This section is written based on materials taken from the site http://randewy.narod.ru/nk/pl.html“Online club for a young sailor”, and is intended to give a general idea of the design and structure of submarines. Although the illustrations date back to the mid-twentieth century, they nevertheless give an idea of the design of modern submarines, which differ from those shown in the drawings, first of all, in their size and shape, adapted for swimming under water, and not for swimming on the surface and “diving” “, as was the case before the advent of nuclear submarines and developed anti-submarine defense.
Submarines can be of one of three architectural and structural types. The figure above shows cross sections of boats of various architectural and structural types (the numbers indicate: 1 - strong hull, 2 - superstructure, 3 - fencing of the wheelhouse and retractable devices, 4 - strong deckhouse, 5 - main ballast tanks, 6 - light hull; 7 - keel; the meaning of these terms is explained further in the text ):
single-hull(s), having a “bare” durable hull, which ends at the bow and stern with well-streamlined ends of a lightweight structure;
one-and-a-half-hull (b), having, in addition to a durable body, also a lightweight one, but part of the surface of the durable body remains open;
double-hulled (in), having two housings: internal - lasting and external - easy. At the same time, the lightweight hull has a streamlined shape, completely envelops the robust hull and extends the entire length of the boat. The inter-hull space is used to accommodate various equipment and parts of tanks.
Submarines of the USSR and Russia are double-hulled. Most US nuclear submarines (they haven't built diesel-electric ones since the early 1960s) are single-hulled. This is an expression of the top priority for naval strategists of various qualities: surface unsinkability for the USSR and Russia and stealth for the USA.
Rugged housing- the main structural element of a submarine, ensuring its safe stay at depth. It forms a closed volume, impenetrable to water. Inside the durable hull there are premises for personnel, main and auxiliary mechanisms, weapons, various systems and devices, batteries, various supplies, etc. Its internal space is divided along the length by transverse waterproof bulkheads into compartments, which are named depending on their purpose and, accordingly, - the nature of the weapons and equipment placed in them.
In the vertical direction, the compartments are separated by decks (stretching along the entire length of the boat's hull from compartment to compartment) and platforms (within one compartment or several compartments). Accordingly, the boat’s premises have a multi-tier arrangement, which increases the amount of equipment per unit volume of the compartments. The distance between decks (platforms) “in the clear” is more than 2 m, i.e. slightly larger than the average human height.
The structurally sound hull consists of frames and plating. The frames, as a rule, have a circular annular shape, and at the ends they can have an elliptical shape and are made of profile steel. They are installed one from the other at a distance of 300 - 700 mm, depending on the design of the boat, both on the inner and outer sides of the hull, and sometimes in combination on both sides.
The casing of the durable hull is made of special rolled sheet steel and welded to the frames. The thickness of the skin sheets reaches 35 - 40 mm, depending on the diameter of the pressure hull and the maximum immersion depth of the submarine.
Pressurized hull bulkheads are strong and lightweight.
Bulkheads divide the internal volume of modern submarines into 6 - 10 waterproof compartments. Strong bulkheads They fence off shelter compartments in it, in which the crew members who survived the accident can prepare to independently ascend from the sunken boat to the surface or wait for outside help. By location, strong bulkheads are internal and end; in shape - flat and spherical (spherical ones are somewhat lighter than flat ones with the same strength and the internal spherical bulkheads are convexly facing the shelter compartments).
Light Bulkheads are designed to separate functionally specialized rooms and ensure the surface unsinkability of the ship (i.e., when the compartments are flooded, they withstand water pressure only if the boat is on the surface or at a depth within 20 - 30 m).
Structurally, bulkheads are made of frames and sheathing. A bulkhead set usually consists of several vertical and transverse posts (beams). The casing is made of sheet steel.
The end waterproof bulkheads of the durable hull are of equal strength and close it at the bow and stern ends. These bulkheads serve on most submarines as rigid supports for torpedo tubes, shafting, steering gear drives, set mountings, and internal structures of light ends.
The compartments communicate with each other through waterproof doors having a round or rectangular shape. These doors are equipped with quick-release locking devices.
In the upper part of the strong hull, a strong wheelhouse is installed, communicating through the lower wheelhouse hatch with the central post (inside the strong hull) and through the upper wheelhouse hatch with the navigation bridge (in the upper part of the wheelhouse fencing and retractable devices - periscopes, antennas). On most modern submarines, the strong deckhouse is made in the form of a round cylinder with a vertical axis or is a combination of a cylindrical part and truncated cones. On some boats, the robust deckhouse is designed so that it can be used as a pop-up rescue chamber, the purpose of which is to evacuate the entire crew or some part of it (which after the accident retained the ability to access the central control room and the pop-up camera) from a dying or sunken submarine.
Currently, on most boats, the main purpose of a strong deckhouse is to place the entrance to the strong hull as high as possible above the surface of the water when sailing on the surface. In addition, since the central post on many boats is one of the shelter compartments, the strong deckhouse is designed to serve as an airlock when people exit a sunken boat.
On the outside, the strong wheelhouse and the retractable devices located behind it, to improve flow around when moving in a submerged position, are covered with lightweight structures called the wheelhouse fencing or the retractable device fencing. At the top of the fence there is a navigation bridge with a full set of devices necessary to control the boat on the surface and means of communication with the central post. From the wheelhouse enclosure there are exits to the upper deck (in fact, the entrance to the strong hull through the hatches of the strong wheelhouse is the main one, since the hatches in the strong hull are prescribed by the boat operating manual to be kept closed in most cases).
The torpedo-loading and access hatches are located in the upper part of the durable hull and are covered on top with lightweight structures called superstructure. In most cases, these hatches are located in shelter compartments and are rescue hatches, for which purpose they are equipped with locking devices. The superstructure also contains devices designed for mooring, towing the boat and ensuring its anchorage.
