https://en.wikipedia.org/wiki/Fairey_Rotodyne https://www.youtube.com/watch?v=y9633v6U0wo
If you wanted to use this for commuting, just add a front electric sustainer to it. By the time the sustainer turns on, the aircraft is already pretty high altitude.
It'd be just as quiet as a land vehicle due to the greater distance away from the hearer.
but yeah, helicopters are likely to be fairly loud.
Sailplanes wouldn't work for commuting because of, in order:
1. Difficulty of training 2. Pilot liability for accidents 3. Weather 4. Space required to take off and land
My expert opinion - for limited delivery applications sailplanes could work. You need to do it right - sample and model atmosphere from the vehicle and ground, use gravity to accelerate and decelerate to flying speed, complete automation to remove the pilot. It's not easy. But it is not impossible.
(Incidentally, if someone is willing to drop me ~500k in an attempt to build a prototype - I might consider investing the time required.)
By talking sailplanes, I didn't mean unpowered flight. Of course you need power, to counteract drag . I was primarily referring to a form-factor (clean, efficient and and silent like a sailplane) and to a mode of takeoff and landing (convert speed to altitude with a wing, instead of eVTOL).
I'm merely pointing out one method that would allow near-elimination of noise.
...and you can fly a sailplane at a younger age (13 for solo flight) than you can drive (usually 16). And driving has most of those concerns as well.
Autonomous sailplane: - flies in 3D space with pitch, roll, yaw - has both MAX (Vne) and MIN (stall) speed, can't stop and wait - can't even stop descending (!) - HEAVILY influenced by wind and thermal conditions - pretty unstable, oscillates when upset - can not use ground as visual reference reliably - flying one is no joke even for a human, requires serious training
Good luck with your full autopilot.
What pilots usually do during emergency is to go through the checklist. There is not much room for improvisation.
Vehicles - it is a completely different level of problem. If you try to drive with dGPS alone, you will collide almost immediately. Even on the empty road, because dGPS is not good enough. And actually, it is almost AGI-complete problem, as you need to model and interact with other traffic participants.
While it doesn't completely negate your argument...
How about a solution for a VTOL craft, like the Boeing vehicle? How about an airship with high speed winches, with smaller drones managing the ends of the cables? The cables could attach to aircraft that want to take off, which would be pulled up to a height where their rotor noise wouldn't be so annoying.
That said, they were also nick named "flying coffins".
re: winch tow - when I was an Air Cadet in canada as a teen, we used to fly in schweizer 2-33's and occasionally went up on the winch - it was absolutely exhilarating!
...I've flown a 2-33. It's not much better than the Waco! :)
Unfortunately, I haven't flown it with a winch.
For example: Elon has proposed a tunnel to Dodger stadium. However, the existing Union Station-Stadium shuttles can (and do) handle 10x the proposed Elontunnel's max daily capacity in about an hour or two depending on traffic.
I don't quite get the hate for Elon's tunnels. Let him and his team try and build them and see if they work. Super cheap tunneling would be great for so many things. That is, unless you think that humans have too much power and think we should regress back to some more primitive lifestyle. "Try to help make a future that you would like to live in." Traffic congestion sucks. It would be great to get rid of it. Cheap tunnels could be one way to help. Why stop people from trying?
He did start and still runs a company that makes reusable rockets. You have to try to do something before you know what is possible.
Transport investment is like planting a tree. The best time to build it is twenty years ago, and the second best time to do it is now. Elon has basically given cover to NIMBYs to hide behind a supposedly new amazing future solution that may never come.
Construction costs has not come down in price over time like many other things have. I think he hopes that the Boring Company can list a price/mile for tunneling that is much lower than current costs and let people actually budget them. Maybe sell these better machines to other construction companies at some point. He broke the cost-plus pricing for satellite launches. Just think what something like that for tunneling could do for transportation systems. Billion dollar overruns are on the digger not the public. That would be great.
The actual cost comes in station digging; stations need to be high throughput and extremely reliable, which favors complexes with a large footprint and thus more required property taking, usually in dense urban areas that require complicated engineering. For highway tunnels the similar cost factor are onramps and offramps; if you want a ramp to be safe and efficient at high speed you need a lot of space.
Hyperloop “solves” this problem by proposing elevators. Very few metro stations are elevator only because they are low throughput and are prone to mechanical failure, as opposed to staircases that are not.
An interesting writeup on the case study of the Second Avenue Subway: https://pedestrianobservations.com/2018/01/27/construction-c...
Ok. Give up I guess; bad idea.
No. Let's start with this one, fix the various problems that arise, discover how to make a good paved road with the least amount of labor and resources, and continue to expand the paved network to reach everywhere in the city.
