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These -operated locos show three styles of diesel locomotive body: (rear), (center) and (front).A diesel locomotive is a type of in which the is a. Several types of diesel locomotive have been developed, differing mainly in the means by which mechanical power is conveyed to the.Early locomotives and railcars used and as their fuel. Patented his first in 1898, and steady improvements to the design of diesel engines reduced their physical size and improved their power-to-weight ratios to a point where one could be mounted in a locomotive.
Dizzle: an alternative of saying the friend version of dog. He's my ' dizzle.' Discover the meaning of the Dizzel name on Ancestry®. Find your family's average life expectancy, most common occupation, and more.
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Internal combustion engines only operate efficiently within a limited range, and while low power gasoline engines could be coupled to mechanical, the more powerful diesel engines required the development of new forms of transmission. This is because clutches would need to be very large at these power levels and would not fit in a standard 2.5 m (8 ft 2 in)-wide locomotive frame, or wear too quickly to be useful.The first successful diesel engines used, and by 1925 a small number of diesel locomotives of 600 hp (450 kW) were in service in the United States. In 1930, Armstrong Whitworth of the United Kingdom delivered two 1,200 hp (890 kW) locomotives using -designed engines to of Argentina. In 1933, diesel-electric technology developed by was used to propel the, a high-speed intercity two-car set, and went into series production with other streamlined car sets in Germany starting in 1935.
In the United States, diesel-electric propulsion was brought to high-speed mainline passenger service in late 1934, largely through the research and development efforts of dating back to the late 1920s and advances in lightweight car body design by the.The economic recovery from caused the widespread adoption of diesel locomotives in many countries. They offered greater flexibility and performance than, as well as substantially lower operating and maintenance costs.
Diesel–hydraulic transmissions were introduced in the 1950s, but, from the 1970s onwards, diesel–electric transmissions have dominated. Shunter of from 1934, in modern liveryIn many railway stations and industrial compounds, steam shunters had to be kept hot during lots of breaks between scattered short tasks. Therefore, diesel traction became economical for before it became economical for hauling trains.
The construction of diesel shunters began in 1920 in France, in 1925 in Denmark, in 1926 in the Netherlands, and in 1927 in Germany. After a few years of testing, hundreds of units were produced within a decade.Diesel railcars for regional traffic. Since 1948In 1945, a batch of 30 Baldwin diesel–electric locomotives, was delivered from the United States to the railways of the Soviet Union.In 1947, the London Midland & Scottish Railway introduced the first of a pair of 1,600 hp (1,200 kW) Co-Co diesel–electric locomotives (later ) for regular use in the United Kingdom, although British manufacturers such as Armstrong Whitworth had been exporting diesel locomotives since 1930. Fleet deliveries to British Railways, of other designs such as Class 20 and Class 31, began in 1957.Series production of diesel locomotives in Italy began in the mid-1950s. Generally, diesel traction in Italy was of less importance than in other countries, as it was amongst the most advanced countries in the electrification of the main lines and, as a result of Italian geography, even on many domestic connections freight transport over sea is cheaper than rail transport.Early diesel locomotives and railcars in Asia JapanIn Japan, starting in the 1920s, some petrol-electric railcars were produced. The first diesel–electric traction and the first air-streamed vehicles on Japanese rails were the two DMU3s of class Kiha 43000 (キハ43000系). Japan's first series of diesel locomotives was class DD50 (国鉄DD50形), twin locomotives, developed since 1950 and in service since 1953.
ChinaOne of the first domestically-developed Diesel vehicles of China was the DMU (东风), produced in 1958. Series production of China's first Diesel locomotive class, the DFH 1, began in 1964 following the construction of a prototype in 1959.Early diesel locomotives and railcars in Australia. A Mckeen railcar in Wodonga, Australia, 1911The built 1912 to 1917 by Commonwealth Railways (CR) passes through 2000 km of waterless (or salt watered) desert terrain unsuitable for steam locomotives.
The original engineer envisaged to overcome such problems. Some have suggested that the CR worked with the South Australian Railways to trial diesel traction.
