Metal engravings. History of development and types of metal engraving techniques
A transport hub is a point at which at least 2-3 lines of one type of transport converge. When in one locality communication routes converge various types transport, it is called integrated. The interconnection of different modes of transport is clearly visible here. In complex transport hubs, cargo is transshipped and passengers are transferred.
Transport hubs are of national, interdistrict, district and local significance. In addition, transport hubs are classified according to purpose, combination of modes of transport, functions performed, transport balance, and volume of cargo turnover. Complex transport hubs can also have combinations: railway-water (rail-river, railway-sea), railway-road, water-road.
State of the art transport system economic regions are not the same. The availability of communication routes, both in total length and in density (kilometers of track per 1000 km2), differs by a factor of ten or more. The most developed transport systems are the Central Black Earth, Central, North-Western, North Caucasus, Volga-Vyatka regions; the least developed are the Far Eastern, East Siberian, West Siberian, and Northern economic regions. The regions also differ in the structure of cargo turnover. In areas where minerals such as iron ore and coal are developed on an interregional scale, the main transportation is carried out by railways; where oil and gas are produced, the share of pipeline transport is large; in areas where forest resources are developed, the share of inland water transport is significant; in areas specializing in manufacturing industries, the main role belongs to railway transport. For example, in the West Siberian region, railway transport predominates and the share of pipeline transport is high; in the Central region, the overwhelming majority of transportation is carried out by rail. The areas of the extractive industry have an active transport balance, i.e., exports exceed imports, since the mass of raw materials and fuel is greater than the mass of finished products, and the areas of the manufacturing industry, accordingly, have a passive balance, i.e., imports exceed exports.
The capacity of transport flows also has significant differences and depends on the location of the main sources of raw materials, fuel, materials, etc. There are three main main directions of the country’s transport system:
1. The latitudinal main Siberian direction “east-west” and back, it includes railways, pipelines and waterways using the Kama and Volga rivers.
2. The meridional main Central European direction “north-south” with access to Ukraine, Moldova, the Caucasus, formed mainly by rail.
3. Meridional Volga-Caucasian mainline “north-south” along the Volga River, railway and pipeline routes, connecting the Volga region and the Caucasus with the Center, the North of the European part of the country and the Urals.
The main freight flows of the country go along these main trunk routes; railway, inland waterway and road transport modes of transport interact especially closely in these directions. Mainline air routes also basically coincide with land routes.
In addition to the main highways, there is a dense transport network of intra-district and local significance. Combining with each other, they form the Unified Transport System of Russia. As the productive forces of the country as a whole and its individual regions develop, the transport system needs constant improvement both in terms of rationalization of placement and in increasing its quality level: updating the material and technical base, improving the organizational and management system, using latest achievements scientific and technological progress. Development of the transport system Russian Federation is aimed at more fully meeting the needs of the country's economy and population with transport services.
A transport hub includes a complex of transport devices at the point of interaction between several types of mainline transport, performing operations to service transit, local and urban transportation of goods and passengers. A transport hub may include railway stations and approaches to main railway lines, sea and river ports or water hubs, main and local highway junctions, airports and other air transport devices, industrial and urban public transport devices.
At the transport hub, passengers are transferred and cargo is transferred from one type of transport to another at connecting points. Passenger connecting points include railway passenger stations, bus stations, sea and river ports, airports, and metro stations. Freight connecting points are freight railway stations, specialized bases, sea and river ports, airports, etc.
Transport hubs specialize: according to the number of modes of transport serving the hub; by the nature of the operational work; according to economic and geographical characteristics; population size of the city served; location of transport devices and geometric shape node diagrams.
Based on the number of modes of transport, there are railway-road (Chelyabinsk), railway-water-road (Moscow, St. Petersburg, Omsk) and water-road hubs (Yakutsk).
According to the nature of operational work, transport hubs are divided into: transit, serving transit flows in direct and mixed types of communications; with large local work, serving transit and local flows (Rostov-on-Don, Yaroslavl); local (Murmansk).
According to economic and geographical characteristics, nodes can be land and located on the banks of rivers and seas. Depending on the population of the city served by the node, they are divided into: small and medium-sized with a population of up to 100 thousand people and a relatively underdeveloped industry; large and large with a population of up to 1 million people. and developed mining and manufacturing industries; the largest with a population of more than 1 million people. and large industry.
According to the location of transport devices, transport hubs are divided into: single-set with a combined arrangement of devices for modes of transport; single-unit with separate passenger and cargo areas; multi-set with a combined arrangement of devices for modes of transport and multi-set combined.
