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109-635: Tatra KT8D5 is a bidirectional light rail vehicle currently (November 2024, and not expected to retire soon) operating in Europe and Asia. In several variations, it was designed and manufactured by Czech engineering corporation ČKD Tatra from 1984 to 1999 and a total of 206 cars were sold. The vehicle has an angular design similar to Tatra T6A5 , Tatra RT8D5M , and Tatra KT4 both outside and inside. During its production period, several versions of KT8D5 were sold. The need for new generation vehicles for Czechoslovakia started in late 1970s. The original goal

218-430: A rail ). For railroads, this is called curve resistance but for roads it has (at least once) been called rolling resistance due to cornering . Rolling friction generates sound (vibrational) energy, as mechanical energy is converted to this form of energy due to the friction. One of the most common examples of rolling friction is the movement of motor vehicle tires on a roadway , a process which generates sound as

327-407: A rubber tire will have higher rolling resistance on a paved road than a steel railroad wheel on a steel rail. Also, sand on the ground will give more rolling resistance than concrete . Sole rolling resistance factor is not dependent on speed. The primary cause of pneumatic tire rolling resistance is hysteresis : A characteristic of a deformable material such that the energy of deformation

436-399: A tractive force equal to 70% of the maximum traction, slip resistance becomes 10 times larger than the basic rolling resistance. In order to apply any traction to the wheels, some slippage of the wheel is required. For trains climbing up a grade, this slip is normally 1.5% to 2.5%. Slip (also known as creep ) is normally roughly directly proportional to tractive effort . An exception

545-622: A tram engine in the UK) at the head of a line of one or more carriages, similar to a small train. Systems with such steam trams included Christchurch , New Zealand; Sydney, Australia; other city systems in New South Wales ; Munich , Germany (from August 1883 on), British India (from 1885) and the Dublin & Blessington Steam Tramway (from 1888) in Ireland. Steam tramways also were used on

654-450: A 20% increase in load decreases Crr by 3%. But, if the inflation pressure is not changed, then a 20% increase in load results in a 4% increase in Crr. Of course, this will increase the rolling resistance by 20% due to the increase in load plus 1.2 x 4% due to the increase in Crr resulting in a 24.8% increase in rolling resistance. When a vehicle ( motor vehicle or railroad train ) goes around

763-434: A 5% slip can translate into a 200% increase in rolling resistance. This is partly because the tractive force applied during this slip is many times greater than the rolling resistance force and thus much more power per unit velocity is being applied (recall power = force x velocity so that power per unit of velocity is just force). So just a small percentage increase in circumferential velocity due to slip can translate into

872-432: A Crr of 0.00013 (axle load of 21 tonnes). For empty freight cars with axle loads of 5.5 tonnes, Crr goes up to 0.00020 at 60 km/h but at a low speed of 20 km/h it increases to 0.00024 and at a high speed (for freight trains) of 120 km/h it is 0.00028. The Crr obtained above is added to the Crr of the other components to obtain the total Crr for the wheels. The rolling resistance of steel wheels on steel rail of

981-520: A Vermont blacksmith, had invented a battery-powered electric motor which he later patented. The following year he used it to operate a small model electric car on a short section of track four feet in diameter. Attempts to use batteries as a source of electricity were made from the 1880s and 1890s, with unsuccessful trials conducted in among other places Bendigo and Adelaide in Australia, and for about 14 years as The Hague accutram of HTM in

1090-401: A by-product. The sound generated by automobile and truck tires as they roll (especially noticeable at highway speeds) is mostly due to the percussion of the tire treads, and compression (and subsequent decompression) of air temporarily captured within the treads. Several factors affect the magnitude of rolling resistance a tire generates: In a broad sense rolling resistance can be defined as

1199-554: A car of 1000 kg on asphalt will need a force of around 100  newtons for rolling (1000 kg × 9.81 m/s × 0.01 = 98.1 N). According to Dupuit (1837), rolling resistance (of wheeled carriages with wooden wheels with iron tires) is approximately inversely proportional to the square root of wheel diameter. This rule has been experimentally verified for cast iron wheels (8″ - 24″ diameter) on steel rail and for 19th century carriage wheels. But there are other tests on carriage wheels that do not agree. Theory of

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1308-484: A coefficient (ratio)or a multiple thereof. If using pounds or kilograms as force units, mass is equal to weight (in earth's gravity a kilogram a mass weighs a kilogram and exerts a kilogram of force) so one could claim that C r r {\displaystyle C_{rr}} is also the force per unit mass in such units. The SI system would use N/tonne (N/T, N/t), which is 1000 g C r r {\displaystyle 1000gC_{rr}} and

1417-404: A curve, rolling resistance usually increases. If the curve is not banked so as to exactly counter the centrifugal force with an equal and opposing centripetal force due to the banking, then there will be a net unbalanced sideways force on the vehicle. This will result in increased rolling resistance. Banking is also known as "superelevation" or "cant" (not to be confused with rail cant of

1526-409: A cylinder rolling on an elastic roadway also gives this same rule These contradict earlier (1785) tests by Coulomb of rolling wooden cylinders where Coulomb reported that rolling resistance was inversely proportional to the diameter of the wheel (known as "Coulomb's law"). This disputed (or wrongly applied) -"Coulomb's law" is still found in handbooks, however. For pneumatic tires on hard pavement, it

