The TGV (''Train à Grande Vitesse'', French for "High-Speed Train") holds a series of land speed records for rail vehicles achieved by SNCF, the French national

railway Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

, and its industrial partners. The high-speed trials are intended to expand the limits of high-speed rail 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 The Ligne à Grande Vitesse Est européenne (East European High Speed Line), typically shortened to LGV Est, is a French high-speed rail line that connects Vaires-sur-Marne (near Paris) and Vendenheim (near Strasbourg). The line halved the ...

TGV 001

The TGV 001 was an experimental gas turbine-electric locomotive-powered

trainset In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often know ...

built by Alstom to break speed records between 250–300 kilometres per hour. It was the first TGV 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 a ...

(360 km/h, 224 mph), took place on 26 February 1981 shortly before the opening of the

LGV Sud-Est The LGV Sud-Est (French: ''Ligne à Grande Vitesse Sud-Est''; English: ''South East high-speed line)'' is a French high-speed rail line which connects the Paris and Lyon areas. It was France's first high-speed rail line. The inauguration of th ...

and ended with a speed record of 380

km/h The kilometre per hour ( SI symbol: km/h; non-standard abbreviations: kph, 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 ho ...

(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

, 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 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, superfici ...

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, one of the six large Paris railway termini, is located in the 14th and 15th arrondissements. The station opened in 1840, was rebuilt in 1852 and relocated in 1969 to ...

in Paris to Le Mans, with a second branch towards

Tours Tours ( , ) is one of the largest cities in the region of Centre-Val de Loire, France. It is the prefecture of the department of Indre-et-Loire. The commune of Tours had 136,463 inhabitants as of 2018 while the population of the whole metro ...

. 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 Courtalain () is a former commune in the Eure-et-Loir department in northern France. On 1 January 2017, it was merged into the new commune Commune nouvelle d'Arrou.points 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, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dy ...

, traction and

electrical Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...

systems, rail and catenary contact,

braking A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction. Backgroun ...

, 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) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

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 valley (the Loir is a tributary of the better-known

Loire The Loire (, also ; ; oc, Léger, ; la, Liger) 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 ...

river) and the line crosses the Loir on a 175 m (575 ft)

bridge A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somethi ...

. 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 1 mm (3/64 in) tolerances, and the

ballast Ballast is material that is used 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 a boat, ship ...

was blasted to remove small, loose gravel. 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 331 km/h (206 mph), 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 gauges were placed in several locations, especially at the expansion joint at the end of the Loir bridge.

Catenary modifications

The

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 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 second pen. If a line dr ...

runs underneath the catenary, it sets up a

wave In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (re ...

-like disturbance which travels down the wire with a speed determined by the tension in the wire and its mass per unit length. When a train approaches this critical speed, the pantograph catches up with the disturbance, resulting in dangerously large vertical displacements of the wire as well as contact interruptions. The top speed of the train is then limited by the critical speed of the catenary. This problem was central to the test runs, since it was desired to test set 325 at speeds well above the critical speed of standard TGV catenary. There were two solutions: increase the tension in the wire or reduce its mass per unit length. TGV catenary is strung in 1200 m (4000 ft) sections, mechanically tensioned by a system of pulleys and

counterweight A counterweight is a weight that, by applying an opposite force, provides balance and stability of a mechanical system. The purpose of a counterweight is to make lifting the load faster and more efficient, which saves energy and causes less wea ...

s. Support masts are spaced at 54 m (175 ft) intervals. The catenary (supporting) wire is made of bronze, with a circular cross-section of 65 mm². The contact wire is made of

copper Copper is a chemical element with the symbol Cu (from la, cuprum) 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 pinkis ...

, and has a cross-section of 150 mm². The cross-section of the contact wire is circular with a flat section on the contact side. Replacing the copper contact wire by a lighter

cadmium Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...

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 20 kN (4500 lbf) was increased to 28 kN (6300 lbf) and exceptionally 32 kN (7200 lbf). For some of the faster runs over 500 km/h (311 mph), the

voltage Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to ...