However, the technology was not developed enough to be reliable.As in Europe, the usage of internal combustion engines advanced more readily in self-propelled railcars than in locomotives. Some Australian railway companies bought. In the 1920s and 1930s, more reliable Gasoline railmotors were built by Australian industries.
Australia's first diesel railcars were the NSWGR 100 Class (PH later DP) Silver City Comet cars in 1937. High-speed vehicles for those days' possibilities on ( 1,067 mm) were the 10 of 1940 for New Zealand.
A diesel–mechanical with a under the cab.The mechanical transmissions used for railroad propulsion are generally more complex and much more robust than standard-road versions. There is usually a interposed between the engine and gearbox, and the gearbox is often of the type to permit shifting while under load. Various systems have been devised to minimise the break in transmission during gear changing; e.g., the S.S.S. (synchro-self-shifting) gearbox used by.Diesel–mechanical propulsion is limited by the difficulty of building a reasonably sized transmission capable of coping with the power and required to move a heavy train. A number of attempts to use diesel–mechanical propulsion in high power applications have been made (e.g., the 1,500 kW (2,000 hp) locomotive), although none have proved successful in the end.
Schematic diagram of diesel–electric locomotiveIn a diesel–electric locomotive, the diesel engine drives either an electrical (generally, less than 3,000 horsepower (2,200 kW) net for traction), or an electrical (generally 3,000 horsepower (2,200 kW) net or more for traction), the output of which provides power to the that drive the locomotive. There is no mechanical connection between the diesel engine and the wheels.The important components of diesel–electric propulsion are the diesel engine (also known as the ), the main generator/alternator-rectifier, traction motors (usually with four or six axles), and a control system consisting of the engine and electrical or electronic components, including, and other components, which control or modify the electrical supply to the traction motors. In the most elementary case, the generator may be directly connected to the motors with only very simple switchgear. Soviet locomotiveOriginally, the traction motors and generator were machines.
Following the development of high-capacity in the 1960s, the DC generator was replaced by an using a to convert its output to DC. This advance greatly improved locomotive reliability and decreased generator maintenance costs by elimination of the and in the generator. Elimination of the brushes and commutator, in turn, disposed of the possibility of a particularly destructive type of event referred to as a, which could result in immediate generator failure and, in some cases, start an engine room fire.Current North American practice is for four axles for high-speed passenger or 'time' freight, or for six axles for lower-speed or 'manifest' freight.
The most modern units on 'time' freight service tend to have six axles underneath the frame. Unlike those in 'manifest' service, 'time' freight units will have only four of the axles connected to traction motors, with the other two as idler axles for weight distribution.In the late 1980s, the development of high-power (VVVF) drives, or 'traction inverters,' allowed the use of polyphase AC traction motors, thus also eliminating the motor commutator and brushes. The result is a more efficient and reliable drive that requires relatively little maintenance and is better able to cope with overload conditions that often destroyed the older types of motors. Model S-3 produced in 1957 for the adhering to designs by.A diesel–electric locomotive's power output is independent of road speed, as long as the unit's generator current and voltage limits are not exceeded. Therefore, the unit's ability to develop (also referred to as drawbar pull or, which is what actually propels the train) will tend to inversely vary with speed within these limits.
(See power curve below). Maintaining acceptable operating parameters was one of the principal design considerations that had to be solved in early diesel–electric locomotive development and, ultimately, led to the complex control systems in place on modern units.Throttle operation. Cab of the Russian locomotive U, 11 — throttleThe prime mover's output is primarily determined by its rotational speed and fuel rate, which are regulated by a or similar mechanism.