1635-436: A faster rate as the torque becomes higher. The rolling resistance coefficient, Crr, significantly decreases as the weight of the rail car per wheel increases. For example, an empty freight car had about twice the Crr as a loaded car (Crr=0.002 vs. Crr=0.001). This same "economy of scale" shows up in testing of mine rail cars. The theoretical Crr for a rigid wheel rolling on an elastic roadbed shows Crr inversely proportional to

1744-417: A loss of traction power which may even exceed the power loss due to basic (ordinary) rolling resistance. For railroads, this effect may be even more pronounced due to the low rolling resistance of steel wheels. It is shown that for a passenger car, when the tractive force is about 40% of the maximum traction, the slip resistance is almost equal to the basic rolling resistance (hysteresis loss). But in case of

1853-726: A similar technology, Pirotsky put into service the first public electric tramway in St. Petersburg, which operated only during September 1880. The second demonstration tramway was presented by Siemens & Halske at the 1879 Berlin Industrial Exposition. The first public electric tramway used for permanent service was the Gross-Lichterfelde tramway in Lichterfelde near Berlin in Germany, which opened in 1881. It

1962-883: A slow rigid wheel on a perfectly elastic surface, not adjusted for velocity, can be calculated by C r r = z / d {\displaystyle C_{rr}={\sqrt {z/d}}} where The empirical formula for C r r {\displaystyle C_{rr}} for cast iron mine car wheels on steel rails is: C r r = 0.0048 ( 18 / D ) 1 2 ( 100 / W ) 1 4 = 0.0643988 W D 2 4 {\displaystyle C_{rr}=0.0048(18/D)^{\frac {1}{2}}(100/W)^{\frac {1}{4}}={\frac {0.0643988}{\sqrt[{4}]{WD^{2}}}}} where As an alternative to using C r r {\displaystyle C_{rr}} one can use b {\displaystyle b} , which

2071-400: A tonne. This lighter weight per passenger, combined with the lower rolling resistance of steel wheels on steel rail means that an N700 Shinkansen is much more energy efficient than a typical automobile. In the case of freight, CSX ran an advertisement campaign in 2013 claiming that their freight trains move "a ton of freight 436 miles on a gallon of fuel", whereas some sources claim trucks move

2180-408: A train is far less than that of the rubber tires wheels of an automobile or truck. The weight of trains varies greatly; in some cases they may be much heavier per passenger or per net ton of freight than an automobile or truck, but in other cases they may be much lighter. As an example of a very heavy passenger train, in 1975, Amtrak passenger trains weighed a little over 7 tonnes per passenger, which

2289-946: A well-known tourist attraction . A single cable line also survives in Wellington (rebuilt in 1979 as a funicular but still called the " Wellington Cable Car "). Another system, with two separate cable lines and a shared power station in the middle, operates from the Welsh town of Llandudno up to the top of the Great Orme hill in North Wales , UK. Hastings and some other tramways, for example Stockholms Spårvägar in Sweden and some lines in Karachi , used petrol trams. Galveston Island Trolley in Texas operated diesel trams due to

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2398-553: Is a different rolling resistance coefficient or coefficient of rolling friction with dimension of length. It is defined by the following formula: F = N b r {\displaystyle F={\frac {Nb}{r}}} where The above equation, where resistance is inversely proportional to radius r {\displaystyle r} seems to be based on the discredited "Coulomb's law" (Neither Coulomb's inverse square law nor Coulomb's law of friction) . See dependence on diameter . Equating this equation with

2507-413: Is assumed that all wheels are the same and bear identical weight. Thus:   C r r = 0.01 {\displaystyle \ C_{rr}=0.01} means that it would only take 0.01 pounds to tow a vehicle weighing one pound. For a 1000-pound vehicle, it would take 1000 times more tow force, i.e. 10 pounds. One could say that C r r {\displaystyle C_{rr}}

2616-434: Is done in this article. They just sum up all the resistance forces (including aerodynamic drag) and call the sum basic train resistance (or the like). Since railroad rolling resistance in the broad sense may be a few times larger than just the pure rolling resistance reported values may be in serious conflict since they may be based on different definitions of "rolling resistance". The train's engines must, of course, provide

2725-529: Is force per unit mass, where g is the acceleration of gravity in SI units (meters per second square). The above shows resistance proportional to C r r {\displaystyle C_{rr}} but does not explicitly show any variation with speed, loads , torque , surface roughness, diameter , tire inflation/wear, etc., because C r r {\displaystyle C_{rr}} itself varies with those factors. It might seem from

2834-429: Is greater than the energy of recovery. The rubber compound in a tire exhibits hysteresis. As the tire rotates under the weight of the vehicle, it experiences repeated cycles of deformation and recovery, and it dissipates the hysteresis energy loss as heat. Hysteresis is the main cause of energy loss associated with rolling resistance and is attributed to the viscoelastic characteristics of the rubber. This main principle

2943-442: Is if the tractive effort is so high that the wheel is close to substantial slipping (more than just a few percent as discussed above), then slip rapidly increases with tractive effort and is no longer linear. With a little higher applied tractive effort the wheel spins out of control and the adhesion drops resulting in the wheel spinning even faster. This is the type of slipping that is observable by eye—the slip of say 2% for traction

