TGV World Speed Record
   HOME

TheInfoList



OR:

The
TGV The TGV (; , , 'high-speed train') is France's intercity high-speed rail service. With commercial operating speeds of up to on the newer lines, the TGV was conceived at the same period as other technological projects such as the Ariane 1 rocke ...
(''train à grande vitesse'', 'high-speed train') holds a series of land speed records for rail vehicles achieved by
SNCF The Société nationale des chemins de fer français (, , SNCF ) is France's national State-owned enterprise, state-owned railway company. Founded in 1938, it operates the Rail transport in France, country's national rail traffic along with th ...
, the French national
railway Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...
, and its industrial partners. The high-speed trials are intended to expand the limits of
high-speed rail High-speed rail (HSR) is a type of rail transport network utilising trains that run significantly faster than those of traditional rail, using an integrated system of specialised rolling stock and dedicated railway track, tracks. While there is ...
technology, increasing speed and comfort without compromising safety. The current world speed record for a commercial train on steel wheels is held by the French TGV at 574.8 km/h (357.2 mph), achieved on 3 April 2007 on the new LGV Est.


TGV 001

The TGV 001 was an experimental gas turbine-electric locomotive-powered trainset built by
Alstom Alstom SA () is a French multinational rolling stock manufacturer which operates worldwide in rail transport markets. It is active in the fields of passenger transportation, signaling, and locomotives, producing high-speed, suburban, regional ...
to break speed records between 250–300
kilometres per hour The kilometre per hour (International System of Units, SI symbol: km/h; non-SI abbreviations: kph, kmph, km/hr) is a Units of measurement, unit of speed, expressing the number of kilometres travelled in one hour. History Although the metre was f ...
. It was the first
TGV The TGV (; , , 'high-speed train') is France's intercity high-speed rail service. With commercial operating speeds of up to on the newer lines, the TGV was conceived at the same period as other technological projects such as the Ariane 1 rocke ...
prototype and was commissioned in 1969, to begin testing in 1972. It achieved a top speed of on 8 December 1972.


Record of 1981


Operation TGV 100

Operation TGV 100, referring to a target speed of 100
metres per second The metre per second is the unit of both speed (a scalar quantity) and velocity (a vector quantity, which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in ...
(360 km/h, 224 mph), took place on 26 February 1981 shortly before the opening of the LGV Sud-Est and ended with a speed record of 380 
km/h The kilometre per hour ( SI symbol: km/h; non-SI abbreviations: kph, kmph, km/hr) is a unit of speed, expressing the number of kilometres travelled in one hour. History Although the metre was formally defined in 1799, the term "kilometres per h ...
(236  mph) set by TGV Sud-Est trainset number 16.


