From the Renaissance to the eighteenth century
It was not until the Renaissance and the development of mining that need a guide rail is felt. The oldest known image of rails is a woodcut showing Cosmographia universalis Sebastian Münster published in Basel in 1544: it shows the equipment in wooden rails Leberthal Alsatian mines. Later, also of cast iron plates were used to cover the wooden rails, to protect them from premature wear caused by the frequent passage of wagons: English Whitehaven collieries and strengthened their ways. In 1767, Richard Reynolds suppressed timber and introduced in the area of Coalbrookdale (Shropshire), the first metal rails.
The invention of the steam engine returns to the French Denis Papin (1647-c. 1712), but the Scotsman James Watt (1736-1819) that belongs to increase in 1769, the machine Steam from the experimental to the industrial implementation, but this machine was fixed. The dream of the "horseless carriage" was realized in 1770 by Nicolas Joseph Cugnot (1725-1804), military engineer Lorraine, who built his famous fardier, intended to travel on a road.
Locomotives
Originally, horses provided the energy needed to pull wagons or carriages on the rails. Subsequently, the invention of the steam locomotive came advantageously replace animal power.
The first locomotive running on rails was the work of Richard Trevithick Columbia (1771-1833) and his cousin Andrew Vivian. In February 1804, this machine ran at a speed of 8 km / h 15 km linking the mines to Penydaren Abercynon (Wales), firing five cars loaded with iron ore and 70 men. However, because of its relatively high capacity (25 t), this heavy vehicle deteriorating roads on which he was traveling. Also the transformer does one mover fixed. Trevithick's invention, however, encouraged other manufacturers to develop an operational locomotive.
Fundamental inventions
At the outset rested manufacturers the problem of lack of adhesion between smooth surfaces, the wheel and rail. A big step was taken in 1812 when John Blenkinsop locomotive built a rack, with two cylinders to avoid timeouts. Weighing about 5 tons, it had a power of 3.7 kW and could take a convoy of 100 tonnes to 6 km / h. This model was used from 1814 and for twenty years on the line-Middleton Leeds so it was the first for a steam train pulling into scheduled service. The problems of adhesion will be a nightmare for engineers until William Hadley (Puffing Billy with his 8 t to 50 t towing 8 km / h) and George Stephenson (with its Blucher) between the two wheels located on same flank by a rod coupling device leveraging the full weight of the machine to prevent wheel spin.
First dedicated to the transportation of minerals, railways relièrent mines to canals, ports and factories. But the concept of passenger transport railway gradually gained many followers, so the British Parliament authorized, in 1821, construction of a dedicated line for travelers, about 40 km long, from Stockton-on -Tees and Darlington and Stephenson appointed chief engineer, he built the Locomotion for this line machine, two axles, connected by external rods, which rolled September 25, 1825.
The Rocket
With his son Robert Stephenson designed a much more potent engine, which he named Rocket (the "Rocket") in October 1829, the locomotive took part in the Rainhill Trials competition, a competition organized jointly by the Railways of Liverpool & Manchester and intended to prove that we could do without traction means fixed (cable) to clear the ramps. Four machines entered in the running: the Perseverance Burstall, the Novelty Braithwaite and Ericsson, Hackworth's Sans Pareil and Rocket of George and Robert Stephenson. Fitted with a tubular boiler (imagined at the same time in France by Marc Seguin), the latter won the race, towing 40 tons at a speed of 26 km / h. The advantages of steam propulsion became obvious: the Rocket proves capable of reaching over 20 km / h in normal and pushing peaks at 46 km / h.
In France, progress was slower, for several reasons: from France, Great Britain enjoyed an indisputable advance in the industrial, maritime and commercial power was great, and she actively operated iron and Coal. In 1823, Antoine Beaunier was allowed to build a railway line from Animal Andrezieux and St. Stephen, on the banks of the Loire in 1826, Marc Seguin won the concession for the section Saint-Etienne - Lyon. He had to face many problems of infrastructure, and was led, in particular, digging the first tunnel railway (Terrenoire). Desiring to abolish animal traction, he purchased two locomotives used to Stephenson and, before their shortcomings, he endowed it with two improvements: his own model of boiler tube and the forced draft, giving the engine its main characteristics current.
Therefore, the railroad quickly spread to the rest of Europe: Brussels-Mechelen-Fürth and Nuremberg (1835), Naples-Portici (1839), St. Petersburg-Moscow (1841), Barcelona-Mataró (1848 ); online Transcaucasus (1880), early-Siberian (1891). In the U.S., the Baltimore-Boston line was completed in 1828. But it was not until 1866 that the first transcontinental link be established. As the front lines of Asia, Oceania and Africa, they date back to 1853, 1854 and 1856. Global network underwent a significant expansion during the latter half of the nineteenth century, going from 15? 000 km in 1850 to 1 million in 1915. It then stabilized and then began to regress.