The governor is designed to react to both the throttle setting, as determined by the engine driver and the speed at which the prime mover is running (see ).Locomotive power output, and thus speed, is typically controlled by the engine driver using a stepped or 'notched' that produces -like electrical signals corresponding to throttle position. This basic design lends itself well to (MU) operation by producing discrete conditions that assure that all units in a respond in the same way to throttle position. Binary encoding also helps to minimize the number of (electrical connections) that are required to pass signals from unit to unit. For example, only four trainlines are required to encode all possible throttle positions if there are up to 14 stages of throttling.North American locomotives, such as those built by or, have nine throttle positions, one idle and eight power (as well as an emergency stop position that shuts down the prime mover). Many -built locomotives have a ten-position throttle. The power positions are often referred to by locomotive crews depending upon the throttle setting, such as 'run 3' or 'notch 3'.In older locomotives, the throttle mechanism was so that it was not possible to advance more than one power position at a time. The engine driver could not, for example, pull the throttle from notch 2 to notch 4 without stopping at notch 3.
This feature was intended to prevent rough train handling due to abrupt power increases caused by rapid throttle motion ('throttle stripping', an operating rules violation on many railroads). Modern locomotives no longer have this restriction, as their control systems are able to smoothly modulate power and avoid sudden changes in loading regardless of how the engine driver operates the controls.When the throttle is in the idle position, the prime mover will be receiving minimal fuel, causing it to idle at low RPM. In addition, the traction motors will not be connected to the main generator and the generator's field windings will not be excited (energized) — the generator will not produce electricity with no excitation.
Therefore, the locomotive will be in 'neutral'. Conceptually, this is the same as placing an automobile's transmission into neutral while the engine is running.To set the locomotive in motion, the is placed into the correct position (forward or reverse), the is released and the throttle is moved to the run 1 position (the first power notch).
An experienced engine driver can accomplish these steps in a coordinated fashion that will result in a nearly imperceptible start. The positioning of the reverser and movement of the throttle together is conceptually like shifting an automobile's automatic transmission into gear while the engine is idlingPlacing the throttle into the first power position will cause the traction motors to be connected to the main generator and the latter's field coils to be excited.
With excitation applied, the main generator will deliver electricity to the traction motors, resulting in motion. If the locomotive is running 'light' (that is, not coupled to the rest of a train) and is not on an ascending grade, it will easily accelerate. On the other hand, if a long train is being started, the locomotive may stall as soon as some of the slack has been taken up, as the drag imposed by the train will exceed the tractive force being developed. An experienced engine driver will be able to recognize an incipient stall and will gradually advance the throttle as required to maintain the pace of acceleration.As the throttle is moved to higher power notches, the fuel rate to the prime mover will increase, resulting in a corresponding increase in RPM and horsepower output. At the same time, main generator field excitation will be proportionally increased to absorb the higher power. This will translate into increased electrical output to the traction motors, with a corresponding increase in tractive force.
Left corridor of power compartment of Russian locomotive U, 3 — alternator, 4 — rectifier, 6 — dieselA locomotive's control system is designed so that the main generator output is matched to any given engine speed. Given the innate characteristics of traction motors, as well as the way in which the motors are connected to the main generator, the generator will produce high current and low voltage at low locomotive speeds, gradually changing to low current and high voltage as the locomotive accelerates. Therefore, the net power produced by the locomotive will remain constant for any given throttle setting ( see power curve graph for notch 8).In older designs, the prime mover's governor and a companion device, the load regulator, play a central role in the control system. The governor has two external inputs: requested engine speed, determined by the engine driver's throttle setting, and actual engine speed.
The governor has two external control outputs: setting, which determines the engine fuel rate, and load regulator position, which affects main generator excitation. The governor also incorporates a separate overspeed protective mechanism that will immediately cut off the fuel supply to the injectors and sound an alarm in the in the event the prime mover exceeds a defined RPM. Not all of these inputs and outputs are necessarily electrical.The load regulator is essentially a large that controls the main generator power output by varying its field excitation and hence the degree of loading applied to the engine. The load regulator's job is relatively complex, because although the prime mover's power output is proportional to RPM and fuel rate, the main generator's output is not (which characteristic was not correctly handled by the elevator- and hoist-type drive system that was initially tried in early locomotives). Instead, a quite complex electro-hydraulic governor was employed. Today, this important function would be performed by the Engine control unit, itself being a part of the Locomotive control unit. An supercharged 12-cylinder diesel engine (square 'hand holes'), stored pending rebuild, and missing some components, most notably the two, with a 16-567C or D 16-cylinder engine (round 'hand holes').As the load on the engine changes, its rotational speed will also change.