3052-407: Is illustrated in the figure of the rolling cylinders. If two equal cylinders are pressed together then the contact surface is flat. In the absence of surface friction, contact stresses are normal (i.e. perpendicular) to the contact surface. Consider a particle that enters the contact area at the right side, travels through the contact patch and leaves at the left side. Initially its vertical deformation

3161-420: Is in lb(tow-force)/lb(vehicle weight). Since this lb/lb is force divided by force, C r r {\displaystyle C_{rr}} is dimensionless. Multiply it by 100 and you get the percent (%) of the weight of the vehicle required to maintain slow steady speed. C r r {\displaystyle C_{rr}} is often multiplied by 1000 to get the parts per thousand, which

3270-433: Is in part due to the fact that there is some slipping of the wheel, and for pneumatic tires, there is more flexing of the sidewalls due to the torque. Slip is defined such that a 2% slip means that the circumferential speed of the driving wheel exceeds the speed of the vehicle by 2%. A small percentage slip can result in a slip resistance which is much larger than the basic rolling resistance. For example, for pneumatic tires,

3379-408: Is increasing, which is resisted by the hysteresis effect. Therefore, an additional pressure is generated to avoid interpenetration of the two surfaces. Later its vertical deformation is decreasing. This is again resisted by the hysteresis effect. In this case this decreases the pressure that is needed to keep the two bodies separate. The resulting pressure distribution is asymmetrical and is shifted to

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3488-428: Is largely dependent on the tractive force , coefficient of friction, normal load, etc. "Applied torque" may either be driving torque applied by a motor (often through a transmission ) or a braking torque applied by brakes (including regenerative braking ). Such torques results in energy dissipation (above that due to the basic rolling resistance of a freely rolling, i.e. except slip resistance). This additional loss

3597-520: Is located on two Jacobs bogies . The tram is bidirectional and has driving cabs at each end and doors on both sides. There are two pantographs, one located on the each end of vehicle. With a capacity of up to 231 passengers, these trams are operated on the busiest routes and during peak hours; due to their bidirectional capability they are also frequently used on routes without termini and during track maintenance for continued operation on only one track in both directions. A new medium low-floor cell based on

3706-501: Is much heavier than an average of a little over one ton per passenger for an automobile. This means that for an Amtrak passenger train in 1975, much of the energy savings of the lower rolling resistance was lost to its greater weight. An example of a very light high-speed passenger train is the N700 Series Shinkansen , which weighs 715 tonnes and carries 1323 passengers, resulting in a per-passenger weight of about half

3815-438: Is notable that slip does not occur in driven wheels, which are not subjected to driving torque, under different conditions except braking. Therefore, rolling resistance, namely hysteresis loss, is the main source of energy dissipation in driven wheels or axles, whereas in the drive wheels and axles slip resistance, namely loss due to wheel slip, plays the role as well as rolling resistance. Significance of rolling or slip resistance

3924-409: Is noteworthy that V s / Ω {\displaystyle V_{s}/\Omega } is usually not equal to the radius of the rolling body as a result of wheel slip. The slip between wheel and ground inevitably occurs whenever a driving or braking torque is applied to the wheel. Consequently, the linear speed of the vehicle differs from the wheel's circumferential speed. It

4033-489: Is often expressed as a coefficient times the normal force. This coefficient of rolling resistance is generally much smaller than the coefficient of sliding friction. Any coasting wheeled vehicle will gradually slow down due to rolling resistance including that of the bearings, but a train car with steel wheels running on steel rails will roll farther than a bus of the same mass with rubber tires running on tarmac/asphalt . Factors that contribute to rolling resistance are

4142-430: Is only observed by instruments. Such rapid slip may result in excessive wear or damage. Rolling resistance greatly increases with applied torque. At high torques, which apply a tangential force to the road of about half the weight of the vehicle, the rolling resistance may triple (a 200% increase). This is in part due to a slip of about 5%. The rolling resistance increase with applied torque is not linear, but increases at

4251-518: Is reported that the effect of diameter on rolling resistance is negligible (within a practical range of diameters). The driving torque T {\displaystyle T} to overcome rolling resistance R r {\displaystyle R_{r}} and maintain steady speed on level ground (with no air resistance) can be calculated by: T = V s Ω R r {\displaystyle T={\frac {V_{s}}{\Omega }}R_{r}} where It

4360-481: Is several times higher than the neglected resistances. The "rolling resistance coefficient" is defined by the following equation:   F = C r r N {\displaystyle \ F=C_{rr}N} where C r r {\displaystyle C_{rr}} is the force needed to push (or tow) a wheeled vehicle forward (at constant speed on a level surface, or zero grade, with zero air resistance) per unit force of weight. It

4469-640: Is still in operation in modernised form. The earliest tram system in Canada was built by John Joseph Wright , brother of the famous mining entrepreneur Whitaker Wright , in Toronto in 1883, introducing electric trams in 1892. In the US, multiple experimental electric trams were exhibited at the 1884 World Cotton Centennial World's Fair in New Orleans, Louisiana , but they were not deemed good enough to replace

