At 357mph, it was impossible to focus on anything within a mile of the train. Even distant hilltop villages flashed past in a second.

The sense of flying across the landscape of the Champagne region was accentuated by being on the top deck of the TGV train.

Engineers had laboured for months to ensure precision to the millimetre in the track geometry, but we still lurched alarmingly. The train seemed to rise from the tracks for one terrifying moment.

We were travelling twice as fast as a passenger jet at the point of take-off, but there were no seatbelts. At that speed, they wouldn’t have saved us anyway.

As the only British journalist on board, I was determined not to show how frightened I was. The assembled French media, politicians and rail bosses seemed to love every second and showed no trace of fear. But then they have absolute faith in the safety of their high-speed lines, with no passenger fatalities in 26 years of operation. I have reported on six crashes that have caused a total 60 deaths on Britain’s so-called fast lines in the past decade and none of the trains was travelling at faster than 125mph.

The most disturbing feature of this journey was not knowing how fast we would go. There had been rumours that the French would try to exceed the 361mph that was achieved by a magnetically levitated Japanese train. But the maglev floats above its concrete guide-way and is far smoother and quieter than wheels on rails.

The speed was displayed in kilometres per hour on screens above our heads and there were cheers as we broke 500km/h (310mph). The cheers grew louder as we edged past the world rail-speed record, set by a TGV in 1990, of 515.3km/h. Then an extra surge pushed us up to 570km/h. We hovered around that speed for about two minutes as the driver seemed to seek one final burst of acceleration.

A camera on the roof showed white flashes on the overhead power lines, from which we were drawing 19.6MW, more power than is used by all the cars that start a grand prix race.

The sense of being on the edge of a void was heightened by the knowledge that, in test runs, this train had taken ten miles to stop after the brakes were fully applied at 506km/h.

There were 40 technicians on board, but none could tell exactly how the train would behave above 350mph, especially in a fairly strong crosswind.

When we slowed to 200mph, which will be the standard speed when the Paris-to-Strasbourg line opens for service in June, it felt like a jaunt on the St Ives branch line.

The record had cost €30 million (£20 million) and taken a year to plan, but none of the French media asked questions about cost yesterday. No one even mentioned that the €5 billion high-speed eastern line, which links Paris and Germany, had been approved despite official predictions that it would never make a profit. Our souvenir tickets had been stamped with the phrase L' excellence française and it would be impossible to put a price on the national pride beaming from every French face on board and reflected in those of the thousands who lined the route.

Fast track

— The Shinkansen Nozomi travels the 325 miles (525km) between Tokyo and Kyoto in 2hr 10min at a cruising speed of 186mph

— The maglev train from Shanghai city centre to Pudong airport has a cruising speed of 248mph and a top speed of 311mph for its 19-mile journey

— The TGV train travels the 285 miles from Paris to Strasbourg at a cruising speed of 200mph

— The fastest rail journey in Britain took place from Glasgow to Euston last September. The Virgin Trains Pendolino covered the distance in less than four hours at an average speed of 102.5mph

Source: Times database

Times recommends

• Oasis of the Seas: the Times review
• The 20 best new year party places to stay
• Green Spaces 2009: are you the winning writer?