TGV world speed record - AbsoluteAstronomy.com

The TGV

TGV

The TGV is France's high-speed rail service, currently operated by SNCF Voyages, the long-distance rail branch of SNCF, the French national rail operator....

(Train à Grande Vitesse, French

French language

French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

for "High-Speed Train") holds a series of world speed records

Land speed record for railed vehicles

Determination of the fastest rail vehicle in the world varies depending on the definition of "rail".Official absolute world record for conventional train is held by the French TGV...

achieved by SNCF

SNCF

The SNCF , is France's national state-owned railway company. SNCF operates the country's national rail services, including the TGV, France's high-speed rail network...

, the French national railway, 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 TGV world speed record is 574.8 km/h (357.2 mph), achieved on 3 April 2007 on the new LGV Est

LGV Est

The LGV Est européenne is an extension to the French high-speed rail network, connecting currently Vaires-sur-Marne and Baudrecourt , and later Vaires-sur-Marne and Vendenheim . , it is the newest high-speed line in France and still under construction, with of a planned in service...

TGV 001

The TGV 001

TGV 001

TGV 001 was a high-speed railway train built in France. It was the first TGV prototype and was commissioned in 1969, to begin testing in 1972...

was an experimental gas turbine-electric locomotive

Gas turbine-electric locomotive

A gas turbine - electric locomotive, or GTEL, is a locomotive that uses a gas turbine to drive an electric generator or alternator. The electric current thus produced is used to power traction motors. This type of locomotive was first experimented with during the Second World War, but reached its...

-powered trainset built by Alstom

Alstom

Alstom is a large multinational conglomerate which holds interests in the power generation and transport markets. According to the company website, in the years 2010-2011 Alstom had annual sales of over €20.9 billion, and employed more than 85,000 people in 70 countries. Alstom's headquarters are...

to break speed records between 250–300 kilometre per hour. It was the first TGV

TGV

The TGV is France's high-speed rail service, currently operated by SNCF Voyages, the long-distance rail branch of SNCF, the French national rail operator....

prototype and was commissioned in 1969, to begin testing in 1972. It acchieved a top speed of 318 kilometres per hour (197.6 mph) on 8 December 1972.

Operation TGV 100

Operation TGV 100, referring to a target speed of 100 metres per second

Metre per second

Metre per second is an SI derived unit of both speed and velocity , defined by distance in metres divided by time in seconds....

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

LGV Sud-Est

The LGV Sud-Est is a high-speed rail line, which links Paris' and Lyon's suburbs, in France. The inauguration of the first section between Saint-Florentin and Sathonay on 22 September 1981 marked the beginning of the re-invigoration of French passenger rail service.This line, subsequently...

and ended with a speed record of 380 km/h

Kilometres per hour

The kilometre per hour is a unit of speed, expressing the number of kilometres traveled in one hour. The unit symbol is km/h or km·h−1....

(236 mph

Miles per hour

Miles per hour is an imperial unit of speed expressing the number of statute miles covered in one hour. It is currently the standard unit used for speed limits, and to express speeds generally, on roads in the United Kingdom and the United States. It is also often used to express the speed of...

) set by TGV Sud-Est

SNCF TGV Sud-Est

The SNCF TGV Sud-Est or TGV-PSE is a French TGV train built by Alstom and operated by SNCF, the French national railway company. It is a semi-permanently coupled electric multiple unit which operates primarily between Paris and the south-east of France....

trainset number 16.

Overview

Operations TGV 117 and TGV 140, referring to target speeds in metres per second

Metre per second

Metre per second is an SI derived unit of both speed and velocity , defined by distance in metres divided by time in seconds....

, were carried out by SNCF from November 1989 to May 1990. The culmination of these test programs was a new world speed record

Land speed record for railed vehicles

Determination of the fastest rail vehicle in the world varies depending on the definition of "rail".Official absolute world record for conventional train is held by the French TGV...

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

LGV Atlantique

The LGV Atlantique is a high-speed railway line running from Paris to Western France. It opened in 1989-1990. It divides into two parts at Courtalain, one going westward to Le Mans , the second one going southwestward to Tours .-Route:The line leaves Gare Montparnasse to cross Paris's southern...

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

Overhead lines

Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...

for testing purposes. However, some sections of the line's profile had been planned since 1982 (shortly after the TGV Sud-Est

SNCF 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

Paris Montparnasse is one of the six large terminus railway stations of Paris, located in the Montparnasse area in the XIVe arrondissement. The station was opened in 1840, and rebuilt completely in 1969...

in Paris to Le Mans

Le Mans

Le Mans is a city in France, located on the Sarthe River. Traditionally the capital of the province of Maine, it is now the capital of the Sarthe department and the seat of the Roman Catholic diocese of Le Mans. Le Mans is a part of the Pays de la Loire region.Its inhabitants are called Manceaux...

