For the movement of goods in construction, land, water and aerial views transport, of which the most massive (more than 90% of all transportation) is ground (automobile, tractor, rail and pipeline).

To share automotive transport accounts for more than 80% of traffic building materials, machinery and equipment. Expenses only for road transport amount to 12 ... 15% of the cost of construction and installation works. Trucks, tractors, pneumatic-wheeled tractors and trailers and semi-trailers of general and special purpose created on their basis carry out the main transportation of goods in construction.

Tractor transport is used less frequently than road transport, in cases where it is not economically feasible to arrange car roads or when by technical reasons the use of vehicles is difficult or impossible.

Trailers and semi-trailers are non-self-propelled vehicles. They are moved behind a tractor.

Through the pipes in construction, they move bulk goods directly in the air stream (pneumatic conveying units) and in containers - containers are usually cylindrical in shape, moved on wheels along rails inside the pipe by air pressure. Also in containers move piece cargo. Due to high capital investments and rigid binding to the place of stations for loading and unloading containers, this type of transport has not yet found wide application in construction.

All other modes of transport are not purely construction, but are also used to transport construction materials. So, railway goods are transported by transport in conditions of concentrated construction of large facilities with transportation distances of more than 200 km. This type of transport is also used for intra-quarry and technological transportation.

Water transport, by which construction materials are transported on river and sea vessels, is used for the same purposes.

Air transport is the most expensive mode of transport, which is why it is used only for construction in hard-to-reach areas in the absence of land and water transport, including when it is impossible to use them due to climatic conditions.

5.2 Trucks

Trucks have a relatively high speed of movement, maneuverability, a small turning radius, they can overcome rather steep ascents and descents, are adapted to work with trailers, semi-trailers for general and special purposes, and can also be equipped with loading and unloading mechanisms.

Distinguish trucks of general purpose, specialized and special.

For general purpose vehicles(Figure 5.1) include vehicles with open platform and tailgates for transportation of any kind of cargo (see figure 5.1, A) including cross-country vehicles (see Figure 5.1, b) with all driving wheels, as well as equipped with a coupling fifth wheel 1 (see figure 5.1, V) for towing trailers and semi-trailers. Together with a trailer or semi-trailer, a vehicle forms road train.

Specialized vehicles(road trains) are designed to transport one or more homogeneous types of cargo (bulk materials, pipes, trusses, reinforced concrete products, etc.). Certain types of specialized vehicles are equipped with lifting devices for autonomous loading and unloading of goods.

For special vehicles include vehicles designed to transport certain types of cargo and equipped with special devices for performing additional non-transport operations (mixing, heating, etc.) to ensure the safety of transported goods.

Mass-produced trucks have a single design scheme and consist of three main parts: engine, chassis and cargo body. The bodies of onboard vehicles are a wooden or metal platform with folding sides and are intended for the transportation of mainly piece cargo. Together with single-axle trailers, flatbed trucks are used to transport long loads - pipes, piles, logs, rolled metal, etc.

On the basis of standard chassis with a shortened base and a shortened rear frame overhang, the industry produces truck-type tractors operating in conjunction with one- and two-axle semi-trailers. A base plate and a fifth wheel coupling are mounted on the chassis frame of such a tractor, which perceives the gravity of a loaded semi-trailer and serves to transfer to it the traction force developed by the car. The use of truck-type truck tractors with semi-trailers allows better use of engine power and significantly increases the vehicle's carrying capacity.

On trucks, internal combustion engines are used - carburetor and diesel engines. The chassis consists of a hydromechanical or mechanical transmission, running gear and machine control mechanisms.

The transmission transmits torque from the engine shaft to the drive wheels, and also drives various equipment installed on the vehicle.

Trucks are designated by the wheel formula A´B, where A is the total number of wheels, B is the number of driving wheels, and the dual slopes of the rear axles are considered as one wheel. The domestic industry produces flatbed vehicles and truck tractors: two-axle with a wheel arrangement of 4´2 and 4´4, three-axle with a wheel arrangement of 6´4 and 6´6. Vehicles with a wheel arrangement of 4´2 and 6´4 are classified as limited cross-country vehicles and are intended for operation on improved and unpaved roads. Vehicles with wheel arrangement 4´4 and 6´6 are classified as off-road and off-road vehicles and can be used in rough terrain and off-road conditions.

In the transmission of vehicles operating with autonomous handling equipment, dump trailers and semi-trailers, and also used as a base construction machines, additionally included is a power take-off to drive the hydraulic system pumps lifting mechanisms and attachments. Chassis The car consists of a carrier frame on which all units are mounted, a body and a driver's cab, front and rear axles with pneumatic wheels and elastic suspension connecting the supporting frame with bridges. The wheels of off-road vehicles have high-pressure pneumatic tires, and off-road vehicles have tires low pressure with increased bearing surface. The control mechanisms are combined into two independent systems: steering - to change the direction of the car by turning the front steered wheels and brake - to reduce speed and quickly stop the car.

TO specialized vehicles include dump trucks and haydite trucks - for the transportation of soil and bulk cargo; panel carriers, farm carriers, plate carriers, sanitary ware carriers, etc. - for transportation building structures; pipe carriers, pole carriers, metal carriers - for the transportation of long loads; container ships - for the transportation of building materials in containers; heavy trucks - for the transportation of technological equipment and construction vehicles.

Dump trucks(Figure 5.2) transport construction cargo in metal bodies with trough-shaped, trapezoidal and rectangular shape cross-section, forcibly tilted during unloading with the help of a lifting (tilting) mechanism back, on the side (one or both) sides, on the sides and back. By purpose, special, mining and universal general construction dump trucks are distinguished. Under construction conditions, universal dump trucks are used, designed to transport soil, gravel, crushed stone, sand, asphalt, concrete mix, mortar, etc. Modern universal dump trucks are produced on the chassis of general-purpose flatbed trucks and are equipped with the same type of hydraulic lifting mechanisms that provide quick lifting and lowering of the body, high reliability and safety.

For the transportation of expanded clay and other bulk materials with a low density, specialized trailers and semi-trailers are used - haydite trucks, which are dump trucks with increased body capacity.

When transporting small-piece and packaged goods (sanitary and ventilation equipment, finishing, insulating and roofing materials, bricks, window and door blocks, small-sized prefabricated reinforced concrete structures, etc.) to construction sites, containerization and packaging. For the delivery of containers and packages, flatbed vehicles, trailers and semi-trailers of general purpose and specialized vehicles are used - self-loading vehicles And container ships(Figure 5.3).

Container semi-trailers

a - with an articulated telescopic boom; b - c lifting device swinging portal

Figure 5.3.

Pipe- And whippers(Figure 5.4) are designed for transportation of pipes up to 12 m long and lashes (sections welded from pipes) up to 36 m long on paved roads, dirt roads, as well as off-road along the pipeline construction route. The pipe or pole carrier consists of a tractor 1 (see figure 5.4, A) and dissolution trailer 2. The tractor and trailer are equipped with horses 4 for laying pipes (lashes) on which there are adjustable stands-stops 5 with pipe lashing devices. Pipes (lashes) during transportation perform the function of a rigid connection between the tractor and the trailer-dissolution. The latter is equipped with a hitch 6 for connecting it to the tractor when driving without a load, as well as a safety rope 3. The carrying capacity of the road train is 9 ... 36 tons.

pipe-carrier

a - general view; b - trailer-dissolution

Figure 5.4.

Panel semi-trailers, farm trucks, sanitary cabin trucks and heavy trucks have similar designs. The front of them rests on truck tractor, for which they are often equipped automatic hitch, the rear part relies on a one- or two-axle, less often on a three- and four-axle (for example, heavy-duty trucks) bogie, which is sometimes made swivel to increase the maneuverability of the road train. Semi-trailers are aggregated with a tractor only for their transportation, and during loading and unloading operations they rely on hydraulic supports. Semi-trailers have a low loading height, convenient for loading and unloading. For loading cars onto heavy trucks under their own power, semi-trailers are equipped with folding ladders installed in their rear. For some heavy trucks, the cargo platform can be raised and lowered within the loading height of 0.5 ... 0.9 m using a volumetric hydraulic drive. All semi-trailers are equipped with braking devices and means for reliable fastening of transported goods.