Tanks designed for immersion, ascent, signboarding and trimming the boat, as well as for storing liquid cargo (fuel, oils, etc.). Depending on their purpose, tanks are divided into tanks: main ballast, auxiliary ballast, ship stores and special. Structurally, depending on the purpose and nature of use, they are either durable, i.e. designed for the maximum immersion depth, or light, capable of withstanding pressure of 1 - 3 kg/cm 2 (kg is an off-system unit, a kilogram of force, equal to the weight of 1 kg of mass with a free fall acceleration of 9.81 m/s 2). They can be located inside the strong hull, as well as in the space between the strong and light hull in the middle part of the ship and in the light ends fore and aft of the strong hull.
Keel- a welded (formerly riveted) beam of box-shaped, trapezoidal, T-shaped, and sometimes semi-cylindrical section, located in the bottom of the boat hull. It is designed to provide longitudinal strength, protect the hull from damage when placed on rocky ground, and to accept and redistribute the load when docking the boat. It can be located in the space between the hulls on double-hull boats, and on one-and-a-half and single-hull boats it can be located both inside the durable hull and outside - depending on what is more important for the customer - good hydrodynamics or protection of the durable hull from mechanical damage if the boat is in for certain tactical purposes they are placed on the ground.
Lightweight body- structurally includes a rigid frame (set), consisting of frames (transverse stiffeners), stringers (longitudinal stiffeners and plate elements of the set), transverse impenetrable bulkheads; the frame is the carrier of the light hull skin. Structurally, the light body kit is connected to a durable body located inside it. The lightweight hull has a streamlined shape that provides the necessary seaworthiness both on the surface and in the submerged position. The light hull is divided into parts: the outer hull, the bow and stern ends, and the superstructure. At the same time, it contains both permeable and impermeable structures (tanks). In addition to the light hull, the design of the boat includes separate, mostly permeable, structural elements: the deckhouse fencing, stabilizers, fairings of various kinds of devices located outside the durable hull and extending beyond the contours of the “ideal” shapes of the light hull.
The outer hull is the waterproof part of the lightweight hull located along the durable hull. It encloses the pressure hull along the perimeter of the boat's cross-section from the keel to the top watertight stringer and extends the length of the ship from the fore to aft end bulkheads of the pressure hull or main ballast tanks. Some boats have an ice belt, which is a thickening of the skin of a light hull in the area of the cruising waterline.
The ends of the light hull serve to streamline the contours of the bow and stern of the submarine; extend from the end bulkheads of the pressure hull to the stem (at the bow) and the sternpost (at the stern), respectively. However, boats (primarily nuclear-powered, which spend most of their voyages underwater) can have a teardrop-shaped hull without a stem or sternpost (the stem and sternpost are vertical stiffening ribs as part of the ship’s hull, giving a sharpness to the bow and stern, respectively, which is necessary to reduce resistance of water when floating on the surface).
The bow end houses: bow torpedo tubes, main ballast and buoyancy tanks, a chain box, an anchor device, receivers and emitters of the main hydroacoustic stations.
The aft end houses: main ballast tanks, horizontal and vertical rudders, stabilizers, propeller shafts and propellers. Some boats have stern torpedo tubes (most modern boats do not have stern torpedo tubes: this is primarily due to the large size of the propellers and stabilizers, as well as the fact that torpedo control algorithms allow them to be placed on almost any course, regardless of direction of the shot).
Below is a longitudinal section of a diesel-electric submarine from the mid-twentieth century, with an explanation of the design elements and devices. (A longitudinal section of the Kursk nuclear submarine with explanations is presented in Fig. 5 in Chapter 6).
1. Durable body. 2. Bow torpedo tubes. 3. Lightweight body. 4. Bow torpedo compartment. 5. Torpedo loading hatch. 6. Superstructure. 7. Durable cutting. 8. Cabin fencing. 9. Retractable devices. 10. Entrance hatch. 11. Stern torpedo tubes. 12. Aft end. 13. Rudder feather. 14. Aft trim tank, the purpose of which is to level the trim - the longitudinal inclination of the boat. 15. Aft watertight bulkhead. 16. Aft torpedo compartment. 17. Internal watertight bulkhead. 18. Main propulsion motors compartment. 19. Ballast tank. 20. Engine compartment. 21. Fuel tank. 22, 26. Stern and bow battery groups. 23, 27. Team living quarters. 24. Central post. 25. Hold of the central post. 28. Nasal trim tank. 29. Bow watertight bulkhead. 30. Nasal extremity. 31. Buoyancy tank (an attribute of some diesel-electric submarines; its purpose is to be empty when floating on the surface in order to give additional buoyancy to the bow so that the boat can easily rise to the wave, and not buried her nose in it - this reduces the speed and worsens controllability).
The following figure shows a cross-section of the deckhouse fence of a one-and-a-half-hull submarine from the mid-twentieth century, indicating the hull structural elements.
1. Navigation bridge. 2. Durable cutting. 3. Superstructure. 4. Stringer. 5. Leveling tank (designed to accurately balance the buoyancy force and weight of the boat in a submerged position). 6. Reinforcing stand (bracket). 7, 9. Brackets (plates to which the set elements are attached, they are designed to distribute the load and eliminate stress concentrations. 8. Platform. 10. Box-shaped keel. 11. Diesel foundation. 12. Sheathing of the strong hull. 13. Frames of the strong hull. 14. Main ballast tank 15. Struts (brackets) 16. Tank cover 17. Light hull plating 18. Light hull frame 19. Upper deck
French military developers have stunned the world with a new warship. Revolutionary is a “submersible frigate” or, as the designers themselves call it, a “surface submarine.”
