UKH

Read that Virgin have tested humans on their prototype hyperloop.

So will hyperloop tech render HS2 obsolete within years of its completion?

It's an interesting idea and I suspect it could eventually come to rival conventional high speed rail as once built it's far less disruptive of the landscape it passes through or over. I doubt I'll live to see it though.

A link tying central London to its surrounding airports or even just linking the airports, effectively turning them into satellite terminals would be interesting. Lots of problems with that though!

Clean regional air travel may well kill it anyway if the airport experience can be improved and the technological hurdles to eliminating fossil (ideally all) hydrocarbon fuel can be overcome. That to me seems more likely as it happens incrementally without the vast capital expense of a new intercity link using novel tech. Then again, I'd have said that about the channel tunnel yet someone figured out how to get that funded.

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Virgin are great at publicity - I'll give 'em that.

In reality: they tested 500m of above-ground track ...

Still waiting for them to explain how they get round expansion of the thousands of km of tube while retaining the vacuum. 

Well, I'm sure all this will be overcome. 

It seems Dubai are throwing big money into a hylerloop freight system.

All these tech issues remind me of various similar issues regarding personal computers, mobile phones, solar energy, wind power, basically any 'disruptive tech' going back to the steam engine.

I am not sure an idea which has been tried on and off since the time of the steam engine can really be considered "disruptive tech".

It does seem to be an idea which could work in certain situations but it has a mix of technical and usability issues.

Yet HS2 was obsolete in business terms before the work started.

In predicting future tech and splitting it from speculative science fiction you need to think more laterally and recognise current competing research prototypes and some known hard limits. Yes this technology will probably gain niche use in the next decades but not in mass transit use as it would be pricy. Why not ask will we need to travel for work so much in the future, when prototype tech for online meetings is improving so fast. I can see 3D tech for on site visualisation in specialist work being commonly available by the time HS2 is complete.

Yes, nobody has ever been able to build steel pipes that travel trans-continental distances whilst maintaining a pressure-tight seal against extreme thermal cycling.

https://en.wikipedia.org/wiki/List_of_oil_pipelines

Of all the problems with the hyperloop concept, this one goes way down the list.

Hyperloop is relatively low occupancy, high speed.  It might compete with first class on the trains but otherwise I don't think so.  The UKs rail network is riddled with obsolete technology - it was only about 20 years ago that the last lamp lighters were retired on signals...  I'm not sure HS2 will be obsolete so much as the wrong solution.  With more WFH the important thing to get off the roads is freight not people, and that doesn't need the more contentious features of HS2.

I'm more excited by the dramatic claims over tunnelling cost coming out of The Booring Company than by Hyperloop style developments.  If Musk sticks with it for the next decade that combined with EVs with auto-drive tunnel capability could significantly change big urban / suburban areas for the better.

A lot of people with tunnelling experience are pretty negative on TBC, but then the space industry was very negative on SpaceX 15 years ago...

Well, lets say a proper serious attempt.

You could date aviation back to Daedalus, calculators to the Antikythera mechanism, the steam engine back to Hero's Engine & so on for probably any idea

I'm not sure. It has a max pax/hr that doesn't hit my local tram service so I'm not sure HS2 would be quaking in it's boots.

It seems ironic that the argument for Hyperloop (faster journey time) is the same that get used against HS2 (we don't need quicker trains) despite the fact that it will have less capacity (this is the big pro for HS2, it will triple/quadruple train capacity) and at a totally unknown cost (tunnelling is not exactly cheap) that seem to potentially lead to very high ticket costs?

I'm reluctant to pour scorn over new technologies but Hyperloop seems to be a solution to a problem no-one has? I hope the final version is a lot less bumpy, it makes the Pendolino look like a lovely ride.

The largest costs of HS2 are presumably acquiring and preparing the land for the track and terminals.

Possibly a hyperloop could be added later if it's straight enough ?

Oil pipelines have z-bends and spools in them to overcome the expansion problem. Z-bends are problematic when you’re in a pod travelling at 1000kph. 

No.  If anything will render HS2 obsolete it's reduced need to travel due to increased quality of videoconferencing solutions and similar (give it another 10-20 years and they'll likely be 3D in some form, as one thing).

That said, people won't fully stop meeting in person, and so that could give HS2 more of a role.  Why would you live in some Godforesaken London suburb if you could, for the same money, have a lovely house in the Lake District and drive your electric car to Lancaster or Oxenholme once a week for a fast train to London?  It's daily London commuting that is probably in its death throes.

