Steam generator (railroad)
A steam generator is a type of boiler used to produce steam for climate control and potable water heating in railroad passenger cars. The output of a railroad steam generator is low pressure, saturated steam, passed through a system of pipes and conduits throughout the length of the train. Steam generators were developed when diesel locomotives started to replace steam locomotives on passenger trains. In most cases, each passenger locomotive was fitted with a steam generator and a feedwater supply tank; the steam generator used some of the locomotive's diesel fuel supply for combustion. When a steam generator-equipped locomotive was not available for a run, a so-called "heating car" fitted with one or two steam generators was inserted between the last locomotive in the consist and the rest of the train. Steam generators would be fitted to individual cars to enable them to be heated independently of any locomotive supply. In Ireland, Córas Iompair Éireann used "heating cars" as standard and CIÉ diesel locomotives were not fitted with steam generators.
During the early days of passenger railroading, cars were heated by a wood or coal fired stove—if any heat was provided at all. It was difficult to evenly heat the drafty cars. Passengers near the stove found it uncomfortably hot, while those further away faced a cold ride; the stoves were a safety hazard. Cars were ignited by embers from the stove in a wreck, when a dislodged stove would overturn, dumping burning coals into the car; the use of steam from the locomotive to heat cars was first employed in the late 19th century. High pressure steam from the locomotive was passed through the train via hoses; the dangers of this arrangement became evident in the accidents. In 1903 Chicago businessman Egbert Gold introduced the "Vapor" car heating system, which used low pressure, saturated steam; the Vapor system was safe and efficient, became nearly universal in railroad applications. When steam locomotives began to be retired from passenger runs, Gold's company, now known as the Vapor Car Heating Company, developed a compact water-tube boiler that could be fitted into the rear of a diesel locomotive's engine room.
Known as the Vapor-Clarkson steam generator, it and its competitors remained a standard railroad appliance until steam heat was phased out. In 1914-16, the Chicago, Milwaukee & St Paul Railway electrified some 440 miles of their line going over the Rocky Mountains and Cascade Range with the 3 kV DC overhead system; the motive power was EF-1s and EP-1s by American Locomotive Company with electrical equipment by General Electric. These articulated 2-section engines in passenger version were equipped with 2 oil-fired steam boilers, one in each section. In Great Britain, steam generators were built for British Railways diesel locomotives by three firms - Spanner and Stone. All types were notoriously unreliable and failures were common. In Poland Vapor steam generators were fitted to diesel passenger locomotives SP45; the boilers were removed in the 80s and 90s and replaced with 3 kV DC generators driven by main engine, when maintenance became too expensive and remaining cars not fitted with electric heating were withdrawn from service.
The New Zealand electric locomotives class ED, used in and around Wellington, were fitted with oil-fired steam boilers manufactured by the Sentinel Waggon Works. The boilers appeared to have been used rarely and were removed during the locomotives’ operational lives; these burned diesel fuel, a lightweight fuel oil. The term steam generator refers to an automated unit with a long spiral tube that water is pumped through and is surrounded by flame and hot gases, with steam issuing at the output end. There is no pressure vessel in the ordinary sense of a boiler; because there is no capacity for storage, the steam generator's output must change to meet demand. Automatic regulators varied the water feed, fuel feed, combustion air volume. By pumping more water in than can be evaporated, the output was a mixture of steam and a bit of water with concentrated dissolved solids. A steam separator removed the water. An automatic blowdown valve would be periodically cycled to eject solids and sludge from the separator.
This reduced limescale buildup caused by boiling hard water. Scale build-up that occurred had to be removed with acid washouts; the New Zealand ED class electric locomotive used around Wellington from 1940 had oil-fired water tube boilers for passenger carriage steam heaters, which were removed. Diesel-hauled passenger trains like the Northerner on the North Island Main Trunk had a separate steam heating van, but the carriages of long distance trains like the Overlander used electric heaters supplied by a separate power or combined power-luggage van. In British electric locomotives the steam generator was an electric steam boiler, heated by a large electric immersion heater running at the line voltages of 600 volts from a third rail or 1,500 volts from an overhead wire; the Polish electric locomotive EL204 of 1937 was fitted with an electric steam generator supplied from overhead lines. The locomotive was destroyed during the second world war. Steam heated or cooled rail cars have been replaced or converted to electric systems.
