency bar. 1 - bar; 2-press screw; 3 - capping washer; 4 - bolt; 5 - stopper.
Emergency materials include the following items: wooden wedges, boards 5, 7.5 and 10 cm thick, beams for spacers, wooden panels, bags tightly filled with tow, felt, lead, drying oil and chalk powder for making liquid putty, which is used to soak felt and tow, cement in barrels, nails 4, 7.5, 10 and 15 cm, brackets for fastening wedges and beams and emergency strips (Fig. 3), specially made for this ship, and plugs (Fig. 4).
Fig.4 Wooden plugs for plugging holes.
Let us now consider the most typical cases of using the listed items when sealing holes:
1. Minor holes (holes from fragments and cracks of diverged grooves and joints of skins, both external and internal, are clogged with wooden wedges. Those surfaces of the wedges that will come into contact with the edges of the hole or joint crack are first generously lubricated with liquid red lead putty.
2. For holes of larger sizes, with torn inner edges, apply felt or a bag of tow, soaking them in a solution of liquid red lead putty. Place on top of felt wooden shield from boards. The outer end of the stop, consisting of a log or block, is attached to the inner edge of the shield (Fig. 5), the opposite end of which is rested against the nearest reliable bulkhead, pillars or carlings. To more securely fasten the entire system, the stop at the inner end is tacked with wooden wedges, subsequently connecting both the wedges and the stops with iron brackets.
Rice. 5. A method of plugging holes from inside a ship using wooden shields, beams, and wedges.
The dimensions of the felt and shield are chosen so that they protrude approximately 25-30 cm beyond the edges of the hole.
3. When sealing large holes, with torn edges protruding strongly into the ship, a shield should not be used. In this case, a box is quickly knocked together from thick boards; the height of its walls should be slightly greater than the largest of the notches (after cutting them). Having laid felt and bags of tow soaked in putty on the bottom, the box is placed on the hole so that all the torn edges go inside it and rest against the felt and bags of tow. The box is reinforced on all sides with stops. The quality of this seal largely depends on the size and strength of the box itself. It is also necessary that the edges of the felt, after placing the box on the hole, protrude beyond its edges, thus forming, as it were, a gasket between the edges of the box and the surface of the side or bottom lining. Boxes are also recommended to be used to reinforce leaking or damaged necks and hatches.
4. When sealing holes in the bottom, as well as in the flooring of platforms, holds and intermediate decks, proceed in the same way. In this case, the inner ends of the stops are attached to beams or carlings.
5. After installing the patch, when it is possible to finally drain the flooded room and there is no significant leakage through the hole, it is recommended to use quickly hardening cement for sealing, the solution of which is filled to the brim of the box, placed over the hole and secured in the manner described above.
A ship that has received a hole, regardless of the recruitment system, has an entire cell filled with cement.
5.1. General provisions, nature of damage. The location of water entry and the nature of damage to the hull depend on the circumstances (collision, grounding, explosion, pile-up, etc.). Such damage appears quite clearly and is relatively easy to detect.
It is more difficult to establish the cause and location of water leakage when fatigue cracks and fistulas appear, divergence of seams in steel structures, or damage to pipelines.
Characteristic features water entering the hull are: the appearance of a static list of the vessel, a change in the nature of the pitching motion under constant external sailing conditions, a noticeable change in the draft of the vessel, a roll of the vessel when the rudder is shifted.
Indirect signs: noise of air being forced out of the compartment through leaks or air pipes; appearing bulges in the bulkheads.
Making a decision to drain an already flooded compartment is a crucial moment, since calculations show that different physical laws apply when flooding and draining compartments.
It is possible to quickly deal with water only in case of small holes, when the time of flooding of the compartment is measured in hours, which makes it possible to clearly prepare and carry out all the operations to seal the hole and drain the compartment.
