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Brunel's atmospheric railway in South Devon is well known (in some circles) but I had not come across others until ...

From The Journal (https://www.thejournal.ie/atmospheric-road-dalkey-4549536-Mar2019/) in Ireland


Some of the operating techniques would probably be not used today:

Not forgetting this one at Crystal Palace https://en.wikipedia.org/wiki/Crystal_Palace_pneumatic_railway

As usual, Wikipedia has a more exhaustive list (pun intended) of atmospheric railways. The Dublin and Kingstown (Dalkey) was, however, the first to operate carrying passengers. There was a lot of contemporary newspaper coverage, much of it being pretty much promotional. Some of the speeds achieved on test do  sound pretty scary for the period - 80 mph for a test carriage on the D&K, despite it being so wiggly, and "the velocity for practical purposes is unlimited ... what velocity may not be attained when the rail is in a tolerably straight line, and the public have become familiar with the idea". There was also a claim that the cost went down with increasing speed, whereas for a locomotive it went up with speed squared!

Like all atmospheric railways built at the time, its main justification was that locomotives lacked tractive effort. But within ten years that was no longer true - bigger and more powerful locos could cope with serious gradients, with banking if need be. Then the huge drawback of having a separate system for an isolated hill meant they were all converted very soon after, and how well they worked simply didn't matter. In the case of the Dalkey Atmosperic this took eighteen months, a lot longer than it was meant to - but then they were Victorians!

Nice piece on Devon Live (https://www.devonlive.com/news/history/brunels-doomed-plans-trains-devon-7724203) on the Exeter to Newton Abbott line that's now part of the GWR main line.

Speeds of up to 70 mph achieved, but it did not last. On its demise, the article reports:


I have to wonder if seals made of modern material some 175 years later, modern communications and signalling, and the replacement of coal with other energy sources such as wind, wave and solar generated electricity would mean that none of the issues reported in the demise would be insoluble today.   Have decarbonisation plans looked at the possibility of atmospheric traction returning, with bi, try, quad, whatever mode trains being once again sucked along the seawall where salt water and electricity are such an uncomfortable mix?

A modern railway worked by air pressure or vacuum could be made far more efficient and reliable than was the case back in ye olde days.

In particular modern seals, and electricity to produce the vacuum rather than steam power would greatly reduce losses.

I doubt however that such a system could compete with OHLE or with batteries for problematic sections such as Dawlish. The losses of vacuum or of air pressure would be considerable and unavoidable. And electricity would still be needed on the trains for lighting, heating, cooling, and other purposes.

Given it's been quite common at the very small end (for money and papers), and Elon Musk says it will work but that's with no air rather than air pushing, maybe any new ones should start small and build up to moving crowds. So how about a very scary ride in a theme park? You get into this little capsule, it's closed up and entirely dark, then you shoot off in an unexpected direction, hurtle round high-g wiggles, and then stop and a bright light floods in ... and you feel very, very ill. Fun, eh? (I said "you" not "I" there for a reason.)

Many of us will be familiar with the post office railway in London, a narrow gauge, driver-less electric railway used until recently.

It was originally proposed to work this railway by air pressure IIRC but electric power was chosen as being simpler.

Elon Musk's fantasy of a vacuum tube railway travelling long distances at Mach 1 will never happen. 10 years since he first mentioned Hyperloop and the best that's been achieved is a 2 person pod reaching 107 mph in a tube evacuated to 100pa or 1 millibar. Said test tube (?!) just 500m long. That's what Virgin Hyperloop have achieved to date. They were obviously pleased with the human test as they've now pulled out of passenger Hyperloop development and are concentrating on freight.

Having a very high speed pressurised passenger carrying vessel inside a vacuum tube subjected to ground level atmospheric pressure is theoretically possible. Making it robust enough to satisfy safety regulations is virtually impossible. Materials feasibility on the one hand, cost on the other. Making it strong and safe enough so that a breach to either the vessel or the tube doesn't kill passengers is, in my opinion, nigh on impossible

San Francisco to Los Angeles in 30 minutes at the speed of sound? For 25USD? Pah!

Elon Musk does some things well, but he's a bit of a snake oil salesman in other areas.

For more technical debunking:
https://youtu.be/RNFesa01llk

It took them a while but Virgin have finally realised that Hyperloop is a technological dead end.

They've pulled out of all development. Virgin branding, advertising and, probably most importantly, money, has gone from the testing programme they were involved in. That programme has returned to its original pre-Virgin name of Hyperloop One. I predict it'll all come to nothing.

Elswhere, the other Hyperloop test programme at SpaceX in Hawthorne, CA has also ended, with their tunnel dismantled. The site has become a parking lot. There's transport progress!

Musk is rich enough to spaff his money on pretty much anything he likes. Unfortunately he has that snake oil salesman charm that attracts others to his more harebrained ideas. His hits outweigh his misses, as proven by his net worth, but that doesn't mean everything he touches turns to gold. To those who buy into his every idea I say, caveat emptor.