Semi-trailers are distinguished by the design of the supporting frame, corresponding to the shape and size of the goods transported. So, semi-trailers-panel carriers (Figure 5.5) have frames of spinal and frame cassette types. For backbone panel carriers, the frame has the form of a trapezoidal cross-section truss (see Figure 5.5, b). The panels are installed obliquely on both sides at an angle of 8…10°. Frame semi-trailers have a frame in the form of a cassette of two longitudinal vertical flat trusses and cross braces (see Figure 5.5, V) or in the form of a supporting frame (see figure 5.5, d). Carried goods are installed vertically and held by separators and side holders. Sometimes they are retrofitted with additional side cassettes (see figure 5.5, G). However, they require symmetrical loading, which is difficult to achieve when transporting an odd number of panels or panels of different weights. In case of backbone-type panel carriers, in addition, with an inclined position of the panels, their damage in the form of cracks, chips, etc. is not ruled out.

Semi-trailer-panel carrier (a) and the location of the panels on

semi-trailers of various types (b - e)

Figure 5.5.

From special vehicles the most widely used in construction are special vehicles for the transportation of liquid (mortars and concretes, molten bitumen, liquid fuel) and pseudo-liquid cargoes (cement, fluff lime, alabaster, gypsum, ground limestone, dry ash, mineral powders, dry mixtures of solutions, fine-grained concretes, their components and other binders). These goods are characterized by increased mobility during transportation, as a result of which traffic safety is reduced in terms of handling, stability and braking properties of the vehicle during movement, especially when the container is partially filled.

Special vehicles for the transportation of liquid and pseudo-liquid cargoes, they are equipped with bucket or bunker types (Figure 5.6, b And V) or tanks (Figure 5.6, a, d, d), as well as devices for performing operations not directly related to transportation (dosed or continuous loading and unloading of materials, their heating and cooling, stimulation, temperature maintenance, mixing, etc.). The containers are located at the rear of the vehicle.

5.3 Tractors

Tractors (Figure 5.7) are used for transporting building materials and equipment on trailers on unpaved and temporary roads, off-road, in cramped conditions, as well as for the movement and operation of mounted and trailed construction machines. They are divided into agricultural, industrial and special. According to the design of the undercarriage, caterpillar and wheeled tractors. The main parameter of tractors is the maximum pulling force on the hook, according to the size of which they are assigned to different classes of traction. In construction, tractors of agricultural type of traction classes and industrial types of traction classes are used. Tractors of industrial type, in terms of their design and operational parameters, most fully meet the requirements for traction means and base machines in construction. Traction class according to industry classification means the maximum traction force without additional load of attachments, providing efficient work with earthmoving equipment.

Pneumowheel tractors have relatively high travel speeds, high mobility and maneuverability; they are used as transport vehicles and as a base for installing various attachments (loading, crane, bulldozer and earthmoving) used in
Vehicles for the transportation of liquid and pseudo-liquid cargoes

a - cement truck; b - concrete truck; c - concrete mixer truck; g - auto-dissolving truck; d - tanker

Figure 5.6.

the production of earthmoving and construction and installation works of small volumes at dispersed objects. Pneumowheel tractors are most effectively used on paved roads. The relatively high specific pressure on the ground reduces the permeability of machines. Caterpillar tractors are characterized by a significant traction force on the hook, reliable grip of the caterpillar track with the ground, low ground pressure and high cross-country ability.

Tractors

tracked with front (a) and rear (b) engine; pneumatic wheels with front steered wheels (c) and articulated frame (d)

Figure 5.7.

The main components of pneumatic wheel and caterpillar tractors are the engine, power transmission, frame, undercarriage, control system, auxiliary and working equipment. The working equipment is designed to use the useful power of the engine when the tractor is working with mounted and trailed machines. Work equipment includes a hitch, power take-offs, drive pulleys and a hydraulic attachment system.

Caterpillar tractors are equipped with diesel engines, mechanical, hydromechanical and electromechanical transmissions. The location of the engine can be front, middle and rear. The most widely used caterpillar tractors with front engine and mechanical transmissions. The transmission is used to transfer torque from the engine shaft to the drive sprockets of the caterpillar tracks, smooth starting and stopping the machine, changing the tractive effort of the tractor in accordance with the driving conditions, changing the speed and direction of its movement, as well as driving the working equipment.

Pneumowheel tractors are equipped with diesel engines and carburetor engines, mechanical and hydromechanical transmissions. According to the type of steering system, tractors are distinguished with front steered wheels, with all steered wheels and with an articulated frame. The most common are pneumatic wheeled tractors with diesel engines, mechanical, transmission and front steered wheels.

5.4 Pneumatic tractors

Pneumowheel tractors are designed to work with various types of removable mounted and trailed construction equipment. Compared to caterpillar tractors, they are simpler in design, have a lower mass, greater durability, are cheaper to manufacture and operate. High speed tractors, good maneuverability greatly contribute to an increase in the productivity of construction machines aggregated with them.

There are one- and two-axle tractors, on which diesel engines are used, and two types of transmissions - mechanical and hydromechanical. The most common tractors with hydromechanical transmission.

Single axle tractor consists of a chassis on which the engine is mounted 6 (figure 5.8.), power transmission, two driving wheels, cab and fifth wheel, consisting of a rack 2 , which can swing relative to the longitudinal horizontal axis fixed on the frame of the tractor, which allows the semi-trailer to warp relative to the tractor in the vertical plane, and the vertical king pin 3 for connecting a tractor with a semi-trailer. The rotation of the tractor relative to the semi-trailer by 90 ° in each direction is provided by two hydraulic cylinders 4. Hydromechanical power transmission consists of a transfer box 7 , torque converter 8 , gearboxes 9 , cardan shafts 10 And 12 , bridge with final drive and differential 11 , axle shafts 13 and planetary gears 14 built into the wheel hubs. From the transfer case through the shaft 12 one or more pumps are driven 5 to ensure the operation of the executive bodies of the trailed implement. Operate the tractor and work equipment using the block 1.

Two-axle pneumatic wheeltractor structurally similar to a pneumowheel tractor with an articulated frame. The transmission of the tractor usually includes a three-speed gearbox, which provides the same forward and reverse speeds.

On the base wheel tractors, using various interchangeable working equipment, it is possible to create many construction and road machines (Figure 5.9).

5.5 Fundamentals of traction and dynamic calculations of construction machines

Traction calculations are carried out to identify the capabilities of self-propelled machines to develop speed and overcome slopes, as well as to determine the free traction force used when working with trailed and attached equipment.

Trailed and attached working equipment of pneumatic wheeled tractors

a - scraper; b - land carrier; c - crane; g - tank for cement and liquids; d - heavy truck; e - pipe-laying crane; g - trench excavator; h - rooter; and - bulldozer; to - ripper; l - loader

Figure 5.9.

The basis of the traction calculation of the car is to solve two problems: identifying the maximum climb to be overcome and determining the speed of movement depending on the nature of the supporting surface.

The scheme for carrying out traction calculation is shown in Figure 5.10.

j- coefficient of adhesion of the propeller to the supporting surface.

From this formula it follows that the maximum slope on which the car can move:

.

Based on the condition of uniform motion, we have:

This ratio is called the dynamic factor of the car and denoted D, i.e. .

Necessary condition for the movement of the road train:

Where P- number of trailers;

G" is the weight of the loaded trailer, N.

Then the dynamic factor is:

.

The traction force developed by caterpillar tractors is spent on overcoming the resistance to the movement of the tractor and overcoming the sum of the resistances that arise when working with trailed and attached equipment.

Necessary condition movement is:

The greatest tractive force of the tractor, implemented by the clutch:

Where G– tractor weight, N;

j is the adhesion coefficient.

The traction force developed by the tractor depending on the engine power:

,

Where N dv- rated power of the engine, kW;

J d– movement speed, m/s;

h fur- transmission efficiency.

Total resistance W S consists of the resistances overcome by the tractor itself, as well as the mounted or trailer equipment both in working and in transport modes.

During the operation of the machine, two characteristic violations of the condition for ensuring movement can occur.

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Ministry of Education of the Russian Federation

Volgograd State Technical University

ControlJob

Promising transport engines

Completed by: Moskovoy S.A.

Checked by: Assoc. Shumsky S.N.

Volgograd 2013

Introduction

A significant role in the use of natural energy sources is played by vehicles that consume about a third of all oil produced in the world, and of all modes of transport, the most energy-intensive is automobile. The use of hydrocarbon fuels of petroleum origin in automobiles is accompanied by the release into the atmosphere of a huge amount of harmful substances. As a result, road transport accounts for 39 to 63% of pollution environment, the scale of which is global - air, land and water.

The traditional approach to solving the energy and environmental problems of motorization is to improve the design of existing internal combustion engines and create more advanced power plants of a new type using more or less conventional hydrocarbon fuels. In the first case, the main attention is paid to increasing the efficiency and reducing the toxicity of vehicles by complex correction of the working process in the engine in order to ensure the maximum completeness of fuel combustion in all operating modes. engine fuel power

New transport engines developed to date include electric propulsion and internal and external combustion heat engines with non-traditional operating processes.

