Aérotrain

The Aérotrain was a hovercraft train developed in France from 1965 to 1977. The lead engineer was Jean Bertin.

The goal of the Aérotrain was similar to that of the magnetic levitation train: to suspend the train above the tracks so the only resistance is that of air resistance. Consequently the Aérotrain could travel at very high speeds with reasonable energy consumption and noise levels, but without the technical complexity and expensive tracks of magnetic levitation.

The track for most aerotrains was an elevated ferroconcrete monorail mounted on pylons. Air pressure between the track and the train lifted the weight of the train. Most designs were powered by gas turbines, but some later designs used linear electric motors.

Five prototypes were built: 01, 02 (shown in picture), S44, I-80 and I-80 HV. I-80 was a full-size 80-passenger car running on 18 km of track. It established the world speed record for overland air cushion vehicles on March 5 1974 with a mean speed of 417.6 km/h (259.5 mph) and a peak speed of 430.4 km/h (267.45 mph).

This project was abandoned in 1977 due to lack of funding, the death of Jean Bertin, and the adoption of TGV by the French government as its high-speed ground transport solution.

Time Line

* 1963: Jean Bertin presents a 1/12th scale model, 1.4 meters in length, to the public authorities and to SNCF.
* 15 April, 1965: creation of the "Société d’étude de l’Aérotrain" (Company for the study of the Aérotrain).
* 16 December, 1965: completion of the construction of Aérotrain 01, a 1/2 scale prototype, which can carry four passengers and two crew. It is propelled by a propeller powered by a convert|260|hp aircraft engine. The air cushion is maintained by two convert|50|hp compressors. It is 10.1 meters long with a weight of 2.6 metric tons.
* 21 February, 1966: official inauguration in Seine-et-Oise (but now in Essonne) of the 6.7 km trial track for Aérotrain 01 between Gometz-le-Châtel and Limours (on the abandoned easement of the Paris-Chartres via Gallardon line). That day, in front of the press, Aérotrain 01 reaches 100 km/h. Days later it reaches 200 km/h.
* 23 December, 1966: with the addition of a rocket, giving a combined power of convert|1700|hp, the Aérotrain 01 reaches a speed of 303 km/h.
* 1 November, 1967: the Aérotrain 01 is equipped with a turboprop engine, reaching a speed of 345 km/h.cite encyclopedia
editor = Roy McLeavy
title = Société de L'Aerotrain, France
encyclopedia = Jane's Surface Skimmers Hovercraft and Hydrofoils
pages = pp. 144-148
publisher = Jane's Yearbooks, London ]
* 1967: construction of Aérotrain 02. It is powered by a JT12 turboprop from Pratt & Whitney.
* 22 January, 1969: Aérotrain 02 reaches the record speed of 422 km/h on the Gometz-le-Châtel trial track.Dummy text]
* 1969: construction of an experimental 18 km track between Ruan, to the north of Artenay, and Saran (Orléans) in the Loiret. The track is elevated 5 meters above the ground and is supported by pillars. It is built on an alignment that would allow it to be used in a future Paris-Orléans line. The alignment allows speeds of 400 km/h. It is equipped with a platform at each end of the line allowing the turning of the aérotrain and a central platform at Chevilly allowing the aérotrain to be housed in a hangar. This line, while abandoned, still exists today, and is clearly visible to the east of RN20 and the Paris-Orléans railway line.
* 1969: construction the Aérotrain I80. This vehicle is 25.6 metres long, 3.2 metres wide, 3.3 metres high, weighs 11.25 metric tons empty and has 80 passenger seats. It is propelled by twin Turboméca Turmo III E3 turbines powering a ducted propeller, 2.3 meters in diameter, with seven blades. A Turmastazou 14 turbo engine powers the air compressors (six horizontal for the support and six vertical for guidance). Braking is typically provided by reverse thrust of the propeller, and in emergencies by a friction brake on the central rail. External noise is 90-95 dBA at convert|65|yd.Dummy text]
* 1969: construction of the Aérotrain S44, a version designed for suburban transport (links between city centres and airports) with electric propulsion. It is equipped with a Merlin-Gérin linear motor and designed for a speed of 200 km/h.
* 7 March, 1970: release of a postage stamp honoring the aérotrain.
* 1973: Realisation of a high speed version of the Aérotrain I80, the I80HV (Haute Vitesse). This version is powered by a JT8 D11 turbofan from Pratt & Whitney.
* 1974: The government abandons the project for the construction of an aérotrain line between the Orly and Roissy airports.
* 5 March, 1974: The Aérotrain I80 breaks the land speed record for railed vehicles for air cushioned vehicle at 430.4 km/h.
* September, 1975: Announcement of a TGV line to be constructed between Paris and Lyon.
* 21 December, 1975: Jean Bertin dies.
* 1977: The project is abandoned.
* July, 2004: The memory of the trials on the Gometz line is memorialized by the dedication of a roundabout in Gometz and a sculpture by Georges Saulterre representing the Aérotrain.