The fight against water involves solving three problems: preventing the spread of water throughout the ship, since almost all transport ships remain buoyant only when one compartment is flooded; sealing
holes in various ways depending on the nature of the damage; removal of water that has already entered the vessel.
There are two ways to repair a hole - from the inside and from the outside.
Repairing the hole from the inside does not require stopping the vessel and allows you to quickly launch emergency work to eliminate water leaks. But in many cases, the use of this method is unrealistic for the following reasons: work is hampered by hydrostatic water pressure; the edges of the hole are most often bent inward and have a ragged shape; the hole may be in hard to reach place; with medium and large holes, flooding of the compartment occurs very quickly, and it is not possible to drain the compartment using ship drainage means.
Sealing a hole along the outer contour- applying a patch - possible even with large holes, regardless of the area of damage.
5.2. Seal small holes and cracks. Minor water leakage caused by cracks, fallen rivets and poor tightness of joint seams structural elements external cladding can be removed in various ways, the most typical of which are as follows.
Sealing with emergency wedges and plugs(Fig. 1.3, a): wedge 1 (or conical plug 2), wrapped in tow, oiled or soaked in red lead, is driven into the crack (or hole from a fallen rivet) with a sledgehammer. Sealing should begin from the widest part of the crack; as it narrows, the thickness of the wedges decreases. The gaps between the wedges and very narrow areas of the crack are caulked with strands of oiled or red lead-impregnated tow. With low water pressure, the work can be done by one person, and with high pressure - at least two people.
Narrow, “tearing” cracks can be sealed with mastic, heated to a dough-like state and composed of seven parts coal tar and one part sulfur with the addition of slaked lime.
The hole from the fallen rivet is sealed cork(described above) or swivel head bolt(Fig. 1.3, b): bolt 3 is inserted into the hole in the casing 7, while head 6 rotates spontaneously, with inside put wooden spacer 5 and washer 4.
Attaching a wooden shield on the hole (Fig. 1.3, c): on the hole in external cladding 7, a wooden shield 9 is placed with a mat 8 attached to it. A wooden spacer 5 is installed on the shield, against which the spacer beam 10 rests. The other end of the beam rests against the foundation 11 of the mechanism and is wedged with wedges 1.
Rice. 1.3. Repairing small holes: a - emergency wedges and plugs; 6 - with a bolt with a rotating head; c - wooden shield; g - a pillow with a tow; d - felt mat or wooden shield; e - emergency clamp; 1 - wedges; 2 - conical plug; 3 - bolt; 4 - washer; 5 - wooden spacer; 6 - bolt head; 7 - casing; 8 - checkmate; 9 - wooden shield; 10 - spacer beam; 11 - foundation; 12 - pillow with tow; 13 - bulkhead; 14 - construction bracket; 15 - wooden shield; 16-felt mat; 17 - clamp; 18 - screw; 19 - capture; 20 - frame; 21 - wooden plaster
Sealing pillow with tow(Fig. 1.3, d): for a hole or crack in the outer skin 7 of the vertical
steel structure a pillow 12 with a tow is placed and pressed through a wooden spacer 5 with a spacer beam 10, which rests against the bulkhead 13 and is wedged with wedges 1.
Sealing felt mat or wooden shield(Fig. 1.3, e) cracks and holes in the bottom of the vessel: using a construction bracket 14, spacer bars 10 are fastened in the form of the letter “T”. A felt mat 16 or a wooden shield 15 is placed on the hole (crack). The fastened beams are lifted and wedged with wedges 1, resting on the ceiling.
Repairing the hole with emergency clamp(Fig. 1.3, f): a wooden patch 21 with soft upholstery is installed on the hole in the outer skin 7. The clamp 17 is attached to the frames 20 with grips 19. The patch is compressed with a screw 18 through a wooden spacer 5.
Other options for sealing small holes are possible: using a rigid wooden patch and a sliding metal stop or a box-shaped patch and a hook bolt, etc.
