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Old December 9th, 2012, 01:56 PM   #141
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The French which, eh? Eliminating the margin of error shall probably proove to bite no matter whomever really HARD in the ass.
You don't measure margin of error of fast trains with full in-cab signaling based on time, but rather based on braking distance, wither using block signals with PTC or the more modern dynamic signaling.

A high-speed train can come to a halt from 300km/h in less than 70 seconds under emergency stop protocols with safety (though a bit of discomfort for passengers). You don't need more than that as a safety margin, you don't want to have the train ddriver deciding whether to stop or not, you want a system that detects a faulty/broken/crashed train or railway with intrusion of foreign object and then suddenly deploys emergency stop activation in your trains in milliseconds.
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Old December 9th, 2012, 09:24 PM   #142
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So many clawbacks being reported are enough to make wonder whether redundancy is no longer devised. Although I haven't done the arithmetic, a 6' headway at great speed strikes me as pushing the braking distance should operations go awry, let alone a 1' one.
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Old December 10th, 2012, 08:01 AM   #143
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So many clawbacks being reported are enough to make wonder whether redundancy is no longer devised. Although I haven't done the arithmetic, a 6' headway at great speed strikes me as pushing the braking distance should operations go awry, let alone a 1' one.
Well, maybe it's time for some arithmetic then.

3' at 360kph means 18km between trains. The normal stopping distance at that speed is about 9 km. So there is still quite a bit of safety margin there.

If you want to reduce headways to 2', you reduce train separation to 12km. That means that your safety margin gets reduced. There are two things you now need to do:
- Shorten your stopping distance. That can be done using eddy current brakes.
- Improve the signalling. That is what ETCS is for. 2' headways at 200kph are already in daily use. The LGV from Paris to Lyon uses 4 minutes as minimum headway, using a system that was originally designed for 5', and will go to 3' soon. It might even go to 2' as this is probably going to be a lot cheaper than building an additional LGV...

So 6' is being very prudent...
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Old December 10th, 2012, 01:26 PM   #144
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Note that off-peak the headways are easy to keep. The xx:30 express train leaves Taibei 6 minutes before the xx:36 milk train, and never approaches. Since it is 24 minutes faster than the xx:00 milk train, it reaches Zuoying 6 minutes after the xx:00 milk train.
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Old December 10th, 2012, 04:19 PM   #145
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So many clawbacks being reported are enough to make wonder whether redundancy is no longer devised. Although I haven't done the arithmetic, a 6' headway at great speed strikes me as pushing the braking distance should operations go awry, let alone a 1' one.
You have the whole concept back to front. Braking distance is a distance in space. Headway is a distance in time. They are not the same thing. Signalling systems separate trains by the necessary distance in space, not time. The headway is something that is an output after the safety of the system has been guaranteed.

Breaking characteristics > Signal block length > then at this point we can go back a calculate minimum headway.

Rather than sticking with a misapprehension, there are lots of sources on the web help understand how signalling systems function.
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Old December 10th, 2012, 07:52 PM   #146
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Implementing a new system will obviously cost manpower, time and money. Right now, in Taiwan, there simply isn't a need to ramp up frequency that much. Not saying that it can't, but right now, I don't think it's a feasible thing to do business-wise. Just because you can doesn't mean you should. However, there are recent reports that THSR plans to ramp up the number of services to over 200 per day... so I guess that will definitely mean higher frequencies. (200 trains north and south over 18hrs)
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Old December 10th, 2012, 08:17 PM   #147
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Implementing a new system will obviously cost manpower, time and money. Right now, in Taiwan, there simply isn't a need to ramp up frequency that much. Not saying that it can't, but right now, I don't think it's a feasible thing to do business-wise.
The THSR trainsets are now all (30 existing, 4 under construction) 12 cars each.

Would it be useful to add smaller trains, e. g. 8 car trains, to THSR so as to increase frequencies without excessive cost?
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Old December 11th, 2012, 02:46 AM   #148
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Good, sounds better I imagined the distance between HSTs running at full speed much less than 12Km.
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Old December 11th, 2012, 08:28 AM   #149
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Note that off-peak the headways are easy to keep. The xx:30 express train leaves Taibei 6 minutes before the xx:36 milk train, and never approaches. Since it is 24 minutes faster than the xx:00 milk train, it reaches Zuoying 6 minutes after the xx:00 milk train.
In this case it makes sense. However they could use the extra 6 minutes to maybe add in another stop on the milk train. I don't know if the times of other trains in Taibei and Zuoying are coordinated with those on the high speed line.

