Comment by Someone1234 | Hacker News Reader

Comment by Someone1234 | Hacker News Reader

I am very surprised this is being built. Who is paying for it?

I am all for new ideas, but the Hyperloop has some safety concerns that need to be ironed out. Even the Channel Tunnel is substantially safer than the Hyperloop's initial design.

For example, if a "train" (pod?) breaks down or gets stuck between stations how do you rescue people? It is a low atmosphere tunnel, you cannot just walk down it, it might take hours to re-compress, plus you're well off the ground so cannot just cut a hole...

What if a fire breaks out on the train? Nowhere to run. So will you build it up to aircraft level-safety standards?

Also how will stations work? You have low atmosphere tunnels, but stations have to be normal breathable spaces, so are they going to have decompression chambers? And if they are then you have to design trains which can be decompressed and recompressed (see aircraft).

Plus these tunnels will have to be pretty large when you consider disabled people and luggage. The initial design showed a super low profile train, so much so that it was impractical for normal commuters, even relative to aircraft. The real thing would have to be much bigger (like road-tunnel sized).

Overall building this is possible. But essentially you're building a fully functional aircraft in a tube with all of the same issues and limitations that go along with air travel. If something "bad" happens then it will get very bad very quickly (like aircraft). So safety has to be aircraft grade too...

I'm sure everyone asked the same questions when people started proposing flight as a legitimate transportation means.

What if a plane breaks down in flight or the flaps get stuck? There's low atmosphere at high altitudes, so you can't just open the door without risking structural damage to the aircraft. What happens if there's a fire on board? Where will these planes land? How big will the runways be?

My point is that the development of commercial flight took place over a long, long time to get where we are today. We're still in the whiteboard stages with the hyperloop. Lots of people had to break a lot of planes to get where we're at now.

I can actually answer some of that. The first flights were unpressurized and there was no door to break down. The first commercial flight was a Benoist seaplane which flew that trip under 50 feet altitude, though it could fly up to 1,000 feet. The first KLM flight (the oldest airline company still in service) used an Airco de Havilland 16 in 1920, a year before the first pressurized cockpit.

Therefore, no one would have asked about problems with low atmosphere or opening doors.

The Wright craft used wing warping, and not flaps, so people didn't ask that question. What if the motor stopped - that's a much more critical question. The Benoist seaplane flight above had problem part-way through. The pilot landed on the water, fixed the engine, and took off again.

As for runways, the Wrights landed on the sand in front of them, the same as Chanute did earlier with his experiments with gliders on the dunes of Michigan. The first airplane flight in New England used a frozen lake surface. Early on people used large fields, like Penn Field or Roosevelt Field. The movies of Lindberg show there wasn't really even a marked route; I assume the better to align with the wind. Runways as we know it took a while to exist - they were airfields.

While I understand your intent, it would have been better to omit examples rather than make ones up. Otherwise your ahistorical comments affect my interpretation of your ability to judge an appropriate development cycle. People aren't talking about problems which might occur after 20-30 years of development, but rather problems that are well-known already.

This would be like telling Félix du Temple in 1870 that steam engines aren't powerful enough for a flying machine to carry humans.

Thanks for the comment. I'm a stats guy who wishes he studied engineering. I'll be more careful in my word choice next time. Learn something new everyday, right?

Your questions are excellent, and they're the exact reason a "test track" is being built.

That is, after all, the point of a "test" - to figure out the fine details.

Most of your scenarios and objections are addressed in the Hyperloop whitepaper. Will these proposed solutions work? Nobody knows. Sounds like a prototype is in order.

I've read the original white paper. They really weren't. Did they release other ones?

I have only seen the one. All of your safety concerns except fire were covered. They really don't mention to much about station design, but does mention the pod withstanding pressurization and depressurization.

As far as size for wheel chairs it mentions having a pod that could fit a car(a Tesla of course) so fitting a wheel chair shouldn't be much of a challenge, or for the smaller pod it mentions being over 6 feet tall and over four feet wide I don't see why you couldn't fit a wheel chair in that amount of space.

Can't work out those problems if you don't build a prototype.

That isn't really true. Most engineering projects of the last one hundred years had no prototype and the engineers were able to foresee and eliminate many of the problems.

In particular I think many of the safety issues need to be considered before they build a scale prototype. Since presumably they wish to put people into the thing, it is a good idea to figure out how to get people out also.

They can do that without including it in the tweet or TC article.

Of course. Please read my post in context, I was responding to someone who suggesting the prototype should do that within its own right.

The prototype isn't just a physical thing. It's an entire process of planning, building and testing that thing. e.g., it includes consideration of the various things you've listed. It goes without saying.

This guy has managed to push the build of a well-reviewed and semi-revolutionary car, not to mention frickin' rockets. I think his staff can foresee the challenges, then design and test for them.

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