Record of 1990


Overview

Operations TGV 117 and TGV 140, referring to target speeds in
metres per second The metre per second is the unit of both speed (a scalar quantity) and velocity (a vector quantity, which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in ...
, were carried out by SNCF from November 1989 to May 1990. The culmination of these test programs was a new world speed record of 515.3 km/h (143.1 m/s or 320.3 mph), set on 18 May 1990. The record runs took place in two separate campaigns, separated by a period of modifications to trainset 325. For each day of testing, the 325 was towed to the test site by TGV Atlantique trainset 308 because its 1500 V DC systems had been removed, preventing operations near Paris. Trainset 308 also performed a sweep of the test track at 350 km/h before each high-speed run. The test runs took place on a section of the Atlantique branch of the TGV network, a few months before the line was opened to TGV revenue service. Strictly speaking, there were no significant alterations of the track or
catenary In physics and geometry, a catenary ( , ) is the curve that an idealized hanging chain or wire rope, cable assumes under its own weight when supported only at its ends in a uniform gravitational field. The catenary curve has a U-like shape, ...
for testing purposes. However, some sections of the line's profile had been planned since 1982 (shortly after the TGV Sud-Est world speed record of February 1981) to allow very high-speed running. Construction of the dedicated tracks of the LGV Atlantique was officially decided on 25 May 1984. Ground was broken on 15 February 1985. The new line was to stretch from slightly outside the
Gare Montparnasse Gare Montparnasse (; Montparnasse station), officially Paris Montparnasse, is one of the seven large List of Paris railway stations, Paris railway termini, and is located in the 14th arrondissement of Paris, 14th and 15th arrondissement of Paris ...
in Paris to
Le Mans Le Mans (; ) is a Communes of France, city in Northwestern France on the Sarthe (river), Sarthe River where it meets the Huisne. Traditionally the capital of the Provinces of France, province of Maine (province), Maine, it is now the capital of ...
, with a second branch towards
Tours Tours ( ; ) is the largest city in the region of Centre-Val de Loire, France. It is the Prefectures in France, prefecture of the Departments of France, department of Indre-et-Loire. The Communes of France, commune of Tours had 136,463 inhabita ...
. The Le Mans branch was opened for 300 km/h (186 mph) revenue service on 20 September 1989, and the Tours branch opened a year later. The two branches separate at Courtalain, 130 km west of Paris, where movable frog
points A point is a small dot or the sharp tip of something. Point or points may refer to: Mathematics * Point (geometry), an entity that has a location in space or on a plane, but has no extent; more generally, an element of some abstract topologica ...
good for 220 km/h (137 mph) in the diverging route direct trains towards either Le Mans or Tours. In the early stages when operation TGV 117 was still being defined, several criteria were settled upon to focus the preparation of a test train. These were
aerodynamics Aerodynamics () is the study of the motion of atmosphere of Earth, air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dynamics and its subfield of gas dynamics, and is an ...
, traction and
electrical Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwel ...
systems, rail and catenary contact, braking, and comfort. The basic purpose of the test program was to push the envelope of the TGV system, and to characterize its behavior at very high speeds. With this in mind, it only made sense to start with a stock TGV trainset and to modify it as little as possible. Brand new TGV Atlantique trainset number 325 (25th of 105 in the Atlantique series) was arbitrarily chosen to be the starting point of the modifications. There was nothing special about this trainset, and it was returned to its intended state after the test program to enter revenue service. Today, the only distinguishing feature on 325, as compared to other Atlantique trainsets, is a blue ribbon painted across the nose, and bronze plaques bolted to the sides of the two power cars to commemorate the event.


Location

The test section itself begins on the common branch, at kilometre 114, at the Dangeau siding. It runs past Courtalain and onto the Tours branch of the line. Between kilometre 135 and kilometre 170, the line was designed with progressively wider curves, reaching a minimum
radius In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...
of after kilometre 150. These curves were built with larger superelevation than strictly necessary for revenue running at 300 km/h (186 mph). At kilometre 160, the line passes through the Vendôme TGV station. At kilometre 166, there is a long 2.5% downhill stretch into the
Loir The Loir is a long river in western France. It is a left tributary of the Sarthe. Its source is in the Eure-et-Loir department, north of Illiers-Combray. It joins the river Sarthe in Briollay, north of the city of Angers. It is indirectly ...
valley (the Loir is a tributary of the better-known
Loire The Loire ( , , ; ; ; ; ) is the longest river in France and the 171st longest in the world. With a length of , it drains , more than a fifth of France's land, while its average discharge is only half that of the Rhône. It rises in the so ...
river) and the line crosses the Loir on a 175 m (575 ft)
bridge A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...
. This is the area where the highest speeds were expected, and most of the activity was concentrated there.


Track preparation

The Tours branch of the line was tested by special computerized Maintenance of Way equipment manufactured by GEISMAR, from the Track Research department of SNCF. Just as on all TGV lines, the rails were aligned to tolerances, and the
ballast Ballast is dense material used as a weight to provide stability to a vehicle or structure. Ballast, other than cargo, may be placed in a vehicle, often a ship or the gondola of a balloon or airship, to provide stability. A compartment within ...
was blasted to remove small, loose
gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...
. In subsequent testing with trainsets 308 and 325, the track was not significantly affected and required only minimal realignment. This was in contrast to the 1955 world speed record of , also set in France, where the track was seriously damaged after the high-speed runs. Large sections of the track were warped and misshapen, as well as the train's pantograph was melted.
Strain gauge A strain gauge (also spelled strain gage) is a device used to measure Deformation (mechanics)#Strain, strain on an object. Invented by Edward E. Simmons and Arthur C. Ruge in 1938, the most common type of strain gauge consists of an Electrical in ...
s were placed in several locations, especially at the
expansion joint A expansion joint, or movement joint, is an assembly designed to hold parts together while safely absorbing temperature-induced expansion and contraction of building materials. They are commonly found between sections of buildings, bridges, s ...
at the end of the Loir bridge.