At the European naval salon EURONAVALE-2010, which opened on October 25 in the Parisian suburb of Le Bourget, many projects of promising warships of the near future were presented. Experts clearly identify two trends: the creation of missile defense ships and ships specially designed to host unmanned aerial vehicles. Among them there are both conventional surface ships and very futuristic projects like the “submersible frigate” SSX-25, proposed by the French concern DCNS.
The French themselves call the unusual ship a “surface submarine”: this is how the French name Sous-marin de surface can be translated into Russian. The 109-meter-long ship has a semi-submersible underwater hull optimized for high speeds on the surface. For this purpose, especially powerful gas turbines are installed in the elongated knife-shaped hull of the ship, driving three water-jet propulsors, while the “surface submarine” will be able to travel at least 2,000 nautical miles at a 38-knot speed.
Turbines and underwater diesel engines are located on a single base in a massive deck superstructure. Upon arrival in the combat area, the ship makes a “dive”, partially turning into a submarine.
At the same time, the air intakes of the turbines and exhaust devices are closed with special dampers, “snorkels” (devices for underwater supply of diesel engines with air) extend from the superstructure, azipods are installed from the central part of the ship, and depth rudders are located in the bow. When submerged, the ship's displacement is 4,800 tons and it is capable of moving at speeds of up to 10 knots.
To observe the surface, a special retractable mast like a periscope, equipped with a radar and various kinds of optical sensors, can be used.
The company does not say whether the ship is capable of operating in a fully submerged state, that is, without retractable devices for taking in atmospheric air, only on electric power. The company emphasizes that its diving ship is not optimized for combating underwater targets, however, it has eight torpedoes in its bow torpedo tubes for self-defense.
The main armament of the ship is 16 universal vertical launchers to accommodate both cruise (including anti-ship) and anti-aircraft missiles.
Thus, as a promising ship, French designers propose a kind of hybrid of a guided missile frigate (high speed, seaworthiness, powerful missile system) and an attack submarine (stealth, ability to attack targets from an underwater position). The submerged hull will provide the hybrid ship with less vulnerability from pitching, making it a stable launch platform, and the developed superstructure will partially get rid of such a drawback of the submarine as cramped space. Moreover, the submerged body also means less visibility in all ranges and high efficiency due to less resistance to movement at the boundary of media.
In addition, as experts note, the developed superstructure allows it to accommodate various fairly comfortable rooms for special forces and their specific equipment - an advantage that special-purpose submarines lack. The superstructure, of course, can also accommodate a special hangar for a UAV (unmanned aerial vehicle); rotary-wing aircraft with vertical take-off are especially attractive in this regard. Such robotic helicopters can be stored in automated racks on the sides of the hangar with a retractable roof that will open to release and receive the UAV.
Obviously, in this configuration, the ship should be considered, first of all, as a reconnaissance aircraft, designed for secretive and long-term collection of information in any coastal area, for one reason or another, not accessible to space or aviation reconnaissance. Another possible purpose of such a ship is clearing a bridgehead for commandos, covert strikes on coastal targets, and clearing beaches before the arrival of the main landing forces. It is clear that it will be most valuable against an enemy who does not have modern anti-submarine warfare capabilities.
One should not think that the French invented something fundamentally new. Diving and semi-submersible submarines have been known since the century before last; some of these ships were even used in combat. Thus, the English K-class squadron boats of the First World War, equipped (due to the lack of powerful diesel engines) with steam turbine units, were actually diving ships and in battles operated from a semi-submerged position, hoping for protection of the hull by the water column. The famous “Monitor” can also be considered a semi-submersible vessel: the first self-propelled iron screw artillery ship, used by the northerners during the American Civil War to shell the Hampleton raid.
One can also recall the German mini-submarines of the Seehunde and Seeteufel types: the former were an attempt to create a kind of naval analogue of a single-seat fighter aircraft, and the latter were a sabotage vessel with the ability to go ashore with the help of tracks.
Various projects of diving ships were also created in the USSR. These were actually the early Soviet Pravda-class submarines. To achieve high surface speed, designer Andrei Asafov tried to give the submarine the contours of a destroyer - the fastest surface ship at that time. But destroyers are characterized by a ratio of length to width and width to draft that is absolutely not characteristic of submarines. As a result, the ship was poorly controlled when submerged, and the high reserve of buoyancy extremely slowed down the dive.
The design of the diving torpedo boat 1231 “Dolphin” also looked extremely original. The idea was personally submitted by Nikita Sergeevich Khrushchev. Once inspecting high-speed boats of the TsKB-19 and TsKB-5 projects at the naval base in Balaklava and observing the submarines based there, he expressed the idea that in order to ensure the secrecy of fleet actions, which is especially important in a nuclear war, it is necessary strive to “submerge” the fleet under water, and proposed to “submerge” a missile boat first.
In accordance with the TTZ, the Project 1231 ship was intended to launch surprise missile attacks on warships and transport in bottlenecks, on approaches to enemy naval bases and ports, to participate in the defense of the coast, fleet basing areas and coastal flanks of ground forces, to repel landings landings and disruption of enemy sea communications, as well as for carrying out hydroacoustic and radar patrols in places where the fleet is dispersed. It was assumed that when solving these problems, a group of similar ships was supposed to deploy in a given area and remain in a submerged position for a long time in a waiting position or approach the enemy also in an underwater position, maintaining contact with him by hydroacoustic means.
Having approached, the missile carriers surfaced, reached the missile salvo line at high speed, fired missiles, then sank again or broke away from the enemy at maximum speed on the surface. The presence of missile carriers in a submerged position and high speed during an attack should have reduced the time they spent under enemy fire, including air attack weapons.