On the Swiss network the departure times of trains are coordinated at the major hubs, and for that reason trains are run as closely as possible on the high speed line from Bern to Olten (with 2' headways), even though with six trains per hour they could spread them out more.
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Old December 14th, 2012, 11:20 PM   #150
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11 Dec 2012 :
Proposed railway service penalties unnnecessary, CN Rail, CP Rail chiefs argue

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Old December 15th, 2012, 11:38 AM   #151
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The THSR trainsets are now all (30 existing, 4 under construction) 12 cars each.

Would it be useful to add smaller trains, e. g. 8 car trains, to THSR so as to increase frequencies without excessive cost?
I've thought about that as well, but it seems that because the 700T is an EMU, rearranging trainsets is difficult. If they want 8car consists, they're going to need a completely new different trainset.

I think, for now, Taiwanese peeps still see trains as "trains" with a timetable, instead of a fast metro service (with insane frequency.)
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Old December 15th, 2012, 02:02 PM   #152
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It's also helpful to have consistent train lengths when the occasional cancelled service (due to breakdown, accident, etc.) needs to be replaced with a spare trainset- you can provide seating for all passengers with reserved tickets who were scheduled to be on the cancelled service. This is one reason why JR Central only runs 16 car trains on the Tokaido Shinkansen.
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Old September 30th, 2015, 10:37 AM   #153
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The UK is of course the place to go if you want to see peak pricing, and it isn't pretty. It can be more than four times as expensive to travel at peak times. On certain long distance routes, peak travel is only affordable for rich businessmen and celebrities. Some companies do not allow employees to travel on peak hour trains unless they get a cheaper advance purchase ticket.

In the evening peak, the first train after the peak if often overcrowded and the last peak train can be empty.

To give you some idea, London to Manchester return can be as much as 329 GBP but off-peak it is 81.60 GBP return (walk on). Advance purchase singles can be less than 20 GBP.
I still say that this kind of pricing is what forces people to turn to other modes over the train. Flat fees are still best in my opinion. The UK is an example of yield management gone absolutely mad. Give me Japanese style TUAG any day.
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Old September 30th, 2015, 11:26 AM   #154
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The UK is of course the place to go if you want to see peak pricing, and it isn't pretty. It can be more than four times as expensive to travel at peak times. On certain long distance routes, peak travel is only affordable for rich businessmen and celebrities. Some companies do not allow employees to travel on peak hour trains unless they get a cheaper advance purchase ticket.
So it seems to be working then.
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Old September 30th, 2015, 11:56 AM   #155
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So it seems to be working then.
But if the meeting overruns, you have to pay top price for a new ticket, and then have to explain the cost when you claim your expenses. Some companies time meetings so that people don't have to travel in peak time. People also stay in hotels to avoid peak hour. Obviously lots drive rather than pay for peak train fares.

Another problem is that people don't know when the peak time is at it varies by route, or even by destination on the same route. So some people pay too much to be safe, or get surcharged because they have the wrong ticket. The good thing about the Dutch system is that it works out the right fare for you automatically.
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Old September 30th, 2015, 12:34 PM   #156
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Guys there is no way around it. Either you incentive non peak travel to smooth demand over the day or you deal with humongous fixed cost assets idling more during non peak time
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Old September 30th, 2015, 12:37 PM   #157
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But if the meeting overruns, you have to pay top price for a new ticket, and then have to explain the cost when you claim your expenses.
So don't let the meeting overrun then. :-)

Really: This is all of economics in one sentence:
"people react to incentives".
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Old September 30th, 2015, 02:49 PM   #158
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All forms of peak travel extract a cost somehow from travelers. Highways get congested (you pay in time). Urban transportation gets very crowded (you pay in discomfort).
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Old September 30th, 2015, 08:47 PM   #159
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All forms of peak travel extract a cost somehow from travelers. Highways get congested (you pay in time). Urban transportation gets very crowded (you pay in discomfort).
No different to the crowded regional trains described above, then. I'd rather have them crowded at peak than institute the stupidity that is yield management. I know many people advocate it, but I lived in the UK with this madness, and now I live in Sweden with this madness. It just puts me off travelling, ever. It doesn't result in a better travel experience at all in my mind, it only benefits the rail operator, not consumers.
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Old September 30th, 2015, 09:08 PM   #160
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No different to the crowded regional trains described above, then. I'd rather have them crowded at peak than institute the stupidity that is yield management. I know many people advocate it, but I lived in the UK with this madness, and now I live in Sweden with this madness. It just puts me off travelling, ever. It doesn't result in a better travel experience at all in my mind, it only benefits the rail operator, not consumers.
The point you miss is that crowded trains are also slower trains. They take longer to cycle through stations. If they are really crowded, then people boarding at intermediate stations cannot board and need to wait for other train or just give up travelling. This is really bad policy.

As I said, Netherlands already has a quite hefty surcharge to travel at peak times, in practice. The only difference it that it is disguised as a "discount for off-peak travel" and then many people buy the spin though maths doesn't lie.
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