Wisps of steam issuing from normal service cars are now history in the UK, USA, much of the rest of the world. In the UK, much preserved stock, including mail-line certified railtour sets, still retains steam heating capability as well as electric heating, this is still sometimes used when the trains are being operated by steam locomotives or pres
Co-Co is the wheel arrangement for a diesel locomotive with two six-wheeled bogies with all axles powered, with a separate motor per axle. The equivalent UIC classification for this arrangement is Co′Co′ or C-C for AAR. Co+Co is the code for a similar wheel arrangement but with an articulated connection between the bogies. Co-Cos are most suited to freight work, they are popular because the greater number of axles results in a lower axle load to the track. The 1Co+Co1 wheel arrangement is a development of the Co-Co arrangement and is used where it is necessary to reduce axle load; each "Co" bogie has an additional non-powered axle in an integral pony truck to spread the load. Notable examples include the British Rail Class 47, the Soviet M62 locomotive and the EMD Series 66, mainstay of many current European heavy rail haulage fleets, over 500 having been built to date; the strong IORE locomotive has this but to allow higher locomotive weight, 30 tonnes per axle. Bo-Bo
A multiple-unit train or multiple unit is a self-propelled train composed of one or more carriages joined together, which when coupled to another multiple unit can be controlled by a single driver, with multiple-unit train control. Note that although multiple units consist of several carriages, single self-propelled carriages - called railcars, rail motor coaches or railbuses - are in fact multiple-units when two or more of this is working connected through multiple-unit train control; the term multiple unit does not denote locomotives using multiple-unit train control. Multiple unit train control was first used in electric multiple units in the 1890s; the Liverpool Overhead Railway opened in 1893 with two car electric multiple units, controllers in cabs at both ends directly controlling the traction current to motors on both cars. The multiple unit traction control system was developed by Frank Sprague and first applied and tested on the South Side Elevated Railroad in 1897. In 1895, derived from his company's invention and production of direct current elevator control systems, Frank Sprague invented a multiple unit controller for electric train operation.
This accelerated the construction of electric traction railways and trolley systems worldwide. Each car of the train has its own traction motors: by means of motor control relays in each car energized by train-line wires from the front car all of the traction motors in the train are controlled in unison. Most MUs are powered either by traction motors, receiving their power through a third rail or overhead wire, or by a diesel engine driving a generator producing electricity to drive traction motors. A MU has the same power and traction components as a locomotive, but instead of the components being concentrated in one car, they are spread throughout the cars that make up the unit. In many cases these cars can only propel themselves when they are part of the unit, so they are semi-permanently coupled. For example, one car might carry the prime mover and traction motors, another the engine for head end power generation. MU cars can be a motor or trailer car, it is not necessary for every one to be motorized.
Trailer cars can contain supplementary equipment such as air compressors, etc.. In most cases, MU trains can only be driven/controlled from dedicated cab cars. However, in some MU trains, every car is equipped with a driving console, other controls necessary to operate the train, therefore every car can be used as a cab car whether it is motorised or not, if on the end of the train. An example of this arrangement is the NJ Transit Arrows. All rapid transit rolling stock, such as on the New York City Subway, the London Underground, other subway systems, are multiple-units EMUs. Most trains in the Netherlands and Japan are MUs, making them suitable for use in areas of high population density. Many high-speed rail trains are multiple-units, such as the Japanese Shinkansen and the latest-generation German Intercity-Express ICE 3 high-speed trains. A new high-speed MU, the AGV, was unveiled by France's Alstom on February 5, 2008, it has a claimed service speed of 360 km/h. India's ICF announced the country's first high speed engine-less train named'train 18', which would run at 250kmph maximum speed.
Multiple unit has been used for freight traffic, such as carrying containers or for trains used for maintenance. The Japanese M250 series train has four front and end carriages that are EMUs, has been operating since March 2004; the German CargoSprinter have been used in three countries since 2003. Multiple units have several advantages over locomotive-hauled trains, they are more energy-efficient than locomotive-hauled trains. They have better adhesion, as more of the train's weight is carried on driven wheels, rather than the locomotive having to haul the dead weight of unpowered coaches, they have a higher power-to-weight-ratio than a locomotive-hauled train since they don't have a heavy locomotive that does not itself carry passengers, but contributes to the total weight of the train. This is important where train services make frequent stops, since the energy consumed for accelerating the train increases with an increase in weight; because of the energy efficiency and higher adhesive-weight-to-total-weight ratio values, they have higher acceleration ability than locomotive-type trains and are favored in urban trains and metro systems for frequent start/stop routines.
