121-581: Tracked Hovercraft was an experimental high-speed train developed in the United Kingdom during the 1960s. It combined two British inventions, the hovercraft and the linear induction motor , in an effort to produce a train system that would provide 250 mph (400 km/h) inter-city service with lowered capital costs compared to other high-speed solutions. Substantially similar to the French Aérotrain and other hovertrain systems of
242-410: A 1-mile (1.6 km) section, in spite of the short track and a 20 mph (32 km/h) headwind. The test was heavily publicised and shown on BBC news throughout the day. Much of the interest stemmed from rumours that the project was facing imminent cancellation. Aerospace Minister Michael Heseltine sent Michael McNair-Wilson to view the test. Heseltine said in an interview that he believed that
363-469: A LIM; the accompanying illustration shows small lift pads like those from the Ford Levapad concept, running on top of conventional rails. After moving to Imperial College London in 1964, Laithwaite was able to devote more time to this work and perfect the first working examples of large LIMs suitable for transport systems. LIMs provide traction through the interaction of magnetic fields generated on
484-408: A carbody design that would reduce wind resistance at high speeds. A long series of tests was carried. In 1905, St. Louis Car Company built a railcar for the traction magnate Henry E. Huntington , capable of speeds approaching 160 km/h (100 mph). Once it ran 32 km (20 mi) between Los Angeles and Long Beach in 15 minutes, an average speed of 130 km/h (80 mph). However, it
605-447: A few centimetres apart. They were positioned so that the aluminium stator plate would fit in the gap between the windings, sandwiching it between them. The advantage to this layout is that the forces pulling one set of windings toward the plate are balanced by the opposite forces in the other set. By attaching the two sets of windings to a common frame, all of the forces are internalised. The Hovercraft Development team quickly picked up on
726-429: A further 2,100 kW (2,800 hp). The combined 4,900 kW (6,600 hp) was not unheard of; existing freight locomotives of similar power were already in use. However, these weighed 80 tons, much of it for the voltage control and conversion equipment, which would be far too heavy for the lightweight TH. THL's solution was to move the power supplies to the trackside and use them to power individual sections of
847-432: A given element is proportional to the length, but inversely proportional to the cross-sectional area. For example, if A = 1 m , ℓ {\displaystyle \ell } = 1 m (forming a cube with perfectly conductive contacts on opposite faces), then the resistance of this element in ohms is numerically equal to the resistivity of the material it is made of in Ω⋅m. Conductivity, σ ,
968-464: A guideway that looked like a rightside-up T, although the vertical section was a trapezoidal girder almost as wide as the top of the T. The reaction plate for the LIM was moved to the underside of the horizontal portion of the T on one side, extending vertically down, while the other side contained the electrical conductors that provided power. In such an arrangement, rain, snow and debris would simply fall off
1089-578: A high-speed railway network in Russian gauge . There are no narrow gauge high-speed railways. Countries whose legacy network is entirely or mostly of a different gauge than 1435mm – including Japan and Spain – have however often opted to build their high speed lines to standard gauge instead of the legacy railway gauge. High-speed rail is the fastest and most efficient ground-based method of commercial transportation. However, due to requirements for large track curves, gentle gradients and grade separated track
1210-610: A low-resistivity material is like pushing water through an empty pipe. If the pipes are the same size and shape, the pipe full of sand has higher resistance to flow. Resistance, however, is not solely determined by the presence or absence of sand. It also depends on the length and width of the pipe: short or wide pipes have lower resistance than narrow or long pipes. The above equation can be transposed to get Pouillet's law (named after Claude Pouillet ): R = ρ ℓ A . {\displaystyle R=\rho {\frac {\ell }{A}}.} The resistance of
1331-474: A material that measures its electrical resistance or how strongly it resists electric current . A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek letter ρ ( rho ). The SI unit of electrical resistivity is the ohm - metre (Ω⋅m). For example, if a 1 m solid cube of material has sheet contacts on two opposite faces, and
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#17327919666951452-405: A mile, compared to the £500,000 spent during the same period by Deutsche Bundesbahn to increase performance of its existing rail lines to only 100 mph (161 km/h). This was all taking place even while many of the "more complacent elements" of British Rail were dismissing the need for any form of high-speed rail. Another serious concern was the rapid development and apparent superiority of
1573-437: A more general expression in which the resistivity at a particular point is defined as the ratio of the electric field to the density of the current it creates at that point: ρ ( x ) = E ( x ) J ( x ) , {\displaystyle \rho (x)={\frac {E(x)}{J(x)}},} where The current density is parallel to the electric field by necessity. Conductivity
1694-546: A new top speed for a regular service, with a top speed of 160 km/h (99 mph). This train was a streamlined multi-powered unit, albeit diesel, and used Jakobs bogies . Following the success of the Hamburg line, the steam-powered Henschel-Wegmann Train was developed and introduced in June 1936 for service from Berlin to Dresden , with a regular top speed of 160 km/h (99 mph). Incidentally no train service since
1815-418: A side fore and aft and riding on the horizontal surface of the guideway. Four more pads, above the lift pads, were rotated vertically to press against the centre beam and kept the craft centred. A test rig of this layout was built at Hythe, which was filmed in operation by British Pathé in 1963, which also showed a model of the proposed full-sized version. As development of the testbed design continued at HDL,
1936-600: A smaller number of vehicles or longer lines where the capital costs were concentrated in the tracks, but neither of these characterised BR's operations. Meanwhile, having exhausted their research abilities using small models, the Hovercraft Development team had been petitioning their parent organisation, the National Research Development Corporation (NRDC), for additional funding to build a full-sized test track. NDRC