This is detected by the governor through a change in the engine speed feedback signal. The net effect is to adjust both the fuel rate and the load regulator position so that engine RPM and (and thus power output) will remain constant for any given throttle setting, regardless of actual road speed.In newer designs controlled by a “traction computer,” each engine speed step is allotted an appropriate power output, or “kW reference”, in software. The computer compares this value with actual main generator power output, or “kW feedback”, calculated from traction motor current and main generator voltage feedback values.
The computer adjusts the feedback value to match the reference value by controlling the excitation of the main generator, as described above. The governor still has control of engine speed, but the load regulator no longer plays a central role in this type of control system. However, the load regulator is retained as a “back-up” in case of engine overload.
Modern locomotives fitted with (EFI) may have no mechanical governor; however, a “virtual” load regulator and governor are retained with computer modules.Traction motor performance is controlled either by varying the DC voltage output of the main generator, for DC motors, or by varying the frequency and voltage output of the for AC motors. With DC motors, various connection combinations are utilized to adapt the drive to varying operating conditions.At standstill, main generator output is initially low voltage/high current, often in excess of 1000 per motor at full power.
When the locomotive is at or near standstill, current flow will be limited only by the DC resistance of the motor windings and interconnecting circuitry, as well as the capacity of the main generator itself. Torque in a is approximately proportional to the square of the current. Hence, the traction motors will produce their highest torque, causing the locomotive to develop maximum, enabling it to overcome the inertia of the train.
This effect is analogous to what happens in an automobile at start-up, where it is in first gear and thus producing maximum torque multiplication.As the locomotive accelerates, the now-rotating motor armatures will start to generate a (back EMF, meaning the motors are also trying to act as generators), which will oppose the output of the main generator and cause traction motor current to decrease. Main generator voltage will correspondingly increase in an attempt to maintain motor power, but will eventually reach a plateau. At this point, the locomotive will essentially cease to accelerate, unless on a downgrade. Since this plateau will usually be reached at a speed substantially less than the maximum that may be desired, something must be done to change the drive characteristics to allow continued acceleration. This change is referred to as 'transition,' a process that is analogous to shifting gears in an automobile.Transition methods include:. Series / Parallel or 'motor transition'.
Initially, pairs of motors are connected in series across the main generator. At higher speed, motors are reconnected in parallel across the main generator. 'Field shunting', 'field diverting', or 'weak fielding'. Resistance is connected in parallel with the motor field.
This has the effect of increasing the current, producing a corresponding increase in motor torque and speed.Both methods may also be combined, to increase the operating speed range. Generator / rectifier transition. Reconnecting the two separate internal main generator of two rectifiers from parallel to series to increase the output voltage.In older locomotives, it was necessary for the engine driver to manually execute transition by use of a separate control. As an aid to performing transition at the right time, the (an indicator that shows the engine driver how much current is being drawn by the traction motors) was calibrated to indicate at which points forward or backward transition should take place. Automatic transition was subsequently developed to produce better-operating efficiency and to protect the main generator and traction motors from overloading from improper transition.Modern locomotives incorporate traction inverters, AC to DC, capable of delivering 1,200 volts (earlier traction generators, DC to DC, were capable of delivering only 600 volts). This improvement was accomplished largely through improvements in silicon diode technology.
With the capability of delivering 1,200 volts to the traction motors, the need for 'transition' was eliminated.Dynamic braking. Main article:A common option on diesel–electric locomotives is.Dynamic braking takes advantage of the fact that the armatures are always rotating when the locomotive is in motion and that a motor can be made to act as a by separately exciting the field winding. When dynamic braking is utilized, the traction control circuits are configured as follows:. The field winding of each traction motor is connected across the main generator. The armature of each traction motor is connected across a forced-air-cooled (the dynamic braking grid) in the roof of the locomotive's hood.