Most of them have cabs at both ends, resulting in quicker turnaround times, reduced crewing costs, enhanced safety. The faster turnaround time and the reduced size as compared to large locomotive-hauled trains, has made the MU a major part of suburban commuter rail services in many countries. MUs are used by most rapid transit systems. However, the need to turn a locomotive is no longer a problem for locomotive-hauled trains due to the increasing use of push pull trains. Multiple units may be made up or separated into sets of varying lengths. Several multiple units may run as a single train be broken at a junction point into shorter trains for different destinations; as there are multiple engines/motors, the failure of one engine does not prevent the multiple unit from continuing its journey. A locomotive-drawn train has only one power unit, whose failure will disable the train. However, some locomotive-hauled trains may contain more than one power unit and thus be able to continue at reduced speed after the failure of one.
They have lig
Railway electrification system
A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electric railways use electric locomotives to haul passengers or freight in separate cars or electric multiple units, passenger cars with their own motors. Electricity is generated in large and efficient generating stations, transmitted to the railway network and distributed to the trains; some electric railways have their own dedicated generating stations and transmission lines but most purchase power from an electric utility. The railway provides its own distribution lines and transformers. Power is supplied to moving trains with a continuous conductor running along the track that takes one of two forms: overhead line, suspended from poles or towers along the track or from structure or tunnel ceilings. Both overhead wire and third-rail systems use the running rails as the return conductor but some systems use a separate fourth rail for this purpose. In comparison to the principal alternative, the diesel engine, electric railways offer better energy efficiency, lower emissions and lower operating costs.
Electric locomotives are usually quieter, more powerful, more responsive and reliable than diesels. They have an important advantage in tunnels and urban areas; some electric traction systems provide regenerative braking that turns the train's kinetic energy back into electricity and returns it to the supply system to be used by other trains or the general utility grid. While diesel locomotives burn petroleum, electricity can be generated from diverse sources including renewable energy. Disadvantages of electric traction include high capital costs that may be uneconomic on trafficked routes. Different regions may use different supply voltages and frequencies, complicating through service and requiring greater complexity of locomotive power; the limited clearances available under overhead lines may preclude efficient double-stack container service. Railway electrification has increased in the past decades, as of 2012, electrified tracks account for nearly one third of total tracks globally. Electrification systems are classified by three main parameters: Voltage Current Direct current Alternating current Frequency Contact system Third rail Fourth rail Overhead lines Overhead lines plus linear motor Four rail system Five rail systemSelection of an electrification system is based on economics of energy supply and capital cost compared to the revenue obtained for freight and passenger traffic.
Different systems are used for intercity areas. Six of the most used voltages have been selected for European and international standardisation; some of these are independent of the contact system used, so that, for example, 750 V DC may be used with either third rail or overhead lines. There are many other voltage systems used for railway electrification systems around the world, the list of railway electrification systems covers both standard voltage and non-standard voltage systems; the permissible range of voltages allowed for the standardised voltages is as stated in standards BS EN 50163 and IEC 60850. These take into account the number of trains drawing their distance from the substation. Increasing availability of high-voltage semiconductors may allow the use of higher and more efficient DC voltages that heretofore have only been practical with AC. 1,500 V DC is used in Japan, Hong Kong, Republic of Ireland, France, New Zealand, the United States. In Slovakia, there are two narrow-gauge lines in the High Tatras.