2057-555: A some other interurban rail cars reached about 145 km/h (90 mph) in commercial traffic. The Red Devils weighed only 22 tons though they could seat 44 passengers. Extensive wind tunnel research – the first in the railway industry – was done before J. G. Brill in 1931 built the Bullet cars for Philadelphia and Western Railroad (P&W). They were capable of running at 148 km/h (92 mph). Some of them were almost 60 years in service. P&W's Norristown High Speed Line
2178-403: A train to approach existing stations at lower speeds, greatly reducing capital costs of bringing the service into cities. The inter-city sections could be re-laid for higher speeds, where the infrastructure costs were generally lower anyway. BR also showed that the capital cost advantages of the hovertrain concept were offset by the higher vehicle costs; the tracked hovercraft concept made sense for
2299-556: A week after McNair-Wilson's comments at the run in February 1973, funding for the Tracked Hovercraft project was cancelled. Heseltine noted problems with the concept, stated that there was no prospect of a system being installed before 1985, and very limited possibilities between then and the end of the century. He stated that further funding, already to the tune of £5 million by this point, made no sense at that time. Work on
2420-569: A world record for narrow gauge trains at 145 km/h (90 mph), giving the Odakyu engineers confidence they could safely and reliably build even faster trains at standard gauge. Conventional Japanese railways up until that point had largely been built in the 1,067 mm ( 3 ft 6 in ) Cape gauge , however widening the tracks to standard gauge ( 1,435 mm ( 4 ft 8 + 1 ⁄ 2 in )) would make very high-speed rail much simpler due to improved stability of
2541-417: Is siemens per metre (S/m). Resistivity and conductivity are intensive properties of materials, giving the opposition of a standard cube of material to current. Electrical resistance and conductance are corresponding extensive properties that give the opposition of a specific object to electric current. In an ideal case, cross-section and physical composition of the examined material are uniform across
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#17327919666952662-476: Is a set of unique features, not merely a train travelling above a particular speed. Many conventionally hauled trains are able to reach 200 km/h (124 mph) in commercial service but are not considered to be high-speed trains. These include the French SNCF Intercités and German DB IC . The criterion of 200 km/h (124 mph) is selected for several reasons; above this speed,
2783-459: Is a type of rail transport network utilizing trains that run significantly faster than those of traditional rail, using an integrated system of specialized rolling stock and dedicated tracks . While there is no single standard that applies worldwide, lines built to handle speeds above 250 km/h (155 mph) or upgraded lines in excess of 200 km/h (125 mph) are widely considered to be high-speed. The first high-speed rail system,
2904-539: Is still in use, almost 110 years after P&W in 1907 opened their double-track Upper Darby–Strafford line without a single grade crossing with roads or other railways. The entire line was governed by an absolute block signal system. On 15 May 1933, the Deutsche Reichsbahn-Gesellschaft company introduced the diesel-powered " Fliegender Hamburger " in regular service between Hamburg and Berlin (286 km or 178 mi), thereby achieving
3025-472: Is the inverse (reciprocal) of resistivity. Here, it is given by: σ ( x ) = 1 ρ ( x ) = J ( x ) E ( x ) . {\displaystyle \sigma (x)={\frac {1}{\rho (x)}}={\frac {J(x)}{E(x)}}.} For example, rubber is a material with large ρ and small σ — because even a very large electric field in rubber makes almost no current flow through it. On
3146-405: Is the inverse of resistivity: σ = 1 ρ . {\displaystyle \sigma ={\frac {1}{\rho }}.} Conductivity has SI units of siemens per metre (S/m). If the geometry is more complicated, or if the resistivity varies from point to point within the material, the current and electric field will be functions of position. Then it is necessary to use
3267-619: The Chicago-New York Electric Air Line Railroad project to reduce the running time between the two big cities to ten hours by using electric 160 km/h (99 mph) locomotives. After seven years of effort, however, less than 50 km (31 mi) of arrow-straight track was finished. A part of the line is still used as one of the last interurbans in the US. In the US, some of the interurbans (i.e. trams or streetcars which run from city to city) of
3388-553: The 0 Series Shinkansen , built by Kawasaki Heavy Industries – in English often called "Bullet Trains", after the original Japanese name Dangan Ressha ( 弾丸列車 ) – outclassed the earlier fast trains in commercial service. They traversed the 515 km (320 mi) distance in 3 hours 10 minutes, reaching a top speed of 210 km/h (130 mph) and sustaining an average speed of 162.8 km/h (101.2 mph) with stops at Nagoya and Kyoto. Speed
3509-681: The Aérotrain , a French hovercraft monorail train prototype, reached 200 km/h (120 mph) within days of operation. After the successful introduction of the Japanese Shinkansen in 1964, at 210 km/h (130 mph), the German demonstrations up to 200 km/h (120 mph) in 1965, and the proof-of-concept jet-powered Aérotrain , SNCF ran its fastest trains at 160 km/h (99 mph). In 1966, French Infrastructure Minister Edgard Pisani consulted engineers and gave
3630-804: The Hovercraft Museum library in Hampshire , England, including technical documents, video footage reels, press books and blueprints. A scale model of the RTV 31, a working miniature LIM, photographs, video footage and archive documents are kept within the Museum. Another scale model of the RTV 31 is kept within the museum at Railworld Wildlife Haven. 52°23′23″N 0°04′57″E / 52.38964°N 0.082397°E / 52.38964; 0.082397 High-speed train High-speed rail ( HSR )
3751-590: The Marienfelde – Zossen line during 1902 and 1903 (see Experimental three-phase railcar ). On 23 October 1903, the S&;H-equipped railcar achieved a speed of 206.7 km/h (128.4 mph) and on 27 October the AEG-equipped railcar achieved 210.2 km/h (130.6 mph). These trains demonstrated the feasibility of electric high-speed rail; however, regularly scheduled electric high-speed rail travel
