Sealing damage to the hull with concrete has significant advantages over other methods, as it is reliable, durable and tight. With the help of concreting, it is possible not only to eliminate the water resistance of the hull, but also to partially restore local strength in the area of the damaged hull. Sealing of holes with concrete is carried out for more reliable sealing of the ship's hull after temporary sealing of the hole with plaster, especially in hard-to-reach places (under the foundations of steam boilers, mechanisms, at the ends and on the cheekbones of the ship). In addition, practice has shown that in most cases, only by concreting it is possible to restore the tightness of the flooded compartments of a vessel sitting on stones or on hard ground.
The disadvantages of concreting damage are that it is a very complex and time-consuming procedure. Concrete does not tolerate vibration well and has low tensile strength. Concreting must be carried out in a dry room, as underwater concreting is much more difficult and less reliable.
Surface and underwater holes can be sealed with concreting. The simplest is the sealing of holes located above the current waterline, in the event that it is not possible to weld these leaks using gas or electric welding. Such sealing is carried out if there are small holes, cracks in the skin, which are previously closed with plasters, plugs, wedges; caulk; the hull of the vessel in the area of damage is thoroughly cleaned, in hard-to-reach places it can be burned with a blowtorch; then formwork is installed and concrete is poured.
Rice. 1. Putting the cement box on the hole. a - bottom; b - onboard; 1 - emphasis; 2 - formwork; 3 - drainage pipe; 4 - hard patch; 5 - wedges for emphasis; 6 - a wedge for a hole.
Installation of a cement box. In general, the organization of the installation of a cement box on a hole located in the underwater part of the ship's hull is carried out as follows (Fig. 1):
Preparation of cement mortar. Cement mortar (concrete) must be made near the place of work (if the dimensions of the emergency compartment allow) on a special deck with boards made of tightly knocked down boards.
The components of the cement mortar and their ratio:
First, filler (sand) is poured onto the flooring, cement is poured on top, then the components of the cement are mixed, as a rule, they work together, raking shovels towards each other.
Pour water into the middle of the mixture in portions and mix thoroughly until a homogeneous mass is obtained, resembling a thick dough.
To reduce the hardening time of the cement slurry, accelerators are added as a percentage of the total composition of the mixture indicated above.
The prepared mortar immediately fills the space between the inner and outer formwork. Cement seizes after about 8-12 hours, and finally hardens after 3 days.
When concreting significant holes in the solution, it is advisable to install reinforcement (steel bars connected by wire) welded to the ship's hull.
Various options for concreting damage are shown in Figures 2 - 7. The installation of a cement box (concreting) is a temporary measure. Therefore, when the vessel is docked or upon its arrival at the port, the damaged connections are replaced or the holes are welded. In the case when it is not possible to dock the ship, the concrete seal on the ship's hull is scalded, i.e. enclosed in a steel box welded to the body. At the same time, if possible, the crack itself or the open seam in the ship's hull is welded from the outside or from the inside. Sheets forming a box wall around a concrete embedment or cement box are usually welded directly to the ship's hull or framing. Then all the free space of the cement box is filled with a new mortar and welded on top with patch sheets.
Rice. 2. Ways of concreting holes. a, b - air concreting; c - underwater concreting; 1 - floor; 2 - formwork; 3 - concrete; 4- box (internal formwork); 5 - drainage tube; 6 - coarse filler; 7 - sheet of iron.
Rice. 3. Welded cement box. 1 - box wall; 2 - cover; 3 - drainage tube; 4 - outer skin; 5 - coarse filler; 6 - a wedge in a hole.
Rice. 4. Concreting holes. a, b - sealing with a box-shaped plaster; c, d - embedding with a pillow with an emphasis; 1 - soft plaster; 2 - box patch; 3 - emphasis; 4 - tube; 5 - coarse filler; 6 - wedges; 7 - timber; 8 - pillow.
Rice. 5. Concreting of cracks or filter joint in the board. a - general view; b - sectional view; 1 - box; 2 - external formwork; 3 - spacer; 4 - frame; 5 - tube; 6 - board for fastening the formwork; 7 - wedge fastening the box.
Rice. 6. Concreting of large cracks. a - view of the formwork attachment from above; b - cross-sectional view; 1 - tube; 2 - external formwork; 3 - rack; 4 - emphasis; 5 - wedge; 6 - filtering water level; 7 - plaster; 8 - internal formwork.