The project developed quite successfully from 1959 until Khrushchev's resignation in 1964, when it was frozen and later closed
The only application in which diving ships have proven themselves are high-speed semi-submersible landing craft, used, for example, by North Korean saboteurs, and for some time now by their Iranian colleagues. The same type of vessels, but “homemade” ones, are also used by Colombian drug traffickers to deliver their goods to the United States. These are low-slung boats up to 25 meters long, the surface part of the boats protrudes above the surface to a height of no more than 45 centimeters, they can take on board up to 10 tons of cocaine. The US military and law enforcement agencies call them Self-Propelled Semi-Submersibles (SPSS). Detection of such vessels is extremely difficult even for such a well-equipped service as the US Coast Guard.
Apparently, this is what the French designers are guided by: some Somali pirates will most likely really not notice a large semi-submersible or diving ship. But is the game worth the candle? Will it turn out that a ship of this class will be more expensive than a frigate and a submarine combined, and worse in efficiency than each individually? It is clear that at the moment no one can answer this question, but it still seems that the future belongs to less exotic ships.
Longitudinal elements (beams) vessel are:
- keel- longitudinal beam of the bottom frame, running along the middle of the width of the vessel;
- stringers- longitudinal beams of the bottom and side frame. Depending on their location, they are: side, bottom and zygomatic.
- Carlings- longitudinal under-deck beams;
Longitudinal stiffeners - longitudinal beams of a smaller profile than those of stringers and carlings. Based on their location, they are called below-deck, side or bottom and provide rigidity to the outer skin and deck flooring during longitudinal bending.
Transverse elements of the vessel
Transverse elements (beams) of the vessel:
- Floras are transverse beams of the bottom set, stretching from side to side. They are waterproof, solid and bracketed;
- Frames are vertical beams of the side frame, which are connected below to the floors using brackets. A bracket is a piece of triangular-shaped sheet steel used to connect various parts of the body. On small vessels (boats), flora may be absent and the frames are solid beams of the side and bottom frames.
- Beams are transverse beams of a deck set, running from side to side. If there are cutouts in the deck, the beams are cut and called half beams. They are connected at one end to the frame, and at the other they are attached to a massive coaming, which borders the cutout in the deck, in order to compensate for the weakening of the deck floor with cutouts.
On rice. 1 shows the simplest structure of the hull of a small boat, indicating the main elements of the set, and on rice. 2 a more complete set of wooden motor boat hulls is presented.
Rice. 1. Structure of the hull of a small vessel.
1 - stem; 2 - keel; 3 - stringer; 4 - side trim; 5 - transom; 6 - frame; 7 - beam; 8 - deck
The ship's frames are numbered from bow to stern. The distance between the frames is called spacing. Vertical, free-standing racks of round or other cross-section are called pillars.
Rice. 2. Elements of a wooden motor boat hull kit.
1 - casing; 2 - deck; 3 - beam; 4 - frame; 5 - seats; 6 - transom; 7 - motor mounting location;
8 - side stringer; 9 - fender; 10 - zygomatic stringer; 11 - keel; 12 - bottom stringers
The pillars serve to reinforce the deck and in its lower part rests on the intersection of the floors (frames - on small ships) with the bottom longitudinal beams (keel, stringer, keelson), and in the upper part - beams with carlings. Piller installation is shown in rice. 3.
Rice. 3. Piller installation
1 - deck flooring; 2 - carlings; 3 - beam; 4 - transverse coaming; 5 - pillers;
6 - second bottom flooring; 7 - flor; 8 - keel; 9 - bottom trim.
Vertical or inclined beams that are a continuation of the keel are called stems (in the bow - stem, in the stern - stern). The ship's hull can be divided into separate compartments using transverse and longitudinal watertight bulkheads. The bow of the ship between the stem and the first bulkhead is called the forepeak, and the aft compartment is the afterpeak. On powerboats, a watertight structure at the transom that forms a niche and is designed to accommodate the outboard motor is called the engine niche. The motor niche, located above the water level and equipped with scuppers - holes for draining water, is called a recess niche.
For a more complete picture of the elements of the body kit, see rice. 4 shows a cross-section of a dry cargo ship with a combined recruitment system, and Fig. 5th set of metal boat hull "Chibis".
Rice. 4. Combined dialing system.
1 - gunwale; 2 - bulwark stand; 3 - bulwark; 4, 10-beams; 5 - deck flooring; 6 - carlings; 7 - stiffener; 8 - hatch coaming;
9 - pillers; 11 - bulkhead pillar; 12 - transverse bulkhead; 13 - second bottom flooring; 14 - keel; 15 - horizontal keel; 16 - bottom stringer;
17 - bottom trim; 18 - flor; 19 - outer double-bottom sheet; 20 - zygomatic keel; 21 - zygomatic belt; 22, 25 - frame;
23 - half beam; 24 - side trim; 26 - knitsa; 27 - shearstrek.
Rice. 5. Boat hull set.
1 - frame frame; 2 - carlings; 3 - coaming; 4 - deck flooring; 5 - fender; 6 - frame; 7 - side trim;
8 - zygomatic square; 9 - flor; 10 - stringer; 11 - keel; 12 - bracket; 13 - bottom plating; 14 - knitsa.
External cladding
The outer plating of the vessel ensures the waterproofness of the hull and at the same time participates in ensuring the longitudinal and local strength of the vessel. On metal ships, the hull consists of steel sheets placed with the long side along the ship. In addition to steel sheets, especially on metal motor boats and boats, sheets of aluminum alloys are used. Sheathing sheets are connected using rivets and butt welding. A series of planking sheets running along the ship is called a belt. The upper belt of the side skin is called shirstrvkom, and below there are side belts and on the cheekbone - the zygomatic belt. The middle bottom belt is called the horizontal keel. The line of connection of one belt with another is called a groove, and the place where the sheets join each other in one belt is called a joint. The sizes of sheets and their thickness are different and depend on the design of the vessel, its size and purpose. For the cladding of boats, motor, sailing and rowing boats, wood materials, laminated plastics, fiberglass, textolites and other materials that meet the requirements of shipbuilding in their properties and strength are very often used.