My understanding is that there are also bellows-style metal expansion joints used on some types of pipeline, although they're more expensive and failure prone than a set of bends.  There are viable solutions to this problem, hence why it's not near the top of my list of problems with it.  I think the expansion issue has been rather over-simplistically represented as an unbeatable problem in the media.

My biggest problem with the concept is rescuing people if there's a disaster.  At height, inside thick steel tubes which are self-supporting between the spans, with very few entrance portals.  It's basically the script for an episode of Thunderbirds, only we don't have magic hovering rocket-planes with magnetic grapples that somehow don't blast the crap out of the stuff under them.  There would have to be a road along the whole route giving immediate access to heavy lifting gear to let giant supports be placed either side of the section with a trapped vehicle in to allow cutting to start.  Most of this kit is not going to travel very fast either.  Just locating vehicles inside a pipeline is non-trivial when you look at the effort needed to find a "lost" PIG in the field and they have bloody big magnets on them compared to a hyperloop car. 

I suspect life, fire and safety will mean that you’ll know exactly where the cabin is at all times. Doing that for a Pig is probably not cost effective compared with avoiding killing a cabin full of passengers. You’d then have to have a way of repressurising the tube in the section you want to enter, or the whole tube. It just sounds an infinitely complex problem to solve. 

Sure. Until the moment it all goes wrong...  

One that probably doesn't need solving.

On the other hand, the pod racer contests are fantastic - SpaceX are throwing resources at those and it's really engaging US and EU university engineering students and staff in some fantastic projects that will be an incredibly learning experience, let alone going along to SpaceX HQ in Hawthorne to do their real, live vacuum runs.  That's incredibly stuff for undergrads and postgrads to be involved in.

Pendolinos feel pretty ruddy luxurious compared to the Class 14X and 15X units used for most commuting purposes!

Ah, but what if we invest in hyperloop and then that's rendered obsolete shortly after? Better to wait for the next, next technology no?

Given the expected number of times there will be a problem I doubt re-pressurising the whole tube is an issue.

What do you mean?

The obvious solution is like with long distance pipelines, you build them from (or in the case of pipelines with) bends then you let them move atop the support pylons. Periodic gas tight slip or bellows joints are also possible and proposed. 'Vacuum' in this context just means <=14.7 psi differential.

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Imagine the additional vulnerability/consequence of HS2 to terrorist attack compared to a conventional highish speed train. Especially when travelling in a proposed elevated section above housing, like it might be in Long Eaton.

It's a solution to medium-long distance travel that is unlikely to challenge the established and or more flexible high speed options (fast rail which we lack, aircraft which we have plenty of). That said for high speed connectivity between city or even airport clusters, being able to hop from one to the next in minutes at a significant fraction of mach does change how those places can be used. I think it'll find a niche, probably in <100mi ultra-fast shuttle roles.

As with airports and flight it's probably more the stuff around it (security, parking, poor roads and poor integration with existing local networks) that will render it far less useful than it has potential to be.

<20min from one end of the 'Northern Powerhouse' to the other makes the drawn out sprawl across the north of England into one big city potentially rebalancing England significantly. Affordability is the challenge.

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Lots of our infrastructure is vulnerable to terrorism/sabotage but it doesn't get touched, mostly because it's a very niche interest, usually very well managed. You could fell a dozen strategically picked pylons in a night totally crippling the nation with nothing more than an angle grinder and a motorbike. Nobody does but it'd be all but impossible to prevent. I'd argue derailing a busy high speed train on a fast stretch would be no less devastating than bursting a well designed 'hyperloop', potentially more so.

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Just so long as there is a total and utter ban on an access portal in the middle of the pennines.  Leave us our god forsaken bog and affordable housing thank you very much...  Although at the rate they're pulling 6th form colleges out of the dales here some kids are suddenly having to do 3-4 hours a day on two busses each way and I doubt many more families of teenagers will be moving to the area, so there'll probably be a clamouring for a midway station.

Agreed, I wouldn't want to be inside a tube with the train on fire, although risk is considered tolerable for underground tube trains where rescue is similarly problematic. I'd also be interested to see energy costs per passenger mile compared against conventional rail.

Is it different to an airliner in that respect? Hyperloop pods would be built stronger at least, more between you and the speeding nothingness than 0.8mm of aluminium and able to bear the weight of a fire suppression system. Also likely never more than 5min from an emergency exit or station which isn't true anywhere at 33,000 ft.