The latter include piston engines with layered charge distribution, gas turbine, steam and rotary engines and Stirling engines.

Some of these engines, in particular Stirling engines, could in principle make it possible to create a low-emission vehicle using conventional fuels to meet future stringent regulations.

Of great interest are electric power plants using electrochemical energy sources - batteries and fuel cells.

Engines used in most modes of transport today

The liberalization trend, which has ensured competition in transport, including competition between different modes of transport, forces us to continuously look for technical and organizational solutions that change the face of the transport world for the better. Over the past ten years, vehicles have changed almost as much as in the previous twenty to thirty years.

The reasons that force old modes of transport to change are pressure from both consumers and politicians for:

Mobility (ability to deliver from door to door;

Profitability (primarily fuel efficiency);

Ecological cleanliness;

Safety.

The fulfillment of all these requirements is very contradictory. For example, making a vehicle heavier generally increases its safety for passengers and the driver, but worsens safety for others (heavier vehicles cause more damage in a collision) and increases fuel consumption, which leads to a deterioration in economy and environmental performance. In public transport systems, greater economy means less mobility, and stops have to be commuted.

In most modes of transport, one or another engine is running, and today in most cases it is

Diesel,

Internal combustion engine,

electric motor,

Turbojet engine.

The electric motor is better in its characteristics than many other drives, it has better resistance to variable loads, and the speed is better regulated (therefore, complex transmission systems are not needed), and the efficiency is better, and it is simpler (it has, for example, fewer moving parts, which leads to more MTBF), besides, it is cheaper (therefore, it can be installed, for example, on each wheel, and not have one on all wheels).

Another thing is that electricity on board is an extremely expensive source of energy. Batteries can not be considered at all, batteries today are incredibly heavy and take a long time to charge, and they have enough charge for a little. The way out is to obtain on-board propulsion power from hydrocarbon fuel either using fuel cells or hybrid solutions.

Fuel cells use hydrogen-containing raw materials as fuel, in the limit it is pure hydrogen (and then they have pure water at the exhaust), but there are options for methyl alcohol, natural gas, gasoline and even diesel fuel. Their installation cost is still quite high, up to $5,000 per kW of power, or even more. Pure hydrogen fuel cells are also the cleanest, but there is no source of hydrogen for them: the cost of hydrogen refueling infrastructure far exceeds the cost of today's hydrocarbon (refined and gas) refueling infrastructure. Therefore, in the short term, the so-called hybrid schemes are more popular, when vehicles have both a conventional engine and an electric one.

Hybrid schemes embody the benefits of two worlds: the world of conventional motors to generate electricity and the electric motor used to drive the wheels. A conventional engine (diesel, internal combustion or even a gas turbine) operates in an optimal uniform mode and charges an on-board battery with a relatively small capacity (much lower than in electric vehicles). And the electric motor turns the wheels, working in a torn mode, depending on the driving conditions (acceleration and braking, lifting, carrying capacity, etc.). As a result, the dynamic characteristics of vehicles from the use of an electric drive are significantly improved on the one hand, and the economy and environmental friendliness are improved due to the fact that a conventional engine operates in optimal mode.

hybrid cars

Hybrid circuits are very different: from the simultaneous operation of an electric motor and a conventional engine synchronized by a computer on the same shaft, to a completely independent gas turbine engine running on a generator and special electric motors mounted directly on the wheels. All these solutions are already on the market and compete. The only question is what to have on board several powerful engines with high efficiency(usual, electric motor-generator (usually a generator too, using recuperation during braking), and sometimes a separate electric generator) is always more expensive than having just one engine. The advantage is the best driving performance, lower fuel consumption and low emission emissions.

At the moment, the benefits of hybrid vehicles are most apparent in difficult decisions trucks and buses, where fuel savings and environmental restrictions can be greater than in passenger cars. Therefore, the main competition for hybrid circuits is flaring up in this sector, while diesel engines remain the main competitor.

Starting from a certain threshold for the spread of hybrids, there will be an avalanche of their mass introduction: due to political changes in the price of fuel. Today, in most countries of the world, road infrastructure is financed through an excise tax on fuel. New cars will consume at least half as much fuel, therefore, to maintain the same level of infrastructure funding, they must either double in number (but then more infrastructure must be financed), or the excise tax must double. At the same time, fuel prices will inevitably rise, and for ordinary cars will become prohibitively expensive. The cost of hybrid cars proper will fall due to scale effects. Therefore, starting from some point, the introduction of hybrid cars instead of ordinary ones that have suddenly become expensive to operate will go like an avalanche, unless the current policy on financing road infrastructure changes.

The state is pushing for the hybridization of transport and the constant tightening environmental standards. Starting at some point, it becomes very expensive to provide the state-required environmental cleanliness of an engine operating in difficult conditions of changing road loads. The way out is to use a hybrid scheme, in which the engine operates in a constantly optimal mode, including the optimal one in terms of minimizing harmful emissions. The hybrid scheme also allows the use gas turbine engines which provide even greater environmental cleanliness.

The market is preparing for the invasion of hybrid vehicles: the market already has separate specialized electric motors up to 350kW (used in heavy trailers and buses), new types of electrified wheels with a single computer control system, specialized transport turbines, etc.

The railroad appreciated hybrid scheme much earlier: since they always needed more traction power, diesel locomotives are, yes, right, powerful hybrid tractors, only put on rails.

It is important to note that the emergence of diesel locomotives means a transition to a single electric power industry and transport. A car or a diesel locomotive with an electric drive is a mobile power plant of relatively high power: hybrid power plants for buses and trailers have a peak power of up to 350kW, for diesel locomotives more than 1MW. A dozen of these trailers or a couple of diesel locomotives resting between trips can compete with some backup power plant in the area and certainly embody the idea of ​​​​distributed generation.

It remains only to correct the legislation so as not to interfere with the development of distributed generation by obligatory subordination of each small generator to the commands of the System Operator. Then technologies will be able to develop and quickly make the joint work of hybrid and electric transport and the power grid profitable.

This connection between energy and transport has always existed, now it is just becoming more obvious. Thus, United Europe, like many other countries, has a single Ministry of Energy and Transport, headed by one minister.

Separately, one can consider the rapidly becoming popular linear motor in maglev trains. But magnetic levitation schemes are still extremely expensive, and this option is unlikely to become popular.

Requirements for a new mode of transport

It is obvious that historically there has been a need for a new type of transport infrastructure that will come after aviation.

The new transport must have a developed infrastructure, assuming its ubiquity. If this infrastructure is not ubiquitous, then the mobility property will not be satisfied.

The main requirement for a new mode of transport is the possibility of its incremental financing: the ability to accept money from many sources, each of which is invested in its own project. This means that a new mode of transport must be defined as a set of standards that ensure the compatibility of its track and mobile infrastructure, traffic management, etc. Then we can identify two main competitions:

Competition of sets of standards that actually define new transport.

Competition between suppliers of track infrastructure and rolling stock within the same set of standards.

Most of the current transport projects of the future do not satisfy the condition of incremental investment, one manufacturer supplies the roadbed, carries out construction work, and supplies the rolling stock for the set of standards developed by him. Therefore, most of the modern projects-candidates for the transport of the future will not continue, they die with each next huge tranche of their funding.

Why have cell phones outperformed regular wired PBXs? The operator's investment in one or two cells was less than the investment in the construction of a conventional exchange and a cable duct device. These investments immediately began to work, serving a small number of consumers at first, and the number of cells could be increased in those places where the growth of consumers was higher, but not before the capacity of the initial cell was exhausted. Cell equipment was supplied by many manufacturers at once, which ensured their low cost but stuck together into a single worldwide telephone network. The same thing happened with ISPs: most of the world's ISPs installed small sets of equipment that stuck together into the global Internet. For infrastructure projects, it is not so much the cost of the final infrastructure that is important, but the possibility of its incremental construction, both technical and organizational and financial.

This is not to say that a single provider of the transport solution of the future will ensure the interconnection of all parts of a huge new project. A project that claims to become a new mode of transport should develop as new market and not be built in a planned manner. Large projects can be done in a planned manner, but not modes of transport are clearly not one project, but something more.

A new mode of transport will be able to outperform existing ones only if it provides a more efficient use of land and materials for building its infrastructure than existing ones. Hence, there is such a great interest in monorails on supports - at least their cost is less by the cost of the land liberated under them.

