TGV
The TGV (french: Train à Grande Vitesse, "high-speed train"; previously french: TurboTrain à Grande Vitesse, label=none) is France's intercity high-speed rail service, operated by SNCF. SNCF worked on a high-speed rail network from 1966 to 19 ...
SNCF
The Société nationale des chemins de fer français (; abbreviated as SNCF ; French for "National society of French railroads") is France's national state-owned railway company. Founded in 1938, it operates the country's national rail traffi ...
, 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
High-speed rail (HSR) is a type of rail system that runs significantly faster than traditional rail, using an integrated system of specialised rolling stock and dedicated tracks. While there is no single standard that applies worldwide, lines ...
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 trav ...
.
TGV 001
The
TGV 001
TGV 001 (''Train à Grande Vitesse 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. The TGV 001 was an experimental gas turbine-electric locomotiv ...
was an experimental
gas turbine-electric locomotive
A gas turbine locomotive is a type of railway locomotive in which the prime mover (locomotive), prime mover is a gas turbine. Several types of gas turbine locomotive have been developed, differing mainly in the means by which mechanical power is ...
-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
Alstom SA is a French multinational rolling stock manufacturer operating worldwide in rail transport markets, active in the fields of passenger transportation, signalling, and locomotives, with products including the AGV, TGV, Eurostar, Avelia ...
to break speed records between 250–300 kilometres per hour. It was the first
TGV
The TGV (french: Train à Grande Vitesse, "high-speed train"; previously french: TurboTrain à Grande Vitesse, label=none) is France's intercity high-speed rail service, operated by SNCF. SNCF worked on a high-speed rail network from 1966 to 19 ...
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
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 ...
TGV Sud-Est
The SNCF TGV Sud-Est was a French high speed TGV train built by Alstom and Francorail-MTE and operated by SNCF, the French national railway company. A total of 111 trainsets were built between 1978 and 1988 for the first TGV service in France b ...
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 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, superficia ...
for testing purposes. However, some sections of the line's profile had been planned since 1982 (shortly after the
TGV Sud-Est
The SNCF TGV Sud-Est was a French high speed TGV train built by Alstom and Francorail-MTE and operated by SNCF, the French national railway company. A total of 111 trainsets were built between 1978 and 1988 for the first TGV service in France b ...
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
Le Mans (, ) is a city in northwestern France on the Sarthe River where it meets the Huisne. 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 Man ...
, 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 Prefectures in France, prefecture of the Departments of France, department of Indre-et-Loire. The Communes of France, commune of Tours had 136,463 ...
. 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
Commune nouvelle d'Arrou (, literally ''New Commune of Arrou'') is a commune in t ...
, 130 km west of Paris, where movable frog 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 dyn ...
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 by ...
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.
Background ...
, 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
The TGV Atlantique (TGV-A) 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.
105 bi-current sets, numbered ...
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 () is a commune in the Eure-et-Loir department in northern France. On 1 January 2018, the former communes of Bullou and Mézières-au-Perche were merged into Dangeau.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
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 ...
. 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 a ...
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
Engineering tolerance is the permissible limit or limits of variation in:
# a physical dimension;
# a measured value or physical property of a material, manufacturing, manufactured object, system, or service;
# other measured values (such as t ...
, 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
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone.
Gravel is classifi ...
. 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 gauge
A strain gauge (also spelled strain gage) is a device used to measure 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 insulating flexible backing which supports ...
s were placed in several locations, especially at the
expansion joint
An expansion joint, or movement joint, is an assembly designed to hold parts together while safely absorbing temperature-induced expansion and contraction of building materials, and vibration, or to allow movement due to ground settlement or seis ...
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 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, superficia ...
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 (res ...
-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
pulley
A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt, or transfer of power between the shaft and cable or belt. In the case of a pulley supported by a frame or shell that ...
s 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 wear ...
s. Support masts are spaced at 54 m (175 ft) intervals. The catenary (supporting) wire is made of
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 metalloids such ...
, 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 m ...
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 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 dete ...
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 measuremen ...
. 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, and ...
membranes covering the gaps between the trailers, and a rear
spoiler
Spoiler is a security vulnerability on modern computer central processing units that use speculative execution. It exploits side-effects of speculative execution to improve the efficiency of Rowhammer and other related memory and cache attacks. Ac ...
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, elevators or electric multiple unit.
Traction motors are used in electrically powered rail vehicles (ele ...
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
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines.
Standards
ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...
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
Transmission may refer to:
Medicine, science and technology
* Power transmission
** Electric power transmission
** Propulsion transmission, technology allowing controlled application of power
*** Automatic transmission
*** Manual 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 pr ...
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 for ...
. 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 resistivity and conductivity, electrical conductivity value falling between that of a electrical conductor, conductor, such as copper, and an insulator (electricity), insulator, such as glas ...
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 al ...
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 rotating 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 the former case, bearing ...
bearings were unmodified items, broken in for 10,000 km in revenue service on 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 ...
. Yawdampers 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
A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated. Most sh ...
with 150 mm (6 in) travel. The main structure of the pantograph is constructed of
cylindrical
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infini ...
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: physicia ...
, 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 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 ...
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 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, superficia ...
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
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' ...
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 Subprefectures in France, subprefecture of the Departments of France, department of Loir-et-Cher, France. It is also the department's third-biggest Communes of France, commune with 15,856 inhabitants (2019).
It is one of 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
Dangeau () is a commune in the Eure-et-Loir department in northern France. On 1 January 2018, the former communes of Bullou and Mézières-au-Perche were merged into Dangeau.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
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 trav ...
prior to its June 2007 opening. The trials were conducted jointly by
SNCF
The Société nationale des chemins de fer français (; abbreviated as SNCF ; French for "National society of French railroads") is France's national state-owned railway company. Founded in 1938, it operates the country's national rail traffi ...
, TGV builder
Alstom
Alstom SA is a French multinational rolling stock manufacturer operating worldwide in rail transport markets, active in the fields of passenger transportation, signalling, and locomotives, with products including the AGV, TGV, Eurostar, Avelia ...
, 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 France, French national railway network from 1997 to 2014. The company was formed with the rail assets of SNCF in 1997. Afterwards, t ...
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 the ...
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
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 trav ...
, 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
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 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 Marne can refer to:
Places France
*Marne (river), a tributary of the Seine
*Marne (department), a département in northeastern France named after the river
* La Marne, a commune in western France
*Marne, a legislative constituency (France)
Nethe ...
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, superficia ...
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 whose oscillations are perpendicular to the direction of the wave's advance. This is in contrast to a longitudinal wave which travels in the direction of its oscillations. Water waves are an example of t ...
induced in the overhead wire by the train's
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 ...
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 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, ...
, 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 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 ...
, 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 demand) ...
images.
See also
*
Land speed record for rail vehicles
The world record for a conventional wheeled passenger train is held by France's TGV (''Train à Grande Vitesse''), set in 2007 when it reached on a section of track.
Japan's experimental maglev train L0 Series achieved on a 42.8 km ma ...
*
TGV
The TGV (french: Train à Grande Vitesse, "high-speed train"; previously french: TurboTrain à Grande Vitesse, label=none) is France's intercity high-speed rail service, operated by SNCF. SNCF worked on a high-speed rail network from 1966 to 19 ...
*
LGV construction
High-speed railway track construction is the process by which (LGV, litt. "''high-speed railway line''"), the land on which TGV trains are to run, is prepared for their use, involving carving the track bed and laying the track. This construction ...