Steam train graveyard at the end of the world

[jjb1970]

http://www.msn.com/en-au/travel/tripideas/the-train-graveyard-at-the-edge-of-the-world/ar-AAhNh5o

 

Apologies if this has been posted before, but it was one of those occasional examples of my web browser home page suggesting a story I'd never noticed before and which is genuinely interesting.

[Dr Gerbil-Fritters]

Quote from the article:  "This increase in altitude lowered the boiling point of the water in the engines from 100 degrees to about 98 degrees which meant the engines would literally run out of steam and derail."

 

Yep, that'll happen - run out of steam, and throw yourself off the rails in a fit of self-loathing

Edited May 17, 2017 by Dr Gerbil-Fritters

[stadman]

Seen the pictures before as I suspect many of us here have. 

Not with so much rubbish written about them though!

[Titan]

Quote from the article:  "This increase in altitude lowered the boiling point of the water in the engines from 100 degrees to about 98 degrees which meant the engines would literally run out of steam and derail."

 

Yep, that'll happen - run out of steam, and throw yourself off the rails in a fit of self-loathing

 

Not only that, but as steam is under high pressure in the boiler, the boiling point is much, much higher than under atmospheric pressure. I don't know what pressure these locos ran at, but even at a relatively modest 150psi the boiling point of water is 181^oC, and if the loss due to higher altitude means that it boils instead at 179^oC you would not notice the difference. The fire burning less brightly due to less oxygen is going to have a far more significant effect!

[jjb1970]

Some of the words are very silly, but there is some beautiful imagery and it is a story I'd never heard before which I found interesting. If an article has beautiful imagery and interests people enough to find out more about the story then it's not all bad and probably no more inaccurate and ill informed than many other articles which we all read and which in many cases we read in ignorance of the errors.

[PhilJ W]

In fact the majority of the locomotives and much of the rolling stock is American in origin not British.

[dullsteamer]

Phil,

 

As far as the locos are concerned, I disagree. Of the eighteen locos there, two were built by Alco-Rogers. The rest were from Kitson, Beyer Peacock, Borsig and Henschel.

 

http://www.derbysulzers.com/uyuni.html

 

It's been years since I visited Uyuni, and I no longer have my notes, but my recollection of the passenger rolling stock is that most was from UK or European builders. The freight cars were a real mixed bag from builders everywhere.

 

All the best,

 

Mark.

[dullsteamer]

Not only that, but as steam is under high pressure in the boiler, the boiling point is much, much higher than under atmospheric pressure. I don't know what pressure these locos ran at, but even at a relatively modest 150psi the boiling point of water is 181^oC, and if the loss due to higher altitude means that it boils instead at 179^oC you would not notice the difference.

 

The atmospheric pressure at any altitude would make no difference to the boiling point of the water in a boiler. As you noted yourself, it's a pressure vessel, it's not open to atmosphere or at atmospheric pressure. That 181^oC at 150psi is a constant regardless of the outside air pressure.

 

Cheers,

 

Mark.

Edited May 17, 2017 by dullsteamer

[EddieB]

Here's a link to the original report, from which the list Mark has linked to was taken: http://www.internationalsteam.co.uk/trains/bolivia01.htm

[Titan]

The atmospheric pressure at any altitude would make no difference to the boiling point of the water in a boiler. As you noted yourself, it's a pressure vessel, it's not open to atmosphere or at atmospheric pressure. That 181^oC at 150psi is a constant regardless of the outside air pressure.

 

Cheers,

 

Mark.

 

 

Actually it does make a difference, because it is 150psi above atmospheric pressure. To take my example if the safety valve lifts at 150psi above atmospheric pressure, it will still lift at 150psi above atmospheric pressure at high altitude. Since the atmospheric pressure is less, the pressure inside the boiler will be less too. And since pressure gauges also work with respect to atmospheric pressure, the pressure gauge would still show 150psi at altitude despite the absolute pressure in the boiler being less.

Edited May 17, 2017 by Titan

[jjb1970]

This is where we get into the difference between gauge pressure and absolute pressure.

Edited May 17, 2017 by jjb1970

[Reorte]

Actually it does make a difference, because it is 150psi above atmospheric pressure. To take my example if the safety valve lifts at 150psi above atmospheric pressure, it will still lift at 150psi above atmospheric pressure at high altitude. Since the atmospheric pressure is less, the pressure inside the boiler will be less too. And since pressure gauges also work with respect to atmospheric pressure, the pressure gauge would still show 150psi at altitude despite the absolute pressure in the boiler being less.

Presumably it's the same difference that also drives the power you get out of it too, the pressure differences inside the cylinder, so it'll all cancel out and the only place it'll have an effect is how well the fire burns.

[PatB]

Regardless of the techniclities of gauge vs absolute pressure, I've always been of the understanding that steam locomotives built in the UK and plenty of places elsewhere have provided excellent service under a wide range of conditions, including ones at least as demanding as Bolivia can muster. Western Australia, for example, had a very successful steam fleet, much of it built in the UK, for a century and, whilst not high altitude, can beat most of the world for heat, salt, grit and operator bodgery. I'd assume that the locos in the Bolivian graveyard would be life expired by now wherever they'd worked.

[hmrspaul]

On a brief day off from looking for endemic parrots I was able to make a brief visit to the graveyard earlier this month and my photos are at https://paulbartlett.zenfolio.com/uyunirailwaycemetery

 

I wasn't fortunate enough to either see a working train - they still work into Chile and the docks, nor the museum at the station in Uyuni itself. We were driven from Sucre and the abandoned railway is to be seen regularly from the road - it must have been stunning when it worked. South & Central America appears to be littered with abandoned Narrow Gauge railways, such as in Argentina and Costa Rica.

 

Paul