151–160 of 237 posts
If they manage to reduce the cost of tunnel boring then that's super exciting and I congratulate them. But all this discussion of what to put in the tunnel seems very silly to me. Are they just re-discovering subways? Do they know that there are subways in the world (e.g. Paris) that run out rubber tires?
Does anyone know the track width? It's more likely to become a global standard if they picked a nice number in meters.
There might already be a standard of some kind that could be used either directly or as a sub-multiple the same way that European kitchen fitments are generally 600 mm wide modules.
There is nothing magical about units of measurement, neither SI nor what Americans persist in calling Imperial (when they mean US Customary or even worse US Survey Foot).
Earlier quoted context omitted.
I'm not sure what you're purporting to show other than two people disagreeing with each other, without providing evidence... Sure, an individual subway car has "more capacity," but does a subway system have more capacity? For example, I rarely see BART trains come within five minutes of each other. A tunnel that allows cars within 10 seconds of each other could provide more capacity than a tunnel with higher-density…
The equivalent of BART in Paris (RER) has 90 seconds intervals between trains in peak time - and thats the regional train system, not the metro. It carries 50k pax per hour in each direction - that would be a lot of cars, like eleven cars a second at 1.2 person occupancy. You mention "cheap tunnel boring" - maybe that is the keystone of Musk's plan that will change the paradigm... With a little knowledge of tunnel bo…
If they manage to reduce the cost of tunnel boring then that's super exciting and I congratulate them. But all this discussion of what to put in the tunnel seems very silly to me. Are they just re-discovering subways? Do they know that there are subways in the world (e.g. Paris) that run out rubber tires?
The problem with subway systems is that they are great once they have enough reach and stops to reliably and frequently get you were you need to go without needing a car. However, a small subway system with infrequent service and only a few stops isn't all that useful. If we take the claims here at face value (not saying we should) then this is a solution that provides value immediately for people commuting by car, a…
Is this safe? I didn't see any escape paths. What happens if there is a fire and you are in the sixth tube down? Electric trains are considered quite safe yet tunnels have a lot of escape paths and service tunnels built parallel to the main one.
As safe as any cave open to the public, which there are many of in state and federal parks often with only 1 or 2 exits.
Also, barring an act of terrorism, it's probably as safe as driving a car, safer than skiing (water or snow), exponentially safer than sky-diving etc.
>What happens if there is a fire and you are in the sixth tube down?
Compared to the feat of actually tunneling the machine, boring small escape tubes would be relatively trivial. Employ magnetic-electric security doors that can be remotely released or unlock in the event of a power failure and anyone able bodied could climb a ladder out, make them wide enough to get a rescue harness down and fabricate in an anchor point for a safety line and anyone not capable could be lifted out not unlike how rescue helicopters lift people with a winch. And really, the operator could install the harnesses and winches too and have them be both electric with a way to easily connect them to an external power source and/or manual for redundancy. All you'd have to do is test them once or twice a year and lubricate as necessary.
I'm pretty risk-averse but I wouldn't hesitate to use one, even without escape shafts.
If they manage to reduce the cost of tunnel boring then that's super exciting and I congratulate them. But all this discussion of what to put in the tunnel seems very silly to me. Are they just re-discovering subways? Do they know that there are subways in the world (e.g. Paris) that run out rubber tires?
Tunneling is currently so expensive that there are few companies doing any innovation on how to properly utilize them. A big part of the problem is actually digging them in a way that is cheap and scaleable. Another part of the problem is the organizations doing the digging and doing the exploitation are typically have misaligned incentives and goals. For example, expanding subway systems is currently in the hands of…
If they manage to reduce the cost of tunnel boring then that's super exciting and I congratulate them. But all this discussion of what to put in the tunnel seems very silly to me. Are they just re-discovering subways? Do they know that there are subways in the world (e.g. Paris) that run out rubber tires?
Tunneling is currently so expensive that there are few companies doing any innovation on how to properly utilize them. A big part of the problem is actually digging them in a way that is cheap and scaleable. Another part of the problem is the organizations doing the digging and doing the exploitation are typically have misaligned incentives and goals. For example, expanding subway systems is currently in the hands of…
2 lanes of 3 rails that are grade leveled should be relatively less expensive than paved, with rebar grade leveled; especially over time, with the increased wear that liquid has.
Umm, and the capacity of these tunnels is also orders of magnitude lower than a subway. It would also be a lot harder to use and available to far fewer people. This entire idea should be laughed out of existence, but despite everything, Musk still gets fawning coverage for any crazy idea he spouts.
Maintenance will be impossible. Breakdowns of any sort would go from being annoyances to a few to being catastrophic failures for the system. Even if the tunnels never degraded, even if no car ever had a flat tire in the middle of the tunnel, and even if you could actually achieve 150mph (which would be extremely unpleasant for the passengers anyway), you couldn't physically fit enough cars through the tunnel to compare to real transit system. Given that this thing requires rigging something up to your vehicle, the onload and offload points would immediately become major bottlenecks to any serious throughput even if you could cram them in bumper to bumper.
The tone of the article is surprisingly hostile. Maybe I'm just used to Canadian media.
American culture has shifted in the last decade to be extremely critical and scathing towards anyone or anything that attempts to change the status quo - even if it's an attempt to make things better. See all the negative comments in this thread, for example. Instead saying "Jeez, this looks interesting. I'm happy some billionaire is trying to fix the horrible traffic problem instead of just buying more McMansions an…
Earlier quoted context omitted.
> Musk played a simulation showing the wheels folding neatly underneath the car’s undercarriage when not in use. Adding them during assembly or after-market would cost $200 to $300, he said, and would not interfere with the vehicle’s normal operation.
Folding wheels .. right I can see some interesting failure modes where the wheels fold up in normal driving. Yeh I know its not supposed to happen but one Uk maker had steering wheels that could come off whilst driving - this was used in my mech eng course as a cautionary example.
Steering wheels come off in MANY race cars, IndyCar it's basically a necessity so you can get in and out of the cockpit.
In the case you mention it just sounds like design incompetence.