Catenary modifications

The
catenary In physics and geometry, a catenary ( , ) is the curve that an idealized hanging chain or wire rope, cable assumes under its own weight when supported only at its ends in a uniform gravitational field. The catenary curve has a U-like shape, ...
was standard TGV style, without any modifications. The only changes were in the tuning. In general, when a
pantograph A pantograph (, from their original use for copying writing) is a Linkage (mechanical), mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a se ...
passes under the catenary, it creates a
wave In physics, mathematics, engineering, and related fields, a wave is a propagating dynamic disturbance (change from List of types of equilibrium, equilibrium) of one or more quantities. ''Periodic waves'' oscillate repeatedly about an equilibrium ...
-like disturbance that travels down the wire at a speed determined by the tension in the wire and its mass per unit length. As a train approaches this critical speed, the pantograph catches up with the disturbance, causing dangerously large vertical displacements of the wire and contact interruptions. The maximum speed of the train is then limited by the critical speed of the overhead line. This problem was central to the test runs, as it was desired to test the 325 set at speeds well above the critical speed of the standard TGV catenary. There were two solutions: increase the tension in the wire or reduce its mass per unit length. The TGV catenary is strung in sections and mechanically tensioned by a system of
pulley Sheave without a rope A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft. A pulley may have a groove or grooves between flan ...
s and
counterweight A counterweight is a weight (object), weight that, by applying an opposite force, provides balance and stability of a machine, mechanical system. The purpose of a counterweight is to make lifting the load faster and more efficient, which saves e ...
s. The masts are spaced at apart. The messenger wire is
bronze Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals (such as phosphorus) or metalloid ...
with a circular cross-section of . The contact wire is
copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...
with a cross-section of . The cross-section of the contact wire is circular with a dovetail cut at the top. Replacing the copper contact wire by a lighter
cadmium Cadmium is a chemical element; it has chemical symbol, symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12 element, group 12, zinc and mercury (element), mercury. Like z ...
alloy wire was considered, but dismissed on the grounds of time and cost. The critical speed of the test track catenary was then to be increased solely by increasing the tension in the wire. For the test runs, the usual tension of was increased to and exceptionally . For some of the faster runs over , the
voltage Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a Electrostatics, static electric field, it corresponds to the Work (electrical), ...
in the catenary was increased from the usual 25  kV 50  Hz to 29.5 kV. At kilometre 166, catenary masts were equipped with sensors to measure the displacement of the wire. During the 18 May 1990 record at 515.3 km/h (320.3 mph), vertical displacements of almost 30 cm (1 ft) were recorded, within 1 or 2 cm of the predictions made by
computer simulation Computer simulation is the running of a mathematical model on a computer, the model being designed to represent the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be determin ...
s. The critical speed of the catenary for that particular run was 532 km/h (331 mph).