In France, we sought the help of British engineers, as William Buddicom, "Entrepreneur of traction" on the railway from Rouen to Paris. Soon, the French industrial locomotives built and invented original auxiliary bodies, such as the boiler feed injector (1858) by Henry Giffard.
The package expands to U.S.
The British influence was felt on the evolution of American railways. At the time, in fact, the United States had only a weak industrial base, and they had to resolve to import locomotives English (one hundred from 1829 to 1841). Thus, the Delaware & Hudson Railroad Company acquired in 1829 the Stourbridge Lion, which proved too heavy and could damage the rails. The locomotive (1831) John Bull, commissioned in 1831 by the Camden & Amboy Railroad, proved more satisfactory and assured soon the passenger throughout New Jersey.
Locomotive (1830) locomotive "Charleston" (1830)
In 1830 the Americans began to build their own machines. If the Tom Thumb ("Tom Thumb") by Peter Cooper, one kilowatt of power, failed to win the famous race who objected to a horse-drawn carriage, she nevertheless persuaded representatives of the Camden & Ohio Railroad of the usefulness of the steam engine. On Christmas Day of that year, the Best Friend of Charleston, first engine sold in the U.S., the U.S. hauled the first train (141 passengers) on an online basis.
Unlike the Rocket, who had two wheels, these machines had four U.S.. John B. Jervis, an engineer at the Mohawk & Hudson Railroad, wanted to remedy their poor mans? Uvrabilité: he built the Experiment in 1832, with two wheels and a swiveling leading truck, which gave it a greater flexibility in curves and significantly increased its speed.
Technological innovations United States
They moved rapidly. In 1836, Campbell Henry, of the Philadelphia Railroad, he developed an eight-wheeled machine (assuming the truck and the two axles), which soon became the archetypal American locomotive and remained for half a century. In 1839, Joseph Harrison, the same company, designed a balancing system which provides a better distribution of weight on the axles. Meanwhile, Isaac Dripper, the Camden & Amboy Railroad, had invented the plow stone front, which he equipped including John Bull, which fix several shortcomings of network American railroad, as the absence of protective barriers along the tracks. In 1836, first in Pennsylvania, the locomotives were fitted with sand, in fact, a swarm of locusts had descended on this state, threatening to paralyze rail traffic and the sand used to improve traction wheel that might drag on crickets. We also installed interiors (cloth and wood) to protect drivers of cold weather, especially severe in northern states. Finally, the bells and whistles were used as a warning when crossing intersections.
Locomotive (1855) locomotive (1900)
On the eve of the Civil War, the American locomotive type was designated by the code 4-4-0 (four front wheels, four wheels, no wheels under the cab), according to the classification of Frederick White. From 1850 to 1860, went 4-4-0 in the 15-25 t Finally, around 1870, it increased the power and size of machines, which they used it exclusively on coal. From 1850, the European and American locomotives began to differentiate significantly. Typically, the first tenders owned vehicles (appendices containing the fuel and water required for the machine) and were devoid of bogies before or hunting-stones, characteristics of American locomotives.
Technical innovations in Europe
In Europe, the improvements of the steam engine allowed to gradually improve the performance (which does not yet exceed 5.5%). The Swiss engineer Anatole Mallet settled in France in 1876 invented the double expansion, which is to work the steam in two successive groups of cylinders, and the first locomotive "compound" movement in France in 1886. In 1898, German inventor Wilhelm Schmidt overheating, which enabled to increase the temperature of the hot spring, then return and admit into the cylinders of dry steam, thereby reducing condensation.
The race for power
In the U.S., the end of the Civil War and 1914, tied the builders of increasing importance to the size and power locomotives. To achieve significant improvements, was changed including the number of axles. So the company adopted Baltimore & Ohio Does gear wheels to ten (4-6-0), while that of Lehig Valley augmented its performance through the introduction of the locomotive type Consolidation (2-8-0, or 140 after the French notation). To enlarge the foyer, he had to move: initially installed between the two rear driving axles, it was subsequently lodged between the wheels of small diameter. This provision type characterized Atlantic (4-4-2, or 221) of 1885 was going to replace the locomotive Pacific (4-6-2, or 231), adopted by all networks: first European Pacific appear in 1907 on the Paris-Orleans.