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Its exciting stuff, I love the elegance in the solution of overcoming cost effective speed limits that are imposed by air resistance by eliminating some of the air.

I do think we should balance the confidence in long distance pipelines from oil and gas with a reflection on how leaky our water mains are.  This is a commodity that as consumers we dont value quite as highly so I'd wonder if a long distance hyperloop would be able to generate the revenue needed to maintain it.

I also wonder how we'd cope with putting a load of tunnels though our famously complex geology. In my part of the world we have the the thrill of old mine workings and high groundwater levels to contend with, maybe a differentiator from Dubai or Musks home turf. Great tv programme recently about the passenger rail line between Liverpool and Manchester and having to float the track on rafts across Risley Moss.

But I agree that the safety aspects is the big one.  Youre still moving squishy humans which aren't engineered for rapid deceleration, fire etc. The more energy you have in a system the higher the consequence if it goes wrong in a big way and the tighter scrutiny the safety case should be under, and slower the process.  If its underground you can't helicopter in to the rescue.

I think HS2 doesn't have to worry just yet, but I'm optimistic that it could be what the future looks like if all the challenges are overcome.  If all of these considerations were total show stoppers nobody would be trying it after all. Similarly, the world has had white elephants before when the supporting tech or market wasnt there.

With an airliner you only have to inspect and maintain the vehicle and terminals, with rail you have the track to worry about and pay to keep safe too.

Weather stations, radar etc to "inspect the track" for airlines brings other advantages such as forecasting, which links into other economies around data, doing forecasts and publishing them in media.  How could we do that for tunnels?  Seismic monitoring for earthquake warnings? Hyperloop running other services down their tunnel?

Probably not, I suppose if you can make a safety case for air travel, carrying tons of flammable fuel, you can do it for Hyperloop.

Another thought, what happens if the pod loses pressure, does everybodys blood boil - like in space?

Same as for a cruising airliner: rapid loss of consciousness followed by death in single digit minutes, double digit if you got the mask on in time.

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Yes, it's costly but we pay for inspection and maintenance in order to safely run trains, why not for hyperloop pods?

Airliner weather reports are as valuable to forecasters as the forecasts are to airliners.

Like railway infrastructure by inspection. The act of inspecting and maintaining a hyperloop is unlikely to have much crossover benefit beyond providing jobs.

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I'd have thought at the speeds we're speaking of if anything went wrong it would be a case of people turned to skin and paint on the  insides of the capsule and tube.

Don't know how long it would have to be shut for tissue recovery, accident investigation and repair - I suppose tissue could be strwn over some miles - perhaps better just call that section a grave?

Hehe, the more I think about the concept, the dafter and more energy profligate it seems. 

I never got the point of it. You need the vacuum to reduce air friction because you want to go fast. Going fast (above 300 km/h) is is only useful if you go far. And then you might as well fly, you'd get the low air pressure for free.

I thought you were asking for for debate on how it would be different safety-wise to planes, and I offered airlines only have to perform maintenance on their planes, runways, radars etc, not the whole airspace.  In comparison to existing rail, hyperlink has additional things to maintain (vacuums etc), I expect the additional speed means maintaining to tighter tolerances, both at additional expense.  Whichever existing transport it is competing against, I imagine it would be at a disadvantage in terms of maintenance costs.  If ticket prices represent TOTEX/passenger throughput, I'm wondering where it will find the competitive edge to be financially viable.

I think we are on the same page there, I just structured my response badly. The "how could we do that?" part was supposed to be "are there any opportunites for crossover benefit?".  Crossover benefits could perhaps help subsidise the operating costs to make the "main product" more competitive.

I'm now pondering whether a decline of airlines would lead to loss of weather data and detriment to the wider aspects of humanity that is currently benefitting from it.

Because it hardly needs any energy compared to flying, and no CO2 emissions.

The big difference is that an aircraft has to carry its own fuel, whereas a vacuum train can be powered by fixed induction motors.  This makes decarbonisation a vastly easier prospect.  Well, apart from all of the challenges to building and maintaining the vacuum track.  

The original Hyperloop concept used on-board batteries for the air compressor (which used the ram-air to run the air bearings under the vehicle) and fixed linear induction units to boost the vehicle as with the Tomahawk in Heinlein's "Starman Jones".  Somewhere there's a popular mechanics article from the 1920s scanned in online with concept art for such pylons. 