Deck flooring
The deck flooring ensures the watertightness of the hull from above and is involved in ensuring the longitudinal and local strength of the vessel. The greatest load during longitudinal bending falls on the deck in the middle part of the ship, so the deck sheets at the end are somewhat thinner than in the midship area. The flooring sheets are located with the long side along the ship, parallel to the centerline plane, and the outermost chords of the left and right sides are located along the sides; they are called deck stringers and are thick. The deck stringer is connected to the shearstrak by riveting, welding or gluing, depending on the material of the decking sheets.
Hatches and necks
Hatches and necks weaken the strength of the deck; stress concentrations arise in their corners, contributing to the appearance of cracks. In this regard, the corners of all cutouts in the hull plating are rounded, and the deck sheets at the corners of the cutouts are made more durable. To strengthen the deck, weakened by the cutouts, and to prevent water from entering the hatch, a coaming is made along the edges of the cutout, which has a device for closing the hatch (neck). The coaming also borders the cutouts in the bulkheads; the coaming is also called the part of the bulkhead under the doorway.
Bulwark and railing
On sea, river and modern pleasure boats, to protect people from falling overboard, open decks have a bulwark or railing.
Bulwark(rice. 6) is, as a rule, a metal belt of the side plating. It is installed on low decks prone to flooding in stormy weather.
Rice. 6. Bulwark.
1 - buttress; 2 - bulwark; 3 - gunwale; 4 - stiffening strut.
On the inside, the bulwark is supported by racks, which are called buttresses and are installed through two or three spacing. To increase the strength of the bulwark, ribs are sometimes welded between its posts. Along the upper edge of the bulwark, a strip is strengthened, which is called a gunwale. To drain water overboard that falls on the deck, cutouts are made in the bulwarks - storm porticoes. Considering that the complete removal of water through the storm ports is prevented by the deck stringer angle, then for complete drainage of water from the deck overboard, scuppers are made - cutouts in the edge of the shearstrake protruding above the deck and in the deck stringer angle. Railing fencing ( rice. 7) consists of vertical posts connected to each other by tightly stretched cables (rails) or chains.
Rice. 7. Guardrail (removable).
The racks can be connected to each other by two, three or four rows of horizontal round rods, most often steel. These horizontal rods are called rails.
Shipbuilding materials
There are basic materials used for the manufacture of hulls, kit elements, ship devices and parts.
Steel- has many properties necessary for building a ship (density 7.8 g/cm3). It is durable and easy to process. The most commonly used shipbuilding steels are carbon and low-alloy steels.
Sheet steel has a thickness from 0.5 to 4 mm (thin sheet) and 4 - 1400 mm. In shipbuilding, the most common sheets are 6-8 m long and 1.5-2 m wide. The following profiles are produced from carbon steels: angle, channel, I-beam, strip-bulb and z-beam, and from low-alloy steels the same profiles are produced, except z-beam and I-beam. Sheet steel is used to make hull plating, bulkheads, second bottom, decks, etc.; from the profile: beams, frames, stringers and other elements of the hull. The casting method produces parts of complex shapes: anchor fairleads, anchors, chains, stems, propeller brackets, etc.
Aluminum alloys have a lower density than steel (2.7 g/cm3) and sufficient strength. The most common are alloys of aluminum with magnesium and manganese. Small vessels, superstructures, partitions, pipelines, ventilation pipes, masts, ladders and other important ship parts are made from these alloys.
Wood and wood materials for many years (until the 19th century) they were the only material for building ships. Having many advantages, wood continues to be used in shipbuilding today. The hulls of small sea and river vessels, boats, dinghies, rowing boats, sports and sailing ships, deck coverings, decoration for ship premises, etc. are made from wood. Pine is most often used in shipbuilding. It is used to make kits and plating. Spruce is used for lining the underwater part of the vessel, because it is less hygroscopic. Larch and teak are used for decking and external cladding, for finishing residential and office premises - oak, beech, ash, walnut, birch and others. In addition, the stems of wooden ships are made from beech and ash, incl. undersized. Beams, boards, slats, plywood and wood slabs are widely used in shipbuilding, used for the manufacture of external cladding of ships, finishing of cabins, salons, etc.
Plastics Due to low density, good dielectric and thermal insulation properties, high corrosion resistance, convenient processing methods and sufficient strength, they increase the service life of individual ship parts. erasers are divided into two main groups: thermoplastics (plexiglass, nylon, polyethylene and other plastics that can again acquire a plastic state when heated and harden when cooled) and thermosets - plastics that cannot be re-softened when heated, i.e. plasticity. The most widely used in shipbuilding are fiberglass plastics - various synthetic resins (epoxy, polyester, etc.) reinforced with fiberglass in the form of fabric, mats, strands. Fiberglass is used to make small vessels (boats, boats, yachts, boats), pipes and other ship structures and parts.
The main disadvantages of plastics are: low heat resistance, low thermal conductivity, tendency to plastic deformation under the influence of constant load at normal temperature (creep).
Cast iron used for the manufacture of cast products: bollards, bale strips, stern tubes, propellers and other parts.
Bronze- an alloy of copper with tin or aluminum, manganese, iron. Sliding bearings, propeller shaft linings, kingston housings, worm wheels and other parts are made from it.
Brass- an alloy of copper and zinc. Pipes for heat exchangers, porthole parts, electrical parts, propellers and other products are made from it.
Reinforced concrete- a material consisting of concrete reinforced with a metal frame. It is mainly used for the construction of floating docks, cranes, and landing stages.