Monorail lines in various projects now cost from $3.5 to $40 million. per kilometer. Reducing their material consumption requires fundamentally new solutions. So, one can point to Yunitskiy's string transport, which uses untwisted, tensioned pair cables, pulled together by several pieces with some kind of filler (for example, concrete) into a stressed structure to obtain a suspended two-rail track. The cost of such a route is $2.5-$3.5 per kilometer with no less reliability than a monorail.

Another fundamental requirement is the maximum use of the existing capillary road structure to reduce the cost of the cost of the last mile for door-to-door transportation. This door-to-door convenience and lack of transfers is what makes private cars unbeatable in the eyes of the population, despite numerous attempts to instill a love of public transport. This requirement can be reformulated as follows: the transport of the future must simultaneously belong to two types, and not to one type.

In fact, all of today's large projects of new types of public transport so beloved by municipalities are single-mode, which proves their complete futility as a new popular transport of the future. The consumer wants to have his own carriage, driving right up to the house and staying near the house for as long as he likes for the convenience of boarding and disembarking (although the garage for such a crew may be located elsewhere). enjoy public transport the consumer does not want if it is possible to have their own vehicle and guaranteed no traffic jams. And the task of the market is to satisfy this need.

Dual-mode transport implies both the possibility of high-speed (200-300 km / h) movement in the mode of dynamically composed trains on suspended rails of the new transport infrastructure, and driving on ordinary roads. It is quite possible that they will receive power from the transport infrastructure of new highways and switch to their own electric batteries or hybrid engines when traveling on an unimproved road/street. True, driving on highways/streets will not require as much engine power and fuel as required when driving on the highway.

The most well-known single-mode transport concept is personal urban public transport. According to this concept, people one by one or in groups of up to 4 people sit at special stops in separate four-seater booths, set the end station, and the automation moves these booths along the guides, combining them into dynamic trains on long main hauls. The main disadvantage of this concept is precisely the fact that it is a variation of public transport, losing in competition to a private car that delivers the passenger, his family, and accompanying goods to the door. You can read more about the materials of the discussion about dual-species versus single-species transport of the future (as well as a discussion of possible technical and organizational solutions) at http://faculty. washington.edu/jbs/itrans/

Dual-species requirements also cancel the forecast that the future of transport belongs to small personal aircraft. This forecast has not come true with helicopters (which were also predicted to be almost automobile in prevalence), and there is no need to talk about airplanes (including those with vertical takeoff / landing). The point here is not only the complexity of managing the movement of thousands and thousands of fast-flying boards outside any road structure, but also the noise produced during takeoff / landing / flight, as well as the resulting fare. And the two-species projects of flying cars that implement the door-to-door mode are frozen almost everywhere due to their complete hopelessness.

An important requirement for a new type of transport is speed, usually this speed is determined at 250-350 km / h. The fact is that people spend on average about one hour a day moving. This figure does not depend too much on the country (it differs significantly only in California where people spend two hours a day on the road, because they eat and make children and generally almost live in a car) and does not depend on the years when the measurements are taken. This is surprising, but humanity does not change its habits of spending about an hour a day on movement, significantly increasing its mobility mainly due to an increase in the speed of movement. And there is no return back to horsepower, walking and cycling. Therefore, it is highly unlikely that the vehicles of the future will be devices such as a two-wheeled Segway electric car, a tiny platform that can reach speeds of up to 20 km / h (the speed of a running person) in urban conditions. Yes, this will help in the current urban traffic jams, but the very idea of ​​a new transport arises precisely from the need to find a technological way out of covering the entire earth with roads.

The projects of high-speed railways and maglev roads have come closest to the required speeds, but their price remains extremely high, and besides, they have all the disadvantages of public transport: getting to the pick-up point and from the drop-off point takes much more time (and nerves), than the move itself.

Conclusion

The main funding for today's transport projects of the future is received from the state.

One of the first such projects was the Heavier-than-Aircraft project, which cost US taxpayers $70,000 and ended in nothing. The Wright brothers competed with this project, and they made the first flying plane, which cost them $2,500. The last noisy transport project, which ended in an equally inglorious waste of taxpayer money, was the Concorde supersonic liner, which did not recoup two-thirds of its cost and did not create a mass market for supersonic passenger aviation. Alas, the state is not a great helper in creating the transport infrastructure of the future:

officials pursue financial and regulatory policies that allow inefficient technologies to survive and bad managers and engineers to live comfortably;

tariffs prescribed by the state (due to a misunderstanding of the natural monopoly of any transport) make profits independent of the results of work, do not stimulate the search for new technologies and the assumption of technological and financial risks. As a result, private capital is either not too eager to participate, or its participation is less effective than capital participation would be under conditions of free prices and market competition.

The state generously finances the development of new transport, because officials allegedly know about technology better than businessmen:

allocate money for research

give benefits, subsidies and organize cross-financing of some technologies

violate the performance-based approach to regulation of safety and environmental friendliness and directly prescribe the use of certain technologies.

To date, the only completed maglev train project exists in the Shanghai Free Economic Zone. The highway, built with public money by the German consortium Transrapid International (which includes Adtranz, Siemens and Tyssen), runs from downtown Shanghai to Pudong Airport. Admittedly, the project had more ideological than transport significance and is perceived more as an attraction than as a means of transportation. In total, this project cost $1.2 billion in investments that will never pay off.

As a result, the state chooses technologies:

expensive, because market success is unimportant (it helps not just the ability to set any tariffs, but the possibility of their subsequent subsidization)

large-scale large sums of money are available, and there is no one to control success

with one owner makes it difficult to raise money to grow the project. In addition, one owner is the lack of competition.

closed connection standards hinders the growth of the project, the lack of competition ensures stagnation

with pre-inflated costs, due to the prevalence of corruption

with incomprehensible economic efficiency (most often in the name of national security or social stability).

Whatever the transport of the future will be, it will certainly be equipped with means of distributed traffic control onboard-infrastructure. On each side there will be a black box to understand what happened during the accident, on each side there will be distress signaling equipment, on each side there will be electronic navigation equipment, collision avoidance, etc. Now there is a re-equipment of water and air transport, the re-equipment of vehicles is being discussed.

Of the novelties, it will be possible to point out the possibility of forming trains from individual vehicles. This mode of an electronically coupled road train is used, for example, to simultaneously accelerate a group of vehicles when starting after a traffic light at a single-level road intersection (increases the capacity of the highway by 3-5 times) or to reduce the aerodynamic drag of a group of vehicles when driving on a freeway with a corresponding reduction in fuel consumption.

List of used literature

1. Transport system / Chests E.Yu. - 961245/28; Appl.27.12.96/Inventions (Applications and patents). - 1998. - No. 36.

2. New urban transport - a car on rails: MEMBRANA - 2002 - No. 1.

3. Aksenov I.Ya. Unified transport system: Proc. for universities - M: Higher. school, 199.

4. Gulia N.V., Yurkov S. A new concept of an electric car: Science and technology 2000 - No. 2.

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Even in ancient times, people tried to use the energy of the fuel to turn it into mechanical. In the 17th century the heat engine was invented, which was improved in subsequent years, but the idea remained the same. In all engines, the energy of the fuel is first converted into the energy of gas or steam, and the gas (steam) expands, does work and cools, and part of its internal energy is converted into mechanical energy. Unfortunately, the ratio useful action not high.

A heat engine is a device that converts the internal energy of a fuel into mechanical energy.

Heat engines include: steam engine, internal combustion engine, steam and gas turbines, jet engine. Their fuel is solid and liquid fuel, solar and nuclear energy.

Heat engines - steam turbines - are also installed at all nuclear power plants to produce high-temperature steam. On all main types of modern transport, heat engines are mainly used: on automobiles, piston internal combustion engines; on water - internal combustion engines and steam turbines; on railway - diesel locomotives with diesel installations; in aviation - piston, turbojet and jet engines. Modern civilization is unthinkable without heat engines. We would not have cheap electricity in abundance and be deprived of all the engines of rapid transit.

Internal combustion engine.

With the complete combustion of hydrocarbons, the final products are carbon dioxide and water. However, complete combustion piston internal combustion engines technically impossible to achieve. Today, about 60% of the total amount of harmful substances emitted into the atmosphere of large cities is accounted for by road transport.

The composition of the exhaust gases of internal combustion engines includes more than 200 different chemicals. Among them:

products of incomplete combustion in the form of carbon monoxide, aldehydes, ketones, hydrocarbons, hydrogen, peroxide compounds, soot;

products of thermal reactions of nitrogen with oxygen - nitrogen oxides;

Compounds of inorganic substances that are part of the fuel - lead and other heavy metals, sulfur dioxide, etc.;

excess oxygen.

The amount and composition of exhaust gases are determined by the design features of the engines, their operating mode, technical condition, quality of road surfaces, weather conditions.