The Hyperloop pressure is much less than that of jetliner altitudes as well.

Compared to flying, a Hyperloop could have departures every 5 minutes which, along with the faster travel time, greatly reduces the total time from A to B if you don't want to plan your day around the scheduled flight times, let alone the actual ones...

So I see the benefit - but I don't know if I'll live to see it realised...

I could swallow that in theory it might be worth it to maintain a vacuum if it reduced the energy spent in fighting air resistance or defying gravity and you could recover the acceleration energy with regenerative brakes.

I could also swallow that the practical implementation of that would be an absolute nightmare, before the pressure to make it profitable. Good for them for trying though!

They're currently levitating the pod which presumably doesn't come free but I'd believe someone if they told me it's more efficient than how planes do it.

good point. But building a 10000 km vacuum tube network also burns some CO2...

This is not a valid comparison. The reason planes don't take off to the same destination every 5 min is because there is no market for it. There won't be for hyperloop either. It's not likely to be much cheaper than flying, right? And I expect the faffing around time with security checks at the terminals to be similar to airports, so unless they can do above 1000 km/h, I don't see much time gained.

If getting from A to B in shortest possible time, at God knows what cost, is so f*cking important, I'm holding out for teleportation.  No messing about with any of this mechanical nonsense.

Should be much cheaper than flying so the market will be increased.

This is very true, although so does building airplanes.  I've no idea at all on the relative merits of either.

I think there's a key difference - the Hyperloop as proposed is ~ 20 people per pod, where-as to get any sort of economy an aircraft needs to be ~ 200 people per plane.  The economies of scale work very differently when you take of the jet engines.   So 1/10th the capacity leaving at least 10x as often.

Perhaps not in my lifetime...  Then again this sort of travel is no more for the and me than Concorde was or the future hypersonic jetliners using SABRE engines will be. One really interesting possibility is a neutrally buoyant transatlantic tunnel...

Yes, the security threats, countermeasures and the bit where some prat will invariably build a perfume shop between the carpark and the boarding door to exploit the traffic will wreck any benefits... 

It’s more likely that there’s a breakdown than a crash. If it’s under the sea then you have big problems. You presumably have several pods stuck at the same time. Even if it’s on land you still have big problems. Planes crash, but not regularly. One plane crash doesn’t stop all the other planes on the same route. A train crash does and it causes pandemonium for weeks. 
 

I’m sure it’s not really a major problem, but it’s one to think about, not simply dismiss. The system will need masses of testing. You’re basically building a rollercoaster. 

Redundancy, build another tube.
Bit like building a second railway

You mean a 3rd tube? I’m guessing each direction needs a tube. 
 

Even running 300miles at 1000kmh it’ll take 30mins per journey for acceleration, deceleration, embarkation and disembarkation. You’d want to be carrying more than 40 people an hour. 

Really? More so than say a fast train?

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Ok, I see. I was really just equating the fire risk. Airliners are utterly mad, they operate in such extremes but we think of them as totally normal. That didn't happen by accident (well strictly I suppose it did, loads of them!) but it's always worth considering when we baulk at a risky seeming new technology or idea.

I'd assume by installing it in roles where the speed really matters to people, airport transfers for example and maybe intercity commuter links.

Fair enough. There's nothing obvious but sub-city tunnels presumably have value to utilities providers.

Yes. Apparently forecasts got notably worse as the pandemic grounded most aircraft. Can't source that beyond 'a chat over dinner with a mate with a PhD in some sort of metrology and some years in the MET office'.

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What, why would you only ever have one pod moving per 300mi tube? They could be each only seconds apart nose to tail in theory. Doesn't work on the railways because the signalling would still be familiar to a Victorian but with a new system come new possibilities.

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OK here are some energy figures(from a maglev company mind):

Shanghai Transrapid maglev: 2.2kWh per 100 seat-km.

ICE train (Germany): 2.9kWh per 100 seat-km.

So Maglev more energy efficient, to operate at least.

But I'd wager by the time all the embodied energy involved in constructing hyperloop, ie more concrete, steel for the tube, tons of fancy magnets, and the energy to maintain the vacuum it will be considerably more energy intensive than conventional high speed rail.

Of course I'd like to see a proper analysis but can't find one.

That’s my point. There wouldn’t be just one pod. 