, with a second branch towards Tours

Tours

Tours is a city in central France, the capital of the Indre-et-Loire department.It is located on the lower reaches of the river Loire, between Orléans and the Atlantic coast. Touraine, the region around Tours, is known for its wines, the alleged perfection of its local spoken French, and for the...

. 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

Courtalain is a commune in the Eure-et-Loir department in northern France.-Population:-References:*...

, 130 km west of Paris, where movable frog points

Railroad switch

A railroad switch, turnout or [set of] points is a mechanical installation enabling railway trains to be guided from one track to another at a railway junction....

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

Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

, traction

Traction (engineering)

Traction refers to the maximum frictional force that can be produced between surfaces without slipping.The units of traction are those of force, or if expressed as a coefficient of traction a ratio.-Traction:...

and electrical

Electricity

Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

systems, rail and catenary contact, braking

Brake

A brake is a mechanical device which inhibits motion. Its opposite component is a clutch. The rest of this article is dedicated to various types of vehicular brakes....

, 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

SNCF TGV Atlantique

The TGV Atlantique is a class of high-speed trains used in France by SNCF; they were built by Alstom between 1988 and 1992, and were the second generation of TGV trains, following on from the TGV Sud-Est....

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

Dangeau

Dangeau is a commune in the Eure-et-Loir department in northern France.-Population:-References:*...

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

Radius

In classical geometry, a radius of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment, which is half the diameter. If the object does not have an obvious center, the term may refer to its...

of 15 km (9.3 mi) 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

Loir

The Loir is a river in western France. It is a left tributary of the Sarthe River. Its source is in the Eure-et-Loir département, north of Illiers-Combray...

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

Loire

Loire is an administrative department in the east-central part of France occupying the River Loire's upper reaches.-History:Loire was created in 1793 when after just 3½ years the young Rhône-et-Loire department was split into two. This was a response to counter-Revolutionary activities in Lyon...

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

Bridge

A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...

. 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, from the Track Research department of SNCF. Just as on all TGV lines, the rails were aligned to 1 mm (3/64 in) tolerances

Tolerance (engineering)

Engineering tolerance is the permissible limit or limits of variation in# a physical dimension,# a measured value or physical property of a material, manufactured object, system, or service,# other measured values ....

, and the ballast

Track ballast

Track ballast forms the trackbed upon which railway sleepers or railroad ties are laid. It is packed between, below, and around the ties. It is used to facilitate drainage of water, to distribute the load from the railroad ties, and also to keep down vegetation that might interfere with the track...

was blasted to remove small, loose gravel

Gravel

Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

. 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 trains pantograph was melted. Strain gauge

Strain gauge

A strain gauge is a device used to measure the strain of an object. Invented by Edward E. Simmons and Arthur C. Ruge in 1938, the most common type of strain gauge consists of an insulating flexible backing which supports a metallic foil pattern. The gauge is attached to the object by a suitable...

s were placed in several locations, especially at the expansion joint

Expansion joint

An expansion joint or movement joint is an assembly designed to safely absorb the heat-induced expansion and contraction of various construction materials, to absorb vibration, to hold certain parts together, or to allow movement due to ground settlement or earthquakes...

at the end of the Loir bridge.

Catenary modifications

The catenary

Overhead lines

Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...

was standard TGV style, without any modifications. The only changes were in the tuning. TGV catenary is strung in 1200 m (4000 ft) sections, mechanically tensioned

Tension (mechanics)

In physics, tension is the magnitude of the pulling force exerted by a string, cable, chain, or similar object on another object. It is the opposite of compression. As tension is the magnitude of a force, it is measured in newtons and is always measured parallel to the string on which it applies...

by a system of pulley

Pulley

A pulley, also called a sheave or a drum, is a mechanism composed of a wheel on an axle or shaft that may have a groove between two flanges around its circumference. A rope, cable, belt, or chain usually runs over the wheel and inside the groove, if present...

s and counterweight

Counterweight

A counterweight is an equivalent counterbalancing weight that balances a load.-Uses:A counterweight is often used in traction lifts , cranes and funfair rides...

s. Support masts are spaced at 54 m (175 ft) intervals. The catenary (supporting) wire is made of bronze

Bronze

Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

, with a circular cross-section of 65 mm². The contact wire is made of copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

, 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.

