TGV world speed record
| Industry | Railway transport |
|---|---|
| Founded | 1938 |
| Headquarters | Paris , France |
| Products | Train services, including TGV high-speed trains |
The TGV (train à grande vitesse, meaning 'high-speed train') has established several land speed records through the efforts of SNCF, France's national railway operator, in collaboration with its industrial partners. These high-velocity experiments are designed to push the boundaries of high-speed rail technology, improving velocity and passenger comfort while maintaining stringent safety standards.
The French TGV currently holds the world record for the fastest commercial train running on steel wheels, reaching 574.8 km/h (357.2 mph) on 3 April 2007 along the newly constructed LGV Est line.
TGV 001
The TGV 001 was a prototype gas turbine-electric locomotive powered trainset, developed by Alstom with the goal of surpassing speed thresholds between 250 and 300 kilometres per hour. Built in 1969 and subjected to trials starting in 1972, it achieved its peak velocity on 8 December 1972.
Operation TGV 100
Operation TGV 100 aimed to reach a velocity of 100 meters per second (360 km/h or 224 mph) and took place on 26 February 1981, shortly before the inauguration of the LGV Sud-Est. This effort culminated in a new speed record of 380 km/h (236 mph) set by the TGV Sud-Est trainset number 16.
Overview
Between November 1989 and May 1990, Operations TGV 117 and TGV 140 were conducted, leading to a world speed record of 515.3 km/h (320.3 mph) achieved on 18 May 1990.
These tests took place on the LGV Atlantique line shortly before it opened for commercial traffic. The track infrastructure and overhead electrical supply were mostly left unchanged for these trials, although certain segments had been engineered since 1982 to accommodate extremely high speeds.
Approval for the LGV Atlantique project was granted on 25 May 1984, with construction commencing on 15 February 1985. The route stretches from near Gare Montparnasse in Paris to Le Mans, featuring a branch line extending to Tours. Commercial operations began on the Le Mans branch at speeds up to 300 km/h on 20 September 1989, followed by the Tours branch one year later. At the junction near Courtalain, where the branches split, movable frog points permit trains to travel at speeds reaching 220 km/h.
During the initial phase of Operation TGV 117, emphasis was placed on optimizing aerodynamics, traction performance, electrical systems, rail and catenary contact quality, braking efficiency, as well as passenger comfort.
To ensure the tests closely reflected operational conditions, modifications were kept to a minimum. The newly manufactured TGV Atlantique trainset number 325 was randomly chosen as the test vehicle. Following completion of the trials, it was restored to its standard configuration for regular service. Today, it is distinguished only by a blue ribbon painted on its front and bronze plaques commemorating its record-setting achievement.
Location
The testing zone begins at kilometre marker 114 along the shared branch at the Dangeau siding and continues beyond Courtalain onto the Tours branch. Between kilometres 135 and 170, track curves gradually widen with a minimum radius of after kilometre 150; these sections incorporate greater superelevation than required for standard operating speeds of up to 300 km/h (186 mph). The Vendôme TGV station is situated at kilometre 160, while at kilometre 166 a descending gradient of 2.5% leads into the Loir valley, where the line crosses the Loir river via a 175 m (575 ft) long bridge. This stretch was specifically targeted for achieving maximum speeds and concentrated testing efforts.
Track preparation
The Tours branch underwent preparation using advanced computerized Maintenance of Way machinery supplied by GEISMAR, the Track Research division of SNCF. Rails were precisely aligned within strict tolerances, and ballast was blasted to clear away loose gravel. Testing with trainsets 308 and 325 revealed minimal impact on the track and only minor realignment requirements, a stark contrast to the substantial track damage recorded during the 1955 world speed record attempts in France. Strain gauges were strategically positioned at critical locations, including the expansion joint on the Loir bridge.
Catenary modifications
While retaining the standard TGV overhead catenary design, adjustments were made to mitigate wave disturbances generated by pantographs at elevated speeds. These wave phenomena limit the maximum velocity since pantographs eventually catch up to them, risking displacement of the wire and loss of electrical contact. To permit test runs beyond this threshold speed, wire tension was increased instead of substituting the copper contact wire with a lighter alloy—an option dismissed due to cost and time constraints.
The catenary system is divided into sections, each tensioned by pulleys and counterweights, with masts spaced at regular intervals. The messenger wire is composed of bronze (cross-sectional area ), while the contact wire consists of copper (cross-section with a dovetail profile).
Tension levels were elevated from the typical 20 kN to 28 kN, reaching up to 38 kN during certain runs. Voltage was raised from 25 kV 50 Hz to 29.5 kV for speeds exceeding . Sensors installed on masts near kilometre 166 monitored wire displacement; during the record-setting run on 18 May 1990 at 515.3 km/h (320.3 mph), vertical displacements approached 30 cm (1 ft), closely aligning with computer model predictions. The catenary’s critical speed for that event was calculated at 532 km/h (331 mph).