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 simulations. 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. 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 (from grc, συμμετρία "agreement in dimensions, due proportion, arrangement") in everyday language refers to a sense of harmonious and beautiful proportion and balance. In mathematics, "symmetry" has a more precise definiti ...

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, multiple unit or tram, often as the lead vehicle; *a vehicle equipped ...

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. Thailand, Malaysia, an ...

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 or hydrogen vehicles, elevators or electric multiple unit. Traction motors are used in electrically powered rail vehicles ( electric multiple ...

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. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...

of the supply

electronics The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification ...

. Technicians had decided upon 4000 rpm 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 is a rotating circular machine part having cut teeth or, in the case of a cogwheel or gearwheel, inserted teeth (called ''cogs''), which mesh with another (compatible) toothed part to transmit (convert) torque and speed. The basic ...

ing and increasing the wheel

diameter In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid fo ...

. 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 which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...

components (especially

thyristor A thyristor () is a solid-state semiconductor device with four layers of alternating P- and N-type materials used for high-power applications. It acts exclusively as a bistable switch (or a latch), conducting when the gate receives a current ...

s) were selected with special regard to quality. The main

transformer A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer' ...

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 defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is ...

levels would never be exceeded in testing. Next, the wheel-rail interface was attended to. Axle bearings were unmodified items, broken in for 10,000 km in revenue service on the

. 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 process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be deter ...

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 with 150 mm (6 in) travel. The main structure of the pantograph is constructed of cylindrical 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. Laboratory services are provided in a variety of settings: physic ...

, 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

contact required manual adjustments to be made by first grounding the

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 utilize ...

. 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 e ...

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 ''chronologia'', from Ancient Greek , ''chrónos'', "time"; and , ''-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. I ...

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

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 Vendôme (, ) is a subprefecture of the department of Loir-et-Cher, France. It is also the department's third-biggest commune with 15,856 inhabitants (2019). It is one of the main towns along the river Loir. The river divides itself at the ...

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

, was a series of high-speed trials carried out on the

prior to its June 2007 opening. The trials were conducted jointly by SNCF, TGV builder Alstom, and LGV Est owner

Réseau Ferré de France Réseau ferré de France (RFF, french: French Rail Network) was a French company which owned and maintained the French national railway network from 1997 to 2014. The company was formed with the rail assets of SNCF in 1997. Afterwards, the train ...

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 (159.6 m/s, 357.2 mph) was reached at kilometer point 191 near the village of Le Chemin, between the Meuse and

Champagne-Ardenne Champagne-Ardenne () is a former administrative region of France, located in the northeast of the country, bordering Belgium. Mostly corresponding to the historic province of Champagne, the region is known for its sparkling white wine of th ...

TGV stations, where the most favorable profile exists. It reached top speed 12 minutes 40 seconds and 73 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

, usually heading west, between kilometer posts 264 (town of

Prény Prény () is a commune in the Meurthe-et-Moselle department in north-eastern France. See also * Communes of the Meurthe-et-Moselle department The following is a list of the 591 communes of the Meurthe-et-Moselle department of France. The ...

) and 120 (near the

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 ( , , , ; wa, Moûze ) or Maas ( , ; li, Maos or ) 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 t ...

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 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, superfici ...

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 induced in the overhead wire by the train's

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

, 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

, 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 Wind tunnels are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft ...

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 A drivetrain (also frequently spelled as drive train or sometimes drive-train) is the group of components that deliver mechanical power from the prime mover to the driven components. In automotive engineering, the drivetrain is the components o ...

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 The TGV POS is a TGV train built by French manufacturer Alstom which is operated by the French national rail company, the SNCF, in France's high-speed rail lines. It was originally ordered by the SNCF for use on the new LGV Est, which was put in ...

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 The Aérospatiale SN 601 Corvette is a French business jet of the early 1970s developed and manufactured by aerospace manufacturer Aérospatiale. Sales of the type were disappointing, leading to only 40 Corvettes being constructed, including the ...

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 over the Internet when content or programming is played continuously (not on deman ...

images.

References

External links

2007 record official site
-
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