The prime mover RPM is increased and the main generator field is excited, causing a corresponding excitation of the traction motor fields.The aggregate effect of the above is to cause each traction motor to generate electric power and dissipate it as heat in the dynamic braking grid. A fan connected across the grid provides forced-air cooling. Consequently, the fan is powered by the output of the traction motors and will tend to run faster and produce more airflow as more energy is applied to the grid.Ultimately, the source of the energy dissipated in the dynamic braking grid is the motion of the locomotive as imparted to the traction motor armatures.
Therefore, the traction motors impose drag and the locomotive acts as a brake. As speed decreases, the braking effect decays and usually becomes ineffective below approximately 16 km/h (10 mph), depending on the gear ratio between the traction motors and.Dynamic braking is particularly beneficial when operating in mountainous regions; where there is always the danger of a runaway due to overheated friction brakes during descent. In such cases, dynamic brakes are usually applied in conjunction with the, the combined effect being referred to as. The use of blended braking can also assist in keeping the slack in a long train stretched as it crests a grade, helping to prevent a 'run-in', an abrupt bunching of train slack that can cause a derailment. Blended braking is also commonly used with to reduce wear and tear on the mechanical brakes that is a natural result of the numerous stops such trains typically make during a run.Electro-diesel. Main article:These special locomotives can operate as an or as a diesel locomotive.
The, and operate dual-mode diesel–electric/third-rail ( on NJTransit) locomotives between non-electrified territory and because of a local law banning diesel-powered locomotives in tunnels. For the same reason, operates a fleet of dual-mode locomotives in the New York area. Operated dual diesel–electric/electric locomotives designed to run primarily as electric locomotives with reduced power available when running on diesel power. This allowed railway yards to remain un-electrified, as the third rail power system is extremely hazardous in a yard area.Diesel–hydraulicDiesel–hydraulic locomotives use one or more, in combination with gears, with a mechanical final drive to convey the power from the diesel engine to the wheels.Hydrostatic transmissionHydraulic drive systems using a hydrostatic have been applied to rail use.
Modern examples included 350 to 750 hp (260 to 560 kW) shunting locomotives by (Belgium), 4 to 12 tonne 35 to 58 kW (47 to 78 hp) narrow gauge industrial locomotives by subsidiary GIA. Hydrostatic drives are also utilised in railway maintenance machines (tampers, rail grinders).Application of hydrostatic transmissions is generally limited to small shunting locomotives and rail maintenance equipment, as well as being used for non-tractive applications in diesel engines such as drives for traction motor fans.
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Hydrokinetic transmission. A Henschel (Germany) diesel–hydraulic locomotive in,Hydrokinetic transmission (also called hydrodynamic transmission) uses a. A torque converter consists of three main parts, two of which rotate, and one (the ) that has a lock preventing backwards rotation and adding output torque by redirecting the oil flow at low output RPM. All three main parts are sealed in an oil-filled housing. To match engine speed to load speed over the entire speed range of a locomotive some additional method is required to give sufficient range.
One method is to follow the torque converter with a mechanical gearbox which switches ratios automatically, similar to an automatic transmission in an automobile. Another method is to provide several torque converters each with a range of variability covering part of the total required; all the torque converters are mechanically connected all the time, and the appropriate one for the speed range required is selected by filling it with oil and draining the others. The filling and draining is carried out with the transmission under load, and results in very smooth range changes with no break in the transmitted power.Locomotives. British Rail diesel–hydraulic locomotives:, andDiesel-hydraulic locomotives are less efficient than diesel–electrics. The first-generation BR diesel hydraulics were significantly less efficient (c. 65%) than diesel electrics (c.
80%)Moreover, initial versions were found in many countries to be mechanically more complicated and more likely to break down. Hydraulic transmission for locomotives was developed in Germany. There is still debate over the relative merits of hydraulic vs. Electrical transmission systems: advantages claimed for hydraulic systems include lower weight, high reliability, and lower capital cost. By the 21st century, for diesel locomotive traction worldwide the majority of countries used diesel–electric designs, with diesel-hydraulic designs not found in use outside Germany and Japan, and some neighbouring states, where it is used in designs for freight work.In Germany and Finland, diesel–hydraulic systems have achieved high reliability in operation. In the UK the diesel–hydraulic principle gained a poor reputation due to the poor durability and reliability of the Maybach hydraulic transmission. Argument continues over the relative reliability of hydraulic systems, with questions over whether data has been manipulated to favour local suppliers over non-German ones.
