Tag Archives: aerotrain

RTV 31 Hovertrain

Information, Transportation, , ,

The 1960s and 70s were an era of grand projects from landing on the moon to Concorde and passenger hovercraft. It was a golden age of engineering when anything seemed possible, even if projects were over budget, technically ambitious and late to deliver.

Long-time readers of GNC will remember I covered France’s Aérotrain, a high-speed hovertrain using aero engines to propel the train on a test track between Ruan and Saran near Orleans. In March 1974 it set a world record with an average speed of 418 km/h (259 mph) and a top speed of 430 km/h (267 mph).

Eventually the Aérotrain was cancelled in favour of the TGV (Train à Grande Vitesse) which like the Aérotrain had dedicated track for high speed sections but was able to run on conventional rail lines coming into the cities. The TGV now routinely runs at 320 km/h (199 mph) covering 460 km from Paris to Lyon in about 2 hours. TGV certainly lives up to its name.

By Chris Allen, CC BY-SA 2.0, Link

France wasn’t alone in its high-speed ambitions. The UK was at it too with the imaginatively named Research Test Vehicle (RTV) 31 by Tracked Hovercraft and a test track was built near Earith in Cambridgeshire, England. Four miles of a planned 20 mile test track were built and in February 1973, the RTV 31 achieved a speed of 104 mph on only 1 mile of track. A week later the funding was pulled by the British government.

Like the French Aérotrain, it too was cancelled in favour of conventional rail, in this case the APT (Advanced Passenger Train) though that never really delivered on its promise. Instead, the highly successful HST (High Speed Train) became the workhorse of British Rail running at 125 mph on existing rail lines. Unlike the Aérotrain, almost nothing remains of the test track and the RTV 31 itself is on display at Railworld Wildlife Haven.

All is not lost though, and remarkable film footage is being restored by Fenland on Film to produce a definitive documentary about the RTV 31 hovertrain with interviews from the original team. You can support their efforts to make the documentary via GoFundMe. There’s promo trailer for the film below.

Aérotrain

Information, Transportation, ,

aerotr1Last week I was on  holiday in France. Driving down from Paris to Orléans on the D2020, I noticed a long raised structure to the east running for several kilometres. It was a few hundred metres from the road so all I could see was a raised platform or aquaduct on stilts. I initially assumed that it was related to the energy industry because the structure passed near a nuclear power station. I thought nothing more about it for a few days and then used Google Maps and Street View to find out that this was an actually the industrial remnants of a high speed transportation experiment called Aérotrain from the 60s and 70s which achieved speeds of over 400 km/h (about 250 mph).

I80_HV_1Generically known as a hovertrain, the Aérotrain used a cushion of air to reduce the rolling resistance of the vehicle, in a similar way to maglevs. Aero engines were used from propulsion, initially with propellors, then turbojets and finally turbofans. A prototype using a linear induction motor was also tested.

The futuristic vehicle on the left is the I-80 HV and is shown on the track that I passed between Ruan and Saran. Able to carry 80 passengers, the I-80 HV established the world speed record for overland air cushion vehicles on 5 March 1974 with an average speed of 418 km/h (259 mph) and a top speed of 430 km/h (267 mph).

This was the brainchild of French engineer Jean Bertin who initially proposed the concept and demonstrated a scale prototype in 1963. Subsequently there were four prototypes built for France and one for the USA which ran on a test track in Pueblo, Colorado.

It’s totally fascinating and there are some comprehensive information resources online including the Association of Friends of Jean Bertin (in French) and Aerotrain.fr (French and English). There are some videos on-line too which show how amazingly futuristic the Aérotrain must have seemed in the 60s. The one below is nearly 20 minutes long. There’s a couple of videos on YouTube too – search for aerotrain.

For a quick 3 minute fix, French pop group Exsonvaldes released a music track with a video about the Aérotrain. There’s brief sequence of the I-80 HV keeping pace with a light aircraft.

State support for the Aérotrain ceased in 1974 and France pushed forward with the TGV for high speed rail transportation. The key benefit of the TGV was that the trains could run on standard rail tracks in urban areas before switching to dedicated high-speed lines in the countryside. Aérotrain needed a completely new infrastructure and the last flight of Aérotrain took place on 29 December 1977.

For comparison, here’s a BBC top five fastest trains. There’s some learning here for Elon Musk’s Hyperloop system.