Tracked Hovercraft - Misplaced Pages Continue
3872-647: The Morning Hiawatha service, hauled at 160 km/h (99 mph) by steam locomotives. In 1939, the largest railroad of the world, the Pennsylvania Railroad introduced a duplex steam engine Class S1 , which was designed to be capable of hauling 1200 tons passenger trains at 161 km/h (100 mph). The S1 engine was assigned to power the popular all-coach overnight premier train the Trail Blazer between New York and Chicago since
3993-545: The Prussian state railway joined with ten electrical and engineering firms and electrified 72 km (45 mi) of military owned railway between Marienfelde and Zossen . The line used three-phase current at 10 kilovolts and 45 Hz . The Van der Zypen & Charlier company of Deutz, Cologne built two railcars, one fitted with electrical equipment from Siemens-Halske , the second with equipment from Allgemeine Elektrizitäts-Gesellschaft (AEG), that were tested on
4114-611: The SI unit ohm metre (Ω⋅m) — i.e. ohms multiplied by square metres (for the cross-sectional area) then divided by metres (for the length). Both resistance and resistivity describe how difficult it is to make electrical current flow through a material, but unlike resistance, resistivity is an intrinsic property and does not depend on geometric properties of a material. This means that all pure copper (Cu) wires (which have not been subjected to distortion of their crystalline structure etc.), irrespective of their shape and size, have
4235-729: The Tōkaidō Shinkansen , began operations in Honshu , Japan, in 1964. Due to the streamlined spitzer -shaped nose cone of the trains , the system also became known by its English nickname bullet train . Japan's example was followed by several European countries, initially in Italy with the Direttissima line, followed shortly thereafter by France , Germany , and Spain . Today, much of Europe has an extensive network with numerous international connections. More recent construction since
4356-532: The United Kingdom , the United States , and Uzbekistan . Only in continental Europe and Asia does high-speed rail cross international borders. High-speed trains mostly operate on standard gauge tracks of continuously welded rail on grade-separated rights of way with large radii . However, certain regions with wider legacy railways , including Russia and Uzbekistan, have sought to develop
4477-483: The Vickers Viscount carried 75 passengers and equipped with a total of 6,000 kW (8,000 hp) for take-off and operated around 4,000 to 5,000 kW (5,400 to 6,700 hp) in cruise. Of much greater concern was the need to take in air for the hover pads, accelerating it from ambient to vehicle speed before being pumped into the pads. This load, which THL referred to as momentum drag , accounted for
4598-474: The World Bank , whilst supporting the project, considered the design of the equipment as unproven for that speed, and set the maximum speed to 210 km/h (130 mph). After initial feasibility tests, the plan was fast-tracked and construction of the first section of the line started on 20 April 1959. In 1963, on the new track, test runs hit a top speed of 256 km/h (159 mph). Five years after
4719-584: The cabinet . He called together the Select Committee on Science and Technology to examine the issue, but they were constantly frustrated in their efforts to obtain cabinet meeting reports. One thing that did surface was that Hawker Siddeley and Tracked Hovercraft were in the process of entering a bid for the GO-Urban system in Toronto , Ontario. This was for the LIM technology, which Hawker Siddeley
4840-543: The resistance between these contacts is 1 Ω , then the resistivity of the material is 1 Ω⋅m . Electrical conductivity (or specific conductance ) is the reciprocal of electrical resistivity. It represents a material's ability to conduct electric current. It is commonly signified by the Greek letter σ ( sigma ), but κ ( kappa ) (especially in electrical engineering) and γ ( gamma ) are sometimes used. The SI unit of electrical conductivity
4961-447: The 1960s, Tracked Hovercraft suffered a fate similar to those of the other projects when it was cancelled as a part of wide budget cuts in 1973. It was noticed early on in the development of the hovercraft that the energy needed to lift a vehicle was directly related to the smoothness of the surface on which it travelled. This was not entirely surprising; the air trapped under the hovercraft will remain there except where it leaks out where
Tracked Hovercraft - Misplaced Pages Continue
5082-573: The 21st century has led to China taking a leading role in high-speed rail. As of 2023 , China's HSR network accounted for over two-thirds of the world's total. In addition to these, many other countries have developed high-speed rail infrastructure to connect major cities, including: Austria , Belgium , Denmark , Finland , Greece , Indonesia , Morocco , the Netherlands , Norway , Poland , Portugal , Russia , Saudi Arabia , Serbia , South Korea , Sweden , Switzerland , Taiwan , Turkey ,
5203-642: The French National Railway started to receive their new powerful CC 7100 electric locomotives, and began to study and evaluate running at higher speeds. In 1954, the CC 7121 hauling a full train achieved a record 243 km/h (151 mph) during a test on standard track. The next year, two specially tuned electric locomotives, the CC 7107 and the prototype BB 9004, broke previous speed records, reaching respectively 320 km/h (200 mph) and 331 km/h (206 mph), again on standard track. For
5324-565: The French National Railways twelve months to raise speeds to 200 km/h (120 mph). The classic line Paris– Toulouse was chosen, and fitted, to support 200 km/h (120 mph) rather than 140 km/h (87 mph). Some improvements were set, notably the signals system, development of on board "in-cab" signalling system, and curve revision. The next year, in May 1967, a regular service at 200 km/h (120 mph)
5445-413: The LIM concept as well. Their initial solution was a track shaped like an upside-down T, with the vertical portion consisting of a central concrete section with aluminium stator plates fixed on either side. Their first design concept looked like the fuselage of an airliner with two decks, riding above the stator beam, with the LIM centred in the middle of the body. Four pads provided lift, arranged two on