In the Netherlands it is used on the main system, alongside 25 kV on the HSL-Zuid and Betuwelijn, 3000 V south of Maastricht. In Portugal, it is used in Denmark on the suburban S-train system. In the United Kingdom, 1,500 V DC was used in 1954 for the Woodhead trans-Pennine route; the system was used for suburban electrification in East London and Manchester, now converted to 25 kV AC. It is now only used for the Wear Metro. In India, 1,500 V DC was the first electrification system launched in 1925 in Mumbai area. Between 2012-2016, the electrification was converted to 25 kV 50 Hz AC, the countrywide system. 3 kV DC is used in Belgium, Spain, the northern Czech Republic, Slovenia, South Africa, former Soviet Union countries and the Netherlands. It was used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensive branch and loop lines in Montana, by the Delaware, Lackawanna & Western Railroad in the United States, the Kolkata suburban railway in India, before it was converted to 25 kV 50 Hz AC. DC volt
Train reporting number
A train reporting number in Great Britain identifies a particular train service. It consists of: A single-digit number, indicating the class of train A letter, indicating the destination area A two-digit number, identifying the individual train or indicating the route; the train reporting number is called the headcode, a throwback to when the number was physically displayed at the head of a train. Headcodes were introduced around 1850 and were shown by oil lamps facing forward on the front of the locomotive; the position of these lamps on the locomotive denoted the class of train, which assisted the signalmen to determine the gaps between trains required in the interval-based signalling system, used at the time. The lamps were lit at night and were painted white to assist with sighting by day. On some lines white discs were used by day in the place of lamps. With the coming of absolute block signalling, the class-based headcodes allowed signallers to identify and regulate trains properly; however on some busy lines busy suburban ones, the headcode denoted the route of the train rather than the class of train.
In these areas junctions were complex and timetables were intense: it was more important that signallers routed the trains than regulated trains by class. This was prevalent in the south of England, where companies used six headlamp positions to show the route of train; some companies had their own code format which led to some confusion where trains from one company ran onto other companies' lines. The Railway Clearing House intervened to standardise headcodes, based on four lamp positions, they were adopted by the majority of lines outside the south of England. At the time of the 1923 Grouping, the standard headcodes were simplified so that only two lamps were used at any one time, these codes were adopted by the London Midland and Scottish Railway, the Great Western Railway and the London and North Eastern Railway; the Southern Railway retained a route-based headcode system, with up to four lamps in six positions. Notable exceptions were former Glasgow and South Western Railway and the Somerset and Dorset Joint Railway lines, which continued with their own headcodes on internal trains.
The Caledonian Railway maintained a different route-based headcode system consisting of a pair of semaphore arms mounted on the locomotive - the angle of the two arms and their position indicated the routing. Train reporting numbers were used to denote trains in the internal working timetable; these contained one or more letters or numbers to either uniquely identify a particular train, or denote its route. Not all lines used these and the details and extent of the practice varied between companies. Although these numbers were in many places confined to timetables and other documentation, in some busier areas they were shown at the head of the train. On the SR, a single alphabetic character system of denoting routes used on suburban lines grew into a two character route-based system; this was developed at the same time as a significant programme of electrification and the consequent introduction of a large number of multiple unit trains. Many of these trains were fitted with display devices to show the route code instead of a lamp or disc-based headcode.
This was a back-lit stencil with the single letter code a two-character roller-blind system was used. The code system had equivalence with the lamp or disc route-based headcodes in assisting signallers with routing trains. On the other railways, the reporting number was on occasion displayed at the head of the train along with the lamp headcode; this happened more than not with special trains or other unusual trains, to allow signallers to identify unfamiliar trains and route them correctly. This code was sometimes either chalked onto the locomotive front or pasted as paper characters onto a headcode disc; the GWR sometimes used a three-character frame mounted on the locomotive smokebox in which the train reporting number could be displayed. After nationalisation, British Railways continued with these headcodes and the new diesel and electric locomotives and multiple units were built either with a disc/lamp system or a two to four character roller-blind display system depending on what part of the network they were to work.
In 1960, the current format was introduced where train class and reporting number information are combined in four characters. All diesel and electric locomotives and multiple units built after that date were fitted with a roller-blind display that could display the full reporting number, except locomotives and multiple units destined for the Southern Region, which continued its long-standing practice of two-character alpha-numeric displays. By 1976, the replacement of the huge number of manual signal boxes with centralised power-signalling coupled with computer-based train control and more modern telecommunications systems meant that it was no longer necessary to display headcodes throughout the railway network. Outside the Southern Region blinds were set to 00 or 0000, discs/lamps to the former express passenger code. Roller blinds were blanked or plated over to show two dots and new trains introduced for service outside the Southern Region after this time had no train reporting number display equipment.