Rice. 7. Concreting holes in the bottom. 1 - floor; 2 - box patch; 3 - wedges; 4 - emphasis; 5 - strap; 6 - external formwork; 7 - internal formwork; 8 - tube; 9 - soft plaster.
MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION
Federal state AUTONOMOUS educational
institution of higher education
"Sevastopol State University »
Institute of Shipbuilding and Maritime Transport
D.V. Burkov, E.S. Kolesnik
Ship sinking
Educational and Methodological Council of the Institute
as a teaching aid
for full-time and part-time students
specialties:
05/26/06 - Operation of ship power plants and
05/26/07 - Operation of ship electrical equipment and automation
full-time and part-time forms of education
Sevastopol
UDC 656.612.088
BBC 39.46
Reviewers: S.V. Taranenko, Ph.D., associate professor of the department SEA
A.R. Ablaev, Candidate of Technical Sciences, Associate Professor of the Department EMSS
E.S. Solodov, Candidate of Technical Sciences, Associate Professor of the RHF Department
D.V. Burkov, E.S. Kolesnik
Ship sinking: teaching aid for a practical lesson in the discipline "Life safety", part 1 Life safety (marine), Module 2. Survival in extreme conditions on a ship. - Sevastopol: FGAOUVO "SevGU", 2015. - 16 p.
The methods of sealing cracks and holes in the ship's hull, the elimination of damage to pipelines are considered. Describes the procedures for placing a patch and a cement box. The methodology for drawing up an operational plan for combating water, restoring stability and straightening an emergency ship is given.
The manual is intended for full-time and part-time students of the Sevastopol State University, the Institute of Shipbuilding and Maritime Transport, specialties: 05/26/06 - Operation of ship power plants and 05/26/07 - Operation of ship electrical equipment and automation.
The training manual provides the study of the following areas of competence in accordance with the STCW convention:
RL 30 - Development of a plan of action in emergency situations and schemes for combating damage to the ship, as well as actions in emergency situations:
RL 30.1 – Ship structure, including damage control.
© Burkov D.V., Kolesnik E.S., 2015
© Publication of FGAOUVO "SevGU", 2015
| 1. Plugging small holes and cracks ……………...……. | |
| 2. Repair of damage to piping ……….………... | |
| 3. Plasters (Mats)…….……………………………………………………………………... | |
| 4. Setting the patch (Matting)…………... ……………………………………………. | |
| 5. Cement box fixing …………………………………….. | |
| 6. Methodology for drawing up an operational plan for combating water, restoring stability and straightening an emergency vessel (Operational plan technique to combat water, restore stability and righting of a disabled vessel)……………………………...…… ……. | |
| 7. Report content of the work implementation | |
| 8. Control questions……………………………………………….. | |
| Reference list…………………………………………………… |
Objective: 1. Study of ways to seal small holes and cracks.
2. Acquaintance with the technique of setting the patch.
Seal small holes and cracks
Termination with emergency wedges and plugs(Fig. 1, a): wedge 7 (or conical plug 2), wrapped in tow (tow), oiled or impregnated with minium, is hammered into a crack (or a hole from a dropped rivet) with a sledgehammer. Embedding should start from the widest part of the crack, as it narrows, the thickness of the wedges also decreases. The gaps between the wedges and very narrow sections of the crack are caulked with strands of oiled or red lead-soaked tow. With a small pressure of water, one person can do the work, and with a large pressure, at least two people.
Narrow, “watery” cracks can be repaired mastic, heated to a pasty state and composed of seven parts of coal tar and one part of sulfur with the addition of slaked lime.
The hole from the dropped rivet close up cork(described above) or swivel head bolt(Fig. 1, b): the bolt 3 is inserted into the hole in the casing 7, while the head 6 spontaneously rotates, a wooden gasket 5 and a washer 4 are placed on the inside.
The objective of the work: 1. Study the ways of plugging small holes and cracks.
Ship unsinkability- its ability to withstand emergency damage, leading to the flooding of one or more compartments, while maintaining a sufficient margin 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 vessel is the Information on the stability of the vessel for the captain. This document contains requirements for stability criteria, the maximum number 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 on the emergency condition of the vessel in various cases of flooding.
At the beginning of the Information are given:
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 non-symmetrical flooding of compartments for typical ship loading options. For each option, the possible consequences of flooding and the necessary measures to save the vessel are indicated.
Floating workshop Antea
Timely detection of outboard water entering the ship's hull is one of the main factors affecting success in the struggle for unsinkability.