Superstructures and deckhouses
Superstructures are all enclosed spaces located above the upper deck from side to side. The bow superstructure is called the forecastle, the stern superstructure is called the poop. The middle superstructure has no special name. A superstructure having a width less than the width of the vessel is called a deckhouse. For example, the chart room. The design of decks and sides of superstructures and deckhouses is similar to the design of other decks and sides on ships. The side plating and bulkheads of superstructures, as a rule, are thinner and may differ in material from the hull.
A deck boat is a relatively new type of pleasure boat, which has become increasingly widespread in recent years in countries with warm, sunny summers. This is the development of the so-called pontoon vessels, which are a platform mounted on two pontoon floats - a welded structure made of aluminum alloys or molded from fiberglass. An uncluttered, rectangular, stable platform, fenced along the perimeter with reliable railings and a low bulwark, creates the illusion for passengers of a pontoon boat of being in a familiar coastal environment: there is no cramped cockpit and rooms, which is typical for small vessels. Thanks to the large deck area, such boats are very convenient for Sunday walks with the whole family or picnics for up to eight people. Pontoon boats are usually equipped with standard sets of furniture (sometimes with a folding summer cottage set) and only a light sun awning, since they are not designed for long-term stays of passengers away from the shore in bad weather (if it gets colder or rains, they usually return to their mooring place at full speed).
Pontoon boats, due to their simplicity of design (the pontoons themselves are most often cylindrical pipes with a diameter of 450-600 mm), are relatively cheap. When disassembled, they can be easily delivered to isolated reservoirs. However, such boats also have a number of disadvantages. First of all, this is a limited navigation area: they can only be sailed along relatively quiet rivers, lakes and well-closed sea bays: it is difficult for a low-sided boat with a developed sail to withstand large waves and strong winds. The planing working area of narrow pontoons in the stern is limited, and this does not allow installing an engine powerful enough to reach high speeds. There is no hold, the volume of which could be used for stowing equipment and supplies.
Boat basic data
Apparently, the desire to maintain “spaciousness” and “freedom of flexible layout” on the deck, but to get rid of these shortcomings, prompted a number of companies in the West to develop and put into production a new type of vessel, called a deck boat. In this version, the hull is most often given trimarain contours, which preserve the almost rectangular outline of the deck and ensure high stability of the boat. The high-sided hull of a wide trimaran motorboat has higher seaworthiness than wave-rolled pontoons; it can install a stationary engine of significant power and enclose spaces for storing luggage. There is no traditional cockpit; the hull is covered by a deck, the entire area of which is used to comfortably accommodate passengers in the same way as on a pontoon boat. The photo shows one version of a typical high-speed deck boat, equipped with a 140-horsepower Mercruiser sterndrive engine.
An interesting version of a deck boat, adapted for river travel, was developed by the famous designer of small boats, David Beach from Chicago (three of his projects - the motor-sailing yacht "Dolphin", a boat with plywood sheathing and a round-billed floating boat were published in, and collections, respectively).
The project, designed specifically for self-construction, was awarded 2nd prize at an international competition organized by the OMS engine-building concern with the aim of expanding the scope of application of the Zephyr stationary installation with an outboard motor engine ().
The design of the hull is designed to be covered with waterproof plywood (aircraft plywood 8 mm thick or bakelized plywood 7 mm thick can be used) over tight frames (600 mm spacing) and longitudinal stringers made of pine slats. The designer provided for the possibility of operating the boat with one Zephyr installation with a capacity of 15 hp. s., as well as with any other engine or outboard motor in a fairly wide power range - up to 140 hp. With. The simplified flat-keeled hull contours are adapted for economical sailing in displacement mode at the lower power limit, and for planing with an engine power of over 60 hp. With. In the attached drawings you can see the rise of the bottom upward at the transom to reduce water resistance at low speeds and a decrease in the deadrise of the bottom towards the stern to facilitate the vessel's entry into planing mode. The developed keel fin protects the propeller from damage when running aground and prevents the ship from drifting in cross winds.
The boat is designed to be towed on a trailer behind a passenger car, which, by American standards, limits the hull's overall beam to 8 feet (2.43 m). The main part of the deck area is occupied by a shallow (its bottom is 200 mm higher than the waterline) self-draining cockpit, the dimensions of which in plan are 2.08X1.54 m. These three square meters can be used depending on the circumstances and the desire of the crew. For example, you can lay out a couple of air mattresses here and arrange a solarium, or sit down for lunch on folding chairs. It is important that even while underway, passengers in the cockpit are reliably protected from wind and splashes: from the bow and stern - by short and high superstructures, which give the boat such an unusual appearance, and from the sides - by low bulwarks. A light tubular frame (collapsible design) between the superstructures serves as the basis for a solar awning, but in bad weather or, say, when mosquitoes appear, fabric sidewalls can be fastened to this awning and you will get a cozy cabin with an inside height of 1.9 m. For an overnight stay in it - again on air mattresses - can accommodate 3-4 people. The cockpit platform is equipped with outboard scuppers to drain any water that gets there.
The superstructures play the role of utility rooms. In the stern there is a sink and gas stove, as well as a toilet with a removable tank (a device required on board pleasure boats according to the rules of most states). This superstructure can be entered from both the deck and the cockpit via sliding doors. Indoor height 1.83 m; in its upper part there is a niche for laying pipes and awning panels.
There is glass attached to the bow superstructure, protecting passengers from headwinds and allowing forward visibility. Inside there are lockers for clothes and various camping equipment. The boat control panel is attached to the front wall on the console. The driver and one of the passengers are located in comfortable chairs right on the foredeck. The steering wheel is mounted on a reversible console, which rotates in a vertical plane in such a way that any of the people sitting here can control the boat.
