This was originally presented as a Mastodon thread in November 2025

On 3 April 2007, Operation V150 successfully ran a steel-wheeled train at 574.8 km/h on an unopened stretch of the LGV Est in France. On 21 April 2015, JR Central successfully ran a maglev train (the L0 series Shinkansen) at 603 km/h on the Yamanashi Test Track. Both of these set world records that still stand today: Operation V150 for steel-wheeled trains, and the L0 series for any train.

Many rail analysts and railfans note that the steel-wheeled world record is so close to the maglev world record, and surmise that there is no point in building maglev, as steel-wheeled vehicles can reach a comparable speed. However, this analysis ignores a number of key differences in the two records, which make this very much an apples-to-oranges comparison.

Despite being a high-speed maglev enthusiast, I recognise that there are many valid critiques of the technology (some of which I’ll touch on in passing later); however, that makes it all the more frustrating to see nonsense arguments occupying time that could be spent on more productive discussion.

The main things that the two events above have in common are:

  • They set world records that stand to this day
  • They were set on sections of track that were not yet open to the public, but were intended to be. (The LGV Est was in final testing before opening, while the Yamanashi Test Track is designed to form an integral part of the linear Chūō Shinkansen when it eventually opens.

That’s about it. Now, the differences.

The Vehicles

Project V150 used SNCF trainset 4402. This started life as a standard production passenger vehicle, but was heavily modified from this configuration for the test. This included making significant weight reductions. Some modifications could be rolled out across an entire fleet—for example, adding additional powered axles, and using lighter motors. But stripping out interior furnishings and not carrying passengers to reduce weight are not compatible with running a revenue service at 574.8 km/h.

The L0 series trainset used for the maglev record is the same test train used day-in day-out for testing by JR Central. While it is a prototype vehicle (because there is not yet a demand for production vehicles, until the full line to Nagoya opens to revenue service), it is designed to be as close as possible to the eventual production vehicles (as it is this that is being tested), and routinely carries passengers in its tests—I believe a full complement of them.

Put briefly, the Project V150 vehicles could not maintain a speed close to its record speed while carrying a typical TGV complement of passengers; the L0 series most likely could.

The Route

Project V150 used a 140km stretch of the LGV Est, in the final months before its opening in June 2007. It took 70km of this route to get up to the record speed. The section where the record was set was specifically chosen for having helpful track gradients—the train was going downhill.

The entire Yamanashi Test Track is only 42.8km long. In this distance, the L0 series has to get up to its record-breaking speed, and slow down to a stop again. If the L0 series took as long to get up to speed as Project V150, then it would be a pancake in a Yamanashi mountain before it set a record.

The Yamanashi Test Track has not been specifically designed to enable record-breaking speeds, except in the sense that it forms part of the Chūō Shinkansen route, all of which has been designed with the gentle curves and gradients needed for 500km/h+ operation. The route isn’t long enough to pick and choose a section to hit the record at to the same extent as could be done on the LGV Est. The L0 Series’s predecessor, the MLX01, still holds the world relative passing speed record of 1,026km/h, suggesting that the 500km/h+ speeds aren’t limited to a single direction; i.e. the track gradient didn’t give a significant advantage.

For the TGV to even hit 574.8 km/h in revenue service would require station stops more than 140km apart. To sustain the speed for a useful period of time would require stops spaced even further apart. The L0 series can hit 600+ km/h in a much shorter distance, allowing a more reasonable stop spacing, and giving much better average speeds across longer sections.

The History

This year the British passenger railway network is celebrating its 200th birthday. The first LGV opened in 1981. We’ve had centuries of development of steel wheel technologies, and decades of running them at high speed.

The Yamanashi Test Track was only completed to its current length in 2013; the 603 km/h record was set in 2015, only two years later. We’ve had barely a decade of being able to test maglev vehicles on this length track, and have never been able to test on a longer stretch of line.

It seems likely that as the full Tokyo–Nagoya stretch is completed, it will be possible to test at higher speeds, using the longer track to accelerate more slowly above 603 km/h.

Conclusions

The French record is incredibly impressive, and a credit to the French HSR network. But I don’t think it makes sense to compare the top speed record directly with the Japanese one.

I’m very hopeful that once we have more track available to test on, we’ll see higher speeds achieved on maglev. Whether it’ll make sense to run passenger service above 500km/h is a different question: the TGV only runs at 320 km/h, despite SNCF having shown they can go faster.

I’m also hopeful that the delay to the Shizuoka construction section will mean that there is a longer test track Tokyo–Yamanashi that can be used to gain experience and confidence of running services over longer distance in advance of the start of service Tokyo–Nagoya.

Maglev as a technology still has many challenges. It is still relatively energy-hungry, in particular at high speeds, and currently the line capacity appears much less (in terms of passengers per hour per direction) than an equivalent steel-wheeled Shinkansen. The platform-train interface appears to be rather more awkward than an equivalent steel-wheeled setup, to avoid allowing metal objects to get too close to the superconducting magnets. I would hope that starting to deploy the technology beyond a single test track will allow some of these issues to be worked out; for example, working out how to safely have shorter headways between trains.

Until then, we just have to be patient, hope that construction continues to go well, and perhaps be less unkind in our comparisons of different rail technologies?