Carbon monoxide (CO) is formed in engines during the combustion of enriched air-fuel mixtures, as well as due to the dissociation of carbon dioxide, at high temperatures. Under normal conditions, CO is a colorless, odorless gas. The toxic effect of CO lies in its ability to convert part of the hemoglobin in the blood into carbo-xyhemoglobin, which causes a violation of tissue respiration. Along with this, CO has a direct effect on tissue biochemical processes, resulting in a violation of fat and carbohydrate metabolism, vitamin balance, etc. The toxic effect of CO is also associated with its direct effect on the cells of the central nervous system. When acting on a person, CO causes headache, dizziness, fatigue, irritability, drowsiness, pain in the heart. Acute poisoning is observed when air is inhaled with a CO concentration of more than 2.5 mg/l for 1 hour.

Nitrogen oxides in exhaust gases are formed as a result of the reversible oxidation of nitrogen with atmospheric oxygen under the influence of high temperatures and pressure. As the exhaust gases cool and dilute them with atmospheric oxygen, nitrogen oxide turns into dioxide. Nitric oxide (NO) is a colorless gas, nitrogen dioxide (NO2) is a red-brown gas with a characteristic odor. Nitrogen oxides, when ingested, combine with water. At the same time, they form compounds of nitric and nitrous acid in the respiratory tract. Nitrogen oxides irritate the mucous membranes of the eyes, nose, and mouth. NO2 exposure contributes to the development of lung diseases. Symptoms of poisoning appear only after 6 hours in the form of coughing, suffocation, and increasing pulmonary edema is possible. NOx is also involved in the formation of acid rain.

Nitrogen oxides and hydrocarbons are heavier than air and can accumulate near roads and streets. In them, under the influence of sunlight, various chemical reactions take place. The decomposition of nitrogen oxides leads to the formation of ozone (O3). Under normal conditions, ozone is unstable and quickly decomposes, but in the presence of hydrocarbons, the process of its decomposition slows down. It actively reacts with moisture particles and other compounds, forming smog. In addition, ozone corrodes the eyes and lungs.

Individual hydrocarbons CH (benzapyrene) are the strongest carcinogens, the carriers of which can be soot particles.

When the engine is running on leaded gasoline, particles of solid lead oxide are formed due to the decomposition of tetraethyl lead. In the exhaust gases, they are contained in the form of tiny particles with a size of 1–5 microns, which remain in the atmosphere for a long time. The presence of lead in the air causes serious damage to the digestive organs, central and peripheral nervous system. The effect of lead on the blood is manifested in a decrease in the amount of hemoglobin and the destruction of red blood cells.

The composition of the exhaust gases of diesel engines is different from gasoline engines. In a diesel engine, fuel combustion is more complete. This produces less carbon monoxide and unburned hydrocarbons. But, at the same time, due to the excess air in the diesel engine, a greater amount of nitrogen oxides is formed.

In addition, the operation of diesel engines in certain modes is characterized by smoke. Black smoke is a product of incomplete combustion and consists of carbon particles (soot) 0.1–0.3 µm in size. White smoke, mainly generated when the engine is idling, consists mainly of aldehydes, which have an irritating effect, particles of evaporated fuel and water droplets. Blue smoke is formed when exhaust gases are cooled in air. It consists of droplets of liquid hydrocarbons.

A feature of the exhaust gases of diesel engines is the content of carcinogenic polycyclic aromatic hydrocarbons, among which dioxin (cyclic ether) and benzapyrene are the most harmful. The latter, like lead, belongs to the first hazard class of pollutants. Dioxins and related compounds are many times more toxic than poisons such as curare and potassium cyanide.

Acreolin was also found in the exhaust gases (especially when diesel engines are running). It has the smell of burnt fats and, at levels above 0.004 mg/l, causes irritation of the upper respiratory tract, as well as inflammation of the mucous membrane of the eyes.

Substances contained in car exhaust gases can cause progressive damage to the central nervous system, liver, kidneys, brain, genital organs, lethargy, Parkinson's syndrome, pneumonia, endemic ataxia, gout, bronchial cancer, dermatitis, intoxication, allergies, respiratory and other diseases. . The probability of occurrence of diseases increases as the time of exposure to harmful substances and their concentration increases.

Worldwide great attention is given to the replacement of liquid petroleum fuels with liquefied hydrocarbon gas (propane-butane mixture) and compressed natural gas(methane), as well as alcohol-containing mixtures.

The advantages of gas fuel are a high octane number and the possibility of using converters. However, when using them, the engine power decreases, and the large mass and dimensions fuel equipment reduce vehicle performance. The disadvantages of gaseous fuels also include high sensitivity to fuel equipment adjustments. With unsatisfactory manufacturing quality of fuel equipment and with a low operating culture, the toxicity of exhaust gases from an engine running on gas fuel, may exceed the values ​​of the petrol version.

In countries with a hot climate, cars with engines running on alcohol fuels (methanol and ethanol) have become widespread. The use of alcohols reduces the emission of harmful substances by 20-25%. The disadvantages of alcohol fuels include a significant deterioration in the starting qualities of the engine and the high corrosiveness and toxicity of methanol itself. In Russia, alcohol fuels for cars are not currently used.

Increasing attention, both in our country and abroad, is being paid to the idea of ​​using hydrogen. The prospects of this fuel are determined by its environmental friendliness (for cars running on this fuel, the emission of carbon monoxide is reduced by 30–50 times, nitrogen oxides by 3–5 times, and hydrocarbons by 2–2.5 times), unlimitedness and renewability of raw materials. However, the introduction of hydrogen fuel is constrained by the creation of energy-intensive hydrogen storage systems on board the car. Currently applied metal hydride batteries, methanol decomposition reactors and other systems are very complex and expensive. Considering also the difficulties associated with the requirements of compact and safe production and storage of hydrogen on board the car, cars with hydrogen engine have not yet had any significant practical application.

As an alternative to internal combustion engines, electric power plants using electrochemical energy sources, batteries and electrochemical generators are of great interest. Electric vehicles are distinguished by good adaptability to variable modes of urban traffic, simplicity Maintenance and environmental cleanliness. However, their practical application remains problematic. First, there are no reliable, light and sufficiently energy-intensive electrochemical current sources. Secondly, the transition of the car fleet to power electrochemical batteries will lead to the expenditure of a huge amount of energy on their recharging. Most of this energy is generated in thermal power plants. At the same time, due to the multiple conversion of energy (chemical - thermal - electrical - chemical - electrical - mechanical), the overall efficiency of the system is very low and the environmental pollution of the areas around the power plants will many times exceed the current values.

Steam turbine.

In modern technology, another type of heat engine is also widely used. In it, steam or gas heated to a high temperature rotates the engine shaft without the help of a piston, connecting rod and crankshaft. Such engines are called turbines.

In modern turbines, to increase power, not one, but several disks mounted on a common shaft are used. Turbines are used in thermal power plants and ships.

Of greatest importance is the use of heat engines in thermal power plants, where they drive the rotors of generators. electric current.

The rapid development of energy in our country is carried out in close unity with environmental protection measures. The latter are necessary because in power plants, for example, at electric thermal stations, solid, liquid, gaseous fuels are widely used. However, before burning fuel, it is necessary to extract valuable industrial products from it. Therefore, such energy processes are being developed and applied that allow the complex processing and use of fuel. For example, gas is subjected to thermal decomposition before combustion, thus obtaining acetylene, ethylene, hydrogen, soot, graphite. These products are used in various industries (for example, graphite in the electrical industry) to obtain useful products, and hydrogen as a fuel that does not pollute nature when burned.

During the operation of thermal power plants, smoke is generated during the combustion of fuel. The smoke contains fuel combustion products (oxides of sulfur, carbon, soot, hydrocarbons, etc.), which pollute the atmosphere. To reduce the degree of atmospheric pollution, ash collectors are installed at power plants, as well as large units are used, in which almost complete combustion of fuel is achieved ( work efficiency modern units reaches 95-99%).

For example, Figure 2 shows a scheme for fuel processing in an energy complex based on thermal power plants. In this case, a complex task is performed: the use of fuel to produce steam that drives a turbogenerator (electricity generation); production of hydrogen, sulfur and products from smelted slag; elimination of emissions of sulfur oxide and other harmful products of fuel combustion into the atmosphere. This is achieved in the following way.

