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Bugatti has broken the 300mph barrier

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Re: Bugatti has broken the 300mph barrier

#61

Post by pmyteh »

TylerE wrote: post #53
beambot wrote: post #31

Earlier quoted context omitted.

> The "obvious" upgrade ... What's stopping the trains from operating autonomously?

Unions, mostly. The tech is there, especially on a 100% grade separated line like the TGV - no road crossings, and the full length is either fenced, in tunnels, or on bridges.

That's true of attempts to remove the guard, but I don't think it's true of automating the driver.

Automatic train operation systems are expensive to design and maintain, and their advantage is mainly in precision: if you're trying to put 30 trains an hour down a segment of tube tunnel, it's very helpful if the system reacts immediately to red signals and brakes at a constant predictable rate.

For longer distance services, not only is the cost of fitting ATO equipment to the track much higher (as the routes are much longer), but the schedules don't need such precise operation. It is probably cheaper to retain drivers.

In practice, even most metro systems with automatic train control still have someone on the train: it's important in an emergency and if there are degraded conditions or unusual operating needs it's helpful to have someone trained to take over.

Re: Bugatti has broken the 300mph barrier

#62

Post by w56rjrtyu6ru »

ollie87 wrote: post #41
mrweasel wrote: post #37

Earlier quoted context omitted.

True, but that just makes the whole exercise even more pointless. There's really no point in building a car that can go above 150km/h, but perhaps some of the aerodynamics can translate into more fuel efficient car. I'm also slightly annoyed by the usage of the word "barrier". There's physical or perceived 300mph barrier. People have built cars that will go a super sonic speeds, so there was never any doubt that it w…

A lot of things humans do are pointless, but all the same we do them. Doesn't stop it being fun does it?

Believe it or not, for some people the pointlessness of an activity greatly ruins the fun of it.

Re: Bugatti has broken the 300mph barrier

#63

Post by pas »

SCdF wrote: post #47

Does anyone have any insights to if this brings any interesting science to the table that is applicable outside of this context? I personally have zero interest in a fast car going fast, but it's always interesting to see how these sorts of difficult feats help humanity in more general ways.

One important side effect of going fast is that you need to slow down fast. So better braking power. (Though the problem with supercars is that simply using something that needs replacement every few hundred miles is "acceptable".)

Similarly anything that rotates has to withstand torque and centrifugal force. Eg wheels. (See also this: https://www.youtube.com/watch?v=K_ImAm1WhcY for what it takes for going 3x faster.)

These advances result in capital investment for R&D, percolate through the supply chain, and this can lead to better techniques here and there. (But I think after a certain point the disparity between the technology - the trade offs - needed for 100 mph and 300 mph become so large, that the resulting new/better capabilities doesn't mean anything for the normal automobile ecosystem.)

Re: Bugatti has broken the 300mph barrier

#64

Post by jgtrosh »

jsiepkes wrote: post #45
Svip wrote: post #25

Earlier quoted context omitted.

This is why the TGV has no signals. Instead it uses a radio communication system. If no radio signal is received within a time frame, the train will warn the driver, and eventually stop. If a train has to perform an emergency stop, all other trains behind it are informed via the same system. If the driver does not react, the train will stop itself. There is a reason why the TGV has seen no accidents since its launch…

While it may be safe, no accidents since launch might be a bit of an overstatement: https://en.m.wikipedia.org/wiki/List_of_TGV_accidents

Thanks I'd never seen this. So there have been quite a few incidents, but the takeway at the top seems to be there has been no fatality “at high-speed”. I guess that's something to be proud of, but that's still far from a perfect track record.

Re: Bugatti has broken the 300mph barrier

#65

Post by pmyteh »

jdietrich wrote: post #43
adrianN wrote: post #30

Earlier quoted context omitted.

A train going faster than 25mph or so is already too fast for the operator to react (braking distances are huge!), so I doubt that the top speed is limited for that reason.

The driver can't usefully brake in response to a person on the track, but they do need to be able to brake in response to a trackside signal. At 140mph, braking distances are greater than sighting distances - by the time you've seen a signal, it's too late to stop. That's catastrophic in a fixed-block signalling system, which can only detect the presence or absence of a train in a particular signalling block; if you…

Just a small nit: almost all high-speed systems still use fixed block signalling, but with in-cab signal indications as you say to give more warning time (and a constant reminder rather than having to spot a signal as it goes by in a flash). Moving block turns out to be much harder to implement than expected; it's included in the European Train Control System's level 3, but even most new installations are of level 2 (fixed block with in-cab signalling).

Re: Bugatti has broken the 300mph barrier

#66

Post by kijin »

StavrosK wrote: post #52
mellosouls wrote: post #29

Earlier quoted context omitted.

British publication. So relatively muscular imperial miles are correctly used. Readers' eyes might pass over in disinterest should weird & weedy "kilometres" be used instead. On a more serious note, I'm sure the various manufacturer marketing departments take every opportunity, imperial, metric, Klingon, whatever, to mark a passing of a numeric "barrier" - i.e. a number ending in zeros.

I'm still waiting for someone to break the mythical 2500 furlong per hour barrier.

If you're going to use furlongs, you gotta use the whole FFF system consistently. 1000 furlongs per millifortnight for the win!

Re: Bugatti has broken the 300mph barrier

#67

Post by zone411 »

parsimo2010 wrote: post #38
tialaramex wrote: post #13

It's futile to actually have road-legal cars that go this fast because you can't do very much useful with the speed. This is much too fast for the human operator (driver) to safely react to things outside the cockpit, which is why for example Britain owns trains capable of 140mph in service but deliberately limits them to 125mph. Tests suggested drivers couldn't be relied on to reliably observe and react to a linesid…

Pretty much all modern cars will go faster than is useful and/or safe. Only a small set of public roads allow cars to go their top speed. I have a 1991 Corvette that will go 153 mph, and I've only done it twice. It scares the crap out of me. Top speed is a cool thing to boast about, but most people won't ever see it, and a few stupid people will hurt themselves with it. That's okay on the balance, because millionaire…

If you haven't pushed it on a race track with long straights, you have to try. I don't know how 1991 Corvette feels at high speeds but in newer sports cars, the long straight will seem like the time to relax a little, even in the 150s.

Re: Bugatti has broken the 300mph barrier

#68

Post by Kuinox »

tialaramex wrote: post #13

It's futile to actually have road-legal cars that go this fast because you can't do very much useful with the speed. This is much too fast for the human operator (driver) to safely react to things outside the cockpit, which is why for example Britain owns trains capable of 140mph in service but deliberately limits them to 125mph. Tests suggested drivers couldn't be relied on to reliably observe and react to a linesid…

140mph -> 225 km/h 125mph -> 201 km/h When converted I understand the high speed you talk about. The TGV go at 300km/h.

Re: Bugatti has broken the 300mph barrier

#69

Post by zone411 »

mrweasel wrote: post #37
ollie87 wrote: post #21

Earlier quoted context omitted.

Mmmmhmmm, don't really see it as an issue here given that not many folks are going to be buying a £2.5m hypercar to drive at three times the speedlimit to work on a Monday morning.

True, but that just makes the whole exercise even more pointless. There's really no point in building a car that can go above 150km/h, but perhaps some of the aerodynamics can translate into more fuel efficient car. I'm also slightly annoyed by the usage of the word "barrier". There's physical or perceived 300mph barrier. People have built cars that will go a super sonic speeds, so there was never any doubt that it w…

It sounds like you don't know about track days or drag strips. That's the way to enjoy a car that goes faster than 150km/h fully. A 300mph Bugatti is still way above any speed you'd reach, though.
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