The death of the vessel from the loss of buoyancy occurs over a long (several hours, and sometimes days) period, which makes it possible to carry out work to save the crew and passengers. When stability is lost, the vessel capsizes in a matter of minutes, which entails a large number of victims.
The reasons for the ingress of water into the ship's hull can be different: holes, fatigue cracks, rupture of seams in the plating, fistulas, violation of the tightness of the outboard closures of ship systems and devices, pipeline leaks, etc.
The basis for controlling 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 with a folding footstock (or other hand-held measuring instrument, Fig. 1) through special measuring tubes leading from the upper deck to the bilge wells.
Rice. 1 Liquid level measuring tape
bilge wells- these are recesses in the corners of the compartment for collecting water. The bilge wells contain the water intakes of the drainage system.
If it is not possible to make measurements, a control pumping of water from the bilge wells is carried out.
Under normal sailing conditions, the water level in the compartments is monitored at least once per watch. When sailing in stormy conditions, in ice and other special conditions, when it is possible for water to enter the ship's hull, water measurements in the compartments should be made at least once an hour. The measurement results should be recorded in the ship's log.
Indirect signs of water entering the compartment can be:
Each crew member, upon detection of signs of water ingress, is obliged to:
Gullkronan medical ship If it is possible, then proceed to repair the damage to the hull, 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 equal. With open openings in the main deck, the water level in the flooded compartment will eventually become equal to the emergency waterline.
Sealing all openings leading to the compartment allows you to restrict the exit of air, which will create an air cushion and limit the flow of water.
Search for damage can be done in 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. A hole in the board can be felt with a long pole, making a transverse bar at the end. A hole in the area of the cheekbone and bottom can be felt with the help of the keel end, fixing some object on it in the middle part that would cling to the edges of the hole when dragged along the skin.
Water removal from adjacent compartments must be carried out as a minimum, for two reasons:
Container ship Sonderborg Strait Bulkhead reinforcement it is necessary to do it from the considerations that in the process of operation, the strength of structures is weakened both due to rusting of the metal, and due to "fatigue". When reinforcing bulkheads, the following rules should be observed:
An emergency supply kit is a set of equipment and materials that is in constant readiness and is designed to deal with emergency water ingress into the vessel. The kit includes: plasters of various types, emergency equipment, emergency materials and tools. All items included in the emergency equipment kit are marked in blue. The locations of emergency supplies are indicated on the deck and in the aisles.
Damage to the ship's hull varies in size: small - up to 0.05 m 2, medium - up to 0.2 m 2 and large - from 0.2 to 2 m 2. Cracks, open seams and small holes are sealed, as a rule, with wooden wedges and plugs.
It consists of sliding stops, emergency clamps, hook bolts, swivel head bolts, tow pads and stuffed bath mats. The design of the devices makes it possible to speed up the work on the elimination of emergency damage to the ship's hull with high reliability (Fig. 2).
Rice. 2 Emergency inventory: 1 - emergency stop; 2 - emergency clamp; 3 - hook bolts; 4 - swivel head bolt emergency materials:
emergency tool- sets of rigging and bench tools: a sledgehammer, a hammer, a rigging mallet, a punch chisel, a pile, a chisel, pliers, notches, a rod drill.
emergency patch- a device for temporary sealing of holes in the underwater part of the ship's hull. By design, the patches are divided into soft, rigid and semi-rigid. The plaster consists of several layers of canvas sheathed around a steel mesh, wooden or steel frame.
Mail 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 chain mail mesh made of galvanized metal rope with square cells and acting as the basis of the plaster. The net-ka-mail is edged with a steel rope connected by benzels to the patch lyktros. Two layers of waterproof canvas are applied to the base on each side, stitched through the entire patch. The plaster lyktros is made of resin hemp rope with four drop-shaped koushki embedded in the corners and with four round koushki in the middle of each side. To the thimble are attached the tail ends, sheets, braces and control rod. The patch has high strength and allows you to close large holes, providing a high fit.