The converter and the steam generator are connected by common gas, air and steam pipelines and form a single energy technology complex. Solid fuel after crushing and breaking enters simultaneously into two chambers of the converter. One of them is used to burn fuel to heat water and produce steam; The combustion products of fuel in the form of gases at temperatures above 1500 degrees from this chamber enter the steam generator, where, during combustion, waste products are released in a smaller amount. This two-stage combustion mode reduces the amount of nitrogen oxides polluting the atmosphere. Pulverized fuel enters the other chamber of the converter by blowing it with steam and hot air; in it there is a conversion (change, processing) of solid fuel; gaseous fuel (conversion gas) is obtained from it, from which hydrogen (a fuel that does not produce hazardous waste) and sulfur are subsequently extracted. The energy required for this process is released by hot water heated in the converter chamber, in which solid fuel is burned.

To reduce the degree of environmental pollution by waste from various industrial enterprises, electrostatic precipitators are widely used. They serve mainly for gases and air from dust. Consider the device and the principle of operation of one of the electrostatic precipitators. The chamber is equipped with corona and collecting electrodes. Corona electrodes are made of wire or metal tape, and collecting electrodes are in the form of metal plates or cylinders.

A negative potential of up to 100 kV is applied to the corona electrodes, and the precipitation electrodes are connected to the positive pole of the current source. In this case, a corona charge arises, as a result of which there is a directed movement of electrons and negative ions from corona to collecting electrodes. Dust particles suspended in the gas (air), moving at low speed in the electrostatic precipitator chamber, adsorb ions, charge and begin to move towards the collecting electrodes. The dust deposited on the collecting electrodes is removed by shaking the electrodes or by washing them off with the help of special tools. To power the electrostatic precipitators, a special rectifier substation is used, equipped with automatic protection against short circuits.

At thermal power plants, as well as at many enterprises in mechanical engineering, metalworking, the chemical industry and others, water is used in large quantities to cool equipment, raw materials, and finished products. As a result, water becomes contaminated with mechanical impurities and soluble chemicals. The flow of such water into reservoirs pollutes them. The most radical way to prevent pollution of water bodies with sewage is the use of waste-free technology, i.e. such technological processes and measures that allow not only to obtain finished products, but also to process production waste and exclude the flow of polluted water. This problem is solved more successfully when creating territorial production complexes.

JET ENGINE

Jet engine, an engine that creates the traction force necessary for movement by converting the initial energy into the kinetic energy of the jet jet of the working fluid; as a result of the expiration of the working fluid from the nozzle of the engine, a reactive force is formed in the form of a reaction (recoil) of the jet, which moves the engine and the apparatus structurally associated with it in the direction opposite to the outflow of the jet. Various types of energy (chemical, nuclear, electrical, solar) can be converted into the kinetic (speed) energy of a jet stream in a rocket engine. A direct reaction engine (direct reaction engine) combines the engine itself with a mover, that is, it provides its own movement without the participation of intermediate mechanisms.

To create jet thrust used by R. d., you need: a source of initial (primary) energy, which is converted into the kinetic energy of the jet stream;

working body, which in the form of a jet stream is ejected from the R. d .; R. D. himself is an energy converter. The initial energy is stored on board an aircraft or other apparatus equipped with RD (chemical fuel, nuclear fuel), or (in principle) it can come from outside (solar energy). To obtain a working fluid in R. d., a substance taken from the environment (for example, air or water) can be used;

the substance which is in tanks of the device or directly in the R.'s chamber of d.; a mixture of substances coming from the environment and stored on board the apparatus. In modern R. d., chemical energy is most often used as the primary one. In this case, the working fluid is incandescent gases - combustion products of chemical fuel. During the operation of a rocket engine, the chemical energy of the burning substances is converted into the thermal energy of the combustion products, and the thermal energy of the hot gases is converted into the mechanical energy of the translational motion of the jet stream and, consequently, the apparatus on which the engine is installed. The main part of any R. d. is the combustion chamber in which the working fluid is generated. The end part of the chamber, which serves to accelerate the working fluid and obtain a jet stream, is called a jet nozzle.

Depending on whether the environment is used or not during the operation of R. D., they are divided into 2 main classes - air-breathing engines (AJE) and rocket engines(RD). All WFDs are heat engines, the working fluid of which is formed by the oxidation reaction of a combustible substance with atmospheric oxygen. The air coming from the atmosphere makes up the bulk of the working fluid of the WFD. Thus, an apparatus with a WFD carries a source of energy (fuel) on board, and draws most of the working fluid from the environment. Unlike the WFD, all components of the working fluid of the RD are on board the apparatus equipped with the RD. The absence of a propulsor interacting with the environment and the presence of all components of the working fluid on board the apparatus make the RD the only one suitable for work in space. There are also combined rocket engines, which are, as it were, a combination of both main types.

The principle of jet propulsion has been known for a very long time. Heron's ball can be considered the ancestor of R. d. Solid rocket engines - powder rockets appeared in China in the 10th century. n. e. For hundreds of years, such missiles were used first in the East, and then in Europe as fireworks, signal, combat. In 1903, K. E. Tsiolkovsky, in his work “Investigation of the World Spaces with Reactive Instruments,” was the first in the world to put forward the main provisions of the theory of liquid rocket engines and proposed the main elements of a liquid-fueled rocket engine. The first Soviet liquid rocket engines - ORM, ORM-1, ORM-2 were designed by V. P. Glushko and created under his leadership in 1930-31 at the Gas Dynamics Laboratory (GDL). In 1926, R. Goddard launched a rocket using liquid fuel. For the first time, an electrothermal RD was created and tested by Glushko at the GDL in 1929-33.

In 1939, missiles with ramjet engines designed by I. A. Merkulov were tested in the USSR. The first diagram of a turbojet engine? was proposed by the Russian engineer N. Gerasimov in 1909.

In 1939, the construction of turbojet engines designed by A. M. Lyulka began at the Kirov Plant in Leningrad. The tests of the created engine were prevented by the Great Patriotic War of 1941-45. In 1941, a turbojet engine designed by F. Whittle (Great Britain) was first installed on an aircraft and tested. The theoretical works of the Russian scientists S. S. Nezhdanovsky, I. V. Meshchersky, and N. E. Zhukovsky, the works of the French scientist R. Enot-Peltri, and the German scientist G. Oberth were of great importance for the creation of R. D.. An important contribution to the creation of the VRD was the work of the Soviet scientist B. S. Stechkin, The Theory of the Air-Jet Engine, published in 1929.

R. d. have a different purpose and the scope of their application is constantly expanding.

Most widely R. d. are used on aircraft various types.

Turbojet engines and dual-circuit turbojet engines are equipped with most military and civil aircraft around the world, they are used in helicopters. These rocket engines are suitable for flights at both subsonic and supersonic speeds; they are also installed on projectile aircraft; supersonic turbojet engines can be used in the first stages of aerospace aircraft. Ramjet engines are installed on anti-aircraft guided missiles, cruise missiles, supersonic fighter-interceptors. Subsonic ramjet engines are used in helicopters (installed at the ends of the main rotor blades). Pulsating jet engines have little thrust and are intended only for aircraft at subsonic speeds. During the 2nd World War of 1939-45, these engines were equipped with V-1 projectiles.

RD in most cases are used on high-speed aircraft.

Liquid-propellant rocket engines are used on launch vehicles of spacecraft and spacecraft as marching, braking and control engines, as well as on guided ballistic missiles. Solid-propellant rocket engines are used in ballistic, anti-aircraft, anti-tank, and other military missiles, as well as on launch vehicles and spacecraft. Small solid propellant engines are used as boosters for aircraft takeoff. Electric rocket engines and nuclear rocket engines can be used in spacecraft.

Environment

Heat engines (including jet engines) are a necessary attribute of modern civilization. With their help, ≈ 80% of electricity is generated. It is impossible to imagine modern transport without heat engines. At the same time, the widespread use of heat engines is associated with a negative impact on the environment.

Fuel combustion is accompanied by the release of carbon dioxide into the atmosphere, which can absorb thermal infrared (IR) radiation from the Earth's surface. An increase in the concentration of carbon dioxide in the atmosphere, increasing the absorption of infrared radiation, leads to an increase in its temperature ( Greenhouse effect). Every year the temperature of the Earth's atmosphere rises by 0.05 °C. This effect can create a threat of melting glaciers and a catastrophic rise in the level of the World Ocean.

The products of fuel combustion significantly pollute the environment.

Hydrocarbons, reacting with ozone in the atmosphere, form chemical compounds that adversely affect the vital activity of plants, animals and humans.

The consumption of oxygen during the combustion of fuel reduces its content in the atmosphere.

To protect the environment, it widely uses treatment facilities that prevent the emission of harmful substances into the atmosphere, sharply limit the use of heavy metal compounds added to fuel, develop

Engines using hydrogen as a fuel ( traffic fumes consist of harmless water vapor), create electric vehicles and cars using solar energy.