Preparation of the train for Operation TGV 117

In preparation for the first round of testing, modifications began by shortening the train from its usual 10 trailers to only 4 trailers, resulting in a significant increase to its
power-to-weight ratio Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement ...
. The resulting train consisted of: power car TGV24049, Trailer R1 TGVR241325, Trailer R4 TGVR244325, Trailer R6 TGVR246325, Trailer R10 TGVR240325 and power car TGV24050. Train length was down to 125 m (381 ft.) from 237 m (777 ft) and weight was down to 300 t from 490 t. The aerodynamics of a TGV Atlantique are already quite good, and improvements were few. It was decided that 325 would have a "front" and "rear" for the high-speed runs, to simplify the modifications. Usually a TGV trainset is
symmetric Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is invariant under some transformations ...
and reversible, but 325's two
power car In rail transport, the expression power car may refer to either of two distinct types of rail vehicle: *a vehicle that propels, and commonly also controls, a passenger train, potentially a multiple unit train, often as the lead vehicle; *a veh ...
s, 24049 and 24050, were defined as leading and trailing units, respectively. On the roof of lead unit 24049, the pantographs were removed and the roof fairing extended over the opening; the same was done to the 1500 V DC pantograph on trailing unit 24050. Only one pantograph was to be used at high speed: the stock Faiveley GPU unit remaining on unit 24050. As in normal TGV running, the lead unit was to be fed power from the trailing unit through the roof line running the length of the train. Further improvements, such as
rubber Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Types of polyisoprene ...
membranes covering the gaps between the trailers, and a rear spoiler on the trailing unit were considered, but abandoned. The synchronous AC
traction motor A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric vehicle, electric or hydrogen vehicles, or electric multiple unit trains. Traction (engineering), Traction motors are used in electrically powe ...
s on 24049 and 24050 could not be allowed to rotate too fast, because of limitations in the switching
frequency Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio ...
of the supply
electronics Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other Electric charge, electrically charged particles. It is a subfield ...
. Technicians had decided upon 4000 
rpm Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or r⋅min−1) is a unit of rotational speed (or rotational frequency) for rotating machines. One revolution per minute is equivalent to hertz. Standards ISO 80000-3:2019 def ...
at 420 km/h (261 mph) to be the optimal
ratio In mathematics, a ratio () shows how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemons is eight to six (that is, 8:6, which is equivalent to the ...
, after testing trainset 325 at high speeds with stock traction equipment. The new traction ratio was achieved by changing the transmission
gear A gear or gearwheel is a rotating machine part typically used to transmit rotational motion and/or torque by means of a series of teeth that engage with compatible teeth of another gear or other part. The teeth can be integral saliences or ...
ing and increasing the wheel
diameter In geometry, a diameter of a circle is any straight line segment that passes through the centre of the circle and whose endpoints lie on the circle. It can also be defined as the longest Chord (geometry), chord of the circle. Both definitions a ...
. Just as with the 1981 test campaign on TGV PSE number 16, 1050 mm (41 in) wheels replaced the stock 920 mm (36 in) wheels under 24049 and 24050. To prevent electrical problems,
semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...
components (especially
thyristor A thyristor (, from a combination of Greek language ''θύρα'', meaning "door" or "valve", and ''transistor'' ) is a solid-state semiconductor device which can be thought of as being a highly robust and switchable diode, allowing the passage ...
s) were selected with special regard to quality. The main
transformer In electrical engineering, a transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple Electrical network, circuits. A varying current in any coil of the transformer produces ...
s in both power cars were replaced by larger models, each able to handle 6400  kW (8500  hp), or double the usual load, on a fairly continuous basis. Extensive tests were conducted on the electrical systems, to establish how far they could be pushed. The resulting ratings ensured that acceptable
heat In thermodynamics, heat is energy in transfer between a thermodynamic system and its surroundings by such mechanisms as thermal conduction, electromagnetic radiation, and friction, which are microscopic in nature, involving sub-atomic, ato ...
levels would never be exceeded in testing. Next, the wheel-rail interface was attended to.
Axle An axle or axletree is a central shaft for a rotation, rotating wheel and axle, wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In ...
bearings were unmodified items, broken in for 10,000 km in revenue service on the LGV Sud-Est. Yaw dampers were stiffened, and doubled up on each side for a total of four yaw dampers on each truck, for redundancy in case of a high-speed failure. As a result of earlier testing and computer simulations, transverse dampers were stiffened on the power trucks. The 1981 test campaign provided valuable data and
computer model Computer simulation is the running of a mathematical model on a computer, the model being designed to represent the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be determin ...
s for interaction of the pantograph with the catenary contact wire, and shed light on the very sensitive dynamics. Very large vertical wire excursion (over 30 cm, or 1 foot) had been observed in the 1981 tests, and were blamed on the pantograph catching up with the travelling wave it set up in the contact wire. For this reason, it was not only necessary to modify the catenary to increase the travelling wave speed, but also to fine-tune the pantograph itself. The pantograph used on 325 was the stock Faiveley GPU. The wiper assembly on this pantograph weighs under 8  kg (18  lb) and is mounted on a vertical
shock absorber A shock absorber or damper is a mechanical or hydraulics, hydraulic device designed to absorb and Damping ratio, damp shock (mechanics), shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typic ...
with 150 mm (6 in) travel. The main structure of the pantograph is constructed of
cylindrical A cylinder () has traditionally been a Solid geometry, three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a Prism (geometry), prism with a circle as its base. A cylinder may ...
tubing, which (Faiveley claims) reduces the pantograph's sensitivity to random variations in environmental factors. The only modifications to the GPU pantograph were an increase in the stiffness of the pneumatic dampers, and a reduced total aerodynamic lift of the structure. The suspension on the trailers was jacked up by 20 mm (1 in) by overinflating the secondary suspension air bladders and inserting shims, to provide additional suspension travel and to make up for the larger wheels on the power cars. The brakes on the trailers were tuned to allow a heat dissipation of 24  MJ per disk instead of the usual 18 MJ, with a total of 20 discs. Many of the modifications listed above, including the synchronous traction motors, were tested at speeds over 400 km/h on TGV Sud-Est trainset 88. In one high-speed test, technicians attempted to provoke a truck into unstable oscillation by drastically reducing the yaw damping, but failed to achieve this. Finally, most of the seating in trailer R1 was removed and the space was transformed into a
laboratory A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratories are found in a variety of settings such as schools ...
, to process and record test data on vehicle dynamics, overhead contact and dynamics, tractive effort, aerodynamics, interior comfort and noise, and a host of other parameters. On 30 November 1989, trainset 325 emerged from the Châtillon shops and set out for the test tracks for its first test run. Technicians at Châtillon put 4500 hours of work into the modifications, which was impressive when one considers that their first priority was the routine maintenance of the TGV Atlantique trainsets in revenue service.