In general, when a pantograph

Pantograph (rail)

A pantograph for rail lines is a hinged electric-rod device that collects electric current from overhead lines for electric trains or trams. The pantograph typically connects to a one-wire line, with the track acting as the ground wire...

runs underneath the catenary, it sets up a wave

Wave

In physics, a wave is a disturbance that travels through space and time, accompanied by the transfer of energy.Waves travel and the wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium—that is, with little or no associated mass...

-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 very 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.

Replacing the copper contact wire by a lighter cadmium

Cadmium

Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...

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 2000 daN (4500 lbf) was increased to 2800 daN (6300 lbf) and exceptionally 3200 daN (7200 lbf). For some of the faster runs over 500 km/h (311 mph), the voltage

Voltage

Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...

in the catenary was increased from the usual 25 kV

Volt

The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...

50 Hz

Hertz

The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....

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

A computer simulation, a computer model, or a computational model is a computer program, or network of computers, that attempts to simulate an abstract model of a particular system...

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

Power-to-weight 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 of actual performance of any engine or power sources...

. 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 metric tons from 490 metric tons.

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 and reversible, but 325's two power car

Power car

A power car is a railroad vehicle that is closely related to the locomotive. What differentiates the two is their construction or their use. A true locomotive can be physically separated from its train and does nothing but provide propulsion . A power car, on the other hand, is frequently an...

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

Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...

membranes covering the gaps between the trailers, and a rear spoiler

Spoiler (automotive)

A spoiler is an automotive aerodynamic device whose intended design function is to 'spoil' unfavorable air movement across a body of a vehicle in motion. Spoilers on the front of a vehicle are often called air dams, because in addition to directing air flow they also reduce the amount of air...

on unit 24050 were considered, but abandoned.

The synchronous AC traction motor

Traction motor

Traction motor refers to an electric motor providing the primary rotational torque of a machine, usually for conversion into linear motion ....

s on 24049 and 24050 could not be allowed to rotate too fast, because of limitations in the switching frequency

Frequency

Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...

of the supply electronics

Electronics

Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...

. Technicians had decided upon 4000 rpm

Revolutions per minute

Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...

at 420 km/h (261 mph) to be the optimal ratio

Ratio

In mathematics, a ratio is a relationship between two numbers of the same kind , usually expressed as "a to b" or a:b, sometimes expressed arithmetically as a dimensionless quotient of the two which explicitly indicates how many times the first number contains the second In mathematics, a ratio is...

, after testing trainset 325 at high speeds with stock traction equipment. The new traction ratio was achieved by changing the transmission

Transmission (mechanics)

A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...

gear

Gear

A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine....

ing and increasing the wheel diameter

Diameter

In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...

. 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

Semiconductor

A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...

components (especially thyristor

Thyristor

A thyristor is a solid-state semiconductor device with four layers of alternating N and P-type material. They act as bistable switches, conducting when their gate receives a current trigger, and continue to conduct while they are forward biased .Some sources define silicon controlled rectifiers and...

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

Transformer

A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...

s in both power cars were replaced by larger models, each able to handle 6400 kW

Watt

The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

(8500 hp

Horsepower

Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...

), 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

Heat

In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...

levels would never be exceeded in testing.

Next, the wheel-rail interface was attended to. Axle

Axle

An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...

bearing

Bearing (mechanical)

A bearing is a device to allow constrained relative motion between two or more parts, typically rotation or linear movement. Bearings may be classified broadly according to the motions they allow and according to their principle of operation as well as by the directions of applied loads they can...

s were unmodified items, broken in for 10,000 km in revenue service on the LGV Sud-Est

LGV Sud-Est

. Yaw dampers

Shock absorber

A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy. It is a type of dashpot.-Nomenclature:...

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 models 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

Kilogram

The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...

(18 lb

Pound (mass)

The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...

) and is mounted on a vertical shock absorber

Shock absorber

A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy. It is a type of dashpot.-Nomenclature:...

with 150 mm (6 in) travel. The main structure of the pantograph is constructed of cylindrical

Cylinder (geometry)

A cylinder is one of the most basic curvilinear geometric shapes, the surface formed by the points at a fixed distance from a given line segment, the axis of the cylinder. The solid enclosed by this surface and by two planes perpendicular to the axis is also called a cylinder...

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

Joule

The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...

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

Laboratory

A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories...

, 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

Châtillon, Hauts-de-Seine

Châtillon is a commune in the southwestern suburbs of Paris, France. It is located from the center of Paris.The town was formerly named Châtillon-sous-Bagneux, and a relic of this denomination remains in at least one road sign in Vanves Châtillon is a commune in the southwestern suburbs of...