5566-540: The LIM would continue to be funded, however, and the Department of Trade and Industry signed a £500,000 contract with Hawker Siddeley to carry on LIM development. Heseltine was accused by Airey Neave and others of earlier misleading the House of Commons when he stated that the government was still considering giving financial support to the hovertrain, when the decision to pull the plug must have already been taken by
5687-508: The London–Manchester and London–Glasgow routes. The options included 'buses, Advanced Passenger Train, Tracked Hovercraft, and VTOL and STOL aircraft. Their December 1971 report strongly favoured APT. The arguments eventually settled on the need to build new lines. APT was intended to enter testing in 1973, and enter pay service before the end of the 1970s. In comparison, Tracked Hovercraft would not be ready for real-world testing until
5808-457: The NRDC decided to spin off the hovertrain group as Tracked Hovercraft Ltd. (THL). They also decided to spool out the funding over four years, starting with a £1 million grant for a single prototype vehicle and a short portion of the test track. Although this funding was enough only for the first stage of a track, the NRDC suggested it would be quite useful for testing low-speed intra-urban versions of
5929-606: The US, 160 km/h (99 mph) in Germany and 125 mph (201 km/h) in Britain. Above those speeds positive train control or the European Train Control System becomes necessary or legally mandatory. National domestic standards may vary from the international ones. Railways were the first form of rapid land transportation and had an effective monopoly on long-distance passenger traffic until
6050-478: The adjacent one. In such cases, the current does not flow in exactly the same direction as the electric field. Thus, the appropriate equations are generalized to the three-dimensional tensor form: J = σ E ⇌ E = ρ J , {\displaystyle \mathbf {J} ={\boldsymbol {\sigma }}\mathbf {E} \,\,\rightleftharpoons \,\,\mathbf {E} ={\boldsymbol {\rho }}\mathbf {J} ,} where
6171-579: The beginning of the construction work, in October 1964, just in time for the Olympic Games , the first modern high-speed rail, the Tōkaidō Shinkansen , was opened between the two cities; a 510 km (320 mi) line between Tokyo and Ōsaka. As a result of its speeds, the Shinkansen earned international publicity and praise, and it was dubbed the "bullet train." The first Shinkansen trains,
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#17327919666956292-443: The cancelation of this express train in 1939 has traveled between the two cities in a faster time as of 2018 . In August 2019, the travel time between Dresden-Neustadt and Berlin-Südkreuz was 102 minutes. See Berlin–Dresden railway . Further development allowed the usage of these "Fliegenden Züge" (flying trains) on a rail network across Germany. The "Diesel-Schnelltriebwagen-Netz" (diesel high-speed-vehicle network) had been in
6413-660: The choice of the coordinate system is free, the usual convention is to simplify the expression by choosing an x -axis parallel to the current direction, so J y = J z = 0 . This leaves: ρ x x = E x J x , ρ y x = E y J x , and ρ z x = E z J x . {\displaystyle \rho _{xx}={\frac {E_{x}}{J_{x}}},\quad \rho _{yx}={\frac {E_{y}}{J_{x}}},{\text{ and }}\rho _{zx}={\frac {E_{z}}{J_{x}}}.} Conductivity
6534-414: The competing maglev concept. A study by THL noted that air drag on a canonical 40-long ton 100-passenger hovercraft at 400 km/h (250 mph) with a (considerable) 70 km/h (43 mph) crosswind would absorb 2,800 kW (3,800 hp). This is not a particularly great amount of power; a commuter STOL aircraft of similar size would likely require two to three times as much power in cruise –
6655-481: The concept. Frustrated with BR's lack of interest in his hovertrain work, and their lack of funding, in 1967 Laithwaite severed his ties with BR and joined Tracked Hovercraft as a consultant. By this time the French government had started providing major funding for Jean Bertin's Aérotrain project, which was substantially similar to the Tracked Hovercraft in concept. Laithwaite, always described as persuasive, convinced
6776-1244: The conductivity σ and resistivity ρ are rank-2 tensors , and electric field E and current density J are vectors. These tensors can be represented by 3×3 matrices, the vectors with 3×1 matrices, with matrix multiplication used on the right side of these equations. In matrix form, the resistivity relation is given by: [ E x E y E z ] = [ ρ x x ρ x y ρ x z ρ y x ρ y y ρ y z ρ z x ρ z y ρ z z ] [ J x J y J z ] , {\displaystyle {\begin{bmatrix}E_{x}\\E_{y}\\E_{z}\end{bmatrix}}={\begin{bmatrix}\rho _{xx}&\rho _{xy}&\rho _{xz}\\\rho _{yx}&\rho _{yy}&\rho _{yz}\\\rho _{zx}&\rho _{zy}&\rho _{zz}\end{bmatrix}}{\begin{bmatrix}J_{x}\\J_{y}\\J_{z}\end{bmatrix}},} where Equivalently, resistivity can be given in
6897-409: The conductor divided by the length ℓ of the conductor: E = V ℓ . {\displaystyle E={\frac {V}{\ell }}.} Since the current density is constant, it is equal to the total current divided by the cross sectional area: J = I A . {\displaystyle J={\frac {I}{A}}.} Plugging in the values of E and J into
7018-562: The construction of high-speed rail is more costly than conventional rail and therefore does not always present an economical advantage over conventional speed rail. Multiple definitions for high-speed rail are in use worldwide. The European Union Directive 96/48/EC, Annex 1 (see also Trans-European high-speed rail network ) defines high-speed rail in terms of: The International Union of Railways (UIC) identifies three categories of high-speed rail: A third definition of high-speed and very high-speed rail requires simultaneous fulfilment of
7139-464: The curve radius should be quadrupled; the same was true for the acceleration and braking distances. In 1891 engineer Károly Zipernowsky proposed a high-speed line from Vienna to Budapest for electric railcars at 250 km/h (160 mph). In 1893 Wellington Adams proposed an air-line from Chicago to St. Louis of 252 miles (406 km), at a speed of only 160 km/h (99 mph). Alexander C. Miller had greater ambitions. In 1906, he launched
7260-603: The deputy director Marcel Tessier at the DETE ( SNCF Electric traction study department). JNR engineers returned to Japan with a number of ideas and technologies they would use on their future trains, including alternating current for rail traction, and international standard gauge. In 1957, the engineers at the private Odakyu Electric Railway in Greater Tokyo Area launched the Odakyu 3000 series SE EMU. This EMU set