Emissions of harmful substances into the atmosphere are not the only side of the impact of energy on nature. According to the laws of thermodynamics, the production of electrical and mechanical energy, in principle, cannot be carried out without significant amounts of heat being removed to the environment. This cannot but lead to a gradual increase in the average temperature on the earth. One of the areas related to environmental protection is to increase the efficiency of energy use, the struggle for its savings.

The vehicle is technical device, the purpose of which is the transportation of people or goods over long distances. There are more than 10,000 such devices in the world today. Therefore, in order to distinguish one transport from another, people came up with a standard classification, thanks to which all types of vehicles can be conditionally divided according to their purpose, the energy used and the medium of movement.

Main types of vehicles

As mentioned above, depending on certain features, all types of vehicles can be divided into three main groups:

• by appointment;
• by energy used;
• on the medium of travel.

Since the above types of vehicles have their own classification, features and differ from each other in certain ways, they can be considered in more detail.

Types of transport by destination

Purpose refers to the area in which a particular mode of transport is used most often. That is, these vehicles can be:

• Special use. These include military (armored vehicles, tanks) and technological transport (track vehicles).
• Common use. This category includes all types of water, air and land transport used in the field of trade and provision of services. For example, a truck that transports goods is already a vehicle that fits into the general use category.
• Individual use, i.e. those vehicles that a person uses personally. The most common individual transport is a personal car or motorcycle.

In addition, there is also a separate subcategory of public transport. This includes urban (public) transport, that is, one that carries passengers on certain routes, according to a schedule and for a fee. These can be buses, trams, trolleybuses, etc.

Types of transport by energy used

Depending on the energy used, there are vehicles:

• Driven by wind power, for example, sailing ships (sailboats).
• Driven by muscular force (moved by a person or animal). The most common human-propelled vehicle is the bicycle, which is propelled by foot pedals. In addition, there are small rowing boats and velomobiles that are less used in everyday life, which also move with the help of human power. Animal-driven vehicles are described in more detail below under the appropriate heading.
• With a personal engine. This type, in turn, is divided into vehicles with a thermal and electronic engine.

A heat-powered vehicle is a mechanical vehicle that works by converting heat into energy needed to move. The source of heat in such engines can be, for example, organic fuel. One of the most famous representatives of transport with a heat engine is a steam locomotive, which is set in motion by processing (kindling) coal.

An electronic vehicle is one whose engine is powered by electricity. The main vehicles of this type are trams, funiculars, monorails, electric cars and electric boats.

Modes of transport by travel medium

Depending on the medium of movement, transport can be:

• ground (road, rail, bicycle, pipeline, as well as transport driven by animals);
• air (aviation and aeronautics);
• water (surface and underwater vessels);
• space (devices and machines moving along airless paths);
• different kind.

Other modes of transport include stationary lifts (elevators), elevators, cable cars, etc.

Ground transport

There are various ground vehicles, which are divided according to a number of criteria:

• By type of mover, there are caterpillar (some types of tanks, tractors and cranes), wheeled (cars, bicycles, mopeds, motorcycles), as well as ground vehicles that are driven by animals.
• By the number of wheels, there are: monocycles (one-wheeled vehicles), bicycles (two-wheeled vehicles), tricycles (three-wheeled vehicles) and ATVs (four-wheeled vehicles).
• According to the types of roads, there are railway and trackless vehicles. TO railway transport refers to any vehicle that transports goods and passengers on rail tracks. That is, it can be locomotives, wagons, trams, monorails and trestle transport. Any land transport, including vehicles that move on land, refers to trackless transport.

Automotive vehicles

The most popular and widespread type of land vehicles is road transport. Automobile includes all types of means by which cargo and passengers are transported along trackless tracks. Many cars are designed not only for transportation over short distances, but also over long distances, especially in cases where it is impossible to deliver passengers, products or materials in any other way.

All road transport is divided into:

• For racing cars, which are most often used in car and sprint races (drag racing, auto slalom, etc.). These include, for example, monoposts - single cars with open wheels used in Formula 1 races.
• On transport vehicles that serve only for the transport of goods and passengers. Depending on the purpose of the destination, they are passenger cars (personal use cars), trucks (vans, tractors, etc.) and transportation (buses, fixed-route taxis, etc.).
• On special machines, which, among other things, are equipped with additional equipment designed for one purpose or another. These include, for example, ambulances or fire trucks.

Vehicles driven by animals

People learned to use animals as means of transportation when other types of land transport did not yet exist. Although years have already passed, modern vehicles have appeared, many still prefer to ride a horse or harness an animal to a wagon to transport any cargo.

Vehicles driven by animals include:

• Horse-drawn transport. Horses, dogs, camels, buffaloes, elephants and other mammals that can be tamed and trained for transportation are mainly used as vehicles for moving cargo and passengers on wagons, carts.
• Pack transport. The very name of pack transport comes from the packing luggage (pack), which is attached to the back of the animal. Such a vehicle is used in cases where horse-drawn transport is impractical, for example, in mountainous areas where the slopes are too steep and narrow roads, which greatly complicates the movement of wagons and carts. In addition to mountainous regions, pack animals are used in rural and swampy areas, as well as in deserts or in northern regions where there are poor roads or there are practically none.
• Horse transport, which is designed both for the transport of passengers and for participation in special sports competitions and competitions. Horses, camels and elephants are the main types of riding transport.

Pipeline vehicles

The main purpose of pipeline vehicles is only the transportation of goods (chemicals, liquid and gaseous products) through special channels (pipes). This type of land transport is the cheapest and most popular, which has no analogues in the world. For example, on the territory of the Russian Federation, pipelines are used to transport more than 95% of the oil produced.

In addition to low cost, pipeline transport has other advantages:

• fast shipping;
• low cost of transportation;
• no loss of cargo during delivery;
• pipelines can be laid anywhere and in any way (not counting airways).

The main types of pipeline vehicles: sewerage, water supply, garbage chute and pneumatic transport (pneumatic mail).

Air Transport

Airplanes appeared at the beginning of the 20th century and quickly gained popularity around the world. This type of transport also includes helicopters, airships, airbuses, airplanes. It is one of the fastest but expensive species vehicles intended for passenger and freight traffic over long distances (more than 1 thousand km) by air. In addition, there are airplanes and helicopters that perform official functions (for example, extinguish fires, spray insecticides over fields, air ambulance, etc.). Typically, air transport is used by tourists and businessmen who want to quickly get to another country or even to another continent. These vehicles transport large and heavy items, products with a short shelf life, as well as valuable items.

Although this mode of transport is a noisy, expensive pleasure, it is indispensable for scientific expeditions that go to distant continents or other hard-to-reach places where it is difficult or impossible to reach in any other way.

Water transport

This is one of the classic types of vehicles. Such transport is intended for transportation along artificial (reservoirs, canals) and natural (lakes, rivers, seas, etc.) waterways.

Unlike air transport, water transport is one of the cheapest after pipeline transport. That is why almost everything is transported by such vehicles: from building materials to minerals. And such watercraft, such as, for example, ferries, are even capable of transporting other vehicles.

But here passenger traffic has become much smaller in recent years. This is justified by the rather low speed with which ships move from one seaport to another.

The main types of vehicles moving along the waterways: surface (boats, boats, liners, ships) and underwater vessels.

Space transport (spacecraft)

Space transport (spacecraft) - a mechanical vehicle designed to transport goods and passengers in a vacuum (in space). Of course, speaking of the transportation of people, it is understood that they are both passengers and the crew that controls the spacecraft. Basically, such transport is intended for more specific purposes. For example, space stations are designed for various studies of the terrain, oceans and atmosphere that cannot be done on Earth, and satellites allow people to watch international television programs and make weather forecasts for meteorologists. In addition, some spacecraft are used for military purposes (surveillance of war zones, reconnaissance of the activities of other countries, detection of approaching space objects, etc.).

From the main space transport can be distinguished: satellites, spacecraft, orbital and interplanetary stations, planetary rovers.

Public (municipal) transport- variety passenger transport as an industry that provides services for the transportation of people along routes that the carrier sets in advance, bringing to general information delivery method (vehicle), amount and form of payment, guaranteeing regularity (repeatability of movement at the end of the production cycle of transportation), as well as the immutability of the route at the request of passengers.