Record run, Operation TGV 117

The first campaign, also known as operation TGV 117, took place between 30 November 1989 and 1 February 1990. After several runs, problems with
pantograph A pantograph (, from their original use for copying writing) is a Linkage (mechanical), mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a se ...
contact required manual adjustments to be made by first grounding the
catenary In physics and geometry, a catenary ( , ) is the curve that an idealized hanging chain or wire rope, cable assumes under its own weight when supported only at its ends in a uniform gravitational field. The catenary curve has a U-like shape, ...
and then sending technicians onto the roof. After a series of increasingly fast runs, the first official speed record of 482.4 km/h (299.8 mph) was set at kilometer point 166 on 5 December 1989, with engineer Michel Boiteau at the controls. At the end of this run, trainset 325 had accumulated at speeds exceeding 400 km/h (249 mph). More high-speed runs were made after this record, investigating effects such as the crossing of two trains with a closing velocity of 777.7 km/h (483 mph). With favorable results indicating that higher speeds were safe, the decision was made to further modify trainset 325 for speeds near 500 km/h (311 mph).


Preparation of the train for Operation TGV 140

On 1 February 1990 at 15:30, 325 returned to the Châtillon shops for the long term. At this time, 325 had set a world record at 482.4 km/h (299.8 mph). Technicians had a 1 March deadline to perform further modifications designed to make possible further data collection and a 500 km/h (313 mph)
publicity stunt In marketing, a publicity stunt is a planned event designed to attract the public's attention to the event's organizers or their cause. Publicity stunts can be professionally organized, or set up by amateurs. Such events are frequently utiliz ...
. This second round of modifications was intended to take direct advantage of the experience gained in the first round. The axles on 24049 and 24050 were removed and on 2 February, shipped to the Bischheim workshops in eastern France for fitting with even larger 1090 mm (43 in) wheels. The lead axle on 24049 was fitted with strain gauges, and returned to Châtillon 8 days after the other axles on 22 February. Initially, the second axle on 24049 had also been scheduled to be fitted with strain gauges, but the 1 March deadline did not allow enough time. To accommodate the bigger wheels, special brake pads had to be manufactured for the brake shoes on 24049 and 24050. With 15 mm (5/8 in) of thickness, only two emergency stops were guaranteed. On 6 February, the trailers were jacked up and trailer R6 was removed. This brought 325 to the minimum possible consist, since the bar trailer R4 functions as the "keystone" of the articulated design of the TGV. 325 now weighed in at 250 t and measured 106 m (348 ft) nose to tail. From 7 to 14 February, the three remaining trailers underwent further modifications. The 25 kV roof supply line to feed the lead unit was replaced by a single cable; this allowed the removal of the insulators supporting the line over the space between trailers, which protruded in the air stream. Rubber membranes were installed to cover the gaps between the trailers, and the Y237B trucks were jacked by 40 mm (1.5 in). In the gap between power cars and trailers, large airdams were installed. These "snow shields", mounted beneath the couplers, were designed to prevent the formation of a low
pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...
area between the vehicles, which had induced significant drag in the earlier testing. On the power cars, sheet metal shields were added over the trucks, and the front airdam was extended downwards by 10 cm (4 in) to compensate for the larger wheels. Finally, a removable spoiler was installed on the nose of trailing unit 24050. The aerodynamic improvements were supposed to yield a 10 % reduction in drag. In the previous round of testing, the atmospheric drag force had reached 88 kN at a speed of 460 km/h (286 mph). On the new version of 325, this magnitude of drag was not expected before 500 km/h (311 mph). On 27 February 1990, after the trainset was coupled together, 325 rolled out from the Châtillon shops for the second time, 2 days ahead of schedule. This time, 2000 hours of shop labour were required to accomplish the changes. The second campaign of testing, culminating in the standing world speed record of 515.3 km/h (320.3 mph) is summed up in the
chronology Chronology (from Latin , from Ancient Greek , , ; and , ''wikt:-logia, -logia'') is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of events. It is also "the deter ...
of the record runs.


