Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

newatlas.com

Post reply on HN
Print view View original

31–40 of 80 posts

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#31

Post by photonbeam »

BirAdam wrote: post #24
cooper_ganglia wrote: post #15

Earlier quoted context omitted.

How is building a rail system for transporting freight to and from the U.S. that runs through Russian territory a good/feasible idea? Even if Russia agreed, Putin or whatever strong-man dictator they have next could suddenly decide it was a bad idea, and to block U.S. freight. Then we have no rail transport AND a grounded air fleet that would take time to get operational at the same output it is today.

When goods stop crossing borders, soldiers start crossing borders. The easiest way NOT to go to war is to have open trade.

Best way to avoid war is to have the border be open ocean.

Having a railroad bridge with russia is inviting problems

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#32

Post by JKCalhoun »

serf wrote: post #23
downrightmike wrote: post #2

What the US needs is to fix its rail system. eminent domain the whole thing, pay off the robber barons and just run it like it matters to get shit from here to there.

> eminent domain the whole thing, pay off the robber barons let's not frame the heaps of collateral damage that would result in as only affecting 'robber barons'.

What would that be?

Not doubting you, just can't think of collateral damage.

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#33

Post by londons_explore »

If you're happy for your gliders to travel at 100 mph instead of 500 mph, you can glide almost fuel free, making use of thermals and winds most of the way.

However, the finances for such a business are hard to make work since, while you save on fuel, your very expensive aircraft does fewer flights per year.

The only way to make it work would be very cheap airframes, probably without humans aboard (meaning factors of safety and maintenance costs can be dropped).

But developing new airframes is awfully hard.

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#34

Post by jeffbee »

downrightmike wrote: post #2

What the US needs is to fix its rail system. eminent domain the whole thing, pay off the robber barons and just run it like it matters to get shit from here to there.

I often advocate this position! The Union Pacific is surprisingly affordable and after you gain a controlling interest it's not as if you've just torched $80 billion, because you bought a valuable asset.

For the state of California to do a hostile takeover of the UPRR, spin off an operating company for the train part, and retain the rights of way while adjusting the attitudes of the executives, would save a large amount of money just by simplifying the High Speed Rail project. It would be well worth it and we can afford it.

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#35

Post by mceachen »

rrrrrrrrrrrryan wrote: post #27
downrightmike wrote: post #2

What the US needs is to fix its rail system. eminent domain the whole thing, pay off the robber barons and just run it like it matters to get shit from here to there.

We're like a couple years away from having the tech to just give all autonomous electric vehicles the leftmost lane on the interstates from 10pm-6am, then raise the speed limit to 90 or 100 mph. Let trucking companies drive these vehicles a few feet apart from each other for aerodynamics. If you could book a sleeper taxi in New York and be in Chicago in the morning, or San Francisco to Seattle, for cheaper than a fli…

I don't know who you've talked to about this, but just because it's electric and robo-driven doesn't mean they get to skip aerodynamic drag. Air resistance increases at the square of velocity. 4 miles/kWh at 55 becomes < 2 mi/kWh at 85. 100 mph and you're measuring in kWh/mile.

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#36

Post by tidbits »

etrautmann wrote: post #30
rrrrrrrrrrrryan wrote: post #27

Earlier quoted context omitted.

We're like a couple years away from having the tech to just give all autonomous electric vehicles the leftmost lane on the interstates from 10pm-6am, then raise the speed limit to 90 or 100 mph. Let trucking companies drive these vehicles a few feet apart from each other for aerodynamics. If you could book a sleeper taxi in New York and be in Chicago in the morning, or San Francisco to Seattle, for cheaper than a fli…

This is roughly equivalent to flying if the car is ICE

And if the car is not ICE then you still have the problem of tire particle pollution. Trains are better.

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#37

Post by kccqzy »

mceachen wrote: post #35
rrrrrrrrrrrryan wrote: post #27

Earlier quoted context omitted.

We're like a couple years away from having the tech to just give all autonomous electric vehicles the leftmost lane on the interstates from 10pm-6am, then raise the speed limit to 90 or 100 mph. Let trucking companies drive these vehicles a few feet apart from each other for aerodynamics. If you could book a sleeper taxi in New York and be in Chicago in the morning, or San Francisco to Seattle, for cheaper than a fli…

I don't know who you've talked to about this, but just because it's electric and robo-driven doesn't mean they get to skip aerodynamic drag. Air resistance increases at the square of velocity. 4 miles/kWh at 55 becomes < 2 mi/kWh at 85. 100 mph and you're measuring in kWh/mile.

If you double the speed, the air resistance gets quadrupled. Power output needed for constant speed travel is octupled (P=Fv). Now you need a higher-power motor and more expensive batteries that can sustain this kind of power output. The typical electric vehicle available today can't sustain a speed of 100 mph without thermal throttling kicking in.

Sure making the electric motor more powerful isn't that big of a problem: just look at electric trains. But making the batteries more powerful will require significant more research.

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#38

Post by nradov »

BirAdam wrote: post #24
cooper_ganglia wrote: post #15

Earlier quoted context omitted.

How is building a rail system for transporting freight to and from the U.S. that runs through Russian territory a good/feasible idea? Even if Russia agreed, Putin or whatever strong-man dictator they have next could suddenly decide it was a bad idea, and to block U.S. freight. Then we have no rail transport AND a grounded air fleet that would take time to get operational at the same output it is today.

When goods stop crossing borders, soldiers start crossing borders. The easiest way NOT to go to war is to have open trade.

That's a nice little platitude but it's not supported by the historical record.

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#39

Post by JumpCrisscross »

mitthrowaway2 wrote: post #21
sarchertech wrote: post #16

Earlier quoted context omitted.

When it comes to freight rail, the US is in the top handful of countries in the world by pretty much any metric. We’re not great at passenger rail, but we beat all of Europe when it comes to the amount of freight shipped via rail per capita, and all of Europe except Switzerland based on the percentage of total freight transported by rail.

This is a myth oft-repeated on HN. US freight rail does cheaply transport a lot of tonnage, but it is a shadow of its former self, after a half-century of digesting the investments of the past. It's squeezed out efficiency by running longer and slower trains (that exceed the length of the rail sidings!) transporting bulk goods on predictable schedules between fixed points (like grain and coal), while slashing routes…

> myth oft-repeated on HN. US freight rail does cheaply transport a lot of tonnage, but it is a shadow of its former self

What is the myth? It is a shadow of its former self. But it retain its mantle of the 1850s as the world’s largest rail network.

Re: Unpowered cargo gliders on tow ropes promise 65% cheaper air freight

#40

Post by JumpCrisscross »

crote wrote: post #9
schiffern wrote: post #3

Earlier quoted context omitted.

>rail Wrong niche. This is in the same market as conventional air freight.

How much air freight really needs to be transferred by air, though? Air freight makes sense when you need to get something across an ocean in less than a month, or across the continent in less than a day. If the US were to invest in running the railroads efficiently, getting a package from NYC to LA in less than 72 hours should be possible - that's fast enough for regular Amazon shipping. If you electrify the railroa…

> If the US were to invest in running the railroads efficiently, getting a package from NYC to LA in less than 72 hours should be possible

Still need air for every other pair of destinations. And in the meantime, I’d be shocked if that freight leg had enough volume to justify that expense over a couple more planes.

Post reply on HN