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4578-508: Is the same as kilograms (kg force) per metric ton (tonne = 1000 kg ), which is the same as pounds of resistance per 1000 pounds of load or Newtons/kilo-Newton, etc. For the US railroads, lb/ton has been traditionally used; this is just 2000 C r r {\displaystyle 2000C_{rr}} . Thus, they are all just measures of resistance per unit vehicle weight. While they are all "specific resistances", sometimes they are just called "resistance" although they are really

4687-734: Is the sole survivor of the fleet). In Italy, in Trieste , the Trieste–Opicina tramway was opened in 1902, with the steepest section of the route being negotiated with the help of a funicular and its cables. Cable cars suffered from high infrastructure costs, since an expensive system of cables , pulleys , stationary engines and lengthy underground vault structures beneath the rails had to be provided. They also required physical strength and skill to operate, and alert operators to avoid obstructions and other cable cars. The cable had to be disconnected ("dropped") at designated locations to allow

4796-713: The Bleecker Street Line until its closure in 1917. Pittsburgh, Pennsylvania , had its Sarah Street line drawn by horses until 1923. The last regular mule-drawn cars in the US ran in Sulphur Rock, Arkansas , until 1926 and were commemorated by a U.S. postage stamp issued in 1983. The last mule tram service in Mexico City ended in 1932, and a mule tram in Celaya, Mexico , survived until 1954. The last horse-drawn tram to be withdrawn from public service in

4905-933: The Lamm fireless engines then propelling the St. Charles Avenue Streetcar in that city. The first commercial installation of an electric streetcar in the United States was built in 1884 in Cleveland, Ohio , and operated for a period of one year by the East Cleveland Street Railway Company. The first city-wide electric streetcar system was implemented in 1886 in Montgomery, Alabama , by the Capital City Street Railway Company, and ran for 50 years. In 1888,

5014-715: The Richmond Union Passenger Railway began to operate trams in Richmond, Virginia , that Frank J. Sprague had built. Sprague later developed multiple unit control, first demonstrated in Chicago in 1897, allowing multiple cars to be coupled together and operated by a single motorman. This gave rise to the modern subway train. Following the improvement of an overhead "trolley" system on streetcars for collecting electricity from overhead wires by Sprague, electric tram systems were rapidly adopted across

5123-824: The West Midlands Metro in Birmingham , England adopted battery-powered trams on sections through the city centre close to Grade I listed Birmingham Town Hall . Paris and Berne (Switzerland) operated trams that were powered by compressed air using the Mekarski system . Trials on street tramways in Britain, including by the North Metropolitan Tramway Company between Kings Cross and Holloway, London (1883), achieved acceptable results but were found not to be economic because of

5232-407: The (amount of) deformation of the wheels, the deformation of the roadbed surface, and movement below the surface. Additional contributing factors include wheel diameter , load on wheel , surface adhesion, sliding, and relative micro-sliding between the surfaces of contact. The losses due to hysteresis also depend strongly on the material properties of the wheel or tire and the surface. For example,

5341-1241: The 1850s, after which the "animal railway" became an increasingly common feature in the larger towns. The first permanent tram line in continental Europe was opened in Paris in 1855 by Alphonse Loubat who had previously worked on American streetcar lines. The tram was developed in numerous cities of Europe (some of the most extensive systems were found in Berlin, Budapest , Birmingham , Saint Petersburg , Lisbon , London , Manchester , Paris , Kyiv ). The first tram in South America opened in 1858 in Santiago, Chile . The first trams in Australia opened in 1860 in Sydney . Africa's first tram service started in Alexandria on 8 January 1863. The first trams in Asia opened in 1869 in Batavia (Jakarta), Netherlands East Indies (Indonesia) . Limitations of horsecars included

5450-713: The 1894-built horse tram at Victor Harbor in South Australia . New horse-drawn systems have been established at the Hokkaidō Museum in Japan and also in Disneyland . A horse-tram route in Polish gmina Mrozy , first built in 1902, was reopened in 2012. The first mechanical trams were powered by steam . Generally, there were two types of steam tram. The first and most common had a small steam locomotive (called

5559-420: The 1980s. The history of passenger trams, streetcars and trolley systems, began in the early nineteenth century. It can be divided into several distinct periods defined by the principal means of power used. Precursors to the tramway included the wooden or stone wagonways that were used in central Europe to transport mine carts with unflanged wheels since the 1500s, and the paved limestone trackways designed by

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5668-481: The Australian state of Queensland between 1909 and 1939. Stockholm , Sweden, had a steam tram line at the island of Södermalm between 1887 and 1901. Tram engines usually had modifications to make them suitable for street running in residential areas. The wheels, and other moving parts of the machinery, were usually enclosed for safety reasons and to make the engines quieter. Measures were often taken to prevent

5777-462: The British newspaper Newcastle Daily Chronicle reported that, "A large number of London's discarded horse tramcars have been sent to Lincolnshire where they are used as sleeping rooms for potato pickers ". Horses continued to be used for light shunting well into the 20th century, and many large metropolitan lines lasted into the early 20th century. New York City had a regular horsecar service on

5886-774: The Entertainment Centre, and work is progressing on further extensions. Sydney re-introduced trams (or light rail) on 31 August 1997. A completely new system, known as G:link , was introduced on the Gold Coast, Queensland , on 20 July 2014. The Newcastle Light Rail opened in February 2019, while the Canberra light rail opened on 20 April 2019. This is the first time that there have been trams in Canberra, even though Walter Burley Griffin 's 1914–1920 plans for