Preparation of the train for Operation TGV 117
For initial trials, the train was shortened from ten to four trailers to enhance its power-to-weight ratio. This consisted of power car TGV24049, trailers R1 TGVR241325, R4 TGVR244325, R6 TGVR246325, R10 TGVR240325, and power car TGV24050. The overall length was reduced from 237 m (777 ft) to 125 m (381 ft), while weight decreased from 490 t to 300 t.
The aerodynamic profile of the TGV Atlantique required only minimal alterations. Trainset 325 featured distinct "front" and "rear" power units—24049 and 24050 respectively—instead of the usual reversible symmetry. Pantographs were removed from lead unit 24049 and from the trailing unit’s 1500 V DC pantograph; only a single Faiveley GPU pantograph on unit 24050 was utilized for high-speed operation. Electrical power was transmitted from the trailing to the leading unit via a roof-mounted line. Although enhancements such as rubber membranes between trailers and a rear spoiler were proposed, they were ultimately not implemented.
Synchronous AC traction motors installed on both power cars faced limitations imposed by supply electronics switching frequency. Optimal performance was achieved at 4000 rpm corresponding to 420 km/h (261 mph) by modifying transmission gearing and increasing wheel diameter from 920 mm to 1050 mm.
Electrical components were upgraded with premium semiconductor devices and larger transformers capable of continuously handling 6400 kW (8500 hp)—twice the normal rating. Rigorous testing confirmed that heat dissipation remained within safe parameters.
Adjustments at the wheel-rail interface included retaining unmodified axle bearings that had been pre-conditioned over more than 10,000 km on LGV Sud-Est, reinforcing yaw dampers by doubling their number per truck for redundancy, and strengthening transverse dampers on power trucks based on prior test results.
Given significant vertical wire excursions observed in earlier tests, pantograph dynamics were crucial. The standard Faiveley GPU pantograph was refined by stiffening pneumatic dampers and reducing aerodynamic lift to maintain optimal contact at high velocity.
Trailer suspension height was increased by approximately 20 mm through overinflated air bladders and shims to accommodate larger wheels on power cars. Trailer braking systems were adjusted for enhanced heat dissipation capacity, increasing from 18 MJ to 24 MJ per disk across twenty disks.
Many upgrades—including synchronous motors—had already been trialed above 400 km/h on TGV Sud-Est trainset number 88. Stability assessments confirmed robust performance even with reduced yaw damping.
Interior modifications converted most seating in trailer R1 into a laboratory space dedicated to monitoring vehicle dynamics, overhead contact behavior, tractive effort, aerodynamics, passenger comfort, noise levels, and other parameters.
Following approximately 4500 hours of modification work completed at Châtillon workshops—conducted alongside routine maintenance of revenue-service Atlantique sets—trainset 325 embarked on its inaugural test run along dedicated tracks on 30 November 1989.
Record Achievement, Operation TGV 117
The inaugural test series, known as Operation TGV 117, took place between 30 November 1989 and 1 February 1990. After multiple runs, issues with the pantograph's contact necessitated manual corrections, which involved de-energizing the overhead lines and dispatching technicians to the train’s roof. Following a sequence of progressively faster trials, the official speed benchmark of 482.4 km/h (299.8 mph) was established at kilometer marker 166 on 5 December 1989, with engineer Michel Boiteau at the helm. By this stage, trainset 325 had completed extensive mileage at velocities exceeding 400 km/h (249 mph). Additional high-speed experiments investigated parameters such as simultaneous crossing of two trains at a combined velocity of 777.7 km/h (483 mph). Favorable outcomes from these tests led to plans for upgrading trainset 325 to approach speeds near 500 km/h (311 mph).
Train Modifications for Operation TGV 140
On 1 February 1990 at 15:30, trainset 325 was returned to the Châtillon workshops for comprehensive alterations designed to surpass earlier records and target a speed of 500 km/h (313 mph) by the deadline of 1 March. Axles from cars numbered 24049 and 24050 were extracted and transported to Bischheim facilities where they were fitted with larger wheels measuring 1090 mm (43 in) in diameter. The leading axle on car 24049 was equipped with strain gauges and reinstalled by 22 February. Due to limited time, only one axle received this instrumentation. Custom brake pads were produced specifically for these oversized wheels, allowing just two emergency braking events while maintaining a thickness of 15 mm (5/8 in).
On 6 February, trailer R6 was detached, reducing the consist to its minimal length while preserving structural strength through bar trailer R4 functioning as the "keystone" element within the articulated assembly. The modified trainset weighed approximately 250 tonnes and extended over 106 m (348 ft). Between 7 and 14 February, further adjustments included replacing the roof power supply line with a single cable to remove insulators that impaired aerodynamic efficiency, fitting rubber membranes between trailers, and raising Y237B bogies by 40 mm (1.5 in).
Additional aerodynamic measures involved installing large airdams ("snow shields") beneath couplers to prevent drag caused by low-pressure zones between vehicles. Sheet metal covers were applied over power car bogies, and the front airdam was lengthened by 10 cm (4 in) to fit larger wheels. A detachable spoiler was mounted on the nose of trailing unit 24050.