5.3. Repairing pipeline damage. The causes of pipeline damage can be: natural aging and wear; external forces - shock during an accident, explosion; violation of technical operation rules - water hammer, freezing of the highway, etc.
Nature of pipeline damage: cracks, fistulas, damage to gaskets, loose connections.
In ship conditions, several methods are used to eliminate damage to pipelines.
Welding damage (fistulas, cracks and small holes) is a quick and reliable way to restore the functionality of a pipeline. To ensure quality welding, the damaged area must be thoroughly cleaned. The pipeline through which petroleum products are pumped must be washed and steamed, and necessary cases additionally degass. Depending on the location and nature of the cargo being transported, the conditions of loading and parking of the vessel, welding work sometimes it is impossible.
Service damaged areas (Fig. 1.4, a) are usually used if the use of other methods is not possible. Wire 2 is laid on pipeline 5 in rings tightly adjacent to each other (types I, II) using a special blade 1 (types I, III). Depending on working environment Before denting, only rubber 4 or additionally a steel pad 3 is applied to the damaged area.
When repairing damage on pipeline bends (Fig. 1.4, b), use gaskets from soft rubber with plates made of sheet brass 6.
Yoke overlay(Fig. 1.4, c) is the most common, convenient and reliable way to eliminate pipeline damage. There are several types of yokes: universal, tape, tape yokes-clamps, hinged and sliding, chain yokes with bolts with linings.
Rice. 1.4. Repairing pipeline damage: a - by slandering; b - using gaskets; c - by applying yokes; 1 - blade; 2 - wire; 3 - steel plate; 4 - rubber gasket; 5 - pipeline; 6 - plate made of sheet brass; 7 - yokes
Yoke lining technology:
Thoroughly clean the damaged area and remove the insulation;
align the edges of the damage, bending all the burrs inward;
drive plugs or wedges made of mild steel, wrapped in rags greased with red lead, into the damaged areas; cut off or saw off the protruding parts of the plugs flush with the surface of the pipeline;
coat the sealing area with mastic and apply gasket 4 so that it covers the damage by 40-50 mm (the material of the gasket depends on the medium carried by the pipeline);
Place a 2-3 mm thick red copper or mild steel overlay on the gasket, curved around the circumference of the pipe;
apply one or more yokes 7 and compress them by tapping them with the handbrake; if there are several yokes, then the tightening is done from the middle to the extreme.
Installation of plugs on pipelines is carried out only in cases where it provides the opportunity to turn on a boiler that has been taken out of operation, to put into operation one or another important mechanism, or to eliminate steam in a compartment in which the presence of people is necessary.
5.4. Combating the spread of water throughout the vessel, strengthening structures. Filtration of water from a flooded compartment to adjacent ones occurs through leaks in watertight bulkheads and closures: cracks, fistulas, ruptures, damage to seals.
To prevent the spread of water throughout the ship when one of the compartments is flooded, it is necessary to carefully check the water tightness and strength of the bulkheads on the side of adjacent compartments. In this case, it is necessary to take into account the load acting on the watertight bulkhead 4 due to the hydrostatic pressure of water that flooded the adjacent compartment (Fig. 1.5). The pressure of water on a watertight bulkhead affects the unsinkability and stability of the vessel. Majority transport ships maintain a reserve of buoyancy when only one compartment is flooded, so that partial or complete flooding of an adjacent compartment can lead to the death of the vessel as a result of loss of buoyancy. When water filters into adjacent compartments, large free surfaces of water can form in them, which will adversely affect the stability of the vessel.
Rice. 1.6. Bulkhead reinforcement: using beams and wedges (a) and strengthening the door using beams and a sliding stop (b): 1 - beams; 2 - wedge; 3 - sliding stop
The fight against the spread of water begins with the external structures enclosing the flooded compartment, while the main attention should be paid to compartments with large volumes and compartments that are vital to the vessel.