7381-508: The development of the motor car and airliners in the early-mid 20th century. Speed had always been an important factor for railroads and they constantly tried to achieve higher speeds and decrease journey times. Rail transportation in the late 19th century was not much slower than non-high-speed trains today, and many railroads regularly operated relatively fast express trains which averaged speeds of around 100 km/h (62 mph). High-speed rail development began in Germany in 1899 when
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#17327919666957502-595: The early 20th century were very high-speed for their time (also Europe had and still does have some interurbans). Several high-speed rail technologies have their origin in the interurban field. In 1903 – 30 years before the conventional railways started to streamline their trains – the officials of the Louisiana Purchase Exposition organised the Electric Railway Test Commission to conduct a series of tests to develop
7623-675: The earthworks between the Old Bedford River and the Counter Drain just to its north, between Earith and the Denver Sluice . The first 4-mile (6.4 km) long section of the planned 20-mile (32 km) long track was laid to Sutton-in-the-Isle . Along the full 20-mile (32 km) length it was expected the train would reach 300 mph (480 km/h). On 7 February 1973 the first test train, Research Test Vehicle 31, or RTV 31, reached 104 mph (167 km/h) on
7744-583: The electrical resistivity ρ (Greek: rho ) is the constant of proportionality. This is written as: R ∝ ℓ A {\displaystyle R\propto {\frac {\ell }{A}}} R = ρ ℓ A ⇔ ρ = R A ℓ , {\displaystyle {\begin{aligned}R&=\rho {\frac {\ell }{A}}\\[3pt]{}\Leftrightarrow \rho &=R{\frac {A}{\ell }},\end{aligned}}} where The resistivity can be expressed using
7865-404: The first expression, we obtain: ρ = V A I ℓ . {\displaystyle \rho ={\frac {VA}{I\ell }}.} Finally, we apply Ohm's law, V / I = R : ρ = R A ℓ . {\displaystyle \rho =R{\frac {A}{\ell }}.} When the resistivity of a material has a directional component,
7986-399: The first operational maglev system. RTV 31 ended up at Cranfield University where it was kept in the open for more than 20 years. In 1996 it was donated to Railworld , where it was later restored and set up as a main display in front of the buildings. The test track was removed, but several concrete footings project, at ground level, from a small pond beside the Counter Drain. The course of
8107-438: The first time, 300 km/h (185 mph) was surpassed, allowing the idea of higher-speed services to be developed and further engineering studies commenced. Especially, during the 1955 records, a dangerous hunting oscillation , the swaying of the bogies which leads to dynamic instability and potential derailment was discovered. This problem was solved by yaw dampers which enabled safe running at high speeds today. Research
8228-575: The following two conditions: The UIC prefers to use "definitions" (plural) because they consider that there is no single standard definition of high-speed rail, nor even standard usage of the terms ("high speed", or "very high speed"). They make use of the European EC Directive 96/48, stating that high speed is a combination of all the elements which constitute the system: infrastructure, rolling stock and operating conditions. The International Union of Railways states that high-speed rail
8349-404: The geometry has a uniform cross-section and the resistivity is constant in the material. Then the electric field and current density are constant and parallel, and by the general definition of resistivity, we obtain ρ = E J , {\displaystyle \rho ={\frac {E}{J}},} Since the electric field is constant, it is given by the total voltage V across
8470-416: The government that they were about to lose out on this burgeoning field of high-speed transit, and eventually won £2 million in additional funding. By the time construction was preparing to start in 1970, a new problem had appeared. Prior to construction most LIMs were test systems that had operated at low speeds, but as the speeds increased it was noticed that the mechanical forces of the LIM windings on
8591-406: The hovercraft arrangement, concluding that the maglev was a better solution. Laithwaite had found that careful arrangement of the LIM allowed a single motor to act as both the lift and traction system, a system he called "traverse-flux", or "river of magnetism". Having continued his research at Derby throughout, when it became clear that Tracked Hovercraft was truly dead, Laithwaite started pushing for
8712-420: The hovertrain concept. At the time, a major problem was selecting a suitable power source. As the hovercraft had no strong contact with a running surface, propulsion was normally provided by an aircraft-like solution, typically a large propeller. This limits the acceleration as well as the efficiency of the system, a major limitation for a design concept that would compete with aircraft on the same routes. Through
8833-414: The impacts of geometric defects are intensified, track adhesion is decreased, aerodynamic resistance is greatly increased, pressure fluctuations within tunnels cause passenger discomfort, and it becomes difficult for drivers to identify trackside signalling. Standard signaling equipment is often limited to speeds below 200 km/h (124 mph), with the traditional limits of 127 km/h (79 mph) in
8954-461: The initial ones despite greater speeds). After decades of research and successful testing on a 43 km (27 mi) test track, in 2014 JR Central began constructing a Maglev Shinkansen line, which is known as the Chūō Shinkansen . These Maglev trains still have the traditional underlying tracks and the cars have wheels. This serves a practical purpose at stations and a safety purpose out on
9075-542: The late 1940s and it consistently reached 161 km/h (100 mph) in its service life. These were the last "high-speed" trains to use steam power. In 1936, the Twin Cities Zephyr entered service, from Chicago to Minneapolis, with an average speed of 101 km/h (63 mph). Many of these streamliners posted travel times comparable to or even better than their modern Amtrak successors, which are limited to 127 km/h (79 mph) top speed on most of
9196-444: The late 1970s, and could not enter service until a completely new set of guideways had been constructed. Arguments in favour of TH included the problem that placing APT on existing lines would simply increase congestion on them, and that its 155 mph (249 km/h) speed was simply too low to compete directly with jet aircraft, unlike the 250 mph (402 km/h) TH. If new lines were going to be laid, TH would cost about £250,000
