sfsuphysics
[H]F Junkie
- Joined
- Jan 14, 2007
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- 15,969
Well the tunnel is less than 2 miles long , if you accelerate at a blistering 1g for half the trip (other half is decelerating at 1g) you will only get to just over 300 mph.
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How so? That's pretty regular speed for high speed passenger trains. The Eurostar goes 100mph in the Channel Tunnel (undersea tunnel from England to France) and as much as 180mph overland. Heck even the Javelin trains that do shorter hops in the UK can get up to 140ish. That's just train speeds, not even really fast train speeds. Putting a train in a tunnel is nothing new or special. As I mentioned, there's a 30 mile tunnel that runs under the English Channel that was built over 2 decades ago. The idea of the "Hyperloop" is supposed to be a vacuum tunnel with supersonic trains. Demonstrating a regular high speed train in a tunnel does not demonstrate they are any closer to that as that is something that the technology is already widely available for.
The Alpha and Omega problem for it is how do you maintain a vacuum in a large tunnel safely and efficiently. Until they can show a solution for that, it is all just fluff. Making the train that can go fast is not the hard part, we do that already.
It's called 'iterative design'. This is a small step in their process. They've finished a usable section of tunnel and they plan on studying that section while people use it. Each stage has a big emphasis on safety and validation.
The Boring Company is Elon's 'casual' company, it's not in a great hurry to change the world.
No. That's one of the things I find funny about this. A while back Elon Musk was complaining about how long it took him to get to SpaceX from the airport. A couple months later, he gets permission to dig a "test tunnel" for his underground city tunnel concept. Now, because he's Elon Musk, he's got a shorter commute and is hailed a visionary.So what? Is there a train line right above the tunnel you can take instead? Are there any train lines going where this tunnel goes?
Technically, there is no defined "supersonic" speed in an absolute vacuum because there can be no sound. While you may think I'm merely being pedantic, I'm not. Supersonic velocities are relative, depending on air pressure; as the air pressure goes down, the velocity goes up. That's the whole reason for the Mach scale.If they're only running it at 155mph, that's a far cry from "working" when the claims have been supersonic travel under a vacuum.
Technically, there is no defined "supersonic" speed in an absolute vacuum because there can be no sound. While you may think I'm merely being pedantic, I'm not. Supersonic velocities are relative, depending on air pressure; as the air pressure goes down, the velocity goes up. That's the whole reason for the Mach scale.
So what? Is there a train line right above the tunnel you can take instead? Are there any train lines going where this tunnel goes?
I'm all for this discussion on vacuums, supersonic transport, and hyperloop projects, but I just want to make sure we're all on the same page here.This is NOT a Hyperloop tunnel. .... There is no vacuum chamber involved.
The point is this in no way is a step towards the Hyperloop. This is technology that is commercially available, in use already, around for decades. People are acting like this is some kind of step forward. It isn't. This is shit that has been done for a long time. This doesn't go anywhere towards solving the problem of maintaining a vacuum in a large chamber safely and economically. This is like if I were to say "I'm going to make a high resolution fully 3D display!" and then I produce a prototype that's a 4k monitor. You'd rightly object that it is just a 4k monitor, something widely available, and I haven't done anything towards solving the issue of making it 3D.
That's a great analogy. Nobody's going to care about an "electric airplane" if the first thing they show is a used 737 airframe.Its like me saying Im going to build an electric airplane and when I say I have the air frame done you go "Big deal, thats been done a thousand times before."
Funny but I thought a tunnel was kinda a prerequisite. Im still firmly in the so what camp. I dont see why your are crapping all over it. Its like me saying Im going to build an electric airplane and when I say I have the air frame done you go "Big deal, thats been done a thousand times before."
Its really too bad they can't do one in a straight line that's only for cargo transport. With speeds that would not be safe for people but would be fine for cargo.
That's because I thought others had already covered this part pretty well: this system is just a test of the tunnel boring, not a real hyper-loop (too short for that). And even in the proposed systems they are not talking about pulling a hard vacuum - that would be too difficult to maintain. It will only be a partial vacuum, probably 5 to 10% sea-level atmospheric normal.The more important part of my sentence that you seem to have glossed over while being pedantic about the use of the word "supersonic" is the vacuum portion. Without that, it's just a train in a tube.
You mean like way back in the first half dozen replies of this thread?That's because I thought others had already covered this part pretty well: this system is just a test of the tunnel boring, not a real hyper-loop (too short for that). And even in the proposed systems they are not talking about pulling a hard vacuum - that would be too difficult to maintain. It will only be a partial vacuum, probably 5 to 10% sea-level atmospheric normal.