Multiple unitsDiesel–hydraulic drive is common in multiple units, with various transmission designs used including torque converters, and in combination with mechanical gearing.The majority of 's second generation passenger DMU stock used hydraulic transmission. In the 21st century, designs using hydraulic transmission include 's, families; diesel engined versions of 's platform, and the.Examples. A diesel–hydraulic locomotiveDiesel–hydraulic locomotives have a smaller market share than those with diesel-electric transmission - the main worldwide user of main-line hydraulic transmissions was the, with designs including the 1950s, and the 1960 and 1970s. Introduced a number of diesel-hydraulic designs during it, initially license-built versions of German designs (see ). In Spain, used high power to weight ratio twin-engine German designs to haul high speed trains from the 1960s to 1990s. (See, )Other main-line locomotives of the post-war period included the 1950s experimental locomotives; the built; in the 1960s bought 18 Krauss-Maffei diesel–hydraulic locomotives.
The also bought three, all of which were later sold to SP.In Finland, over 200 Finnish-built VR class and Dr14 diesel–hydraulics with transmissions have been continuously used since the early 1960s. All units of Dr14 class and most units of Dv12 class are still in service. VR has abandoned some weak-conditioned units of 2700 series Dv12s.In the 21st century series production standard gauge diesel–hydraulic designs include the, ordered by, and the, and designs, all manufactured in Germany for freight use.Diesel–steam. Main article:Steam-diesel hybrid locomotives can use steam generated from a boiler or diesel to power a piston engine. The Cristiani Compressed Steam System used a diesel engine to power a compressor to drive and recirculate steam produced by a boiler; effectively using steam as the power transmission medium, with the diesel engine being the Diesel–pneumaticThe diesel-pneumatic locomotive was of interest in the 1930s because it offered the possibility of converting existing steam locomotives to diesel operation. The frame and cylinders of the steam locomotive would be retained and the boiler would be replaced by a diesel engine driving an.
The problem was low because of the large amount of energy wasted as heat in the air compressor. Attempts were made to compensate for this by using the diesel exhaust to re-heat the compressed air but these had limited success. A German proposal of 1929 did result in a prototype but a similar British proposal of 1932, to use an locomotive, never got beyond the design stage. Diesel–electric locomotive built by EMD for service in the UK and continental Europe.Most diesel locomotives are capable of (MU) as a means of increasing and when hauling heavy trains. All locomotives, including export models, use a standardized electrical control system interconnected by a 27-pin between the units. For UK-built locomotives, a number of incompatible control systems are used, but the most common is the Blue Star system, which is electro-pneumatic and fitted to most early diesel classes. A small number of types, typically higher-powered locomotives intended for passenger only work, do not have multiple control systems.
In all cases, the electrical control connections made common to all units in a are referred to as.The result is that all locomotives in a behave as one in response to the engine driver's control movements.The ability to couple diesel–electric locomotives in an MU fashion was first introduced in the four-unit demonstrator that toured the United States in 1939. At the time, American railroad work rules required that each operating locomotive in a train had to have on board a full crew. Circumvented that requirement by coupling the individual units of the demonstrator with instead of conventional and declaring the combination to be a single locomotive. Electrical interconnections were made so one engine driver could operate the entire consist from the head-end unit. Later on, work rules were amended and the semi-permanent coupling of units with drawbars was eliminated in favour of couplers, as servicing had proved to be somewhat cumbersome owing to the total length of the consist (about 200 feet or nearly 61 meters).In mountainous regions, it is common to interpose in the middle of the train, both to provide the extra power needed to ascend a grade and to limit the amount of applied to the of the car coupled to the head-end power. The helper units in such configurations are controlled from the lead unit's cab through coded radio signals. Although this is technically not an MU configuration, the behaviour is the same as with physically interconnected units.Cab arrangementsCab arrangements vary by builder and operator.