Timber carrier Stepan Geyts Lightweight patch 3x3 m in size, is included in the emergency supply of ships of an unlimited navigation area with a length of 70-150 m or tankers, regardless of their length. It consists of two layers of water-resistant canvas and a pad of coarse wool felt between them (1). Diagonal through stitches are 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 lyktros made of hemp resin rope (2). In the corners of the lyktros with benzels (3) there are thimbles for fastening the tail ends and braces (4). In the middle of the upper luff there is a crengel (5), to which a marked control pin is attached to determine the position of the patch on the ship's side. On one side of the patch, at a distance of 0.5 m from each other, there are pockets for metal rods or pipes, which stiffen the patch.
larded plaster 2x2 m in size is included in the emergency supply of vessels of an unlimited navigation area 24-70 m long. It consists of two layers of water-resistant canvas and a stuffed mat superimposed on them over the entire plane with a pile outward, edged with resin hemp lyktros with thimbles. Through the entire plane, a through firmware with a square size of 400x400 mm is made.
Training patch size 2x2 m is available on ships for training in patching. It differs from the stuffed plaster by the absence of a stuffed mat - only two layers of water-resistant stitched canvas, edged with a lyk-rope with thimbles. If necessary, it can be used as an additional combat plaster.
Wooden hard plaster from two wooden shields with a mutually perpendicular arrangement of boards, between which a layer of canvas is laid. Pillows made of resin tow and canvas are pierced along the perimeter of the inner shield. The size does not exceed the size of one spacing.
Sealing a hole with a soft plaster is a reliable way to eliminate it, since the plaster is pressed against the hydrostatic pressure of the water. The disadvantages of the method:
The emergency supply needed to put the patch on the hole is stored next to it in an emergency post or a special box.
Lighter carrier Castoro Otto Tail ends. They are made of steel cables or rigging chain with a strength of 10% higher than the strength of the patch lyktros. The tail ends are attached to the lower corners of the patch, pass under the bottom of the vessel and go to the deck of the opposite side, have thimbles at the ends.
Sheets. They are made from a vegetable cable for all patches, except for chain mail, for which sheets are made from a steel cable. There are thimbles in both ends of the sheet. The keel ends and sheets are attached to the patch with the help of rigging brackets.
Guys. They are made from vegetable, as well as from a flexible steel cable. At the ends of the braces 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 ship. Guys are intended for stretching and aiming at a hole in chain mail and lightweight patches.
Control pin from a vegetable line, it is laid in the middle thimble of the lyktros using a quick-release connection (hook-rattsa) and is equal in length to the length of the sheet. The control pin is broken every 0.5 m from the center of the patch and marked like a lotline. For chain mail patches, the middle sheet with the indicated marking is used as a control pin. Tape hoists have swivel hooks.
Canifas blocks. They are made with swivel grips for mounting on the deck, excluding the possibility of spontaneous laying out.
Before applying the plaster, mark with chalk on the deck the boundaries of the damage to the hull of the ship, which should be covered with a plaster. At the same time, the keel ends from the bow of the vessel begin to wind up (Fig. 3). Winding of the tail ends is one of the most labor-intensive and time-consuming operations. During winding, the keel ends are given some slack to avoid snagging on the underwater part of the hull. In order to reduce the likelihood of the keel ends getting caught on the side keels, it is recommended to fix two shackles in their middle part at a distance exceeding the width of the vessel. Around the superstructures, the keel ends are carried around with the help of auxiliary conductors submitted in advance. After that, the tail ends are drawn along the sides to the hole and placed on both sides of it.
If necessary (when placing soft patches on large holes, especially if they are at great depths), along with the tail ends, false frames are started from the steel cables available on the ship (mooring lines, spare pendants, etc.) carried over the hole and tight-fitting. The ends of the false frames on the deck are connected with screw lanyards and tightly tightened.
Rice. 3 Setting a soft patch: 1 - guy; 2 - hoist; 3 - sheet; 4 - rope to the hoist (winch); 5 - tail ends; 6 - plaster; 7 - control pin; 8 - false frames Simultaneously with winding the tail ends, a patch with all its equipment is brought to the place of damage. By the time the patch is applied, the ship should not be moving. The tail ends with the help of staples are attached to the thimble in the lower corners of the patch (there are three on the chain mail patch, on all other types of patches there are two tail ends). The patch is unfolded and gradually lowered overboard, attaching sheets and a control line to the upper luff. Guys are additionally attached to the side luffs of the chain mail and lightweight patches. As the patch is lowered, the keel ends are tightened from the opposite side. When the patch, according to the indications of the control pin, is lowered to a predetermined depth, the sheets are fixed, and the tail ends from the opposite side are tightly fitted with grip-hoists or through canifas-blocks, they are wound up on closely spaced winches and fitted with their help. To protect the tail ends from damage during tightening, it is recommended to place logs or boards under them on sharp bends.