If they're only running it at 155mph, that's a far cry from "working" when the claims have been supersonic travel under a vacuum.
Except the entire point, is to be a train/car/module/whatever in a vacuum. If this is not in a vacuum, then it's no different than any other rail system except having Elon's name on it.
The more important part of my sentence that you seem to have glossed over while being pedantic about the use of the word "supersonic" is the vacuum portion. Without that, it's just a train in a tube.
You meet a mechanical engineer that claims they're going to build a race car that will beat F1 lap times. Crazy! You swing by their house and see that they are building a vehicle in their garage. It's an offroad 4x4 pickup truck. Before the engineer says anything you say something like:Boring tunnels and then running a train through them without doing anything else regarding the vacuum has nothing to do with what was being proposed regarding hyperloop.
If you're going to be pedantic and then point out that you missing something so obvious was because it was already covered... maybe check who said what when it was "already covered".
There's nothing "hyperloop" about this, it's a train with a short route in a tunnel. Whoopdeedoo.
You meet a mechanical engineer that claims they're going to build a race car that will beat F1 lap times. Crazy! You swing by their house and see that they are building a vehicle in their garage. It's an offroad 4x4 pickup truck. Before the engineer says anything you say something like:
"Thats a far cry from a race car!"
with a serious face.
The engineer says "This was never meant to be a race car", not really sure if they should even continue this discussion or if this is some joke,
You reply with "I pointed that out but without the positive spin."
Do you think the engineer is going to think you made a clever observation that can lead to some fruitful discussion? Or perhaps at this point there is not much left to discuss and maybe the engineer should go get you a beer because perhaps you are a better conversationalist when you are buzzed (risky move! maybe it's better to just try to get rid of you !)
You meet a mechanical engineer that claims they're going to build a race car that will beat F1 lap times. Crazy! You swing by their house and see that they are building a vehicle in their garage. It's an offroad 4x4 pickup truck. Before the engineer says anything you say something like:
"Thats a far cry from a race car!"
with a serious face.
The engineer says "This was never meant to be a race car", not really sure if they should even continue this discussion or if this is some joke,
You reply with "I pointed that out but without the positive spin."
Do you think the engineer is going to think you made a clever observation that can lead to some fruitful discussion? Or perhaps at this point there is not much left to discuss and maybe the engineer should go get you a beer because perhaps you are a better conversationalist when you are buzzed (risky move! maybe it's better to just try to get rid of you !)
Which articles are you referring to? This is Loop (not HyperLoop). Boring doesn't claim anything about speeds above 155mph on their website:I mean he has a point, they promised 760 mph tunnels. Now they say here it is at 155mph and we will be working to get it to around 300mph over time (this is in the article that was linked). .
maybe I missed something?What's Loop?
Loop is a high-speed underground public transportation system in which passengers are transported on autonomous electric skates traveling at 125-150 miles per hour. Electric skates will carry between 8 and 16 passengers (mass transit), or a single passenger vehicle.
Loop does not have a goal of 500+mph trains or vacuums.*sigh*
Making trains run at speeds that other companies have been doing for decades is not an accomplishment. Putting trains in a tunnel is not an accomplishment. Neither one of these steps is any closer to the goal of 500+ mph train in a vacuum tunnel than any other company has done.
Cargo is too heavy to go fast. On cargo-only lines like the heavy rail in the US, usually 70-80mph is all you go, and often slower than that. Same deal with dual-use stuff. Like the Swiss Gotthard tunnel operates at 120mph or so for passenger trains, but only about 60mph for freight. When they get really laden with cargo you can't make them accelerate fast even if you wanted to and you don't want your top speed to be too high for safety. However though not fast, it is super efficient. Shipping cargo by rail takes something like 1% or less of the energy as shipping it by truck.
Which articles are you referring to? This is Loop (not HyperLoop). Boring doesn't claim anything about speeds above 155mph on their website:
maybe I missed something?
maybe I missed something?
Yeah I see it now, thanks. I skimmed the articles before but was having trouble finding that part.Yeah, you know the article linked in the OP. That I guess no one read as usual. I'll admit this one is a little harder to click on than average, the hyper link to the article is the word hopes in the OP, there you will find what I found.
Like I said very underwhelming.
I thought it was agreed that the thread title got it wrong and this isn't hyperloop.You don't understand why anyone is mentioning the hyperloop, that this obviously isn't? Try reading the thread title?