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Will we ever fly supersonically over land?

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Re: Will we ever fly supersonically over land?

#211

Post by marcosdumay »

cortesoft wrote: post #38
marcosdumay wrote: post #32

Earlier quoted context omitted.

Well, in a plane trip you have 3 lost hours before it starts and after it ends, so a normal train, running at 130km/h will be faster than a plane at 850km/h for any trip of less than ~460km. If you make it a fast train, at 350km/h, it will beat the plane on any trip up to 1700km. Most trips are short, so no, most trips can be done by train and people still spend less time on them than by plane.

I live in Southern California, with family in Kansas, Wisconsin, and New York. The closest one is 2500kms away. The longest is almost 5000kms A train would take a lot longer than a plane. Even more than just the distance, though, is the fact that there would be no practical way to have direct rail lines to every major city in the US. Trains are useful, but there is no way they could replace air travel in the US.

Yes, you are not on that "most" category. (But that 2500km is close to it, so trains may still be more comfortable.)

to be fair, even for short trips trains require a minimum passenger flux before it's more efficient than planes. So even strictly talking about carbon emissions, trains are a net loss for most trajectories, but a large gain for most passengers.

Re: Will we ever fly supersonically over land?

#212

Post by marcosdumay »

sokoloff wrote: post #98
marcosdumay wrote: post #32

Earlier quoted context omitted.

Well, in a plane trip you have 3 lost hours before it starts and after it ends, so a normal train, running at 130km/h will be faster than a plane at 850km/h for any trip of less than ~460km. If you make it a fast train, at 350km/h, it will beat the plane on any trip up to 1700km. Most trips are short, so no, most trips can be done by train and people still spend less time on them than by plane.

I don’t lose 6 hours on a typical airline trip. Domestic, I tend to arrive around an hour before gate close time. International from the US, about 90 minutes. For a train, I’d still plan on a 30 minute safety buffer (to protect against en route delays to the station). Add another 30 minutes over the train for boarding, push, and taxi. So, I’m probably giving up an hour plus/minus however closer the train station is v…

The numbers on my comment are for 3 hours, not 6. (Yeah, the text is not very clear on that.)

Re: Will we ever fly supersonically over land?

#213

Post by syntheticnature »

Judgmentality wrote: post #69
syntheticnature wrote: post #54

Earlier quoted context omitted.

Military supersonic flight over land in the US is supposed to only happen over unpopulated areas. Having lived near a coastline (~1 mile from the shoreline) along a military flight path, I know they occasionally went a little early.

How loud was it and how often did you experience it?

Didn't have a decibel meter, but pretty loud, rattled the house and windows. Not as bad as someone using tannerite, though it might just be that the tannerite is a relatively recent experience and the sonic booms were a while ago.

Re: Will we ever fly supersonically over land?

#214

Post by pdoege »

hugh-avherald wrote: post #132
FridayoLeary wrote: post #73

Earlier quoted context omitted.

Also, shattered windows. A boom can easily smash windows.

Not that easily. Even with a fighter at 500 ft above, Mythbusters couldn't break windows. The Oklahoma tests had eight booms a day using very large aircraft. It took months before windows broke.

The Space Shuttle's sonic boom broke one of my bay windows when I was living in Orlando. Mythbusters was an entertainment TV show, I wouldn't extend their results to real life.

Re: Will we ever fly supersonically over land?

#215

Post by Leherenn »

jaclaz wrote: post #157
sokoloff wrote: post #98

Earlier quoted context omitted.

I don’t lose 6 hours on a typical airline trip. Domestic, I tend to arrive around an hour before gate close time. International from the US, about 90 minutes. For a train, I’d still plan on a 30 minute safety buffer (to protect against en route delays to the station). Add another 30 minutes over the train for boarding, push, and taxi. So, I’m probably giving up an hour plus/minus however closer the train station is v…

Of course it depends, but train stations tend to be in the center of a city, so you start from the center of A and arrive to the center of B. With planes, airports are way off the city centre, I think that there are few airports (here in Europe) serving large cities that can be reached in less than 1 hour from the city centre, and that applies to both A and B, to this you add, unless you use a private means of transp…

That kinda implies you leave and go to the city centre each time, which might not be the case. Living next to a major train station is usually very expensive. If you're visiting family in the suburbs, you might be closer to the airport than the city centre (or be "unlucky" and have the airport on the other side of the city). It sounds pretty situational to me.

Re: Will we ever fly supersonically over land?

#216

Post by bluGill »

tshaddox wrote: post #144
bluGill wrote: post #94

Earlier quoted context omitted.

Please do so. Airports are nothing compares to just I80 across the US. There are a lot of other roads as well that we could downgrade if more people flew.

The interstates tend to go to the airports though.

Interstates go a lots of places, airports is just one. they also cross Nebraska for example.

Re: Will we ever fly supersonically over land?

#217

Post by billyruffian »

nradov wrote: post #143
katbyte wrote: post #110

Earlier quoted context omitted.

very loud sounds can panic/shock animals and if it's too much for them, they die.

Is there documented proof of this actually happening?

Rural person here from Wales where sonic booms from military aircraft were moderately common.

Animals panic when they hear the boom: they tend to stampede, fall off cliffs, break legs, trample each other, lambs get separated, break through hedges and into traffic.

The booms were severe enough to occassionally shatter the Royal Doulton in the house, much to my mother's disgust.

Re: Will we ever fly supersonically over land?

#218

Post by beerandt »

ClumsyPilot wrote: post #125
beerandt wrote: post #109

Earlier quoted context omitted.

Yea, which is why trains costs are so sensitive to distance- it's massive up front cost is a function of that distance. It's not the stations, it's the rails and right-of-way. The problem most people ignore is that train marginal-increases max-out at some number of trains per day, before you need an additional set of tracks. And that happens at a much lower number than most people assume, especially if you're plannin…

>"Whereas the airline equivalent is whether to schedule an additional flight. Which is easier to commit to than whether a new track is justified." Except many world's biggest airports, like Heathrow, are operating at peak capacity and building another runway at heathrow is expensive, controvertial, involves relocating people's homes and is still a political football

Air still has the advantage- runway is not a function of distance to the destination, and runways are not destination specific.

So it's more appropriate to compare it to part of the station cost, along the lines of another boarding area & track, increasing arrivals and departures.

Re: Will we ever fly supersonically over land?

#219

Post by beerandt »

Clewza313 wrote: post #137
beerandt wrote: post #109

Earlier quoted context omitted.

Yea, which is why trains costs are so sensitive to distance- it's massive up front cost is a function of that distance. It's not the stations, it's the rails and right-of-way. The problem most people ignore is that train marginal-increases max-out at some number of trains per day, before you need an additional set of tracks. And that happens at a much lower number than most people assume, especially if you're plannin…

With dedicated track, though, those limits can be quite high. The Yamanote Line in Tokyo carries around 4 million passengers per day on two tracks.

Yes- and imho, that's the way to do it. Make it competitive in terms of time and trouble and cost and usability. But it's still not going to be more energy efficient than air for most situations & destinations.

Re: Will we ever fly supersonically over land?

#220

Post by fastball »

pyrale wrote: post #172
fastball wrote: post #106

Earlier quoted context omitted.

Ok, but... airplanes use the least land?

Much like the difference in land use with or without cars is not simply roads and parkings, but also the horizontal development of cities rather than vertical, the land use involved by planes is not simply the airstrips. Among others, it is also all the land developed specifically for vacation in remote places. If you look at [1] for instance, this area would simply not be developed if planes were not a thing. [1]: h…

What is wrong with vacations in remote places?
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