These aerodynamic refinements aimed to reduce drag forces by roughly 10%. Previously, drag forces reached up to 88 kN at speeds of around 460 km/h (286 mph); with these enhancements, such drag levels would only be encountered near speeds of approximately 500 km/h (311 mph).
Following reassembly on 27 February 1990, trainset 325 departed Châtillon workshops two days ahead of schedule. Completing these modifications required nearly 2000 hours of labor. This second phase of testing culminated in setting a standing world speed record at 515.3 km/h (320.3 mph), as detailed in the record run chronology.
Record Achievement, Operation TGV 140
The second series of tests under Operation TGV 140 occurred from 5 March through 18 May 1990 after completion of train modifications. An electrical malfunction during the initial high-speed attempt damaged the main transformer in the rear power car, necessitating almost a month-long repair period to prepare a replacement transformer capable of handling high power demands. Testing recommenced on 4 May 1990, immediately exceeding previous speed records on its first run back. Speeds unofficially surpassed the 500 km/h (311 mph) threshold on multiple occasions on 9 May, reaching velocities of 506.5 km/h and later 510.6 km/h. The train negotiated switches near Vendôme station at a velocity of approximately 502 km/h. Despite intermittent pantograph-to-catenary contact issues causing sporadic disruptions, runs above the half-thousand mark continued consistently. On 18 May, carrying dignitaries and journalists onboard, the train attained a peak velocity of 515.3 km/h (320.3 mph) close to kilometer post 166.8. Throughout this campaign, speeds exceeding 500 km/h were recorded nine times, establishing a new world speed record.
Summary
Operation V150, named after its intended velocity in meters per second, consisted of a series of high-velocity tests conducted on the LGV Est prior to its official inauguration in June 2007. This initiative, carried out by SNCF, TGV manufacturer Alstom, and the infrastructure owner Réseau Ferré de France between January and April 2007, culminated in an official speed record attempt on 3 April. The train achieved a peak velocity of 574.8 km/h (357.2 mph) near kilometer marker 193 at Le Chemin, situated between Meuse and Gare de Champagne-Ardenne TGV. This site was chosen due to its optimal track profile. Starting from rest at Prény, the train reached maximum speed within 12 minutes and 40 seconds, covering a distance of 71 km.
Throughout the testing phase, the previous unofficial speed record of 515.3 km/h was exceeded multiple times, beginning with a 554.3 km/h run on 13 February and concluding with a 542.9 km/h achievement on 15 April.
Track modifications
The record-setting runs took place along a 140 km stretch of track 1 on the LGV Est, heading westbound between kilometer points 264 (Prény) and 120 (close to the Champagne-Ardenne station). This section was selected for its advantageous vertical alignment and gentle curvature, featuring downhill gradients between kilometer markers 195 and 191 that facilitated reaching top speeds. Superelevation of the track was enhanced, while catenary voltage was increased from the standard 25 kV to 31 kV. The mechanical tension applied to the overhead wire rose from 25 kN to 40 kN, which raised the velocity of transverse waves generated by the train’s pantograph to 610 km/h, thus maintaining safety margins beyond operational speeds. Dedicated measurement stations tracked stresses on the track, noise levels, aerodynamic effects, and catenary behavior, with intensive monitoring concentrated between kilometers 223 and 167 where speeds surpassed 500 km/h.
Train modifications for Operation TGV 150
The V150 trainset consisted of three modified Duplex cars equipped with two powered bogies akin to those used on the AGV prototype, positioned between two TGV power cars from the POS trainset number 4402. This assembly included four additional powered axles compared to the record-setting trainset 325 from 1990 and produced a peak power output of 19.6 MW (26,800 hp), more than double the standard TGV POS power rating of 9.3 MW. The design aimed to validate several innovations such as asynchronous traction motors installed on POS power cars, lightweight synchronous permanent magnet motors on AGV bogies, actively regulated pantographs, and the Duplex bi-level configuration under extreme speed conditions.
Aerodynamic enhancements reduced drag by approximately 15% relative to conventional configurations through features like a front air dam, roof fairings covering pantograph recesses, membranes connecting cars, and a flush-fitted windshield. Over 600 sensors were deployed to monitor various parameters across engines and passenger cars. Additionally, larger wheels measuring 1092 mm in diameter replaced the standard size of 920 mm to decrease rotational velocity within the drivetrain.
Record attempt: Operation TGV 150
From mid-January through mid-April 2007, the V150 train consistently exceeded speeds of 500 km/h over an aggregate distance totaling 728 km. Prior to each high-speed trial, another TGV performed a clearing run along the track at a sustained speed of approximately 380 km/h—matching the maximum velocity recorded during the 1981 record run—with the TGV POS trainset number 4404 configured as an eight-car set. The V150 accelerated over a span of roughly 70 km during these runs. For select trials including the official record attempt, an Aérospatiale Corvette aircraft was deployed to relay data and provide live television coverage.
See also
- Land speed record for rail vehicles
- TGV
- LGV construction
- AGV Automotrice à grande vitesse – Successor to the TGV