If signs of damage to the strength and waterproofness of the bulkheads (bulges, cracks, loose seams) appear, it is necessary to reinforce the bulkheads using sets of beams 1 (Fig. 1.6, a). To avoid bulging of the bulkhead web, the support of the beams should be on the elements of the set.
If necessary, reinforce the door (hatch) leading to the flooded compartment (Fig. 1.6, b). For this purpose, wooden beams 1 and sliding stops 3 are used. The reinforcement beams are wedged, for which wedges 2 are driven in with sledgehammers.
When choosing a reinforcement scheme for watertight ship structures, all factors must be taken into account: location, nature, extent of damage; effective loads; complete set of ship emergency equipment; the ability to access damaged areas and their design features.
5.5. Placing the patch. A soft patch is applied when the hole is large, when it is impossible to drain the flooded compartment without first sealing the hole. Before applying the patch, it is necessary to accurately determine the location of the hole, which can sometimes only be done with a diving inspection of the damaged area.
To bring the patch to the hole and install it on it, use special equipment(Fig. 1.7, a): heel ends 5, sheets 3, guys 1, control pin 7. Heel ends are made of soft steel rope, and sheets and guys are made of vegetable rope; on the chainmail patch, the sheets and guys are steel.
To apply the patch, the following operations are performed sequentially (see Fig. 1.7, a, b):
Rice. 1.7. Installation of a soft patch: 1 - guy; 2 - hoist; 3 - sheet; 4 - rope to the hoist (winch); 5 - undercut ends; 6 - patch; 7 - control pin; 8 - false frames; A, B - positions of the under-keel ends
bring the under-keel ends 5 from the bow of the vessel, gradually etching and shifting them along the sides (positions A and B), and bring them to the hole; the keel ends can also be inserted from the stern, depending on the location of the hole, but they can get caught on the propeller blades or rudder blade; the operation of inserting the under-keel ends is very labor-intensive, and a sufficient number of people must be provided for each under-the-keel end;
simultaneously with the installation of the under-keel ends, patch 6 is laid out on the deck in the area of the frames that determine the position of the hole;
the lower luff of the patch is taken overboard and the under-keel ends are attached to the lower corner thimbles using staples;
sheets 3 are attached to the upper corner thimbles, and guy ropes 1 are attached to the middle side thimbles and they begin to select the under-keel ends from the opposite side with hoists 2 or winches, pulling the sheets and
the patch is lowered overboard until it closes the hole, the position of the patch in depth is established according to the control pin 7, which is spaced every 0.5 m;
after installing the patch on the hole, the sheets and guys are attached and pulled tightly under the keel ends - the patch is pressed against the hole by the hydrostatic pressure of water, stopping the flow of water into the hull of the vessel;
if the hole is large, then in order to avoid pressing the plaster into the compartment, false frames 8 are inserted simultaneously with the under-keel ends - tightly covered steel ropes, passing through the plane of the hole (see Fig. 1.7, b).
5.6. Setting up a cement box. Concreting and placing a cement box allows you to completely eliminate water leakage and creates necessary conditions to continue swimming.
Sequence of operations for setting up a cement box (Fig. 1.8, a, b):
temporarily seal the hole (crack) using one of the methods discussed above: placing wedges,
installing hard shields or patches various designs, placing a soft patch;
Rice. 1.8. Placing a cement box on the hole: a - bottom; b - onboard; 1 - emphasis; 2 - formwork; 3 - drainage pipe; 4 - hard patch; 5 - wedges for emphasis; 6 - wedge for a hole.