9317-422: The lifting surface contacts the ground – if this interface is smooth, the amount of leaked air will be low. This is the purpose of the skirt found on most hovercraft; it allows the fuselage to be some distance from the ground while keeping the air gap as small as possible. The surprising discovery was that the amount of energy needed to move a given vehicle using hover technology could be lower than
9438-432: The lines in the event of a power failure. However, in normal operation, the wheels are raised up into the car as the train reaches certain speeds where the magnetic levitation effect takes over. It will link Tokyo and Osaka by 2037, with the section from Tokyo to Nagoya expected to be operational by 2027. Maximum speed is anticipated at 505 km/h (314 mph). The first generation train can be ridden by tourists visiting
9559-1192: The more compact Einstein notation : E i = ρ i j J j . {\displaystyle \mathbf {E} _{i}={\boldsymbol {\rho }}_{ij}\mathbf {J} _{j}~.} In either case, the resulting expression for each electric field component is: E x = ρ x x J x + ρ x y J y + ρ x z J z , E y = ρ y x J x + ρ y y J y + ρ y z J z , E z = ρ z x J x + ρ z y J y + ρ z z J z . {\displaystyle {\begin{aligned}E_{x}&=\rho _{xx}J_{x}+\rho _{xy}J_{y}+\rho _{xz}J_{z},\\E_{y}&=\rho _{yx}J_{x}+\rho _{yy}J_{y}+\rho _{yz}J_{z},\\E_{z}&=\rho _{zx}J_{x}+\rho _{zy}J_{y}+\rho _{zz}J_{z}.\end{aligned}}} Since
9680-440: The more simple definitions cannot be applied. If the material is not anisotropic, it is safe to ignore the tensor-vector definition, and use a simpler expression instead. Here, anisotropic means that the material has different properties in different directions. For example, a crystal of graphite consists microscopically of a stack of sheets, and current flows very easily through each sheet, but much less easily from one sheet to
9801-403: The most general definition of resistivity must be used. It starts from the tensor-vector form of Ohm's law , which relates the electric field inside a material to the electric current flow. This equation is completely general, meaning it is valid in all cases, including those mentioned above. However, this definition is the most complicated, so it is only directly used in anisotropic cases, where
9922-505: The network. The German high-speed service was followed in Italy in 1938 with an electric-multiple-unit ETR 200 , designed for 200 km/h (120 mph), between Bologna and Naples. It too reached 160 km/h (99 mph) in commercial service, and achieved a world mean speed record of 203 km/h (126 mph) between Florence and Milan in 1938. In Great Britain in the same year, the streamlined steam locomotive Mallard achieved
10043-469: The official world speed record for steam locomotives at 202.58 km/h (125.88 mph). The external combustion engines and boilers on steam locomotives were large, heavy and time and labor-intensive to maintain, and the days of steam for high speed were numbered. In 1945, a Spanish engineer, Alejandro Goicoechea , developed a streamlined, articulated train that was able to run on existing tracks at higher speeds than contemporary passenger trains. This
10164-402: The other hand, copper is a material with small ρ and large σ — because even a small electric field pulls a lot of current through it. This expression simplifies to the formula given above under "ideal case" when the resistivity is constant in the material and the geometry has a uniform cross-section. In this case, the electric field and current density are constant and parallel. Assume
10285-608: The planning since 1934 but it never reached its envisaged size. All high-speed service stopped in August 1939 shortly before the outbreak of World War II . On 26 May 1934, one year after Fliegender Hamburger introduction, the Burlington Railroad set an average speed record on long distance with their new streamlined train, the Zephyr , at 124 km/h (77 mph) with peaks at 185 km/h (115 mph). The Zephyr
10406-546: The plates. The new guideway design was simulated at the Atlas Computer Laboratory . This work included the generation of films showing the vehicle in-action, using a Stromberg-Carlson SC4020 microfilm recorder. While the hovertrain was being developed, BR was running an extensive research project on the topic of high-speed wheeled trains at their newly opened British Rail Research Division in Derby . This
10527-448: The problem of high-speed loads on the guideway became obvious. In spite of its light weight compared to conventional train sets, the Tracked Hovercraft operated at such high speeds that its passage induced vibration modes in the guideway that needed to be damped out. This was a relatively new field for the civil engineers that were working on the guideway design, as their field was more generally concerned with static loads. The train layout
10648-509: The project would not be cancelled. By the time construction started on Tracked Hovercraft's test track, British Rail was well advanced on their plans for the steel-wheeled Advanced Passenger Train (APT). The government found itself in the position of funding two different high-speed train systems whose proponents were quick to point out problems in the competing system. To gain some clarity, they formed an interdepartmental working party that studied several potential inter-city transit solutions on
10769-584: The rear of the vertical wing-like surfaces on either side of the vehicle, and the sparks they threw during operation are easily visible on test runs. Starting in the 1970s, construction of test track started in the fens at Earith in Cambridgeshire, supported by Tracked Hovercraft Ltd offices in Ditton Walk in Cambridge city. The track was about 6 feet (1.8 m) off the ground, running along
10890-404: The same resistivity , but a long, thin copper wire has a much larger resistance than a thick, short copper wire. Every material has its own characteristic resistivity. For example, rubber has a far larger resistivity than copper. In a hydraulic analogy , passing current through a high-resistivity material is like pushing water through a pipe full of sand - while passing current through
11011-520: The same period, Eric Laithwaite had been developing the linear induction motor (LIM) at the University of Manchester . By 1961 he had built a small demonstration system consisting of a 20-foot-long (6.1 m) LIM reaction plate and a four-wheeled cart with a seat on top. In 1962 he started consulting with British Rail (BR) on the idea of using LIMs for high-speed trains. A November 1961 Popular Science article shows his Hovertrain concept using