This is what happened. Would you want to go back to unpaved roads in a city? Traffic congestion is killing American society. I like American society. Many people don't like to live all packed together but still want to work with other people and have the amenities that cities enable. Cars and interstate roads allowed that for a few decades but now we need a new system to continue expansion of the free flow and interaction of people. Underground roads could replace interstates and we could turn them into grand boulevards for pedestrians, bikes, and other slow vehicles. Wouldn't that be great? Almost all car traffic is underground. Would you support such an idea?
For example: Elon has proposed a tunnel to Dodger stadium.
Fixed wing airplanes are the worst flight alternative. The passenger capacity of a single hot air balloon far exceeds the passenger capacity of an airplane. For example: A Wright Flyer.
Sorry, but this is a bit strawmannish. You do realize it's a proof of concept project, right? It's not like the Falcon 1 disproves the capacity of all SpaceX rockets, ever.
Second even with a single passenger vehicle, a tunnel can move people over it’s full distance at the same time. Consider a bus moving people on a 5 minute trip vs 50 minute trip on the second case it’s got 1/10 the capacity.
Sure, a 3.5 mile tunnel adds little on it’s own. But, then again it’s also short.
While we're at it, optimizing for number of vehicles rather than number of passengers is a very...how do I put it...rich way of thinking about things. Which jibes very well with Elon Musk's whole thing: "mass transit is great so long as I don't have to see the poors."
donoteat01 does pretty fantastic video work about a number of urban planning topics and he's shot this one full of holes already. You should watch it if you're curious. https://www.youtube.com/watch?v=4dn6ZVpJLxs
Why is that the case and can it be fixed? I would say that this problem would be easier to solve than the problem of getting a orbital class rocket booster to go into space, launch the second stage, and then return to the launch pad and land.
Musk likes to work from first principles to try and understand what is possible. What is the physics behind why you can't have a very full, steady stream of vehicles going through a tunnel? Nothing really. The vehicles just have to be very well controlled. With a good auto-vehicle you should be able to pack them in and have them enter and exit into the stream of traffic. Like a real road, only better. Why would you not want someone of Musk's caliber to not try to do this? My dad would rather have him working more on getting the automatic car working so he can continue commuting to work. I can understand that objection, but he says the Boring Company is only about 2-5% of his time. If you want something to happen you try and decide if it is possible, and then try and do it. Not spend you time figuring out how not to do it.
The rest of your post is weird heroification and I'd have to bleach myself after interacting with it, so I won't.
True, but a loading/unloading time of 30-60 seconds only means the tunnels are less feasible for short trips.
And we haven't even gotten into how a top speed of 140mph will burn the hell out of street tires.
It's just...dumb. It's not thought out. It's aggressively reality-averse. It's thought-leadery as hell.
People are super confused about this. The reporting wasn't very good and you have to look beyond it. The original idea is
- little 16 person passenger pods with bikes, wheelchairs, and luggage. $1 fare.
- possibly sleds for cars
- you can stack tunnels (think of them as car lanes in 3D), so you can have 20, 50 or 100 lane highways
- you make lane changes autonomously, so the subway pods can have different destinations
- it's all electric so there isn't poisonous engine exhaust
This is just people boarding a bus, the throughput is super high.
Even sled loading can be pretty fast, imagine replacing 20 street parking spots with sled elevators. Then accelerated to 100 mph, that too is a lot of throughput.
Here's the pod part of the Boring company talk. It's worth watching to see what they are proposing. https://youtu.be/AwX9G38vdCE?t=1372
Elon and company got excited that they built a tunnel, which is a real achievement. So they drove a Tesla through it. The media knows what you want, which is max outrage, so they reported that the 1% will get tunnels with their Teslas. You will be stuck in gridlock behind a diesel truck.
They should not have driven a Tesla through it, it was a PR blunder.
Here is a Heathrow pod experiment: http://www.bbc.com/autos/story/20140910-hands-off-with-heath...
The main issue with building tunnels is cost. Tunnels aren't cheap and are hard to scale because soil conditions are extremely local and you have to tailor boring machines to ground conditions. Egress points are expensive, especially in dense urban areas where property values are sky high. You could use elevators instead of stairs, but the problem is that elevators are low-throughput and unusable in the event of unreliability.
Even considering all that, Elon did build a tunnel, but the tunnel was quite short and also quite small. There's not really room for emergency ventilation, or egress walkways with exits or safety points every 300m, or really anything that modern fire codes would require. Once you add all that in the tunnel is not really narrower than a subway train, at which point you might as well build a subway train. And why not? The New York subway has a capacity of 60,000 people per hour per direction using signals from the 1930s. A highway lane only carries about 2,000 people per hour. And all of that's assuming your low-capacity elevator entry can handle all of that.
PRT just combines the inefficiency of the automobile with the cost of actually building transit. There is a reason that PRT experiments have never been replicated elsewhere at large scale.