Continental flights in the very near futur will be replaced by High Velocity trains 3

[0707]

Because of pollution, Continental flights in the very near futur will be replaced by High Velocity trains, because trains are much less polluent and will compete more and more in velocity with planes. Intercontinental flight planes will keep going on making sense but, they have to change to a less poluent combustible maybe hydrogen will be well positioned.

luis

 

[WKTaylor]

a little off-topic.... Anyone watch Sci-Fi Show 'SnowPiercer'?

UGHHHH the engineering Impossibilities/improbabilities portrayed were so mind-boggling I had-to step-away from the TV in disgust... I couldn't suspend my beliefs for the show's premise.

A 1000 car train speeding indefinitely around a snowy [semi croyogenic temperatures] mountain-side track. Hmmmmm

For starters assume each train car is 80-feet [24.384-M] [avg] long connection-to-connection... The train is only 80,000-feet [15.15 Miles] [24.384-km] long.

Then the mechanics of rolling stock on rails at -100F [-74C], for years... using a power-source of...?

It ain't gonna happen.



Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[3DDave]

Look for the YouTube reviews of SnowPiercer as a sequel to Willie Wonka and the Chocolate Factory. At first it seems that the jump is impossible, but then the details come one after the other and, as ridiculous as the mechanics of the movie are, the themes line up in a horrific way.

In the movie version there are spaces to work in too small for adults. Who would design such a thing? One would if one depended on Oompa-Loompa labor, but then they died from the cold, so children were forced to labor.

Anyway, those reviews put the story into a better perspective of purely speculative fiction rather than science fiction.

(fixed movie titles)

 

[IRstuff]

The train is just a prop to set up a story that's about power and class struggles.

Jennifer Connelly is as awesome as ever

TTFN (ta ta for now)
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[Comcokid]

If you search for maglev trains, you find a lot of 'technology demonstrators' licensed to carry passenger short distances that have since closed.

1979 Hamburg Germany
1979 Moscow USSR
1984-85 Birmingham UK
1984-2012 Emsland Germany (1984-2006 for passengers. Strictly a test train after 26 passengers killed in 2006)
1986-88 Vancouver Canada
1986-88 Hamburg
1989-92 Berlin

These are the maglev trains operational today. Only two have significant track length.
1993 Daejeon Expo Maglev, South-Korea - Length 1 km (0.62 mi)
2004 Shanghai Maglev, China - 30.5 km (19 mi)
2005 Linimo Maglev, Japan - 8.9 km (5.5 mi
2016 Incheon Airport Maglev, South-Korea - 6.1 km (3.8 mi)
2016 Changsha Maglev Express, China - 18.55 km (11.53 mi)
2017 Beijing S1 Metro Line, China - 8.25 km (5.13 mi)

More magleve trains have been shut-down than are still operating. Maglev trains carrying passengers began 41 years ago.

Let's compare 41 years of development with the airplane. The Wright brothers first flew in 1903, and 41 years later in 1944 the use of aircraft had dominated the world for passenger, commercial, and military uses.

Lets compare 41 years of development with the steam locomotive. The first working railway steam locomotive was built in the UK in 1804 by Richard Trevithick. 41 years later in 1845 most major countries had train networks.

Using historical comparisons, maglev technology has failed to be anything more than a expensive side-show.

 

[0707]

"The Concorde was famously loud: a take-off at Washington airport in 1977 measured 119.4 decibels.

By comparison, a clap of thunder hits 120 decibels while the pain threshold for the human ear is around 110.

When the jet broke through the sound barrier, it created a "sonic boom", a huge crashing noise which led many countries to banish it from flying over their territory.

Fuel guzzler

Another black mark was the Concorde's high fuel consumption. Its four Rolls-Royce/Snecma Olympus 593 engines together guzzled on average 20 tonnes of kerosene per hour of flight and 450 litres (nearly 120 gallons) per minute at take-off.