11132-407: The same vehicle on steel wheels, at least at high speeds. Over 140 mph (230 km/h), conventional trains suffered from a problem known as hunting oscillation that forces the flanges on the sides of the wheels to hit the rail with increasing frequency, dramatically increasing rolling resistance . Although the energy needed to keep a hovercraft in motion also increased with speed, this increase
11253-461: The sample, and the electric field and current density are both parallel and constant everywhere. Many resistors and conductors do in fact have a uniform cross section with a uniform flow of electric current, and are made of a single material, so that this is a good model. (See the adjacent diagram.) When this is the case, the resistance of the conductor is directly proportional to its length and inversely proportional to its cross-sectional area, where
11374-413: The stator plate gave rise to a serious safety issue. Magnetic forces vary with the cube of distance, so any change in distance between the motor and stator plate caused it to be pulled more strongly to the closer side. At high speeds, the forces involved were so great that it was possible for the stator plate to crack along vertical joins in the plates, at which point it could strike the motor, or portions of
11495-482: The surface needed to support the same vehicle on wheels; hovertrains could be supported on surfaces similar to existing light-duty roadways, instead of the much more complex and expensive railbeds needed to support the weight on two rails. This could greatly reduce infrastructure capital costs. In 1960 several engineers at Christopher Cockerell 's Hovercraft Development Ltd. in Hythe, Hampshire , began early studies on
11616-413: The suspension system could be greatly reduced. Additionally, since the load is spread out over the surface of the lifting pads, the pressure on the running surface is greatly reduced – about 1 ⁄ 10,000 the pressure of a train wheel, about 1 ⁄ 20 of the pressure of a rubber tyre on a road. These two properties meant that the running surface could be considerably simpler than
11737-533: The test track to be converted to a testbed for his maglev design. By that point Rohr, Inc. in the US were already experimenting with their own LIM arrangement of this sort on their ROMAG personal rapid transport system, and there were several German maglev efforts underway as well. In the end the TH test track was abandoned. Laithwaite's work would eventually be used as the basis for the Birmingham Maglev ,
11858-535: The test track. China is developing two separate high-speed maglev systems. In Europe, high-speed rail began during the International Transport Fair in Munich in June 1965, when Dr Öpfering, the director of Deutsche Bundesbahn (German Federal Railways), performed 347 demonstrations at 200 km/h (120 mph) between Munich and Augsburg by DB Class 103 hauled trains. The same year
11979-463: The track as the vehicle passed, but this was at the great expense of requiring such equipment to be distributed along the line. In general terms, the maglev simply replaced the hover pads with electromagnets. Removing the motors and fans and replacing the pads with magnets reduced vehicle weight by about 15%. This change meant that the relatively low payload fraction of the hovercraft was greatly increased, as much as doubling it. But much more important
12100-444: The track itself can be seen in aerial photography, as it has been re-used as a dirt road. Further along the river bank, the engineering shed survives at Earith . The only surviving evidence of the offices in Ditton Walk, Cambridge is an electrical substation named "Hovercraft", which was installed to support the high-power electrical research work there. Many original documents from the Tracked Hovercraft project are stored within
12221-497: The two to repel each other. By moving the fields down the windings, the motor pushes itself along the plate with the same force that is normally used to create rotation in a conventional motor. A LIM eliminates the need for strong physical contact with the track, requiring instead a strong reaction plate. It has no moving parts, a major advantage over conventional traction. In Laithwaite's original designs, known as double-sided sandwich motors , two sets of windings were used, positioned
12342-409: The vehicle and a fixed external conductor. The external conductor was normally made of plates of aluminium, chosen due to its high conductivity in relation to its price. The active portion of the motor consists of a conventional electric motor winding stretched out under the vehicle. When the motor windings are energised, an opposing magnetic field is induced in the nearby reaction plate, which causes
12463-417: The vehicle behind the crack point. Even without an outright failure, any mechanical motion in the plate due to the forces of the passing train could induce waves in the stator that travelled along with it. If the vehicle then decelerated these waves could catch up with it. Additionally, the passing of the train heated the plate, potentially weakening it mechanically. Laithwaite concluded that the double-sided LIM
12584-540: The wider rail gauge, and thus standard gauge was adopted for high-speed service. With the sole exceptions of Russia, Finland, and Uzbekistan all high-speed rail lines in the world are still standard gauge, even in countries where the preferred gauge for legacy lines is different. The new service, named Shinkansen (meaning new main line ) would provide a new alignment, 25% wider standard gauge utilising continuously welded rails between Tokyo and Osaka with new rolling stock, designed for 250 km/h (160 mph). However,
12705-629: The world's population, without a single train passenger fatality. (Suicides, passengers falling off the platforms, and industrial accidents have resulted in fatalities.) Since their introduction, Japan's Shinkansen systems have been undergoing constant improvement, not only increasing line speeds. Over a dozen train models have been produced, addressing diverse issues such as tunnel boom noise, vibration, aerodynamic drag , lines with lower patronage ("Mini shinkansen"), earthquake and typhoon safety, braking distance , problems due to snow, and energy consumption (newer trains are twice as energy-efficient as