For reliable fastening, the sheets should be stretched at an angle to the vertical of about 45 °, the keel ends should be tightly fitted perpendicular to the keel of the vessel. When installing chain mail and lightweight patches, the guy lines should be carried as far as possible from the patch to the bow and stern in order to bring the angle between the guy line and the leech as close as possible to 90 °, at which the leech will be most tightly pressed to on board the ship.
To close large holes, it is most advisable to use stronger chain mail or lightweight patches, and when using a chain mail patch, pre-install false frames, and when placing a lightweight patch on a hole in an area where the side of the vessel does not have a longitudinal curvature, spacers should be installed.
Ro-Ro Car Hvitanes SUBSTANCE: invention relates to ship's emergency equipment for fighting water in the presence of a hole in the ship's hull. The method for sealing a hole in the ship's hull includes sealing the internal cavity of the compartment from the external environment and equalizing the external and internal pressure. After that, a patch with flexible edges is installed and its edges are attached to the edges of the hole. The aqueous medium is removed from the compartment by supplying a gaseous medium under pressure into the compartment with the branch pipe in the lower part of the compartment open. Next, carry out the power sealing of the hole. An increase in the buoyancy of the vessel is achieved by stopping the leak through the hole when the vessel is moving.
SUBSTANCE: invention relates to emergency equipment of a vessel for stopping a leak in a vessel's hull through a hole formed as a result of a collision with a third-party object, during an explosion or upon contact with a reef, and also as a result of the destruction of the hull from a storm. In all cases, the formation of a roll above the permissible value or loss of stability occurs. To reduce the effect of changing the position of the vessel, there are airtight bulkheads that separate adjacent rooms from the room with a hole ("Elementary textbook of physics" edited by Ladsberg, volume 1, pp. 352-353). Of course, the ship loses its seaworthiness. However, it is more dangerous when there are instruments or cargo in the compartment that do not allow interaction with the aquatic environment, for example, the reactor compartment near the submarine or the compartment where the control part of the submarine and its functional units are located. In all cases, a flexible patch is applied from the side of hydrostatic pressure or mats with power stops are applied from the internal cavity of the vessel. However, this method of repair is not always possible, because. the submarine may be at considerable depth, and therefore the hydrostatic pressure will be significant, and the surface vessel may grapple with the object of collision. Applying a patch to a significant hole under the high-speed pressure of the aquatic environment is very difficult. And such cases took place in world practice, when the Titanic collided with an iceberg, the Admiral Nakhimov collided with a ship. There is a method of installing a patch with flexible edges that cover the hole, placed in the hole of the tube into which coolant is supplied (AC N 1188045, class B 63 C 7/14, 1984). This method can be used in the absence of a leak, because. otherwise, heat removal from the water mass will not be carried out due to its mobility. This method also cannot be used when the ship is moving, and this is important for warships of any purpose. The purpose of the technical solution is to eliminate these shortcomings, namely, to stop the leak when the ship is moving with the possibility of sealing the hole and placing all elements of the compartment and cargo in the air, because not every cargo can interact with the aquatic environment, as well as control devices. The technical result is achieved by sealing the internal cavity of the compartment from the external environment with equalization of the internal pressure in the cavity with external pressure, installing a flexible patch and fixing it on the hole along its edges and removing the aqueous medium through the pipe at the lower point of the compartment with a valve for supplying the gaseous medium under pressure in the compartment. Explanations for the method 1. After the formation of a hole, there can be two cases: the hole is located at the bottom of the compartment. Then, after sealing the compartment of a surface vessel or underwater, the aquatic environment can be displaced by the gaseous medium under pressure completely and immediately through the hole and the branch pipe with the valve. The worst case is when the hole is formed at the waterline or at the top of the submarine compartment. In this case, after sealing the compartment, it is necessary to equalize the external and internal pressures by the inflow of water mass. This pressure can be significant for a submarine. After equalizing the pressure, rescuers in space suits enter the compartment through the airlocks, unfold the plaster, which should be in each compartment, and fix it on the inner surface of the hull, blocking the hole. The fastening can be adhesive compounds or, for example, magnets, if the body is ferromagnetic, or on technological hooks with a strap for pressing the edge. Any option is possible, because. the patch is not load-bearing and only needs to support the mass of the patch. Then a branch pipe with a valve at the bottom of the compartment is opened, and then a gaseous medium is supplied under pressure until the aqueous medium is completely expelled from the compartment. After that, the pipe is closed with a valve. If possible, the repair team puts mats and shields on the hole, forming a force seal of the hole. In the latter case, the pressure in the compartment can be reduced to normal and the compartment can be put into operation. If power termination is not possible, then the ship should go to the place of repair. 2. The method is universal and can be used while the ship is moving. It is necessary to provide for the possibility of sealing technological methods, locking to go to the compartment, spacesuits for the repair team and plaster in the compartments. 3. The method allows you to quickly and reliably stop the leak and block the hole with pumping out the water mass by squeezing it out with the pressure of the gaseous medium. Thus, all the goals that were formulated above are achieved with the simplicity of eliminating the emergency with little effort from the team.