5995-583: The Irish coach builder John Stephenson , in New York City which began service in the year 1832. The New York and Harlem Railroad's Fourth Avenue Line ran along the Bowery and Fourth Avenue in New York City. It was followed in 1835 by the New Orleans and Carrollton Railroad in New Orleans, Louisiana , which still operates as the St. Charles Streetcar Line . Other American cities did not follow until

6104-755: The KT8D5N was installed in Tatra KT8D5 trams in the Czech Republic and Slovakia , and in one tram in Strausberg , Germany . The Thongil 181, which is based on the KT8D5, was introduced in Pyongyang , North Korea in 2018. From 1998 to 1999, ČKD built seven Tatra KT8D5N trams with a medium low-floor cell, IGBT transistors, and TV14 electrical equipment. This article incorporates information from

6213-545: The Netherlands. The first trams in Bendigo, Australia, in 1892, were battery-powered, but within as little as three months they were replaced with horse-drawn trams. In New York City some minor lines also used storage batteries. Then, more recently during the 1950s, a longer battery-operated tramway line ran from Milan to Bergamo . In China there is a Nanjing battery Tram line and has been running since 2014. In 2019,

6322-789: The North Sydney line from 1886 to 1900, and the King Street line from 1892 to 1905. In Dresden , Germany, in 1901 an elevated suspended cable car following the Eugen Langen one-railed floating tram system started operating. Cable cars operated on Highgate Hill in North London and Kennington to Brixton Hill in South London. They also worked around "Upper Douglas" in the Isle of Man from 1897 to 1929 (cable car 72/73

6431-747: The Romans for heavy horse and ox-drawn transportation. By the 1700s, paved plateways with cast iron rails were introduced in England for transporting coal, stone or iron ore from the mines to the urban factories and docks. The world's first passenger train or tram was the Swansea and Mumbles Railway , in Wales , UK. The British Parliament passed the Mumbles Railway Act in 1804, and horse-drawn service started in 1807. The service closed in 1827, but

6540-577: The Second Street Cable Railroad, which operated from 1885 to 1889, and the Temple Street Cable Railway, which operated from 1886 to 1898. From 1885 to 1940, the city of Melbourne , Victoria, Australia operated one of the largest cable systems in the world, at its peak running 592 trams on 75 kilometres (47 mi) of track. There were also two isolated cable lines in Sydney , New South Wales, Australia;

6649-887: The UK at Lytham St Annes , Trafford Park , Manchester (1897–1908) and Neath , Wales (1896–1920). Comparatively little has been published about gas trams. However, research on the subject was carried out for an article in the October 2011 edition of "The Times", the historical journal of the Australian Association of Timetable Collectors, later renamed the Australian Timetable Association. The world's first electric tram line operated in Sestroretsk near Saint Petersburg invented and tested by inventor Fyodor Pirotsky in 1875. Later, using

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6758-604: The UK took passengers from Fintona railway station to Fintona Junction one mile away on the main Omagh to Enniskillen railway in Northern Ireland. The tram made its last journey on 30 September 1957 when the Omagh to Enniskillen line closed. The "van" is preserved at the Ulster Transport Museum . Horse-drawn trams still operate on the 1876-built Douglas Bay Horse Tramway on the Isle of Man , and at

6867-440: The above definition of C r r {\displaystyle C_{rr}} that the rolling resistance is directly proportional to vehicle weight but it is not . There are at least two popular models for calculating rolling resistance. The results of these tests can be hard for the general public to obtain as manufacturers prefer to publicize "comfort" and "performance". The coefficient of rolling resistance for

6976-508: The advantages over earlier forms of transit was the low rolling resistance of metal wheels on steel rails, allowing the trams to haul a greater load for a given effort. Another factor which contributed to the rise of trams was the high total cost of ownership of horses. Electric trams largely replaced animal power in the late 19th and early 20th centuries. Improvements in other vehicles such as buses led to decline of trams in early to mid 20th century. However, trams have seen resurgence since

7085-575: The busiest tram line in Europe, with a tram running once per minute at rush hour. Bucharest and Belgrade ran a regular service from 1894. Ljubljana introduced its tram system in 1901 – it closed in 1958. Oslo had the first tramway in Scandinavia , starting operation on 2 March 1894. The first electric tramway in Australia was a Sprague system demonstrated at the 1888 Melbourne Centennial Exhibition in Melbourne ; afterwards, this

7194-439: The capital then in the planning stage did propose a Canberra tram system. In Japan, the Kyoto Electric railroad was the first tram system, starting operation in 1895. By 1932, the network had grown to 82 railway companies in 65 cities, with a total network length of 1,479 km (919 mi). By the 1960s the tram had generally died out in Japan. Two rare but significant alternatives were conduit current collection , which

7303-458: The car up the hill at a steady pace, unlike a low-powered steam or horse-drawn car. Cable cars do have wheel brakes and track brakes , but the cable also helps restrain the car to going downhill at a constant speed. Performance in steep terrain partially explains the survival of cable cars in San Francisco. The San Francisco cable cars , though significantly reduced in number, continue to provide regular transportation service, in addition to being