Criteria

The difference between public transport and other types and methods of passenger transportation:

• the availability of transportation services to the widest strata of the population, without any class, professional and other restrictions of a social type, on the basis of a single requirement fulfilled by the carrier in the presence of seats on the sole condition of payment for this service at established rates.
• payment for the service, which does not exclude the possible differentiation of the tariff according to the criterion of the age of the passenger
• the return nature of the movement, its regular and intensive repetition for the majority of passengers on the corresponding route for a long time.
• lack of institutional intermediaries in the purchase of transportation services (individual and direct nature of the act of purchasing travel documents)
• in the modern world - the mandatory participation of local authorities in the regulation of this sector, coordination and supervision of the activities of carriers - providers of transportation services
• sufficient capacity of the vehicle (massity of the service), which implies the possibility of sharing it simultaneously with two or more independent passengers (this criterion excludes trips by cabs, taxis and rickshaws).

In practice, when considering the operation of public transport from the standpoint of one or another type of vehicle (buses, trolleybuses, trams, metro, ferries, ships, etc.), among their passengers there is often a certain proportion of tourists who travel beyond the program of the tour they paid for, as well as military and other categories of citizens whose trips are free due to local laws. Nevertheless, shuttle bus does not lose its belonging to public transport even if at some point it is 100% filled with soldiers going to the bathhouse under the command of an ensign. The opposite is also true: a bus belonging to a military unit does not become public transport only by virtue of the owner's permission for civilians to board it.

It should also be noted the existence of unofficial public transport, when legally the route or flight of the route does not exist, but drivers or specially authorized persons collect passengers at certain points. According to Russian law, such transportation, if paid, is an illegal business, and is punishable by a fine or imprisonment. In terms of the form of service provision, such activities also apply to public transport, since passengers are recruited from all comers, and most often there is movement along a certain route (for example, city A near the bus station - city B near the bus station)

Ferries are becoming a means of providing public transport services both directly and in delivery passenger cars and/or motor vehicles, whose passengers fall under the contingent of public transport customers, i.e. carry out their return trips regularly and usually in connection with industrial activities, and not in the order of tourism or emigration. The same criteria for classifying public transport apply to the carriage of passengers on passenger-and-freight ships.

Much less often, a trolleybus (intercity line in Crimea, intercity bus No. 284 Saratov-Engels, a trolleybus line between the cities of Bendery and Tiraspol) and a tram (64-kilometer line along the Belgian coast) act as intercity public transport.

In cities with steep slopes sometimes specialized transport is arranged - funiculars, elevators, escalators. Escalators and elevators are also installed in underground and elevated pedestrian crossings. In mountainous conditions, as well as to overcome water obstacles, cable cars are used; this type of transport is rarely used in cities.

There are non-excursion ships used within cities (river trams), also related to public transport. In Russia and other countries with cold winters, their widespread use is hindered by the freezing of water bodies.

Story

The first type of passenger transport, determined by the criteria of regularity of movement along a previously known route, without restrictions on the status of passengers, was water transport - transportation across rivers. Satisfaction with the conditions of the last filter, the conditions of payment, became possible with the appearance in the VIII century BC. e. money . Money originated in the Aegean civilization, and it is no coincidence that it is in Greek mythology that Charon appears - a boatman (ferryman, carrier), ferrying passengers across the river for money. Behind this myth, which gave rise to the tradition among the Hellenes of putting a coin under the tongue of the dead, is a specific practice from the world of the living: the dispersion of the Hellenes over the numerous islands of the Archipelago created a significant natural prerequisite for this.

The economic prerequisite for the emergence of public transport as an industry is the emergence of a market for personally free labor, supplemented by the factor of urbanization. In pre-class states, each community member, by definition, on the one hand, had personal transport, and on the other - did not feel the need for regular long-distance travel "light". In antiquity, owning one's own departure or at least the horse becomes the privilege of the master class, but here, too, subsistence farming, coupled with the enslavement of the peasants, frees the exploited from the need for other people's paid services for regularly moving themselves to the place of application of their labor power and back.

The answer to the question about the presence of public transport in ancient Babylon, Alexandria, Rome, and later Constantinople, which grew to a million people or approaching that, is most likely negative. On the one hand, there is no historical evidence for this. On the other hand, the bulk of the population of these "megacities" were, in addition to slaves and warriors, small and medium-sized artisans, whose additional labor force (if required) settled within walking distance. In addition, the very level of development of productive forces in those eras was insufficient to allocate a certain part of the total volume of goods produced for the “feeding” of public transport, as a special non-productive industry.

Public transport received the widest development in the 19th and first half of the 20th century. However, in the 1930s - 1960s, in many countries there was a process of curtailing public transport due to competition with personal cars becoming more and more accessible to the general public. Trams were completely eliminated in many cities. They were nationalized as state company British Rail in 1947, however were re-privatized in the 1990s.

A private car usually provides much faster door-to-door travel with high comfort, but motorization creates many problems. Cities (particularly older cities whose historical cores developed in the pre-automobile era) suffer from congested streets and insufficient parking spaces; tense car traffic creates loud noise and air pollution. Ensuring the mobility of the motorized population requires large social costs.

There are different views on the relationship between public and individual transport:

• The extreme "automobile" point of view assumes the total motorization of the population and the complete eradication of public transport as unnecessary and interfering with the movement of individual transport. The solution to the problems of motorization is seen in the extensive development of road networks, the introduction of new, more economical and “cleaner” engines and fuels. However, in practice, huge social costs (both direct for the construction and maintenance of roads, and indirect due to increased pollution, loss of natural complexes, etc.) hinder movement along this path. It should be noted that full motorization is not possible due to the fact that many people are physically or mentally unable to drive vehicles. Regular taxi rides are too expensive for most residents, not everyone recognizes hitchhiking, as some individuals are embarrassed by it.
• The extreme "anti-car" point of view considers the individual car to be an absolute evil. The solution to the transport problems of society is seen in the development of public transport networks, providing members of society with a level of mobility and comfort comparable to individual transport. However, in practice, achieving high level comfort is problematic, especially in areas with low population density.

Nowadays, transport planning tends to avoid both extremes, valuing both passenger convenience and social and natural balance. Thus, in zones of low density of settlement, conditions are provided for widespread motorization, and in more densely populated cities Public transport is considered the preferred mode of transportation. Solutions that allow mixed modes of movement (for example, intercepting parking lots) are widely used. The conditions of each individual society (political system, economic situation, stereotypes of behavior, settlement system) determine to which extreme point of view the emphasis is shifted.

IN modern Russia, due to the economic situation and the mentality of certain social strata (primarily those working in the public transportation system), the majority of the population (including those who are unable to have their own car and are interested in public transport) have formed a strong dissatisfaction with public transport - the condition of the rolling stock, the quality of the service. The reasons for this relationship are:

• Some drivers and conductors do not value the opinion of passengers about the service provided, do not perceive passengers as a source of their income, although this fact seems to be obvious. The reason, first of all, is that the manifestation of rudeness and disrespect for a single passenger will not affect the business as a whole, since the rest of the passengers will still use their transport;
• Some owners of this business solve their own interests, ignoring the interests of passengers: transport runs mainly during rush hours, leaves routes early, idles at the terminals until fully loaded, ignoring the schedule, the owner sets the driver an extremely short time on the way from terminal to terminal, as a result of which drivers driving with excess speed and violating traffic rules, etc.;
• many passengers themselves cultivate such an attitude towards them by silence and unwillingness to get involved in disputes and in defending their rights;
• In some transport enterprises, the transport is worn out and its owners are reluctant to repair it; salons are not maintained in a neat condition: worn seats are not replaced, windows and walls are not washed for months;
• it is not uncommon for this business to be controlled by organized crime groups or law enforcement agencies, as a result of which attempts to influence the authorities and society remain futile.

Fixed public transport infrastructure

In addition to vehicles, fixed engineering structures are used:

• Depot buildings, parks, repair shops, assembly and repair enterprises;
• Road and rail track;
• Fuel supply devices;
• Power supply device;
• Buildings of enterprises for the operation of road and road facilities, power stations and substations, gas stations, fuel and spare parts warehouses;
• bridges;
• Tunnels;
• Buildings of control rooms and administrative buildings;
• Buildings, devices and structures for automation, telemechanics, communications, power supply, a set of fuel, water, lubrication;
• Rest rooms for drivers, pilots, helmsmen, machinists, sailors;
• Stands, cabinets, posters with posted schedules, electronic scoreboards, clocks;
• Buildings and structures for waiting for transport. From a canopy from a rain to large buildings - stations. It should be noted that the word station often refers to railway transport, for other modes of transport, modified terms are used - bus station, air terminal, river station, sea station. Some farms bus transport call their bus stations bus stations. In Russia, the term airport is much more popular instead of an air terminal, and port instead of a sea station. A river station is often also called a river port or pier. Stations (let's call it in general for all types of transport) may have seating areas, long-term rest rooms with sleeping places for passengers, canteens, toilets, showers, trade facilities, hairdressers, postal telephone and telegraph offices for passengers.