Any shipbuilder who plans to provide freight or passenger flows should be aware of how ships are being created correctly. The device of ships is a whole science that allows one to foresee and correctly evaluate the behavior of a ship during its operation in any, even the most difficult situations.
What is a ship?
The ship is a complex floating engineering structure, which solves a number of problems - from national economic to public and special. Each floating vessel consists of a huge number of mechanisms and components, devices and apparatuses, the integral and stable operation of which creates ships. The structure of ships is complex and obeys the laws of physics, and is also built on the basis of modern advanced knowledge and progressive achievements. Modern ships are presented in a huge variety, depending on the features of their design and basic characteristics. Vessels are self-propelled and non-self-propelled, floating above water, on and under water, with different types of hull.
Depending on the area of navigation, the vessels are divided into sea, inland navigation (that is, river and lake) and mixed types, that is, those that transport between sea and river ports. Depending on the type of motor that sets the vessel in motion, steamboats, motor ships and diesel ships are allocated. Engines in ships can be screw, with a wing propeller, paddle wheels, the ship can move on sails or oars.
What are civil courts?
The arrangement of ships engaged in civil transport is thought out in such a way as to ensure the normal operation of the facilities, depending on their purpose. The most popular civilian vessels are transport and fishing vessels. Transport craft are designed to transport passengers or goods, or both at the same time and are divided into liners and trams. Fishing species are represented in a larger number of species - fishing, whaling, floating bases, cannery trawlers and so on.
Key Performance Features
Each vessel has certain technical properties. Such indicators as transport ability and profitability shown by ships depend on them. The device of vessels depends on the following parameters:
- lifting capacity: this indicator characterizes the loads that the ship can carry without changing the design landing; net carrying capacity is the total weight of the payload that the vehicle carries, and deadweight is the total weight of the entire cargo carried, including fuel, boiler water, baggage and crew, that is, the sum of all cargo on the ship;
- displacement: this is the sum of the total constant weight, which affects the total weight of the entire vessel;
- cargo capacity: this is the volume of all cargo spaces on the ship;
- grain capacity: this is the theoretical volume of cargo spaces in which the volume of the hull and other internal structures is not considered;
- net capacity: this indicator indicates the conditional volume of all the premises of the vessel in which goods and passengers are transported;
- speed: the economic efficiency of the vessel and its carrying capacity depend on this indicator;
- Cruising range: that is, the distance that a ship can travel at a certain speed without the need to replenish supplies;
- maneuverability: this parameter indicates the ability of the vessel to perform certain maneuvers, primarily to change direction and speed;
- autonomy of navigation: this is an indicator of the time the vessel operates without replenishment of fuel, water, food supplies;
- survivability, that is, the ability of the ship in unforeseen circumstances to complete a safe navigation.
Stability is an important indicator.
The theory of the device of the vessel involves attention to the stability of each floating craft. This parameter refers to the conditions under which the vessel moves in a vertical position and straightens after inclinations. An important role is played by the correct loading of each vessel, taking into account its reliability and efficiency. The vessel can change its balance under the influence of wind and waves, and the stability depends on the position in which the metacentre is in relation to the center of gravity. A true metacenter is the point at which two adjacent directions of buoyancy force intersect. The moment of stability affects the straightening of the court until the center of gravity lies above the true metacentre. If the metacentre is lower, then the vessel will not maintain equilibrium.
How is the ship arranged?
The general structure of ships in the most general terms is as follows. The main element is the body, consisting of the outer skin - it serves as the basis for the bottom and side. On top of the hull is covered by a deck, and there may be several of them, depending on the type of vessel. The upper deck has a length from side to side and from the bow of the vessel to its stern - on it premises for various purposes are arranged. If the deck is long - from side to side, then it is called a superstructure, if it occupies only part of the vessel - this is the cabin. On some vessels, even shorter decks may be attached to the upper deck - these may be boat, pleasure decks. Decks even higher have a special purpose, for example, a radio room or a central control room.
For sheathing, sheet steel of different thicknesses is used, while it relies on the inner frame, which is called the set of the vessel. It includes transverse frames, longitudinal beams, stringers, beams supporting the deck. In decks hatches and cutouts can be cut out, which must be durable - for this they are finished with steel sheets and squares.
The bottom of most modern ships is double, with internal flooring. Such a thoughtful design is associated with the safety of the product. In the double bottoms, liquid fuel, fresh water, ballast water can be stored, which level the vessel and immerse it deeper in the water. Inside the hull is divided into compartments by transverse bulkheads, due to which the transverse strength and unsinkability of the vessel is achieved.
Includes a number of vital elements of the vessel. The diagram shows that the ship has an engine, propulsion and steering wheel. Mover is a device that affects the conversion of mechanical energy of the engine into the energy of movement of the vessel. The steering wheel is needed to control the vessel, while in the modern version it has transformed. Consider the features of some ship systems in more detail.