Record run, Operation TGV 140

The second campaign, also known as operation TGV 140, took place between 5 March 1990 and 18 May 1990, after the train modifications were complete. On the first high-speed run, an electrical malfunction destroyed the main
transformer In electrical engineering, a transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple Electrical network, circuits. A varying current in any coil of the transformer produces ...
of the rear power car and damaged many low voltage circuits. The damage was found to require nearly a month of repairs, primarily because a new transformer able to sustain the high power loads had to be prepared. The 325 returned to testing on 4 May 1990 and exceeded the 5 December record on its first run of the day. The 500 km/h (311 mph) mark was unofficially broken on 9 May 1990, with runs at 506.5 km/h (315 mph) and 510.6 km/h (317.3 mph). The switches in the Vendôme station were passed at 502 km/h (312 mph). Instability of the contact dynamics between the pantograph and catenary caused trouble during the next several days, although intermittent runs achieved speeds above 500 km/h. Following the resolution of this problem, the final record attempt took place on 18 May 1990, with dignitaries, and journalists joining the usual complement of technicians on board the train. The 325 started its run at 9:51 from Dangeau and accelerated for 15 minutes, achieving a top speed of 515.3 km/h (320.3 mph) at the bottom of the hill at kilometer post 166.8. At the conclusion of the test campaign, the train had reached top speeds in excess of 500 km/h on nine separate occasions, including the world speed record.


Record of 2007


Overview

Operation V150, where 150 again refers to a target speed in
metres per second The metre per second is the unit of both speed (a scalar quantity) and velocity (a vector quantity, which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in ...
, was a series of high-speed trials carried out on the LGV Est prior to its June 2007 opening. The trials were conducted jointly by
SNCF The Société nationale des chemins de fer français (, , SNCF ) is France's national State-owned enterprise, state-owned railway company. Founded in 1938, it operates the Rail transport in France, country's national rail traffic along with th ...
, TGV builder
Alstom Alstom SA () is a French multinational rolling stock manufacturer which operates worldwide in rail transport markets. It is active in the fields of passenger transportation, signaling, and locomotives, producing high-speed, suburban, regional ...
, and LGV Est owner Réseau Ferré de France between 15 January 2007 and 15 April 2007. Following a series of increasingly high-speed runs, the official speed record attempt took place on 3 April 2007. The top speed of 574.8 km/h (159.7 m/s, 357.2 mph) was reached at kilometer point 193 near the village of Le Chemin, between the Meuse and Champagne-Ardenne TGV stations, where the most favorable profile exists. It reached top speed 12 minutes 40 seconds and 71 km after leaving Prény from a standstill. The 515.3 km/h speed record of 1990 was unofficially broken multiple times during the test campaign that preceded and followed the certified record attempt, the first time on 13 February 2007 with a speed of 554.3 km/h, and the last time on 15 April 2007 with a speed of 542.9 km/h.


