In 2004 the world started to become aware that the the ralway to Lhasa indded was becoming a fact. The near-completion started a chain of reactions : in some Chinese netizens it became an object of national pride (some would say chauvinism) , and among others it was seen as one more nail in the coffin containing Tibetan culture. The Wikipedia article soon became a battle ground along predictable lines , starting with What is Tibet , anyway ?
In the media , a lot of attention was centered on the engineering challenges of worlds highest railway , running over 5000 meters high , and the brand new , shiny thing : the worlds first train with a pressure cabin . Everyone – the BBC, Guardian etc went aah .. – so did I .
The one question that would have blown this story to bits was never asked : so what happens when we pop off for a nice cup of tea in the restaurant car that looks so nice ? No air locks ..
The pressure cabin myth has acquired a life on it´s own : you still hear of people boarding the train with that thought , being awakened by the sound of hard drives going clunk! . Bye , bye , iPod.
What eventually materialised was a train with oxygen generators , spiking the atmosphere up to 23-24 percent (according to the latest issue of High Altitude Medicine), and nasal cannulas with low (undefined ) flow of pure oxygen.
Oxygen enrichment was not a new concept , it has been used in high altitude observatories up to 5000+ meters for a number of years , but the train solution is obviously a compromise between comfort/safety and economy : the observatories run by Caltech University use for example 24 % in their observatory at 3800 meters , and 27 % in their highest facility the Cosmic Background Imager at (corrected for difference in air pressure) around 4800 meters , very close to the long high run of the Tibet train.
So how does these numbers work out ? Well , in the context of travelling to Lhasa : surprisingly well . Assuming these figures are correct , you will breathe the same effective oxygen concentration at 4500 meters as in Lhasa – with the added benefit of having access to the supplemental oxygen by nasal cannulas.
This is if everything works as stated – I would expect the whole car dropping down to 21 % more or less immediately every time people get off the train, for one thing .
Not worse than flying in , with a very limited advantage in the time spent before Golmud . Basically the first twenty or so hours on the train is a dead loss , acclimatisation wise , you need to reach something like 2000 meters to start effective acclimatisation. If your motivation to take the train is to be gentle on your system , you will profit a lot more by flying in to Xining , and take train the next day . Golmud would be even better , at 2800 meters , but by all reports it´s harder to arrange your travel onwards from there.
Minimising your time in Beijing , if you have flown in , will also a give a subtle advantage , tying together the time at cabin pressure (2100 meters, at best ) with the second half of the track.