Comparison with TGV

The aérotrain was abandoned by the French government in favour of TGV. A short comparison is given below.

Advantages of TGV

* Unlike aérotrain, TGV could use existing rail lines in metropolitan areas. Aérotrain would have required new lines, easements and stations in metropolitan areas.
* As developed, the aérotrain had much lower capacity.
* After the first oil shock, the chemical propulsion used by the Aérotrain I80 would be too costly, thus requiring propulsion by electric linear motor. This may have been much more expensive than the wheel based propulsion used by TGV.
* The rail world was totally unfamiliar with the technology used by the aérotrain.

Advantages of Aérotrain

* Less pressure on track, with possible lower construction and maintenance costs.
* Less friction, with possible lower energy requirements.
* Less noise, because it had no wheels and transmitted less vibration to the track.Dummy text]

It should be noted that aérotrain shares these advantages and disadvantages with the magnetic levitation train and thus may have been a competitor where maglev has been used.

The American Aérotrain

In 1970, Rohr Industries decided to develop an aérotrain as part of a project by the Urban Mass Transit Administration to sponsor development of new mass transit technology to meet future transit requirements.

The Rohr prototype aérotrain was propelled by linear motor and was designed to carry 60 passengers at 150 mph (240 km/h). It had a length of 94 ft (28 m) and an empty weight of 46,000 pounds (20.8 metric tons).

A test track was built in Pueblo, Colorado, where the prototype reached speeds of 145 mph (constrained by the length of track). Funding from UMTA ceased and the Rohr Industries Aérotrain was never commercialized.

The British Aérotrain

In Britain a similar technology was developed under the name of "tracked hovercraft" or "hovertrain", mainly by Eric Laithwaite However, this development effort did not get as far as the aérotrain technology. There was an attempt to build a test track but this failed due to civil engineering problems [http://groups.google.com/group/uk.railway/msg/6bd290a20a58fbaa] .

References

ee also

* Ground effect train
* N500 Naviplane
* Transrapid 03
*

External links

* [http://aernav.free.fr/English_Index.html Aérotrain]
* [http://www.shonner.com/aerotrain/ Rohr Industries Aérotrain]
* [http://www.windridertrain.org Windrider Train Company] - A small company begun by university students hoping to develop the aérotrain technology.
* [http://www.juergen-koerner.de/aerotr.htm Das französische Schwebebahnprojekt Aérotrain]
* [http://www.luftkissenzug.de/ Der Luftkissenzug Aérotrain]
* [http://www.ifs.tohoku.ac.jp/kohama-lab/aerotrain_outline-e.html Aero-Train]
* [http://www.art-omma.org/projectroom/n3/zarka.htm Pentacycle] - A human-powered vehicle designed to run on the abandoned Aerotrain track.

Pictures

* [http://aernav.free.fr/Galerie/Photos.html Aérotrain Photo Gallery]
* [http://www.luftkissenzug.de/fr_htm/af_fahrzeuge.htm Extensive Aérotrain Gallery]
* [http://www.geocities.com/AMFMonorail/safege/bertin.html Recent photos of the remains of some aérotrain vehicles]
* [http://www.juergen-koerner.de/aero_fr.htm#Images Recent photos of aérotrain test track]
* [http://www.sens-giratoire.com/textesrp/exposition.php?clecir=4;465;00;9;9;;0;0;&has=1 Distant] and [http://www.sens-giratoire.com/textesrp/detail.php?clecir=4;465;00;9;9;;0;0;&has=1 close] photos of the aérotrain statue.
* [http://www.aerotrain.fr Recent Aérotrain photo gallery] (in French)

Videos

* [http://www.bertin.fr/en/le_groupe_bertin/notre_vocation/aerotrain/ Bertin Technologies: Aérotrain Film]
* [http://aernav.free.fr/Aerotrain/Video/Video_Aerotrain.html Gallery of short Aérotrain Films]