Track preparation

The record runs took place on a 140 km section of track 1 on the LGV Est, usually heading west, between kilometer posts 264 (town of Prény) and 120 (near the Champagne-Ardenne TGV station). This section of the LGV was chosen for its vertical profile and gentle curves, with favorable downhill segments leading to the highest speeds between kilometer posts 195 and 191, near the border between the
Meuse The Meuse or Maas is a major European river, rising in France and flowing through Belgium and the Netherlands before draining into the North Sea from the Rhine–Meuse–Scheldt delta. It has a total length of . History From 1301, the upper ...
and Marne departments. The track superelevation was increased to support higher speeds.
Catenary In physics and geometry, a catenary ( , ) is the curve that an idealized hanging chain or wire rope, cable assumes under its own weight when supported only at its ends in a uniform gravitational field. The catenary curve has a U-like shape, ...
voltage was increased to 31 kV from the standard 25 kV. The mechanical tension in the wire was increased to 40 kN from the standard 25 kN. The speed of the
transverse wave In physics, a transverse wave is a wave that oscillates perpendicularly to the direction of the wave's advance. In contrast, a longitudinal wave travels in the direction of its oscillations. All waves move energy from place to place without t ...
induced in the overhead wire by the train's
pantograph A pantograph (, from their original use for copying writing) is a Linkage (mechanical), mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a se ...
was thus increased to 610 km/h, providing a margin of safety beyond the train's maximum speed. Several measurement stations were installed along the test tracks to monitor stresses in the track and
ballast Ballast is dense material used as a weight to provide stability to a vehicle or structure. Ballast, other than cargo, may be placed in a vehicle, often a ship or the gondola of a balloon or airship, to provide stability. A compartment within ...
, noise, aerodynamic effects, and catenary dynamics. Between kilometer posts 223 and 167, where speeds exceeded 500 km/h, the track was under close surveillance.


Preparation of the train for Operation TGV 150

The train used for the speed record was code named V150, and comprised three modified Duplex cars, fitted with two powered bogies similar to the AGV prototype, marshalled between a pair of TGV power cars from POS trainset 4402. The train had four more powered axles than trainset 325 used in the 1990 speed record, and had a maximum power output of 19.6  MW (26,800  hp) instead of the 9.3 MW on a standard TGV POS. This unusual composition was used to obtain high-speed test data on disparate technical elements including the new asynchronous traction motors on the POS power cars, the lightweight synchronous permanent magnet traction motors on the AGV bogies, the actively controlled
pantograph A pantograph (, from their original use for copying writing) is a Linkage (mechanical), mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a se ...
, and the Duplex bi-level configuration which had never been used in very high-speed trials. Aerodynamic improvements, similar to the 1990 record train, were refined in a
wind tunnel A wind tunnel is "an apparatus for producing a controlled stream of air for conducting aerodynamic experiments". The experiment is conducted in the test section of the wind tunnel and a complete tunnel configuration includes air ducting to and f ...
and provided a 15% reduction in drag from the standard configuration. These improvements included a front air dam, roof fairings over the pantograph openings, membranes to cover the space between the cars, and a flush-mounted windshield. Over 600 sensors were fitted on various parts of both the engines and the cars. The train set ran with larger wheels with a diameter of 1092 mm instead of 920 mm, to limit the rotational speed of the
powertrain In a motor vehicle, the powertrain comprises the main components that generate engine power, power and deliver that power to the road surface, water, or air. This includes the internal combustion engine, engine, transmission (mechanics), trans ...
.


Record run, Operation TGV 150

Between 15 January 2007 and 15 April 2007, the V150 train traveled at 500 km/h and above for a cumulative distance of 728 km. For each high-speed run, another TGV performed a sweep of the track before the V150 train was cleared to start. This sweep was performed at a sustained 380 km/h, incidentally the peak speed reached in the record of 1981, with TGV POS trainset 4404 in a standard 8-car configuration. The acceleration of the V150 train took place over a distance of 70 km. During certain runs, including the official record run, the V150 train was chased by an Aérospatiale Corvette airplane to provide data relay and uplink of
live television Live television is a television production broadcast in real-time, as events happen, in the present. In a secondary meaning, it may refer to streaming television where all viewers watch the same stream simultaneously, rather than watching vide ...
images.


See also

*
Land speed record for rail vehicles This article provides an overview of speed records in rail transport. It is divided into absolute records for rail vehicles and fastest connections in the timetable. Current speed records The world record for a conventional wheeled passenger ...
*
TGV The TGV (; , , 'high-speed train') is France's intercity high-speed rail service. With commercial operating speeds of up to on the newer lines, the TGV was conceived at the same period as other technological projects such as the Ariane 1 rocke ...
* LGV construction *AGV Automotrice à grande vitesse - TGV Replacement


References


External links


Video of the record being broken
- DailyMotion.com
NAMTI's view of the TGV's Speed record's true meaning
- TGV’s 357Mph Demo Proves There Are Speed/Maintenance Limitations On HSR {{Records Land speed record rail vehicles TGV