European Tribune - Comments - European Salon de News, Discussion et Klatsch

European Salon de News, Discussion et Klatsch - 10 March | 107 comments (107 topical, 0 editorial, 0 hidden)

Re: Living off the Planet (4.00 / 2)

For freight I think they are, and even if you have a single line that goes 5000km, that is a lot of 500km sub trips. I'm pretty sure china is more interested in fast freight.

In general the formula is something like
d = (a*c)(a - t)

where d is the maximum supported distance, and a is the speed of planes, t is the speed of trains and c is the cost of going to an airport. so if a = 600km/hr, t = 300km/h and c is 1.5 hour, we have a limit of 600*1.5(600-300) = 450km.

by njh on Tue Mar 9th, 2010 at 10:46:56 PM EST
[ Parent ]

Re: Living off the Planet (none / 1)

I think the formula you wanted is d = a*t*c/(a-t). (Leaving SCOOP's auto format on turned the / into italics.) Putting your numbers into it one correctly gets 900 km.

This is the formula for equal city center to city center travel times. The plane and train speeds in that formula are travel speed, that is, departure to arrival average speeds (which, for both planes and trains, depend on distance if top speed is the same), and "time to the airport" is the sum of those for arrival and departure airports.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Thu Mar 11th, 2010 at 03:33:42 AM EST
[ Parent ]

Re: Living off the Planet (none / 1)

Ah yep, I got distracted halfway through, and when I got back it no longer made sense :o I presume there are much fancier rules used in practice, which include distributions of source travels, preference for comfortable seats, certain psychological preferences for travel times (people treat trips under half an hour quite differently to trips over half an hour). I suspect there are similar steps for long distance trips: Once I am committed to a long trip, I would rather do it slower and in comfort than at top speed, so I choose the 10 hour train journey to my grandmas rather than the 1 hour plane flight (requiring me to leave home 3 hours before hand, at 4am). I expect reliable and cheap internet access will tilt this even more.

by njh on Thu Mar 11th, 2010 at 05:03:41 PM EST
[ Parent ]

Re: Living off the Planet (none / 0)

BTW, given other obligations, that diary I promised you may take some time... in the meantime, you can read Why Glaeser Got It Wrong: Re-Running The Numbers On High Speed Rail » INFRASTRUCTURIST, which goes beyond picking apart that old hack job which was brought up again by fairleft in the China HSR diary, by doing a detailed calculation for a Dallas-Houston line.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Fri Mar 12th, 2010 at 03:10:56 PM EST
[ Parent ]

Re: Living off the Planet (none / 0)

That's great, exactly the sort of thing I would like to see more of. Incidentally, he says re CO2 and concrete in construction: "On a somewhat smaller scale, the same can be said for new terminals or runways at airports." James Strickland showed that the concrete and steel in a single runway corresponds to about 650km of high speed rail (though this was for ballasted track rather than slab construction).

by njh on Fri Mar 12th, 2010 at 04:22:13 PM EST
[ Parent ]

Re: Living off the Planet (none / 0)

I did ad hoc high speed line to airport comparisons in Railways, energy, CO2 - Part 2, too, with much more CO2 for HSR. In that calculation, based on the Frankfurt-Cologne line in Germany (which has slab track), most of the concrete was in tunnel linings, but long bridges (like on Asian lines) would exceed slab track similarly.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Fri Mar 12th, 2010 at 05:11:39 PM EST
[ Parent ]

Re: Living off the Planet (none / 0)

That looks great. One thing to note with steel is that unlike concrete, it can be very efficiently recycled, using little extra CO2. I wonder if this means we should consider building more with steel and less with concrete (or use steel coated in cement for weather resistance - a few cms of low water/cement mortar can protect steel for hundreds of years.

by njh on Sat Mar 13th, 2010 at 06:23:40 AM EST
[ Parent ]

Re: Living off the Planet (none / 0)

There are some good counterstudies in the comments you should read, it seems that the analysis is still rather weak.

by njh on Fri Mar 12th, 2010 at 04:50:03 PM EST
[ Parent ]

Re: Living off the Planet (none / 0)

Well, it's nowhere near a serious study (like the British HS2 study discussed in another Salon), but it can be called one, while Glaeser's is a joke.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Fri Mar 12th, 2010 at 05:02:02 PM EST
[ Parent ]

European Salon de News, Discussion et Klatsch - 10 March | 107 comments (107 topical, 0 editorial, 0 hidden)

. Home
. About
. Contact
. New User Guide
. FAQ
. ET Editorial Guidelines
. Search
. Search (Google)

Username:
Password:

. Make a new account
. Reset password

Recommended Diaries

Socratic Economics XII: Utopian Government Finance
by Zwackus - May 25
273 comments

A Star is Born
by ChrisCook - May 23
23 comments

The French newspaper Le Monde reports 1.5 million living the...
by Democrats Ramshield - May 27
8 comments

$1,000,000,000,00
0 or what we must remember
by Metatone - May 19
69 comments

The balance of anger and fear
by Frank Schnittger - May 17
44 comments

Stable pricing is to metaphysics as variable pricing is to...
by Upstate NY - May 16
8 comments

Another NRW election
by DoDo - May 13
118 comments

Bundesrat saves PV (and loses Röttgen)
by DoDo - May 12
18 comments

Recent Diaries

The French newspaper Le Monde reports 1.5 million living the...
by Democrats Ramshield - May 27
8 comments

Socratic Economics XII: Utopian Government Finance
by Zwackus - May 25
273 comments

A Star is Born
by ChrisCook - May 23
23 comments

$1,000,000,000,00
0 or what we must remember
by Metatone - May 19
69 comments

The balance of anger and fear
by Frank Schnittger - May 17
44 comments

Stable pricing is to metaphysics as variable pricing is to...
by Upstate NY - May 16
8 comments

A little American intercine battling
by rootless2 - May 14
27 comments

Another NRW election
by DoDo - May 13
118 comments

Bundesrat saves PV (and loses Röttgen)
by DoDo - May 12
18 comments

The mainstream German Magazine Spiegel asks, has the US mixed ...
by Democrats Ramshield - May 10
27 comments

Short Term Climate Forces: Black Carbon, Methane, and...
by gmoke - May 9

Twenty days of Crisis for Cameron
by ceebs - May 9
22 comments

SYRIZA and the Eurocrats: a letter of intent
by talos - May 9
363 comments

French Parliamentary Elections: a look under the hood
by Bernard - May 8
59 comments

Why haven't we had WWIII yet?
by Migeru - Apr 30
258 comments

More Diaries...

Occasional Series

Click for full list