The fuel consumption per passenger was 14-17 litres for every 100 kilometres travelled—four times more than for an aircraft today."

luis

 

[IRstuff]

Fuel consumption is not surprising; air resistance increases as the square of the velocity.

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[rb1957]

how's supersonic flight relevant to this discussion ? commercial transports are sub-sonic.

mind you there's a lot of interest in supersonic business jets, which IMHO is a waste of carbon/energy.

another day in paradise, or is paradise one day closer ?

 

[0707]

SpaceX launch technologie can be adapted for long distance earth passengers transportation within fifteen years?


luis

 

[rb1957]

it "could", but I doubt it … mind you I would've doubted landing a rocket but they do that, so what do I know ?

Whilst it may be reliable, it is still awfully prone to single source failures with catastrophic consequences … not something you want in a commercial transport.

I don't know the accelerations during launch, but not something I see 60 year old, or highly unfit/obese, people putting up with. Also deceleration on landing. Mind you they could probably redesign the trajectory to accommodate, possibly a 3g limit … even that is quite a lot … a sustained 2g turn is quite something !
Then the effects of sub-orbital reduced g (zero g ?) in the cabin would be "interesting", but for less than 1/2 hour ?

Then you've got the infrastructure to build, fuel depots etc.

Again, would these trips use less fuel than current (or future) airliners ?

It'd also "only" replace intercontinental flights, those long enough to justify a suborbital launch

another day in paradise, or is paradise one day closer ?

 

[IRstuff]

If you're not trying to get into orbit, the acceleration can be much less. Nevertheless, the amount of fuel burned for brute-force lift an vehicle straight up is gigantic; a typical ICBM lifts a payload that's less than 1000 lb, so 5-ish passengers. 4 Minuteman II ICBMs are about as long as an SST, so carrying 20-ish passengers, compared to the SST stated capacity of 128 passengers.

The faster and higher you go, the more fuel you burn per mile traveled.

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[rb1957]

sure … time saved = more energy expended

another day in paradise, or is paradise one day closer ?

 

[IRstuff]

If it were linear, that might not be so bad, but it's way worse, something like 12 mi/pass/gal for SST vs. 107 mi/pass/gal for a conventional plane. Since drag goes as the square of velocity, that's a big chunk of it.

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[rb1957]

the transition to supersonic flight kills the v^2 relationship

another day in paradise, or is paradise one day closer ?

 

[IRstuff]

It breaks the constant drag coefficient, which increases dramatically, and then slowly drops down to something that's still larger than the subsonic coefficient. Nevertheless, the drag coefficient is still multiplied by velocity squared to get the drag force.

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[rb1957]

yes I know drag is proportional to v^2, except that the constant of proportionality takes over as you go trans-sonic.

if you double speed from 200 kts to 400 kts (still subsonic) you'd expect drag would increase by a factor of 4 (assuming spherical chickens in a vacuum).
if you double from 400 kts to 800kts drag will increase significantly more than 4 time (assuming cubic chickens in an inviscid liquid).
the () expressions mean a host of simplifying assumptions not grounded in reality.

another day in paradise, or is paradise one day closer ?

 

[IRstuff]

Sure. I agree with that; either way, the Concorde's fuel efficiency is a factor of 2 poorer than a straight v^2 relationship would give us, but that was a given, because the drag coefficient would have been different anyway.

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[0707]

"Passenger planes could be flown without a pilot in the next decade, according to a new study.

The research was conducted by investment bank UBS, which found that new technology is being developed that would make remotely flying an aircraft feasible in the near future."

Aibus has allready made some experiments on this subject from airport of Touluse.

luis

 

[SWComposites]

Yep, bankers are airplane design and cert experts. Right. Another fantasy.

 

[0707]

Drone planes and cars are not a fantasy.

 

[rb1957]

you are quite correct "passenger planes Could be flown without pilots in the next decade" … "could" being the operative word.

the likelihood is, IMAO, vanishingly small.

another day in paradise, or is paradise one day closer ?