make and install formwork 2 - install a wooden rectangular box without two edges with side ribs to the hole, the upper open part is used to load concrete; after installation, ensure rigid fixation of the box by installing stops 1 and wedges 5;
clear out metal surface in the area of damage from dirt, rust, traces of petroleum products;
install drainage (water drainage) pipes 3 in case of possible water filtration so that one end of the pipe is brought to the place of filtration, and the other goes beyond the formwork; the diameter of the pipe should ensure free drainage of water and prevent its accumulation;
for large holes along the damaged area, reinforcement made of steel rods or pipes can be secured;
make a creation - low-sided wooden box for preparing concrete; prepare concrete;
fill the formwork with concrete solution so that it is evenly distributed throughout the entire volume of the cement box; concreting must be done as quickly as possible, since if there are accelerators in the solution, it begins to harden within a few minutes; slow, intermittent supply of concrete can lead to delamination of the monolith;
delete drainage pipes after the concrete has hardened, fill the holes with wooden wedges 6;
After the concrete has completely hardened, remove the soft plaster, which will allow the vessel to move.
Concrete preparation technology:
prepare a dry mixture of cement and sand in a ratio of 1:2 or 1:3, mixing it thoroughly with shovels; use Portland cement of a grade not lower than 400 (400, 500, 600) - these numbers mean the permissible load on concrete in units of kgf/cm; the cement should be in a powdery state, without lumps or grains; the sand must be coarse-grained, river or quarry; the use of fine-grained sand is undesirable;
add water in small portions and mix thoroughly; A concrete solution that easily slides off a shovel is considered normal; if there is too much water, the concrete sticks to the shovel; if there is not enough water, it is difficult to mix; the amount of water directly affects the setting speed of the solution and the strength of concrete; recommended to use fresh water, since sea water reduces the strength of concrete by 10%;
Before preparing the solution, add a hardening accelerator to the water, which can be used as: liquid glass(add up to 50% of the total volume of the mixture); calcium chloride (7-10%), caustic soda (5-6%), hydrochloric acid (1-1.5%); with increasing accelerator dosage, the strength of concrete decreases, however emergency situations the decisive factor is the speed of its hardening; at low temperatures, concrete should be mixed in heated water (not lower than 30 ° C); if the water is fresh, add salt to it at the rate of two handfuls per bucket; add filler (gravel, crushed stone, broken brick, slag); the filler increases the strength of concrete, but, as a rule, it is not used in ship conditions.
All preparatory work the installation of the cement box must be done in advance, which will ensure quick completion of the main work and high quality concreting.
6. Fighting steam. The ship has a boiler plant with a steam pipeline, which, if damaged, creates an emergency situation. The most typical damage includes: the formation of fistulas and cracks due to natural wear and tear; punching gaskets, loosening fastenings; rupture of a steam pipeline as a result of hydraulic shock.
Damage to the steam line leads to steam leakage, which can have dangerous consequences: steam displaces oxygen from the room and sharply increases the temperature; having high humidity, it can damage electrical equipment; In case of leaks in cargo holds, vapor with dust from some cargo forms an explosive mixture.
Fighting steam is one of the forms of fighting for the survivability of a ship, and the ship's alarm schedule must provide for specific actions of the crew in this case.
Each crew member who discovers a steam leak must immediately report it to the watch officer or engineer and, observing all safety measures, begin to eliminate the damage.
The officer of the watch announces a general alarm indicating the emergency room and the need to comply with safety measures.
The mechanic on watch is obliged to: disconnect the damaged section of the steam pipeline; take measures to protect people from damage by steam, and, if necessary, remove them through emergency exits, protecting them with water spray; open all skylights and ventilation vents leading to the open deck; turn on all forced ventilation to create air pressure; begin repairing the damage.
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, driven manually from the inside of the body; 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, such as sand, gravel, must be washed in clean water and not have 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 special box- created. 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. At small sizes damage (cracks, etc.) the box can be immediately filled with concrete. If there is a hole of significant size, it must first be covered with reinforcement made from steel tubes and twigs arranged in the form of a grid with cells (from 0 to 25 cm) tied at intersections with wire. To avoid erosion of the concrete by water seeping through the hole, before it finally hardens, special drainage tubes are installed in the cement box to drain the water. 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.