Claim
A method for sealing a hole in a ship's hull, including installing a patch with flexible edges and attaching its edges to the edges of the hole, characterized in that the internal cavity of the compartment is sealed from the external environment and the external and internal pressures are equalized, the patch is installed, the aqueous medium is removed from the compartment by supplying a gaseous medium under pressure into the compartment with an open branch pipe at the bottom of the compartment, after which the hole is force sealed.
Similar patents:
The invention relates to the field of operation of rigid tanks used for the storage and transportation of various liquids and gases, and is intended for repairing holes in these tanks in a filled state, and can also be used when sealing holes in ship hulls
The invention relates to transport emergency equipment, namely to devices for structuring liquid substances with increased chemical activity and fluidity, for example, nitrogen-containing and hydrocarbon fuels, to prevent their spreading and ignition in the event of an accident with tankers, as well as with road and rail tanks
The invention relates to emergency equipment for stopping the leakage of liquid substances with increased chemical activity and fluidity and can be used to seal holes in the hulls of ships and in rail and road tanks
The invention relates to rescue equipment for water vehicles, in particular to patches for sealing holes in the hull of the vessel, and is intended for sealing objects under pressure, such as oil tanks, oil pipelines
The plasters used as emergency equipment are soft, wooden, metal and pneumatic.
Soft plasters are wound to temporarily seal the hole in order to drain the flooded compartment and then reliably restore the water tightness of the hull. The most durable soft patch is the chain mail patch. It is elastic, adheres well to the figured surface of the ship's hull and at the same time has a certain rigidity, which is created by chain mail in the form of interlaced rings made of flexible galvanized steel cable with a diameter of 9 mm.
Lightweight patch measuring 3x3 m consists of two layers of canvas with a felt pad between them. To stiffen the patch, 25 mm steel pipes or a 20 mm steel cable are attached parallel to the upper edge at half-meter intervals from its outer side.
The stuffed plaster (2x2 m) is made of two-layer canvas and a stuffed mat stitched on the inside with a dense dense pile outside.
The patch-mattress can be made by the crew on board. To do this, a canvas bag of the required size is stuffed with tar tow to a thickness of about 200 mm. From the outside, narrow boards 50–75 mm thick (with gaps between them) are attached to the mattress obtained in this way, and a steel cable for winding is nailed to them with building brackets.
Wooden rigid plaster is usually made on the ship "in place" after receiving a hole in the hull. It is most expedient to use it to close holes located near or above the waterline, as well as in cases where the hole can be exposed by heeling or trimming the vessel.
Metal patches used to seal small holes are shown in fig. 6
Pneumatic plasters (tubular, spherical, soft box-shaped, semi-rigid and rigid) are designed to seal small holes from the outside at a depth of up to 10 m.
Holes with a diameter of 35 - 100 mm with a torn edge height of up to 15 mm can be repaired metal patch with clamping bolt PB-1. The patch can be applied by one person, and does not require additional fastening after installation. On the ship, the PB-1 patch (Fig. 5) is stored in a permanent readiness for use, assembled, the nut with handles should be located in the upper threaded part of the clamping bolt.
To install the patch on the hole, you must:
install the swivel bracket, overcoming the force of the spiral spring, parallel to the axis of the clamping bolt;
insert the clamping bolt with the swivel bracket into the hole so that, having gone beyond the skin, it turns under the action of the spring perpendicular to the axis of the clamping bolt;
holding the patch by the bolt, by turning the nut by the handles, press the rubber seal with the pressure disk against the skin until the water leak from the hole is eliminated.
The non-working surfaces of the patch are painted with red lead, the workers (clamping bolt, spring, nut thread) are lubricated with grease, the rubber seal is covered with chalk.