Practice in the U.S. Has traditionally been for a cab at one end of the locomotive with limited visibility if the locomotive is not operated cab forward. This is not usually a problem as U.S. Locomotives are usually operated in pairs, or threes, and arranged so that a cab is at each end of each set. European practice is usually for a cab at each end of the locomotive as trains are usually light enough to operate with one locomotive. Practice was to add power units without cabs (booster or ) and the arrangement was often A-B, A-A, A-B-A, A-B-B, or A-B-B-A where A was a unit with a cab. Center cabs were sometimes used for switch locomotives.Cow-calf.
Main article:In North American railroading, a set is a pair of switcher-type locomotives: one (the cow) equipped with a driving cab, the other (the calf) without a cab, and controlled from the cow through cables. Cow-calf sets are used in heavy switching and service.
Some are radio controlled without an operating engineer present in the cab. This arrangement is also known as. Fittings and appliances FlameproofingA standard diesel locomotive presents a very low fire risk but “flame proofing” can reduce the risk even further. This involves fitting a water-filled box to the exhaust pipe to quench any red-hot carbon particles that may be emitted.
Other precautions may include a fully insulated electrical system (neither side earthed to the frame) and all electric wiring enclosed in conduit.The flameproof diesel locomotive has replaced the in areas of high fire risk such as. Preserved examples of flameproof diesel locomotives include:. Francis Baily of Thatcham (ex-) at. Naworth (ex-) at theLatest development of the 'Flameproof Diesel Vehicle Applied New Exhaust Gas Dry Type Treatment System” does not need the water supply. See also:Although diesel locomotives generally emit less sulphur dioxide, a major to the environment, and greenhouse gases than steam locomotives, they are not completely clean in that respect. Furthermore, like other diesel powered vehicles, they emit and, which are a risk to public health.
In fact, in this last respect diesel locomotives may perform worse than steam locomotives.For years, it was thought by American government scientists who measure that diesel locomotive engines were relatively clean and emitted far less health-threatening emissions than those of diesel trucks or other vehicles; however, the scientists discovered that because they used faulty estimates of the amount of fuel consumed by diesel locomotives, they grossly understated the amount of pollution generated annually. After revising their calculations, they concluded that the annual emissions of nitrogen oxide, a major ingredient in and, and soot would be by 2030 nearly twice what they originally assumed. In Europe, where most major railways have been electrified, there is less concern.This would mean that diesel locomotives would be releasing more than 800,000 tons of nitrogen oxide and 25,000 tons of soot every year within a quarter of a century, in contrast to the EPA's previous projections of 480,000 tons of and 12,000 tons of soot. Since this was discovered, to reduce the effects of the diesel locomotive on (who are breathing the noxious emissions) and on and, it is considered practical to install traps in the diesel engines to reduce pollution levels and other forms (e.g., use of ).Diesel locomotive pollution has been of particular concern in the city of. The Chicago Tribune reported levels of diesel soot inside locomotives leaving Chicago at levels hundreds of times above what is normally found on streets outside.
Residents of several neighborhoods are most likely exposed to diesel emissions at levels several times higher than the national average for urban areas. MitigationIn 2008, the (EPA) mandated regulations requiring all new or refurbished diesel locomotives to meet pollution standards that slash the amount of allowable soot by 90% and require an 80% reduction in emissions. See.Other technologies that are being deployed to reduce locomotive emissions and fuel consumption include 'Genset' switching locomotives and hybrid designs. Genset locomotives use multiple smaller high-speed diesel engines and generators (generator sets), rather than a single medium-speed diesel engine and a single generator. Because of the cost of developing clean engines, these smaller high-speed engines are based on already developed truck engines. Green Goats are a type of switching locomotive utilizing a small diesel engine and a large bank of rechargeable batteries.