Features of the shape of the hull
The theory of the device of the ship proceeds from what kind of load it has. The hull is under the influence of hydrostatic pressure forces, which increase with increasing depth. Due to the pressure of sea water, transverse loads and the load from the vehicle’s own volume, as well as buoyancy force, act on the vessel. As a result, the shape of the hull depends on the type of vessel and its purpose, as well as deadweight, the required volume of holds, the number of decks, speed and lateral stability. In addition, the shape of the hull depends on the purpose of the floating craft and its operational characteristics.
Main materials
Shipbuilding is a labor-intensive process in which every detail plays a role. Modern forms of buildings are significantly different from those that were originally. And first of all, the changes affected the materials and technologies used. If initially floating craft were created from wood, then gradually it was replaced by metal, steel. An important role is played by the low weight of the structures while maintaining strength. The use of welding elements for joining made it possible to significantly reduce the number of structural elements and make them lighter and more durable.
Modern craft have parts of mild steel and cast steel, light alloys and plastics. Moreover, plastic is widely used not only for the production of parts, but also when creating small vessels, for example, fishing or sports or lifeboats.
Features of the outer skin
The outer skin is the outer shell of the hull, which accounts for the pressure of the water. The strength of the case depends on it. The outer skin is separate sheets joined together by welding. The thickness of this layer varies and depends on the length of the ship, the height of its side, as well as on the draft and the distance between the frames - hull ribs, on which the shape of a particular ship depends. The structure of the marine vessel is such that the same vessel can have different skin thicknesses in different areas. The middle part of the vessel experiences more stress, therefore there the thickness of the sheets is greater than at the extremities. The bottom set on the bow and stern of the vessel is reinforced, which is associated with the impact of pitching.
Deck and Deck Set
Deck is an important element of any ship. From the structural point of view, the external arrangement of marine vessels is the same where the deck is a horizontal floor in the hull. The upper continuous deck is considered the main one - it forms the general shell of the ships. All decks located below the main one are needed to increase the useful area of the vessel. The decks arranged above are called superstructures. The decking of the main deck can be of different thicknesses - it depends on the length of the vessel and the height of its side.
Steering Features
The steering device of the vessel fulfills the main goal - to counteract external forces, that is, wind, current, which can lead to deviation of vessels from course. In ancient times, oars at the stern were used instead of rudders, then they were replaced by a hinged rudder, which was placed on the main deck. Today, several types of rudders are known - from the ordinary and balancer to the bow thruster. Steering wheels can also be active and passive: the latter allow you to turn the vessel while the water is moving in relation to the hull. An active steering wheel allows you to rotate both a moving and a standing vessel.
The passive steering device of the vessel includes a steering column with a transmission, a steering machine, a rudder feather. In the old ships, single-layer rudders have been preserved, and today, mainly shaped curly rudders are used. The active steering wheel performs its functions even if the vessel is without movement, that is, at anchor. The active steering wheel is widely used in equipping floating fish factories, whalers and repair vessels.
To increase the maneuverability of the vessel, a boat thruster is often used. They are mounted on the bow or stern across the boat in the tunnel, where two propellers are also located . This auxiliary means is necessary in order to control the vessel at extremely low speed. The steering device is selected depending on what the vessel is used for: one group of rudders affects the stability of the course, the other helps to ensure good agility.
Anchor is an important element
The anchor device of the vessel is necessary in order to keep the floating means in a certain position when it is necessary to resist such external factors as wind, waves, current. Ships anchored in a raid or awaiting entry to the harbor, as well as in emergency situations. Modern anchors are presented in a wide variety and are divided into groups. For example, rod anchors, rod anchors, Trotman anchors and Hall anchors equip sports vessels or sailing training aids.
Anchor devices of ships operate as follows: when returning, the anchor drops to the bottom, after which it is towed by the ship. When moving, the anchor clings to the bottom with its “paws”. To raise it, an anchor chain is used: it lifts the anchor from the bottom surface, tearing it off the ground. The length of the anchor chain depends on wind pressure, wave impacts and must take on all these external forces. An anchor device is most often located on the bow of the vessel, where an anchor winch is installed, which operates on an electric or hydraulic drive.
A number of important details
The mooring device of the ships is necessary so that the ship can stand at the pier while docking in the port. Mooring is carried out by means of mooring lines - they stretch diagonally from the vessel to the shore. Today, these elements are made from durable synthetic materials. When ships approach the shore, mooring cables are thrown from them .
The general structure of the vessel is also represented by numerous ship systems in the form of drainage and ballast systems, heating and air conditioning. Each of them plays a role: drainage helps to divert the water collected on the bottom overboard, ballast is needed to drain and fill the tanks with sea water, and the safety and comfort of each vessel depends on other systems.