the railway system is much too large to study in its entirety so i've just been looking at how they have been expanding its reach along their western and northern borders ... at the same time, i had little or no concept of china's scale and the variety of its landscapes ... but mostly i've been trying to get to grips with their strategy ... what they build first, and what follows ... it all started when donald box told me, back in 1986, that he was working as an economics consultant for the chinese railways ... i had no idea that they were tapping european expertise in that way when china had seemed to be so closed off and insular ... but it wasn't my subject and i didn't think about it again until i began to look at the background of a mining disaster that happened in tibet early in 2013 ... they were quarrying copper ore off the tops of mountains, 17000 feet up and about 30 miles east of lhasa ... it was a big shareholder operation with offices in canada, and they were intent on extracting vast amounts from a whole cluster of high altitude mines and quarries ... i wondered how they would transport increasing quantities of ore or refined products ... the roads were'nt good and the nearest rail head, the only one in tibet, was thirty miles away ... this map shows lhasa on the left and the mines at the right ...

... so then i started looking for new roads and railways and discovered that they were already "on the drawing board" but would take a considerable time ... indeed, on the current map shown by google earth, you can see the construction work of a new motorway from lhasa to southern china is making very rapid progress, and it goes right past the bottom of the miners' valley ... i don't know if they'll put in a railway but it wouldn't surprise me

and then my curiosity led me into the subject that now interests me ... as i began to look at the complicated route taken by the tibetan rail project which leads out of lhasa and crosses a huge remote plateau going north before descending to the huge city of Xining, a journey of one thousand two hundred and fifteen miles ... it became obvious that the chinese don't spare any expense in building railroads, and as i returned to study the route in subsequent years it became obvious that they were constantly making improvements, changing the route, engineering short cuts through ambitious tunnels, etc, and once you got to the point where the tibetan line joined the network, then you saw the gob-smacking bravery of their ambitions ...
http://www.chinadaily.com.cn/a/201812/28/WS5c26213aa310d912140518d9_1.html
recently, a shortcut from the tibet railway towards the west has been opened, see above ... from golmud, in northern tibet, you can now turn left and head across the desert and mountains to dunhuang, and then on north again towards a line that now connects china to western europe via kazakhstan ... no direct passenger services from tenby so far but i live in hope
for a perspective on china's entire rail system, start here ...
https://en.wikipedia.org/wiki/Rail_transport_in_China