7412-402: The cars to coast by inertia, for example when crossing another cable line. The cable then had to be "picked up" to resume progress, the whole operation requiring precise timing to avoid damage to the cable and the grip mechanism. Breaks and frays in the cable, which occurred frequently, required the complete cessation of services over a cable route while the cable was repaired. Due to overall wear,

7521-409: The city's hurricane-prone location, which would have resulted in frequent damage to an electrical supply system. Although Portland, Victoria promotes its tourist tram as being a cable car it actually operates using a diesel motor. The tram, which runs on a circular route around the town of Portland, uses dummies and salons formerly used on the Melbourne cable tramway system and since restored. In

7630-482: The classic tramway built in the early 20th century with the tram system operating in mixed traffic, and the later type which is most often associated with the tram system having its own right of way. Tram systems that have their own right of way are often called light rail but this does not always hold true. Though these two systems differ in their operation, their equipment is much the same. Rolling resistance Analogous with sliding friction , rolling resistance

7739-416: The combined coal consumption of the stationary compressor and the onboard steam boiler. The Trieste–Opicina tramway in Trieste operates a hybrid funicular tramway system. Conventional electric trams are operated in street running and on reserved track for most of their route. However, on one steep segment of track, they are assisted by cable tractors, which push the trams uphill and act as brakes for

7848-744: The corresponding article on the Czech Misplaced Pages. [REDACTED] Media related to Tatra KT8D5 at Wikimedia Commons Tram A tram (also known as a streetcar or trolley in the United States) is a type of urban rail transit consisting of either individual railcars or self-propelled multiple unit trains that run on tramway tracks on urban public streets; some include segments on segregated right-of-way . The tramlines or tram networks operated as public transport are called tramways or simply trams/streetcars. Because of their close similarities, trams are commonly included in

7957-679: The downhill run. For safety, the cable tractors are always deployed on the downhill side of the tram vehicle. Similar systems were used elsewhere in the past, notably on the Queen Anne Counterbalance in Seattle and the Darling Street wharf line in Sydney. In the mid-20th century many tram systems were disbanded, replaced by buses, trolleybuses , automobiles or rapid transit . The General Motors streetcar conspiracy

8066-404: The driving wheel(s) becomes greater than the vehicle speed due to slippage. Since power is equal to force times velocity and the wheel velocity has increased, the power required has increased accordingly. The pure "rolling resistance" for a train is that which happens due to deformation and possible minor sliding at the wheel-road contact. For a rubber tire, an analogous energy loss happens over

8175-410: The energy dissipated by vibration and oscillation of both the roadbed and the vehicle, and sliding of the wheel on the roadbed surface (pavement or a rail). But there is an even broader sense that would include energy wasted by wheel slippage due to the torque applied from the engine . This includes the increased power required due to the increased velocity of the wheels where the tangential velocity of

8284-418: The energy to overcome this broad-sense rolling resistance. For tires, rolling resistance is defined as the energy consumed by a tire per unit distance covered. It is also called rolling friction or rolling drag. It is one of the forces that act to oppose the motion of a driver. The main reason for this is that when the tires are in motion and touch the surface, the surface changes shape and causes deformation of

8393-446: The engines from emitting visible smoke or steam. Usually the engines used coke rather than coal as fuel to avoid emitting smoke; condensers or superheating were used to avoid emitting visible steam. A major drawback of this style of tram was the limited space for the engine, so that these trams were usually underpowered. Steam trams faded out around the 1890s to 1900s, being replaced by electric trams. Another motive system for trams

8502-429: The entire length of cable (typically several kilometres) had to be replaced on a regular schedule. After the development of reliable electrically powered trams, the costly high-maintenance cable car systems were rapidly replaced in most locations. Cable cars remained especially effective in hilly cities, since their nondriven wheels did not lose traction as they climbed or descended a steep hill. The moving cable pulled

8611-401: The entire tire, but it is still called "rolling resistance". In the broad sense, "rolling resistance" includes wheel bearing resistance, energy loss by shaking both the roadbed (and the earth underneath) and the vehicle itself, and by sliding of the wheel, road/rail contact. Railroad textbooks seem to cover all these resistance forces but do not call their sum "rolling resistance" (broad sense) as

8720-439: The fact that any given animal could only work so many hours on a given day, had to be housed, groomed, fed and cared for day in and day out, and produced prodigious amounts of manure, which the streetcar company was charged with storing and then disposing. Since a typical horse pulled a streetcar for about a dozen miles a day and worked for four or five hours, many systems needed ten or more horses in stable for each horsecar. In 1905

8829-739: The force per the rolling resistance coefficient , and solving for b {\displaystyle b} , gives b {\displaystyle b} = C r r r {\displaystyle C_{rr}r} . Therefore, if a source gives rolling resistance coefficient ( C r r {\displaystyle C_{rr}} ) as a dimensionless coefficient, it can be converted to b {\displaystyle b} , having units of length, by multiplying C r r {\displaystyle C_{rr}} by wheel radius r {\displaystyle r} . Table of rolling resistance coefficient examples: [3] For example, in earth gravity,