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

Pantograph (rail)

contact required manual adjustments to be made by first grounding the catenary

Overhead lines

Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...

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 337 km (209.4 mi) 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

Publicity stunt

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...

. 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

Bischheim

Bischheim can refer to the following:*a municipality in the German district of Donnersbergkreis; see Bischheim, Germany*a canton in France; see Canton of Bischheim*a town in this canton; see Bischheim, Bas-Rhin...

shops 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 metric tons 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

Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...

area between the vehicles, which had induced significant drag

Drag (physics)

In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...

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%

Percentage

In mathematics, a percentage is a way of expressing a number as a fraction of 100 . It is often denoted using the percent sign, “%”, or the abbreviation “pct”. For example, 45% is equal to 45/100, or 0.45.Percentages are used to express how large/small one quantity is, relative to another quantity...

reduction in drag. In the previous round of testing, the atmospheric drag force had reached 9 metric tons of force 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

Chronology is the science of arranging events in their order of occurrence in time, such as the use of a timeline or sequence of events. It is also "the determination of the actual temporal sequence of past events".Chronology is part of periodization...

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

Transformer

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

Vendôme is a commune in the Centre region of France.-Administration:Vendôme is the capital of the arrondissement of Vendôme in the Loir-et-Cher department, of which it is a sub-prefecture. It has a tribunal of first instance.-Geography:...

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

Dangeau

Dangeau is a commune in the Eure-et-Loir department in northern France.-Population:-References:*...

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.

Overview

Operation V150, where 150 again refers to a target speed in metres per second

Metre per second

Metre per second is an SI derived unit of both speed and velocity , defined by distance in metres divided by time in seconds....

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

LGV Est

prior to its June 2007 opening. The trials were conducted jointly by SNCF

SNCF

The SNCF , is France's national state-owned railway company. SNCF operates the country's national rail services, including the TGV, France's high-speed rail network...

, TGV builder Alstom

Alstom

, and LGV Est owner Réseau Ferré de France

Réseau Ferré de France

Réseau Ferré de France , , owns and maintains the French national railway network. The trains are operated by SNCF, the national railway company, but due to European Union Directive 91/440, the French government was required to separate train operations from the railway infrastructure.Unlike other...

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 TGV stations, where the most favorable profile exists.

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

LGV Est

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

Prény

Prény is a commune in the Meurthe-et-Moselle department in north-eastern France.-See also:*Communes of the Meurthe-et-Moselle department*Parc naturel régional de Lorraine...

) 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

Meuse

Meuse is a department in northeast France, named after the River Meuse.-History:Meuse is one of the original 83 departments created during the French Revolution on March 4, 1790...

and Marne

Marne

Marne is a department in north-eastern France named after the river Marne which flows through the department. The prefecture of Marne is Châlons-en-Champagne...

departments. The track superelevation

Cant (road/rail)

The cant of a railway track or a road is the difference in elevation between the two edges...

was increased to support higher speeds. Catenary

Overhead lines

Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...

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

Transverse wave

A transverse wave is a moving wave that consists of oscillations occurring perpendicular to the direction of energy transfer...

induced in the overhead wire by the train's pantograph

Pantograph (rail)

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

Track ballast

, 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

Automotrice à grande vitesse

The Automotrice à grande vitesse ' is an Alstom train intended as the successor to France’s TGV high-speed trains; the name stands for automotrice à grande vitesse, or ‘high-speed self-propelled carriage’...

prototype, marshalled between a pair of TGV power cars from POS

SNCF 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 into service in 2007...

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

Horsepower

) 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

Pantograph (rail)

, 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 tunnel

A wind tunnel is a research tool used in aerodynamic research to study the effects of air moving past solid objects.-Theory of operation:Wind tunnels were first proposed as a means of studying vehicles in free flight...

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

Powertrain

In a motor vehicle, the term powertrain or powerplant refers to the group of components that generate power and deliver it to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive...

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

Aérospatiale Corvette

|-See also:-References:...

airplane to provide data relay and uplink of live television

Live television

Live television refers to a television production broadcast in real-time, as events happen, in the present. From the early days of television until about 1958, live television was used heavily, except for filmed shows such as I Love Lucy and Gunsmoke. Video tape did not exist until 1957...

images.

External links

2007 record official site
INA (Institut national de l'audiovisuel
Institut national de l'audiovisuel
The Institut national de l'audiovisuel , is a repository of all French radio and television audiovisual archives. Additionally it provides customers with a free and immediate access to archives of countries such as Afghanistan and Cambodia...

) - Here you can find many videos of TGV records
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

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