Many trains intended to run over Southern Region lines were designed to display the numeric route-code portion of the train reporting number, which they still display as a dot-matrix display. The main purpose of the headcode is to assist the signaller in routing and regulating the t
Scrap consists of recyclable materials left over from product manufacturing and consumption, such as parts of vehicles, building supplies, surplus materials. Unlike waste, scrap has monetary value recovered metals, non-metallic materials are recovered for recycling. Scrap metal originates both in business and residential environments. A "scrapper" will advertise their services to conveniently remove scrap metal for people who don't need it. Scrap is taken to a wrecking yard, where it is processed for melting into new products. A wrecking yard, depending on its location, may allow customers to browse their lot and purchase items before they are sent to the smelters, although many scrap yards that deal in large quantities of scrap do not selling entire units such as engines or machinery by weight with no regard to their functional status. Customers are required to supply all of their own tools and labor to extract parts, some scrapyards may first require waiving liability for personal injury before entering.
Many scrapyards sell bulk metals by weight at prices below the retail purchasing costs of similar pieces. A scrap metal shredder is used to recycle items containing a variety of other materials in combination with steel. Examples are automobiles and white goods such as refrigerators, clothes washers, etc; these items are labor-intensive to manually sort things like plastic, copper and brass. By shredding into small pieces, the steel can be separated out magnetically; the non-ferrous waste stream requires other techniques to sort. In contrast to wrecking yards, scrapyards sell everything by weight, instead of by item. To the scrapyard, the primary value of the scrap is what the smelter will give them for it, rather than the value of whatever shape the metal may be in. An auto wrecker, on the other hand, would price the same scrap based on what the item does, regardless of what it weighs. If a wrecker cannot sell something above the value of the metal in it, they would take it to the scrapyard and sell it by weight.
Equipment containing parts of various metals can be purchased at a price below that of either of the metals, due to saving the scrapyard the labor of separating the metals before shipping them to be recycled. Scrap prices may vary markedly over time and in different locations. Prices are negotiated among buyers and sellers directly or indirectly over the Internet. Prices displayed. Other prices are not updated frequently; some scrap yards' websites have updated scrap prices. In the US, scrap prices are reported in a handful of publications, including American Metal Market, based on confirmed sales as well as reference sites such as Scrap Metal Prices and Auctions. Non-US domiciled publications, such as The Steel Index report on the US scrap price, which has become important to global export markets. Scrap yards directories are used by recyclers to find facilities in the US and Canada, allowing users to get in contact with yards. With resources online for recyclers to look at for scrapping tips, like web sites and search engines, scrapping is referred to as a hands and labor-intensive job.
Taking apart and separating metals is important to making more money on scrap, for tips like using a magnet to determine ferrous and non-ferrous materials, that can help recyclers make more money on their metal recycling. When a magnet sticks to the metal, it will be a ferrous material, like iron; this is a less expensive item, recycled but is recycled in larger quantities of thousands of pounds. Non-ferrous metals like copper and brass do not stick to a magnet; some cheaper grades of stainless steel are other grades are not. These items are higher priced commodities for metal recycling and are important to separate when recycling them; the prices of non-ferrous metals tend to fluctuate more than ferrous metals so it is important for recyclers to pay attention to these sources and the overall markets. Great potential exists in the scrap metal industry for accidents in which a hazardous material present in scrap causes death, injury, or environmental damage. A classic example is radioactivity in scrap.
Toxic materials such as asbestos, toxic metals such as beryllium and mercury may pose dangers to personnel, as well as contaminating materials intended for metal smelters. Many specialized tools used in scrapyards are hazardous, such as the alligator shear, which cuts metal using hydraulic force and scrap metal shredders. According to research conducted by the US Environmental Protection Agency, recycling scrap metals can be quite beneficial to the environment. Using recycled scrap metal in place of virgin iron ore can yield: 75% savings in energy. 90% savings in raw materials used. 86% reduction in air pollution. 40% reduction in water use. 76% reduction in water pollution. 97% reduction in mining wastes. Every ton of new steel made from scrap steel saves: 1,115 kg of iron ore. 625 kg of coal. 53 kg of limestone. Energy savings from other metals include: Aluminium savings of 95% energy. Copper savings of 85% energy. Lead savings of 65% energy. Zinc savings of 60% energy; the metal recycling industry encompasses a wide range of metals.