Single-package transport hubs serve small, medium or large compact cities. They have one integrated station where all transport facilities are concentrated, an industrial area served by this station, and a combined railway and road station. IN big cities in single-unit units it is possible to separate passenger and cargo areas. Multi-unit units are typical for large and major cities. They have several industrial areas with freight stations serving them, one or more marshalling stations, a consolidated passenger area with independent stations for modes of transport, and stopping points for rail, road and water transport.
According to their geometric shape, transport nodes are divided into terminal, radial, elongated, radial-semi-circular, radial-circular and combined.
The terminal nodes are located near seas, large rivers and high mountains (Arkhangelsk, Vladikavkaz). They have no big number junctions of railway lines and highways with pronounced character finite flows of passengers and cargo. End nodes typically serve small cities.
Radial nodes are most typical for large cities (Yaroslavl, Nizhny Novgorod). In them, railways and roads converge in radial rays to one area of the city, or railway lines converge to one area, and roads to another. At radial transport hubs, railway lines can be located in a radial, triangular or cruciform pattern.
Long transport hubs are typical for areas with difficult topographical conditions, on the banks of big rivers and seas (Volgograd). These nodes serve cities that are elongated in length, and the approaches of railways and roads in them are located at opposite ends. Such nodes are formed at the confluence of converging railway lines on the approaches to the city. Several sequentially located stations are built in them, serving non-public tracks and performing train formation work. When designing nodes that are elongated in length, it is necessary to provide for junctions of lines that ensure minimal angular flows.
Radial semicircular units big cities, usually located on the shores of seas and large rivers, have one ring or several semi-rings (St. Petersburg), and radial-ring nodes of large cities have several rings of railways and roads with radii and diameters inside the city (Moscow). Such nodes are easy to use, ensuring uniform distance of transport infrastructure from the city center.
Combined nodes are a combination of the schemes discussed above. The most common nodes include: dead-end railway and radial road nodes with a rectangular or radial layout of street networks; railway junction with parallel tracks and radial road junction; a railway junction, elongated in length, or with parallel tracks and a radial road junction.
The same type of transport hub can correspond to a significant number of different types of schemes individual parts, but unitable general patterns development, characteristic devices and operating conditions.
The development of various types of transport and industry in cities creates conditions for changing the layout and types of railway and road junctions, sea and river ports, thereby changing general scheme transport hubs. Radial nodes are usually transformed into radial-semi-circular and radial-circular, and then into combined ones. The location of transport hubs is determined by the location of productive forces and the historically established network of cities and their layout.
Transport hubs are classified according to the following signs:
1. According to the number of modes of transport serving the node: nodes are: railway-road, railway-water-road, water-road
2. By the nature of the operational work:
Transit, which serve traffic flows in direct and mixed traffic;
With a lot of local work - they serve transit and local flows (including transshipment);
Final
3. By geographical location nodes are divided into:
- land;
Located on the shores of seas and navigable rivers
4. By population:
Small and medium-sized - with a population of up to 100 thousand people, with underdeveloped industry;
Large and large - with a population of up to 1 million people, with the location of large processing and mining enterprises;
- the largest - with a population of over 1 million people, with a very developed industry
5. According to the location of transport devices:
Single-set: with a combined arrangement of devices for the main types of transport
with separate location of passenger and cargo areas of the main modes of transport
Single-complex transport hubs are located in areas of small, medium and large compact cities and have one integrated station where all transport facilities are concentrated, one industrial area served by this station and a combined railway and road station. In large cities, single-unit hubs usually separate freight and passenger areas.
- multi-set:
with a combined arrangement of devices for various types of transport, combined
Multi-unit units are typical only for large and major cities. They have several industrial areas with freight stations serving them, one or two marshalling stations, stopping points for railway, road and water transport located in different areas of the city, and a consolidated passenger area with independent stations for different types of transport. 6. According to the geometric design (or depending on the node diagram, which depends on local conditions and features of the city layout):
The final ones are located near the seas, large rivers, and mountainous areas. They are usually compact, have a small number of railway and road lines, with a pronounced terminal traffic and nature of freight and passenger operations. Usually located in small cities.
Radial - typical for the former territory of the USSR. Railways and highways converge in radial rays to one area. There are nodes with two centers (railway and road). Railway lines are arranged in radial, triangular or cruciform patterns.