Switching locomotives are of particular concern as they typically operate in a limited area, often in or near urban centers, and spend much of their time idling. Both designs reduce pollution below EPA Tier II standards and cut or eliminate emissions during idle. Advantages over steamAs diesel locomotives advanced, the cost of manufacturing and operating them dropped, and they became cheaper to own and operate than steam locomotives. In North America, were custom-made for specific railway routes, so economies of scale were difficult to achieve. Though more complex to produce with exacting manufacturing tolerances ( 1⁄ 10000-inch or 0.0025-millimetre for diesel, compared with 1⁄ 100-inch (0.25 mm) for steam), diesel locomotive parts were easier to mass-produce. Offered almost five hundred steam models in its heyday, while offered fewer than ten diesel varieties. In the United Kingdom, built steam locomotives to standard designs from 1951 onwards.
These included standard, interchangeable parts, making them cheaper to produce than the diesel locomotives then available. The capital cost per was £13 6s (steam), £65 (diesel), £69 7s (turbine) and £17 13s (electric).Diesel locomotives offer significant operating advantages over steam locomotives. They can safely be operated by one person, making them ideal for switching/shunting duties in yards (although for safety reasons many main-line diesel locomotives continue to have two-person crews: an engineer and a conductor/switchman) and the operating environment is much more attractive, being quieter, fully weatherproof and without the dirt and heat that is an inevitable part of operating a steam locomotive. Diesel locomotives can be worked with a single crew controlling multiple locomotives in a single train — something not practical with steam locomotives. This brought greater efficiencies to the operator, as individual locomotives could be relatively low-powered for use as a single unit on light duties but marshaled together to provide the power needed on a heavy train.
With steam traction, a single very powerful and expensive locomotive was required for the heaviest trains or the operator resorted to with multiple locomotives and crews, a method which was also expensive and brought with it its own operating difficulties.Diesel engines can be started and stopped almost instantly, meaning that a diesel locomotive has the potential to incur no fuel costs when not being used. However, it is still the practice of large North American railroads to use straight water as a coolant in diesel engines instead of coolants that incorporate anti-freezing properties; this results in diesel locomotives being left idling when parked in cold climates instead of being completely shut down. A diesel engine can be left idling unattended for hours or even days, especially since practically every diesel engine used in locomotives has systems that automatically shut the engine down if problems such as a loss of oil pressure or coolant loss occur. Automatic start/stop systems are available which monitor coolant and engine temperatures. When the unit is close to having its coolant freeze, the system restarts the diesel engine to warm the coolant and other systems.Steam locomotives require intensive maintenance, lubrication, and cleaning before, during, and after use. Preparing and firing a steam locomotive for use from cold can take many hours. They can be kept in readiness between uses with a low fire, but this requires regular stoking and frequent attention to maintain the level of water in the boiler.
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This may be necessary to prevent the water in the boiler freezing in cold climates, so long as the water supply is not frozen.The maintenance and operational costs of steam locomotives were much higher than diesels. Annual maintenance costs for steam locomotives accounted for 25% of the initial purchase price. Spare parts were cast from wooden masters for specific locomotives. The sheer number of unique steam locomotives meant that there was no feasible way for spare-part inventories to be maintained.
With diesel locomotives spare parts could be mass-produced and held in stock ready for use and many parts and sub-assemblies could be standardized across an operator's fleet using different models of locomotive from the same builder. Modern diesel locomotive engines are designed to allow the power assemblies (systems of working parts and their block interfaces) to be replaced while keeping the main block in the locomotive, which greatly reduces the time that a locomotive is out of revenue-generating service when it requires maintenance.Steam engines required large quantities of coal and water, which were expensive variable operating costs. Further, the of steam was considerably less than that of diesel engines. Diesel's theoretical studies demonstrated potential thermal efficiencies for a compression ignition engine of 36% (compared with 6–10% for steam), and an 1897 one-cylinder prototype operated at a remarkable 26% efficiency.However, one study published in 1959 suggested that many of the comparisons between diesel and steam locomotives were made unfairly. Mostly because diesels were newer. After painstaking analysis of financial records and technological progress, the author found that if research had continued on steam technology instead of diesel, there would be negligible financial benefit in converting to diesel locomotion.By the mid-1960s, diesel locomotives had effectively replaced steam locomotives where electric traction was not in use.
Attempts to develop continue in the 21st century, but have not had a significant effect.
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