For shortest travel times you would want to accelerate as quickly as the human body allows, up to maximum system speed.  Then slow down at the same rate the other end.  The same as space travel.

The energy for acceleration would be recovered when slowing down.

Using it like a rail gun firing into another rail gun at the other end.  It could be the basis of a theoretically zero energy link from Earth to Mars.

It’s slower than Concorde.

I don’t see this being any good for local travel in the U.K. It’s long haul flight replacement. 

Both of those operate at atmospheric pressure.

Electric cars, 2-up, would use ~600kWh/100seat-km so those figures are quite impressive.

Based on a 2.4m, 8mm wall tube hyperloop's tube (not track system) uses about 2.5 as much steel as conventional rails (not electrified) but it's not a wear surface and not stressed the same, it would likely last much longer before needing to be recycled. There would be no fancy permanent magnets except perhaps a few in the pods but it would require a hell of a lot of aluminium and/or copper which is expensive.

Conventional rail uses very roughly 400kg of concrete/meter of track, that's just the sleepers plus several tons of ballast. Support pylons for hyperloop probably would require a bit more cement but the land immediately around them remains useable and navigable.

All in all it looks a bit more resource intensive up front but potentially longer lived and with the ability to stay working year round in hostile environments.

Some sort of passive air-bearing maglev hybrid solution seems likely, the air bearing gives rigidity at speed and some fault tolerance while maglev manages friction at lower speed and provides the propulsion.

Yes it will doubtless leak a bit and each entry/exit will need pumping down but air ingress with the pods can be minimised by careful design of the loader/extractor or if roomier loading tubes are desired to increase throughput a reasonable fraction of the energy could be recovered using turbines in the air inlet system. It functions a lot like a canal, losing energy at the (air)locks. It's not worth recovering energy from canal locks because for most systems the replenishing water is free, as you note a vacuum isn't though it could be powered by a PV array along the tube.

I'm not so sure, I suspect they're closer than you think in simple up front resource use. How we'd react to the appearance of a massive metal snake through our landscape, I suspect that would drive objections and therefor cost.

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Have you ever visited the Falkirk wheel?  The high level aqueduct and the wheel put me in mind of the stator rings from Heinlein's "Tomohawk".  I wouldn't mind more of that sort of thing although I'm probably in a minority...

My thoughts were that the rate at which you can decelerate a human body without suffering internal bleeding imposes a minimum space between pods that is greater than the safe stopping distance.

Sanitised lengths of track with only one pod on it, a bit like a rollercoaster. I assume trains do something similar.

But I just did a quick calc, and at a g it does indeed come out at a few seconds.  Long space apart, but only a short time apart. So the limiting factor then seems more like how long it takes to get everyone onboard and restrained.

But then that's (in concept) easily overcome by having terminals set up for multiple embarkation/disembarkation happening in parallel in readiness for the pod joining the track. Like, y'know, train stations. Increases the footprint required, but we're putting these underground, right?

If passengers aren't constantly seated with the lap bar down, then you'd have to factor in how long it would take to convince them to finish what they're doing and dawdle back to their seats.  So human nature and need for bathroom breaks might be another limiting factor against long haul. 

So limit long haul to freight or have scheduled or request stops at intermediate stations where passengers can get on or off. Or accelerate/decelerate at a rate that wont throw you smear you up the wall. Like, y'know, trains do.

Over the course of composing this reply I've completely changed sides on the issue of pod/passenger throughout.

No, it's on the list but SWMBO is unsurprisingly never quite as keen as me on the diversion when we're driving past.

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I don't see it as a viable long-haul system for a number of reasons but yeah, needing to stay seated in a small pod is one of them. More than about half an hour without comfort breaks isn't very viable so that's ~300 miles max.

Yeah, there's no need for ludicrous accelerations. At a sedate 0.3g (9sec 0-60 for comparison to something everyone is familiar with) which you'd barely notice in a reclined supportive seat you're over 600mph in just 1.5 minutes. Much higher acceleration would need space consuming swinging seats in bigger pods and bigger tube in order to keep g 'downwards' and the puke in.

In a supportive deeply reclined seat you'd stay put and not suffer any ill effects from a 3g emergency stop. From 280m/s (~0.85 Mach, 630mph) you're stopped in 9.5 seconds and 1.4km. I find more than 3g sustained feels pretty unpleasant but for a one off if you're restrained it's potentially tolerable. Seated like that, deeply reclined even a normal stop would be comfortable at 1g lateral.

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