During the First World War, the Union Railroad Administration said the acquisition of some 1? 390 machines that meet specific standards of manufacturing, 50% of them being Mikado type (2-8-2, or 141). In the 1920s, American companies of railways of 15 endowed? 000 new locomotives. Among the most powerful were articulated models consisting of two groups of axles powered by a single engine boiler. Finally, around 1950, the Union Pacific acquired 25 Big Boy 2-4-4-2 type (similar to the Anglo-Saxon 4-8-8-4), 400 t, 35.10 m long, with wheels of 170 cm in diameter and developing a power 5150 kW. In half a century, the horsepower of steam engines had almost trebled.
In France, the steam locomotive survived until the early 1970s. Engineers valuable their name tied to important improvements: Andre Chapelon, 1933, which built the network for the Pacific Northwest's most powerful European and Louis Armand (he was president of the SNCF), who developed a device treatment of boiler feed water. The recent series studied and constructed by the station from 1942 were the culmination of sophisticated machinery from the old networks, such as Mountain P 241 and other neighbors. As for the 242 A 1, a Mountain-State amended in 1945, its total mass reached 148 t, with more than 2? 700 kW, it was the most powerful machine from Europe.
Electric locomotives
The principle of electric locomotive was invented in 1873 by van Depoele (Chicago) and implemented for the first time in 1879 by Siemens and Halske, as tram. The first heavy machinery (1700 t towed) was born in 1895. By 1900, several American companies (Baltimore & Ohio, New York, New Haven & Hartford) put up electrified tracks, which proved very satisfactory. In France, the first trials were held in 1894 between Saint-Germain-State and Saint-Germain-belt in 1900, the section Invalides - Issy-Plaine was electrified with 650 V DC third rail, and Section Austerlitz - Orsay equipped a driver's air powered V in 1500, also continued. Tensile tests were performed on AC power in 1903 in Germany, then Switzerland. In 1920 France adopted the 1500 V DC electrification of main lines and the electrified network grew from 184 km in 1920-3? 340 km in 1938.
The locomotives were specialized: the 2D2 for rapid and express the BB for the other passenger trains and freight services. In 1949 appeared the locomotive CC-7101 high-power and fully bonded, able to respond to wider needs. The electric motor was equipped with a speed reduction gear, to choose between maximum speed for trains faster and slower speed for a towed important.
The electric drive requires an external energy source, in return, the machines are light and excellent performance, while the engine can operate as generators in the raids and restore energy to the grid. They currently provide 70% of traffic in Europe. Consumption SNCF represents 1% of French consumption of energy.
The current industrial electrification
This type of electrification (25 kV, 50 Hz), experienced in Savoy then put into practice on the line Valenciennes - Thionville in 1954, represented most significant breakthrough in electric traction. It allowed, in fact, save 40% of the amounts of fixed investments, because of the almost direct connection to the catenary to the electricity grid. The single-phase locomotives, equipped with a transformer followed by rectifiers, could adapt to different supply voltages alternative or even continuous, live this way reveals dual power machines and even tri-and quadruple (CC-40100, traveling between Paris-Nord, Belgium and the Netherlands). The electrified lines totaled 10? 481 km in 1981. Subsequent to being considered a turbine-wheel drive is also pulling power which was used for the TGV, despite the difficulties of developing the pantograph-catenary system outlet at high speed. The studies were fully successful: the speed record on rails set May 16, 1990 with 515.3 km / h demonstrated.
The advantages of electric locomotives
Electric locomotives offer significant advantages compared to steam, and reveal additional non-polluting. On easy maintenance, the machines generally have a longer life than that of diesel. The major drawback lies in the electrical pathways that involve considerable investment in mains, substations and other facilities necessary, investments can be recouped only in densely populated areas, high traffic, and with a high voltage grid sufficiently dense conditions found together especially in Europe or Japan.
Sybic or Asytrit?
In the jargon of the French railways, the terms and Sybic Asytrit designate two types of electric locomotives using the latest technology in railway traction. The previous generation of engines used, with few exceptions almost experimental, traction motor dc, when the machine is powered by alternating current, a transformer lowers the voltage to the proper value, then a solid state rectifier provides power DC motors.
The drive type BB-26000 is equipped with motors powered by alternating current three phase variable frequency speed synchronizing the frequency, as they are dual power locomotives, one understands the meaning of Sybic: dual power synchronous. Three phase motors are rated double that of DC motors of similar mass, such as those of South-East TGV: TGV Atlantique trainset or ACE has an output of 8800 kilowatts, 6,800 kilowatts cons for his senior South-East. A variant of AC motors (those of high-speed Eurostar or motor Z-20 500 in the Paris suburbs) is even more interesting, because the rotor does no more winding, and therefore has no brushes or collector; No weight gain is not negligible, but the gain on the interview is even more significant. This will be the traction of BB-36000, asynchronous and tritension (Asybit).
