We reached Golmod at 10.30 last night. This is the place where the climb really begins. I didn’t get off to supervise, but I could feel lots of shunting going on. I’m guessing that this is where the high altitude engines are added and whatever changes are made to the air supply take place. I was trying to get to bed early. Some hope!
Once we set off there was a new noise in the the darkness of our cabin. At first it sounded like I might have accidentally switched on the radio, and all that was coming out was static or white noise. I found my headtorch and had a look round. The answer was that oxygen was now being pumped in to each of the connectors, one per berth.
It made me wonder how they can do this, as to keep this up would surely consume vast amounts of O2 – we would need a tanker of the stuff. I wondered also if it might be just air enriched with a bit extra O2. If it is pure I hope the smokers on board are aware of the inherent dangers that now give our carriage fire characteristics similar to an Apollo spacecraft.
I would like to tell you that I slept soundly, but it was another dreadful night. I lay in my berth panting and suffering from what I think they call “periodic breathing”. From what I understand your breathing pattern changes and getting rid of CO2 becomes more important than breathing air at altitude. This can cause problems with sleep, and the result is that you can actually stop breathing for short periods, then wake up in a panting panic. My dreams were about running out of air whilst diving. When I woke I would find my ears popping and my body was very hot – the train seems not to be able to support both air con and enriched air supply at the same time.
For the record, here is the altitude profile of the journey:
Local time/elevation above sea level (metres)
16.40 3200m
19.36 2980m
22.30 2828m (Golmud)
00.39 4159m
00.55 4767m
04.10 4500m
06.11 5072m (Tanggula Pass)
07.36 4594m
08.35 4513m
11.02 4306m
13.03 3641m (Lhasa)