The voluminous forepeak serves as a storage room, and to facilitate its use, two hatches are equipped on the deck. A wide double hatch at the stern provides access to the engine compartment, where one or two Zephyrs or another stationary engine can be installed. Fuel tanks are also located here. In addition to the cockpit, a fairly large free deck area is preserved: the covers of all hatches are made “hidden”, there are passages along the boat along the side footpaths.
In general, an amateur boater who has built such a boat will have at his disposal a fairly comfortable floating cottage, suitable for both Sunday relaxation and longer family voyages.
In our conditions, instead of the “Zephyr” installation, an outboard motor can be used, mounted in the usual way on the transom (it is worth equipping an under-engine niche) or installed permanently in the engine compartment (see the book “Boats, boats and motors in questions and answers.” L., “Shipbuilding”, 1977). Considering the relatively low speed of movement with moderate power of 20-25 hp. pp., it is useful to use a propeller with a smaller pitch and a ring-profiled nozzle, which significantly increases the efficiency of the propulsion unit.
In this note, I bring to your attention the firepower that the boats had. I again reviewed the topic briefly, without providing details and nuances, since a detailed coverage of this issue would require writing at least a large review article. To begin with, to make it clear how the Germans highlighted the issue of the need to have a gun on board and its use, I will give an excerpt from the “Manual for Submarine Commanders”, where the following is said about this:
"Section V Artillery weapons of submarines (submarine as a carrier of artillery)
271. The presence of artillery on a submarine is fraught with contradictions from the very beginning. The submarine is unstable, has a low-lying gun and surveillance platform, and is not equipped to conduct artillery fire.
All artillery installations on a submarine are poorly suited for an artillery duel, and in this respect the submarine is inferior to any surface ship.
In an artillery battle, a submarine, as opposed to a surface ship, must immediately bring all its forces into action, because even one hit in the strong hull of a submarine already makes it impossible for it to dive and leads to death. Therefore, the possibility of an artillery battle between a torpedo submarine and military surface ships is excluded.
272. For submarines used for torpedo attacks, artillery is, as it were, a conditional and auxiliary weapon, because the use of artillery over water contradicts the entire essence of a submarine, i.e., a sudden and covert underwater attack.
Based on this, it can be said that on a torpedo submarine, artillery is used only in the fight against merchant ships, for example, to delay steamships or to destroy unarmed or weakly armed ships (§ 305)."(With)
Deck artillery
Caliber, Type, Shooting, Rate of fire, Elevation angle , Effect. range, Calculation
105 mm SK C/32U - U-boot L C/32U Single 15 35° 12,000 m 6 persons
105 mm SK C/32U - Marine Pivot L Single 15 30° 12,000 m 6 persons
88 mm SK C/30U - U-boot L C/30U Single 15-18 30° 11,000 m 6 people
88 mm SK C/35 - U-boot L C/35U Single 15-18 30° 11,000 m 6 people
Of all types of German submarines designed and built from 1930 to 1945, boats of the I, VII, IX and X series were armed with deck artillery with a caliber of over 88 mm. At the same time, only the VII series carried an 88-mm caliber gun; the rest of the indicated series of boats had a 105-mm gun. The cannon was located directly on the upper deck in front of the wheelhouse; the ammunition was stored partly there in the superstructure of the boat, partly inside the durable hull. Deck artillery was in the department of the second watch officer, who performed the duties of a senior gunner on the boat.
On the "sevens" the gun was installed in the area of frame 54 on a pyramid specially reinforced in the superstructure, which was reinforced with longitudinal and transverse beams. In the area of the gun, the upper deck was expanded to 3.8 meters in length, thereby forming a place for artillery crews. The standard ammunition for the boat was 205 shells - 28 of which were in special containers in the superstructure next to the gun, 20 shells in the wheelhouse, and the rest in the "weapons room" inside the durable hull in the second compartment from the bow.
The 105 mm gun was also mounted on a pyramid, which was welded to the pressure hull. Depending on the type of boat, the ammunition for the gun ranged from 200 to 230 shells, of which 30-32 were stored in the superstructure next to the gun, remaining in the “weapons room” located in the central control room and galley.
The deck gun was protected from water by a waterproof plug on the barrel side, and by a special plug sleeve on the breech side. A well-thought-out lubrication system for the gun made it possible to keep the gun in working condition at different temperatures.
I mentioned various cases of using deck guns
And .
By the end of 1942, the command of the submarine forces came to the conclusion that the deck guns on boats that participated in the fighting in the Atlantic theater of operations should be dismantled. Thus, almost all “sevens” of type B and C lost such artillery. The guns were retained on Type IX submarine cruisers and Type VIID and X mines. But by the end of the war it was already difficult to find a German boat of any type that could carry deck artillery.
88 mm U29 and U95 guns. The waterproof plug is clearly visible.
Elevation angle of the 88 mm gun on the U46. It seems that it still exceeds those 30 and 35 degrees indicated in the technical characteristics. The gun had to be raised with its barrel up when loading torpedoes into the bow compartment. The photo below shows how this happened (U74 preparing to take a torpedo) 
105 mm gun on the U26 "one" 
105 mm guns U103 and U106 
General view of the 105 mm gun with its mounts. 
Gunners U53 and U35 prepare for practical shooting 
Artillery crew U123 is preparing to open fire. A tanker is visible straight ahead. The target will be sunk by artillery fire. Completion of Operation Paukenschlag, February 1942. 