Elongated in length - characteristic of areas with difficult topographic conditions. They are located on the banks of rivers, seas, and in mountainous areas. The railway and road approaches are located at diametrically opposite ends. The main disadvantage is the very high intra-node mileages.
Radial semi-ring - typical for large cities located on the shores of seas, large rivers, lakes and artificial reservoirs, they have one ring and several semi-rings of automobile and railways.
Radial-ring - typical for large cities and capitals of states, they have several rings of railways and roads with radii and diameters inside the city.
Combined - represent a combination of dead-end railway and radial road junctions with a rectangular or radial layout of street networks; a railway junction with parallel tracks with a rectangular layout and a radial road junction; a railway junction, elongated in length or with parallel tracks with a radial layout and a radial road junction.
Each type of transport hub can correspond to a large number of options.
The boundaries of a transport hub are the merging points of lines approaching the node and the points that carry out the work of distributing arriving transport units of each type of transport (along the main route, bypass, ring and intra-nodal connections). For each type of transport it is established independent border, including passenger transportation. Fundamentals of transport hub technology
The work of transport hubs must be carried out according to strict technology, which is established by the technological process.
The unified technological process (UTP) of a transport hub combines private technological processes of various types of transport available in the hub.
The technological process of the transport hub is based on the following principles:
Interaction and coordination of all types of transport;
Maximum use of mixed types of communications for the transportation of goods;
Organization of work of connecting modes of transport according to a combined contact schedule and a single technological process based on coherence and consistency in the actions of workers of different modes of transport;
Widespread use of advanced labor methods when serving passengers
and transportation of goods.
A scientifically based technological process allows us to reduce the time spent within the hub of passengers and cargo due to:
Coordinated supply of rolling stock (trains, cars, etc.) to connecting points;
Cargo transfer using the direct option car-car, car-ship and vice versa;
Rational joint use of technical means of various types of transport;
Concentration of cargo work at a smaller number of specialized points;
Organization of information and operational planning at points of passenger transfer and cargo transshipment;
Constructions of combined (with appropriate justification) railway-automobile, railway-sea, railway-river, railway-automobile-air stations. Content unified technological process, on the basis of which the interaction of all modes of transport is carried out at the node depends on many factors. These include specific operating conditions of related enterprises and their technical equipment; the applied system for organizing the flow of rolling stock; cargo transshipment options; intensity and degree of unevenness of cargo flows; operating mode of enterprises (number of shifts, their duration); commercial conditions for the transportation of goods to different types transport and conditions for transferring goods from one type of transport to another, etc.
The use of a unified integrated technology of a transport hub predetermines the need to organize centralized management of its operation. The centralized management system is subject to such basic requirements as high efficiency, reliability and complete control over the progress of work related to the transportation process, as well as optimal subordination of management bodies of transport enterprises in the hub.
An integrated system for managing the operation of a transport hub includes subsystems for solving such problems as organizing operational work, accounting, control, analysis and reporting.
At the first stage of introducing centralized operational management of the operation of the node, it is recommended to create a single control room on a parity basis. It should include shift dispatchers of all types of transport, headed by a senior shift dispatcher. In addition, the position of chief node dispatcher is being introduced, based on the leading mode of transport at the node. It is also necessary to create a central information bureau, a computer center, and form a group for analyzing and recording work.
Planning for the upcoming work of the node is carried out by a collegial body - the coordination center.
Placement of devices of various types of transport at transport hubs The location of devices of various types of transport in transport hubs depends on economic and geographical conditions, circuit solutions and prospects for the development of transport hubs.
The placement of railway devices at transport junctions depends on the layout of the railway junction.
The location of sea and river transport devices is determined taking into account: the minimum costs for the construction and operation of port devices, the permissible load of devices; flow of cargo flows through the node along the shortest route, good use of vehicle access opportunities; opportunities for rational interaction with railway transport.
Devices for serving passengers located in places that provide convenient exits to the city and connections with urban modes of transport, the safest shortest passages for passengers.
Road transport devices are also placed in conjunction with other modes of transport. They try to combine bus stations at hubs with railway, sea and river stations, which creates convenience for passengers and reduces the costs of constructing and maintaining devices. This takes into account the load on city streets.
The placement of air transport devices is planned taking into account a sufficiently free area with a calm topography, the possibility of limiting the development of the airfield area to 2.5 km, and the availability of a reserve territory for further development airfield complex.
They try to locate airports in the suburban area at a distance of about 30 km; solutions are considered unsuccessful when the airports are too remote or, on the contrary, are located inside the city, which creates inconvenience in operation and poor living conditions for the population.