8938-551: The late 19th and early 20th centuries a number of systems in various parts of the world employed trams powered by gas, naphtha gas or coal gas in particular. Gas trams are known to have operated between Alphington and Clifton Hill in the northern suburbs of Melbourne , Australia (1886–1888); in Berlin and Dresden , Germany; in Estonia (1921–1951); between Jelenia Góra , Cieplice , and Sobieszów in Poland (from 1897); and in

9047-402: The late 19th and early 20th centuries. There was one particular hazard associated with trams powered from a trolley pole off an overhead line on the early electrified systems. Since the tram relies on contact with the rails for the current return path, a problem arises if the tram is derailed or (more usually) if it halts on a section of track that has been heavily sanded by a previous tram, and

9156-534: The necessity of overhead wire and a trolley pole for street cars and railways. While at the University of Denver he conducted experiments which established that multiple unit powered cars were a better way to operate trains and trolleys. Electric tramways spread to many European cities in the 1890s, such as: Sarajevo built a citywide system of electric trams in 1895. Budapest established its tramway system in 1887, and its ring line has grown to be

9265-533: The oldest operating electric tramway in the world. Also in 1883, Mödling and Hinterbrühl Tram was opened near Vienna in Austria. It was the first tram in the world in regular service that was run with electricity served by an overhead line with pantograph current collectors . The Blackpool Tramway was opened in Blackpool, UK on 29 September 1885 using conduit collection along Blackpool Promenade. This system

9374-637: The poor paving of the streets in American cities which made them unsuitable for horsebuses , which were then common on the well-paved streets of European cities. Running the horsecars on rails allowed for a much smoother ride. There are records of a street railway running in Baltimore as early as 1828, however the first authenticated streetcar in America, was the New York and Harlem Railroad developed by

9483-665: The right. The line of action of the (aggregate) vertical force no longer passes through the centers of the cylinders. This means that a moment occurs that tends to retard the rolling motion. Materials that have a large hysteresis effect, such as rubber, which bounce back slowly, exhibit more rolling resistance than materials with a small hysteresis effect that bounce back more quickly and more completely, such as steel or silica . Low rolling resistance tires typically incorporate silica in place of carbon black in their tread compounds to reduce low-frequency hysteresis without compromising traction. Note that railroads also have hysteresis in

9592-481: The roadbed structure. In the broad sense, specific "rolling resistance" (for vehicles) is the force per unit vehicle weight required to move the vehicle on level ground at a constant slow speed where aerodynamic drag (air resistance) is insignificant and also where there are no traction (motor) forces or brakes applied. In other words, the vehicle would be coasting if it were not for the force to maintain constant speed. This broad sense includes wheel bearing resistance,

9701-465: The square root of the load. If Crr is itself dependent on wheel load per an inverse square-root rule, then for an increase in load of 2% only a 1% increase in rolling resistance occurs. For pneumatic tires, the direction of change in Crr (rolling resistance coefficient) depends on whether or not tire inflation is increased with increasing load. It is reported that, if inflation pressure is increased with load according to an (undefined) "schedule", then

9810-542: The suburban tramway lines around Milan and Padua ; the last Gamba de Legn ("Peg-Leg") tramway ran on the Milan- Magenta -Castano Primo route in late 1957. The other style of steam tram had the steam engine in the body of the tram, referred to as a tram engine (UK) or steam dummy (US). The most notable system to adopt such trams was in Paris. French-designed steam trams also operated in Rockhampton , in

9919-430: The sum of components ): Wheel bearing torque losses can be measured as a rolling resistance at the wheel rim, Crr . Railroads normally use roller bearings which are either cylindrical (Russia) or tapered (United States). The specific rolling resistance in bearings varies with both wheel loading and speed. Wheel bearing rolling resistance is lowest with high axle loads and intermediate speeds of 60–80 km/h with

10028-410: The tire. For highway motor vehicles, there is some energy dissipated in shaking the roadway (and the earth beneath it), the shaking of the vehicle itself, and the sliding of the tires. But, other than the additional power required due to torque and wheel bearing friction, non-pure rolling resistance doesn't seem to have been investigated, possibly because the "pure" rolling resistance of a rubber tire

10137-558: The tracks. Siemens later designed his own version of overhead current collection, called the bow collector . One of the first systems to use it was in Thorold, Ontario , opened in 1887, and it was considered quite successful. While this line proved quite versatile as one of the earliest fully functional electric streetcar installations, it required horse-drawn support while climbing the Niagara Escarpment and for two months of

10246-416: The tram and completing the earth return circuit with their body could receive a serious electric shock. If "grounded", the driver was required to jump off the tram (avoiding simultaneous contact with the tram and the ground) and pull down the trolley pole, before allowing passengers off the tram. Unless derailed, the tram could usually be recovered by running water down the running rails from a point higher than

10355-466: The tram loses electrical contact with the rails. In this event, the underframe of the tram, by virtue of a circuit path through ancillary loads (such as interior lighting), is live at the full supply voltage, typically 600 volts DC. In British terminology, such a tram was said to be 'grounded'—not to be confused with the US English use of the term, which means the exact opposite. Any person stepping off

10464-427: The tram, the water providing a conducting bridge between the tram and the rails. With improved technology, this ceased to be an problem. In the 2000s, several companies introduced catenary-free designs: Alstom's Citadis line uses a third rail, Bombardier's PRIMOVE LRV is charged by contactless induction plates embedded in the trackway and CAF URBOS tram uses ultracaps technology As early as 1834, Thomas Davenport ,