But sometimes the tools were used for other purposes :-)
The pictures below show U107 and U156 
Flak
Caliber, Type, Shooting, Rate of fire, Elevation angle , Effect. range, Calculation
37 mm SK C/30U - Ubts. LC 39 Singles 12 85° 2,500 m 3/4 persons
37 mm M42 U - LM 43U Automatic (8 rounds) 40 80° 2,500 m 3/4 persons
37 mm Zwilling M 42U - LM 42 Automatic (8 charges) 80 80° 2,500 m 3/4 persons
30 mm Flak M 44 - LM 44 Automatic (exact characteristics unknown. For type XXI submarines)
20 mm MG C/30 - L 30 Automatic (20 rounds) 120 90° 1,500 m 2/4 persons
20 mm MG C/30 - L 30/37 Automatic (20 rounds) 120 90° 1,500 m 2/4 persons
20 mm Flak C/38 - L 30/37 Automatic (20 rounds) 220 90° 1,500 m 2/4 persons
20 mm Flak Zwilling C/38 II - M 43U Automatic (20 rounds) 440 90° 1,500 m 2/4 persons
20 mm Flak Vierling C38/43 - M 43U Automatic (20 rounds) 880 90° 1,500 m 2/4 persons
13.2 mm Breda 1931 Automatic (30 rounds) 400 85° 1,000 m 2/4 persons
Quad units are highlighted in red, dual units are highlighted in blue.
Of the fire weapons that the German submarines had, the most interesting were anti-aircraft weapons. If deck guns were obsolete by the end of the war, then the evolution of anti-aircraft fire among the Germans is clearly visible from the above table.
By the beginning of the war, German submarines had only a minimum of anti-aircraft guns, since it was believed that the threat from the air was clearly underestimated by the fleet command. As a result, the designers in the projects included no more than one anti-aircraft gun on the boat. But during the war the situation changed and reached the point that some submarines were literally studded with anti-aircraft guns, such as “anti-aircraft boats” (flakboats).
The main weapons of the boats were initially recognized as 20-mm 20-round anti-aircraft guns, which were installed on all types of boats with the exception of the II series. On the latter they were also provided, but were not included in the standard armament of the boats.
Initially, on the first "sevens" in pre-war times, a 20-mm anti-aircraft machine gun of the MG C/30 - L 30 type was supposed to be installed on the upper deck behind the wheelhouse. This is clearly seen in the example of U49. Behind the open hatch you can see the anti-aircraft gun carriage. 
But already in wartime, the 20-mm anti-aircraft gun was moved to a site located behind the bridge. It is clearly visible in the photo. Alternately, anti-aircraft platforms U25, U38 (Karl Doenitz himself is on the bridge of the boat), U46 
Depending on the type and purpose of the boat, "Dvoyki" received anti-aircraft weapons, both pre-war and during the war. The gun was located in front of the wheelhouse. Either a carriage was installed for it, or it was installed there on a waterproof container (in the form of a barrel) in which the machine gun was stored in a disassembled state).
U23 before the war 
Waterproof "barrel", also known as a carriage on U9 (Black Sea) 
Same thing on U145 
And this is already in finished form. U24 (Black Sea) 
Option for installing an anti-aircraft gun on a carriage. U23 (Black Sea) 
The "Twos" operating in the Black Sea underwent some modification. In particular, the deckhouse was modified towards standard ocean-going boats by adding a platform for installing additional firepower. Due to this, the armament of boats of this type at the World Theater Championship increased to 2-3 guns per submarine. The photo shows U19 in full armor. Anti-aircraft gun in front of the wheelhouse, twin guns on the platform behind the bridge. By the way, machine guns installed on the sides of the cabin are visible. 
The growing threat from the air forced the Germans to take measures to increase anti-aircraft weapons. The boat received an additional platform for placing fire weapons, on which two pairs of 20-mm machine guns and one (or two) 37-mm machine guns could be placed. This site received the nickname "Winter Garden" (Wintergarten). Below are photos of boats that surrendered to the Allies U249, U621 and U234 
As the pinnacle of the evolution of anti-aircraft weapons on German boats, the quad anti-aircraft gun Flak Vierling C38/43 - M 43U, which was received by the so-called “anti-aircraft boats”. As an example U441.
In the Mediterranean, the "Sevens" received additional weapons by installing Italian "Breda" machine guns in the form of twin-arms. As an example U81 
A special word worth mentioning is such a “miracle” weapon as the 37 mm SK C/30U - Ubts anti-aircraft gun. LC 39, which fired single shots. This gun was installed on later types of submarine cruisers of type IX (B and C) and submarine tankers of type XIV. The "cash cows" carried two guns of this type on either side of the wheelhouse. "Nines" had one installed behind the wheelhouse. Below are examples of such a weapon on the U103. 
Since I did not set myself the task of conducting a complete and detailed description of anti-aircraft weapons, I omit such nuances as ammunition and other characteristics of this type of weapon. I once mentioned the training of anti-aircraft gunners on submarines. Examples of confrontation between submarines and aircraft can be found if you look at the topics in my tag.
Firearms and signal weapons
Caliber, Type, Shooting, Rate of fire, Elevation angle , Effect. range, Calculation
7.92 mm MG15 Automatic (50/75 rounds) 800-900 90° 750 m 1-2
7.92 mm MG34 Automatic (50/75 rounds) 600-700 90° 750 m 1-2
7.92 mm MG81Z Automatic (Tape) 2.200 90° 750 m 1-2
In addition, the submarine’s crew had at their disposal 5-10 Mauser 7.65 mm pistols, 5-10 rifles, MP-40 assault rifles, hand grenades and two flare guns.
MG81Z on U33 
In general, I would like to note that German submarines had fire weapons that were quite modern at that time, which worked well during combat operations. In particular, the British noted after testing the artillery they captured U570 that, compared with the 3-inch gun of the 1917 model mounted on S-type boats, the 88-mm German gun was superior to the British one. The 20-mm anti-aircraft machine gun was recognized by them as an excellent and effective weapon, which, to their surprise, did not vibrate when fired and had a good magazine.
Photo resource used to illustrate the note http://www.subsim.com
As usual, Vladimir Nagirnyak pored over the analysis.