Aeroflot agencies are usually located in central areas, together with other devices.
Urban transport devices are usually built at junctions of various types of transport that have large flows corresponding to each other (railway station, river port, etc.), as well as at junction points of the main streets of the city.
The work of a transport hub for the development of passenger transportation depends on the layout of cities and networks of main streets. Rational modes of transport operation are provided by main streets that have: good connections with non-urban roads; external transport devices (terminals, stations, port, airport); convenient messages between the most important elements cities by shortest distances; good connections between residential areas and industrial enterprises.
Pipeline transport devices are usually built outside the city and transport hub. Pipelines are supplied to oil loading areas along the seabed or by a special overpass. In seaports, storage tanks are located 10 km or more outside the city and hub. Specialized loading areas are organized.
The layout of the transport hub is influenced by the location of industrial enterprises.
Enterprises gravitating towards water transport and railway transport are located near port facilities, as well as in areas with convenient connections to railway marshalling yards. Depending on the type of transport hub, enterprises served by rail are usually located near marshalling stations and try to move them outside the city.
Related information.
Metal engraving as an art form arose during the Renaissance. A bunch of famous artists worked in the technique of engraving. Works are known not only on plates, but also on daggers, swords, and bracelets. There are many techniques, each with its own aesthetics and language.
Today, metal engraving is experiencing a rebirth. Thanks to the use of new technologies, it is possible to create a unique masterpiece to order.
Metal engraving
History and technology
New genres and trends took root more easily in engraving than in painting, which is why many Renaissance artists willingly turned to this type of art. His works could be replicated in hundreds of copies, they became available to wide sections of the population. In addition, engravings brought in good income.
The first engravings served a purely practical purpose: they were used to print images of saints and playing cards.
The very first to appear was engraving. It required effort on the part of the artist. Using a chisel (cutter), the master created strokes, overcoming the resistance of the metal. It is characterized by mintness and at the same time expressiveness of the figures. Albrecht Durer worked in this technique. His three works “The Knight, Death and the Devil”, “Saint Jerome in the Cell” and “Melancholy” are considered masterpieces of engraving art and still cause controversy among art critics.
Etching
It was invented in the 16th century. This method bears little resemblance to working with a graver. An artist doesn't have to put in so much effort. The etching needle easily scratches the film, which ensures smooth, light lines. An etching is similar to a drawing, while a chisel is more likely associated with a sculptural bas-relief.
Landscapes, portraits, and sketches were made using this technique. Van Dyck worked in the genre of etching - he created portraits of his contemporaries. The works of students of Rubens-Snyders and Jordaens are known. Rembrandt created a number of masterpieces.
Metal engraving in the genre of etching flourished in France in the 18th century. Francois Boucher was not only an artist, but also an outstanding etcher in the Rococo genre. The master's series depicting intimate, street scenes, life of the peoples of the East. He made a number of engravings based on Watteau's drawings. Boucher's works are grace, sophistication and freedom of composition.
In Russia, not many masters worked in the etching genre. The heyday of this genre occurred in the 19th century. Ivan Shishkin, Andrey Somov, Taras Shevchenko worked in this technique.
Sword engraving
Aquatint, a type of etching, allows you to create engravings with a wider range of tones. Francisco Goya did a lot for the development of this genre. He is known as the inventor of a system of techniques in this technique. Aquatint remains one of the most complex techniques and in our time. It requires a workshop and a number of tools.
Other techniques
- Mezzotint - another type of metal engraving - allows you to obtain a special depth and velvety tones. This technique is also used to produce color printing. The technique was invented in XVII century. The artists Johann Pichler, John Farber and an outstanding artist of the 20th century worked there. Maurits Cornelius Escher.
- Drypoint, unlike etching, does not require engraving or etching. Strokes are applied not only with steel, but also with a diamond cutter. The softness and unusualness of the impression is given by the barba - a groove with burrs. Rembrandt and Durer worked in this technique (along with other genres of engraving). Many artists of the 20th century practiced the drypoint technique: Max Beckman, Milton Avery, David Milne, etc.
- Mederite - metal engraving, which became famous in Belarus XVII-XVIII centuries. The metal was etched with nitric acid. Mederite was used in cartography and book publishing.
- Several other techniques are known, for example, soft varnish, lavis, reserve. Some artists work in mixed media, which allows you to create your own unique style.
Engraving continues to attract artists in our time. Today, laser and electromechanical engraving are common. There are a number of workshops that specialize in performing work using this technique.