The more recycled metals are scrap steel, lead, copper, stainless steel and zinc. There are two main categories of metals: ferrous and
A loading gauge defines the maximum height and width for railway vehicles and their loads to ensure safe passage through bridges and other structures. Classification systems vary between different countries and gauges may vary across a network if the track gauge remains constant; the loading gauge limits the size of passenger carriages, goods wagons and shipping containers that can be conveyed on a section of railway line. It varies across the world and within a single railway system. Over time there has been more standardization of gauges. Containerisation and a trend towards larger shipping containers has led rail companies to increase structure gauges to compete with road haulage; the term "loading gauge" can refer to a physical structure, sometimes using electronic detectors using light beams on an arm or gantry placed over the exit lines of goods yards or at the entry point to a restricted part of a network. The devices ensure that loads stacked on open or flat wagons stay within the height/shape limits of the line's bridges and tunnels, prevent out-of-gauge rolling stock entering a stretch of line with a smaller loading gauge.
Compliance with a loading gauge can be checked with a clearance car. In the past, these were physical feelers mounted on rolling stock. More lasers are used; the loading gauge is the maximum size of rolling stock. This is distinct from the structure gauge, the minimum size of bridges and tunnels, must be larger to allow for engineering tolerances and car motion; the difference between the two is called the clearance. The terms "dynamic envelope" or "kinematic envelope" – which include factors such as suspension travel, overhang on curves and lateral motion on the track – are sometimes used in place of loading gauge; the height of platforms is a consideration for the loading gauge of passenger trains. Where the two are not directly compatible, stairs may be required, which will increase loading times. Where long carriages are used at a curved platform, there will be gaps between the platform and the carriage door, causing risk. Problems increase where trains of several different loading gauges and train floor heights use the same platform.
The size of load that can be carried on a railway of a particular gauge is influenced by the design of the rolling stock. Low-deck rolling stock can sometimes be used to carry taller 9 ft 6 in shipping containers on lower gauge lines although their low-deck rolling stock cannot carry as many containers. Larger out-of-gauge loads can sometimes be conveyed by taking one or more of the following measures: Operate at low speed in places with limited clearance, such as platforms. Cross over from a track with inadequate clearance to another track with greater clearance if there is no signalling to allow this. Prevent operation of other trains on adjacent tracks. Use refuge loops to allow trains to operate on other tracks. Use of Schnabel cars that manipulate the load up and down or left and right to clear obstacles. Remove obstacles. Use gauntlet track to shift the train to center. For locomotives that are too heavy, ensure that fuel tanks are nearly empty. Turn off power in overhead wiring or in the third rail.
Rapid Transit railways have a small loading gauge, which reduces the cost of tunnel construction. These systems only use their own specialised rolling stock; the loading gauge on the main lines of Great Britain, most of which were built before 1900, is smaller than in other countries. In mainland Europe, the larger Berne gauge was agreed to in 1913 and came into force in 1914; as a result, British trains have noticeably and smaller loading gauges and smaller interiors, despite the track being standard gauge along with much of the world. This results in increased costs for purchasing trains as they must be designed for the British network, rather than being purchased "off-the-shelf". For example, the new trains for HS2 have a 50% premium applied to the "classic compatible" sets that will be able to run on the rest of the network, meaning they will cost £40 million each rather than £27 million for the captive stock, despite the captive stock being larger; the International Union of Railways has developed a standard series of loading gauges named A, B, B+ and C.
PPI – the predecessor of the UIC gauges had the maximum dimensions 3.15 by 4.28 m with an round roof top. UIC A: The smallest. Maximum dimensions 3.15 by 4.32 m. UIC B: Most of the high-speed TGV tracks in France are built to UIC B. Maximum dimensions 3.15 by 4.32 m. UIC B+: New structures in France are being built to UIC B+. Up to 4.28 m it features a width of 2.50 m to accommodate ISO containers. UIC C: The Central European gauge. In Germany and other central European countries, the railway systems are built to UIC C gauges, sometimes with an increment in the width, allowing Scandinavian trains to reach German stations directly built for Soviet freight cars. Maximum dimensions 3.15 by 4.65 m. In the European Union, the UIC directives were supplanted by ERA Technical Specifications for Interoperability of European Union in 2002, which has def