Diesel Locomotives
The engine designed by Rudolf Diesel in 1893 (completed in 1897) greatly improved the capabilities of locomotives. In 1912, the Swiss company Sulzer Brothers produced the first locomotive diesel engine: it circulated in German. In 1932, the French network Paris - Lyon - Marseille (PLM) went into service early shunting locomotives Diesel-electric in 1903, the first fast train propelled diesel-electric was put into service on the Berlin - Hamburg. In 1937, PLM went into service between Paris and Menton (1? 111 km) two locomotives Diesel-electric power three? 300 kilowatts, weighing 228 tons, they were traveling at an average speed approaching 100 km / h.
The railcars built by Michelin (the famous "Michelin"), Renault Bugatti circulated since 1931, when they began, they were usually equipped with gasoline engines.
In the U.S., the Central Railroad of New Jersey was the first company to operate rail diesel engine, from 1920. Then in 1935 the Burlington and Union Pacific followed his example for transport of passengers. Finally, the company adopted the Santa Fe diesel in 1941 for the delivery of goods. The progress of this new kind of tension was rapid in North America: 1945, Diesel engines assured 7% of freight transport, 10% of passenger and 25% of operations of various maneuvers in 1952, the number locomotives of this type exceeded that of steam engines, five years later, these devices involved 92% of freight transport, 93% passenger and 96% of operations maneuvers. Other countries recorded a similar pattern.
The principle of the diesel locomotive
In Diesel engines, diesel engine powers the wheel motors via hydraulic or mechanical transmission. In fact, using the electric transmission more likely indirect. In this case, we speak of diesel-electric machines: the main engine drives a generator which in turn feeds the electric motors, one per axle.
The advantages of the diesel locomotive
This system has many advantages when compared to steam traction. The relatively high purchase price of diesel (about twice that of steam power equal to) is pretty quickly recouped by savings arising from their use, and which are not only fuel: indeed, these systems does not require extensive maintenance and are particularly reliable (when he should be checked daily or home boilers of steam engines, diesels can travel thousands of miles between revisions) transmission is also more flexible and eliminates the shocks, and hence the stress on the rail that caused the steam engines. Like the electric motor, diesel-electric locomotives were able to "reverse" their engines to brake. They also allow the addition of auxiliary units that do not impose a larger maintenance staff.
The development of diesel locomotives and the increase in power have allowed the station to stop use of steam locomotives since 1974.
General Technical Issues
An essential characteristic of a locomotive traction on the hook, which depends not only power but also the adhesion, which is proportional to axle load (adhering weight). For this reason, modern locomotives have only axles and axle weight is higher (20 to 23 t and 35 t in Europe in the U.S.) that is compatible with the structure of channels . The suspension problems are solved by joint use of rubber blocks, springs, pneumatic and hydraulic dampers, a significant reduction in unsprung mass and the use of guidance systems with low friction (rods).
A steam boiler, and consisting mainly of food as fuel, the mechanism and the chassis, and finally the wheels. For reasons of space, there is not, in general, condenser. The mechanism consists of the cylinders (double acting), usually in even numbers, which can be single or compound growth, the distribution mechanism and reversal (drawers and valves) and coupling rods. Reserve fuel and water is usually contained in the tender. On the latest machinery, food sized coal is from the tender worm. In some locomotives, the heating is provided by oil.
Electric locomotives may be DC powered, the tension being 0.6, 0.75, 0.85, and above 1.5 or 3 kV. It is a very simple solution, since it neither requires nor transformer rectifier, however, the intensity of the supply current imposes heavy and catenary supply units together. Disadvantages substantially reduced by the current industrial electrification at 25 kV and the separation of distribution substations. In addition, transformers and rectifiers mercury vapor from the beginning have now been replaced by dry rectifiers, thyristors, which can vary the voltage continuously and eliminate the starting resistors.
Diesel locomotives are distributed in machines with mechanical transmission (mechanical or hydraulic clutch and gearbox), whose power is limited by power unit to around 2000 hp, and diesel-electric machinery (electrical generator operating engines). This technique, similar to that of electrical machinery, enjoys its improvements, in addition, it allows very high powers. The first gas turbine engines generally included electric transmission; overall design was therefore quite similar to that of diesel-electric machinery. Today, the use of aviation turbine tends to favor mechanical transmissions and, given their limited power (about 1,000 hp), the number of drivers.
