Comment by tempguy9999 | Hacker News Reader

Comment by tempguy9999 | Hacker News Reader

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> The original article made the case that this was cheaper than upgrading existing infrastructure

which part of "I'll happily accept that new tracks need to be built" was unclear?

> designing it to be 250mph capable seems sensible

I understand it's not going to be run at that speed for much of its length, so what's the cost benefit?

> Theres also the fact that this route will have competition, against aircraft and cars, ideally it needs to be quicker than its alternatives in order to succeed

Interesting question whether we will have fossil-fuel powered aircraft for many decades, and as for cars it's a matter of cost. Trains are expensive now - that's where it will compete with cars; they often are already faster than cars for long distances.

> Longer trains probably will increase capacity

'probably'?

> but mailing around TB hard drives probably has higher bandwidth than the average internet connection

false equivalence. Trains can already be faster than cars.

I don't think it's beyond the wits of engineers to work out which parts of the track need to be 250mph capable given the acceleration profile of the trains that are likely to use it. The ECML out of King's Cross is a 125mph route but unsurprisingly the points outside the station aren't designed for anything close to that.

Relevant snippet from https://www.channel4.com/news/factcheck/factcheck-qa-how-doe...

<<<

Will HS2 be the world’s fastest bullet train?

[...] But HS2 told FactCheck that there are actually no plans to operate at this speed. What’s more, they say this was never the plan. Indeed, the track, control systems and trains being purchased are not physically capable of it.

The confusion has arisen because HS2 says it has allowed enough flexibility to potentially do a major upgrade of the line at some point in the distant future, should the government want to. The curves in the route could theoretically see speeds of up to 400km per hour.

>>>

So my claim taken from wiki is not incorrect but not relevant yet.

Back to your point "I don't think it's beyond the wits of engineers to work out which parts of the track need to be 250mph capable given the acceleration profile of the trains that are likely to use it"

Good point! However while the engineering of the tracks can vary the trains have to be made to run at that spec speed even if it was for 1 yard. On t'other hand, judging by the jaw-dropping price of the tracks (£104.8m per kilometre, source is same as above) perhaps the trains are the cheap bit.

OK, you are right.

"false equivalence"

That wasn't the point I was trying to make, in the quoted paragraph

Passengers may value the speed more than the capacity. If you quadrupled capacity, but halved speed would that be better or worse for the railway, or the internet?

Door to door train v car journey is more marginal that what you suggest. I would have to spend 2 hours to get to the east cost mainline. In a car I could be over halfway to London by then. And i could have the same problem at the other end. In the same way you'll never be as fast as a plane, but you don't have to turn up 2 hours early for a train.

> If you quadrupled capacity, but halved speed would that be better or worse for the railway, or the internet?

Bandwidth is speed in most cases for the internet, lag intolerant games being an exception. Also my 10Mbit link is good enough for me despite having 100Mbit available. So the question is about comparing things which are not really comparable. Well, TBF, I can't.

> Passengers may value the speed more than the capacity

well they might, and they might want the carriages painted polkadot with hot podium dancers at each end, so how about arguing from a basis of fact instead?

from https://press.which.co.uk/whichpressreleases/rail-companies-... and with a table at the bottom. Speed is not mentioned in the report. Clearly other things really are hurting them.

As to speed vs capacity, look in the chart at 'standing room' and 'availability of seats'. That's about capacity.

> Door to door train v car journey is more marginal that what you suggest

For you I wouldn't doubt, but there's a lot of others who may feel different. Pace but arguing from 1 data point is not rigorous. I've heard of people spending £5,000 a year for their work commute (that may be reporting bias but it's another data point).

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