10573-804: The wider term light rail , which also includes systems separated from other traffic. Tram vehicles are usually lighter and shorter than main line and rapid transit trains. Most trams use electrical power, usually fed by a pantograph sliding on an overhead line ; older systems may use a trolley pole or a bow collector . In some cases, a contact shoe on a third rail is used. If necessary, they may have dual power systems—electricity in city streets and diesel in more rural environments. Occasionally, trams also carry freight . Some trams, known as tram-trains , may have segments that run on mainline railway tracks, similar to interurban systems. The differences between these modes of rail transport are often indistinct, and systems may combine multiple features. One of

10682-409: The winter when hydroelectricity was not available. It continued in service in its original form into the 1950s. Sidney Howe Short designed and produced the first electric motor that operated a streetcar without gears. The motor had its armature direct-connected to the streetcar 's axle for the driving force. Short pioneered "use of a conduit system of concealed feed" thereby eliminating

10791-532: The world's first hydrogen fuel cell vehicle tramcar at an assembly facility in Qingdao . The chief engineer of the CSR subsidiary CSR Sifang Co Ltd. , Liang Jianying, said that the company is studying how to reduce the running costs of the tram. Trams have been used for two main purposes: for carrying passengers and for carrying cargo. There are several types of passenger tram: There are two main types of tramways,

10900-401: The world. Earlier electric trains proved difficult or unreliable and experienced limited success until the second half of the 1880s, when new types of current collectors were developed. Siemens' line, for example, provided power through a live rail and a return rail, like a model train , limiting the voltage that could be used, and delivering electric shocks to people and animals crossing

11009-682: Was a case study of the decline of trams in the United States. In the 21st century, trams have been re-introduced in cities where they had been closed down for decades (such as Tramlink in London), or kept in heritage use (such as Spårväg City in Stockholm). Most trams made since the 1990s (such as the Bombardier Flexity series and Alstom Citadis ) are articulated low-floor trams with features such as regenerative braking . In March 2015, China South Rail Corporation (CSR) demonstrated

11118-491: Was built by Werner von Siemens who contacted Pirotsky. This was the world's first commercially successful electric tram. It drew current from the rails at first, with overhead wire being installed in 1883. In Britain, Volk's Electric Railway was opened in 1883 in Brighton. This two kilometer line along the seafront, re-gauged to 2 ft  8 + 1 ⁄ 2  in ( 825 mm ) in 1884, remains in service as

11227-487: Was installed as a commercial venture operating between the outer Melbourne suburb of Box Hill and the then tourist-oriented country town Doncaster from 1889 to 1896. Electric systems were also built in Adelaide , Ballarat , Bendigo , Brisbane , Fremantle , Geelong , Hobart , Kalgoorlie , Launceston , Leonora , Newcastle , Perth , and Sydney . By the 1970s, the only full tramway system remaining in Australia

11336-566: Was restarted in 1860, again using horses. It was worked by steam from 1877, and then, from 1929, by very large (106-seat) electric tramcars, until closure in 1960. The Swansea and Mumbles Railway was something of a one-off however, and no street tramway appeared in Britain until 1860 when one was built in Birkenhead by the American George Francis Train . Street railways developed in America before Europe, due to

11445-628: Was tested in San Francisco , in 1873. Part of its success is attributed to the development of an effective and reliable cable grip mechanism, to grab and release the moving cable without damage. The second city to operate cable trams was Dunedin , from 1881 to 1957. The most extensive cable system in the US was built in Chicago in stages between 1859 and 1892. New York City developed multiple cable car lines, that operated from 1883 to 1909. Los Angeles also had several cable car lines, including

11554-635: Was the Melbourne tram system. However, there were also a few single lines remaining elsewhere: the Glenelg tram line , connecting Adelaide to the beachside suburb of Glenelg , and tourist trams in the Victorian Goldfields cities of Bendigo and Ballarat. In recent years the Melbourne system, generally recognised as the largest urban tram network in the world, has been considerably modernised and expanded. The Adelaide line has been extended to

11663-411: Was the cable car, which was pulled along a fixed track by a moving steel cable, the cable usually running in a slot below the street level. The power to move the cable was normally provided at a "powerhouse" site a distance away from the actual vehicle. The London and Blackwall Railway , which opened for passengers in east London, England, in 1840 used such a system. The first practical cable car line

11772-491: Was to make a light rail vehicle with a higher capacity to meet growing demands for public transport. The project to design and build the KT8D5 was approved in 1982, and the first prototype was constructed in 1984. The first vehicles entered operation 1986 in Prague , Brno , Most and Košice . The Tatra KT8D5 is a large, high capacity tram constructed using three articulated body sections riding on four bogies. The middle section

11881-830: Was widely used in London, Washington, D.C., and New York City, and the surface contact collection method, used in Wolverhampton (the Lorain system), Torquay and Hastings in the UK (the Dolter stud system), and in Bordeaux , France (the ground-level power supply system). The convenience and economy of electricity resulted in its rapid adoption once the technical problems of production and transmission of electricity were solved. Electric trams largely replaced animal power and other forms of motive power including cable and steam, in

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