12826-473: Was "far too dangerous" to use. Most systems using LIMs – there were dozens by this point – redesigned their tracks to use a single-sided LIM over a stator plate lying flat between the rails. This led to another redesign of the Hovertrain guideway as a square box girder with the LIM stator attached flat on the top of the box, and the electrical pick-ups below on either side of it. Power pick-ups extended from
12947-470: Was achieved by providing the locomotive and cars with a unique axle system that used one axle set per car end, connected by a Y-bar coupler. Amongst other advantages, the centre of mass was only half as high as usual. This system became famous under the name of Talgo ( Tren Articulado Ligero Goicoechea Oriol ), and for half a century was the main Spanish provider of high-speed trains. In the early 1950s,
13068-530: Was also made about "current harnessing" at high-speed by the pantographs, which was solved 20 years later by the Zébulon TGV 's prototype. With some 45 million people living in the densely populated Tokyo– Osaka corridor, congestion on road and rail became a serious problem after World War II , and the Japanese government began thinking about ways to transport people in and between cities. Because Japan
13189-403: Was extended a further 161 km (100 mi), and further construction has resulted in the network expanding to 2,951 km (1,834 mi) of high speed lines as of 2024, with a further 211 km (131 mi) of extensions currently under construction and due to open in 2031. The cumulative patronage on the entire system since 1964 is over 10 billion, the equivalent of approximately 140% of
13310-492: Was inaugurated by the TEE Le Capitole between Paris and Toulouse , with specially adapted SNCF Class BB 9200 locomotives hauling classic UIC cars, and a full red livery. It averaged 119 km/h (74 mph) over the 713 km (443 mi). Electrical conductivity Electrical resistivity (also called volume resistivity or specific electrical resistance ) is a fundamental specific property of
13431-543: Was made of stainless steel and, like the Fliegender Hamburger, was diesel powered, articulated with Jacobs bogies , and could reach 160 km/h (99 mph) as commercial speed. The new service was inaugurated 11 November 1934, traveling between Kansas City and Lincoln , but at a lower speed than the record, on average speed 74 km/h (46 mph). In 1935, the Milwaukee Road introduced
13552-407: Was not only a part of the Shinkansen revolution: the Shinkansen offered high-speed rail travel to the masses. The first Bullet trains had 12 cars and later versions had up to 16, and double-deck trains further increased the capacity. After three years, more than 100 million passengers had used the trains, and the milestone of the first one billion passengers was reached in 1976. In 1972, the line
13673-489: Was proposing to combine with their rubber-tired Hawker Siddeley Minitram system. The GO-Urban contest was eventually won by a low-speed maglev, the Krauss-Maffei Transurban , a choice that occurred while the committee was meeting. Laithwaite was as publicly critical of the government's cancellation as he had been of BR's earlier efforts on LIM research. However, by this time he had distanced himself from
13794-441: Was redesigned with a box-like main girder, with a top-mounted reaction plate being used for the LIM, and the vertical sides of the guideway being used for centring. Wing-like extensions extended down from the body of the train and covered the centring pads. A version with this layout was built as a scale model at Hythe, and featured in another Pathé film in 1966. This version was shown at Hovershow '66. A further modification produced
13915-525: Was resource limited and did not want to import petroleum for security reasons, energy-efficient high-speed rail was an attractive potential solution. Japanese National Railways (JNR) engineers began to study the development of a high-speed regular mass transit service. In 1955, they were present at the Lille 's Electrotechnology Congress in France, and during a 6-month visit, the head engineer of JNR accompanied
14036-414: Was slower than the sudden (and sometimes catastrophic) increase due to hunting. That implied that for travel above some critical speed, a hovercraft could be more efficient than a wheeled vehicle running on the same route. Better yet, this vehicle would also retain all of the positive qualities of a hovercraft. Small imperfections in the surface would have no effect on the ride quality, and the complexity of
14157-402: Was still more than 30 years away. After the breakthrough of electric railroads, it was clearly the infrastructure – especially the cost of it – which hampered the introduction of high-speed rail. Several disasters happened – derailments, head-on collisions on single-track lines, collisions with road traffic at grade crossings, etc. The physical laws were well-known, i.e. if the speed was doubled,
14278-477: Was that there was no need to ingest and accelerate air to feed into the pads, which eliminated 2,100 kW (2,800 hp) and replaced it by the power needed to operate the magnets, estimated to be as little as 40 kW (54 hp). This meant that the Tracked Hovercraft found itself squeezed between the zero-energy lift system of the steel-wheeled APT and the low-energy lift system of the maglev, leaving no role that one of those systems didn't better serve. Only
14399-435: Was the first group to characterise the hunting oscillation in detail. Their work clearly suggested that careful design of the suspension system could eliminate the problem. This would allow high-speed trains to be built using conventional steel-wheel technology. Although high-speed travel would require new lines to be laid, expensive ones, such a train could use existing rail infrastructure at lower speeds. This would allow such
14520-477: Was too heavy for much of the tracks, so Cincinnati Car Company , J. G. Brill and others pioneered lightweight constructions, use of aluminium alloys, and low-level bogies which could operate smoothly at extremely high speeds on rough interurban tracks. Westinghouse and General Electric designed motors compact enough to be mounted on the bogies. From 1930 on, the Red Devils from Cincinnati Car Company and
14641-420: Was unsuccessful in raising new capital from the government and decided to put in £1 million from their own pre-assigned discretionary budget to start construction of a track, hoping that additional funding would be forthcoming from industry. On 1 April 1967, Hovercraft Development was officially transferred to National Physical Laboratory . Seeking to protect their investment, and finding little external funding,
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