Supertrains are sexy. Politicians love to show them off. But to allow more Chinese people to get where they want to go at a reasonable price, then three less glamorous types of investment would yield better returns. China Rail, the state near-monopoly, is deficient in all three.
http://www.economist.com/node/21542420
Go for the glitz, or what better fits the needed service? The issue is not limited to China.
Unfortunately this article only looks at one side of the question of infrastructure.
Mainline track and its top speed is all that is addressed in most articles.
The number of Chinese people that travel is mind numbing with departures on some city pairs evey 10 minutes during the day.
I have no idea what the yard infrastructures are in China so I will instead use the NEC to give examples.
At present Acelas cover BOS - WAS at ~ 6:37. To cover this city pair requires 20 trains with 7 coaches or 140 total coaches. . Assuming a one hour turn around and same number of passengers If time is decreased to 5:37 then approximately 122 - 125 coaches would be needed… Therefor there is less rolling stock needed and less locos.
The same example can also be used for NEC regional trains that take ~ 8:00 Bos - WAS. Reduce the time 1 Hr ??
Now if a RR does not need as many coaches for a certain level of passengers then not as much storage track length will be needed. I can suppose that 1 MILE OF NEW STORAGE track costs at WAS Ivy City yard, PHL Race street yard, NYC Sunnyside yard, BOS Southhampton yard may be the same as several miles of track in suburban areas. ie track, signals, CAT, utility support of water sewer, HEP, service roads. Also the need for servicing bay space may be less.
WAS Ivy City storage is at capacity now. VRE, MARC cannot any more cars to any of their trains for storage. VRE went to the expense of adding a storage siding south of WAS Union station to store one train set.
At NYP NJ Transit actually dead heads several EMU sets back to Newark for daytime storage.
The costs for D/H equipment to storage tracks that are not close can be considerable + wear and tear on rolling stock…
10 Labor costs of on board crew is also increased the slower trains go.
To return to the needs in China cutting a presennt 8
You can run roughly twice as many trains in a 24 hour period if you cut the time between endpoints in half. Result? Far greater capacity to transport the mind-numbing passenger loads on the same trackage. That is one of the efficiencies of higher speed and tighter headways.
Schlimm,
As speed increases stopping distance increases, which means that frequency of trains may or may not increase as speed increases in the limiting case of running the maximum number of trains possible.
In fact. there has to be some cushion of time/distance in addition to the absolute minimum required for safety if the line is to operate reliably regardless of speed. If a line has lots of excess capacity adding more trains per hour may be easy, but the closer you get to capacity the more difficult it gets. The point is that higher speeds does not necessarily mean more trains per hour.
Mac
Do the math. In a 24 hour period, you can either transport more people or the same number as before with less equipment if you increase the speed. As I initially said, it isn’t exactly doubled if speed doubles b/c of braking, etc., but pretty close. And I am not saying this alone would be good reason to move toward higher speeds, just one of many factors to consider.
Schlimm: Precisely. Although I would expect maybe a 70% increase of number of passengers carried with the same amount of equipment due to turn around times and some additional maintenance due to additional wear because of higher speeds. If BS - WAS Acela times were reduced 1 hour then to carry the expected passengers with order of 40 additional Acela cars only 20 would be needed. But the higher speeds might require all 40 cars.
If I am a passenger railroad I would rather put my capital into revenue producing trackage instead of storage trackage that does not provide any revenue and adds additional storage operational costs. A RR needs enough storage for all its equipment in case of an unforseen shutdown so it is able store all its rolling stock.
The close / tight headways you mention may certainly justify the performance metrics that are specified with PTC. The rolling blocks will certainly increase capacity.
Schlim,
The maximum capacity of a one way line is based on stopping distance, which controls block length, and the number of blocks between trains. The number of blocks between trains depends on how many signal aspects you have. Three or four are common in North America.
Imagine the initial condition is mile long blocks, four aspect signaling and five block separation to avoid the trailing train riding the leading train’s block. Assume the speed limit is 60 MPH for passenger trains, to make the math easy. If nothing goes wrong a lineside viewer would see a train every five minutes or 12 trains per hour.
Now imagine that we want to run trains at 120 MPH and keep the same signal aspects and 5 block separation. The first thing we have to do is lengthen the blocks since it takes longer to stop from 120 MPH than from 60 MPH. Without getting into complex train simulations, I would suggest it will take twice as long to stop from 120 MPH as from 60 MPH. Now our trains run 10 miles apart, but the line side observer will still see one every 5 minutes, and my capacity is still 12 trains per hour.
Certainly if you double speed you do not need as much equipment to move a given traffic, because of more trips per day, week, month.
Mac
The problem is the assumptions, the French TGVs with TVM430 cab signalling run at 300 kph (186 mph) with three minute headways. With full service (but not emergency braking) a TGV can stop from 270 kph (168 mph) in 2.7 miles. If they engage the Eddy Current braking it is even faster, but it will be rough on the passengers (but if it avoids hitting something it will be better),
The gain you describe is due to the moving block system, not to speed.
Mac
Nobody but Rapid Transit systems which operate at relatively low speeds with homogeneous equipment uses Moving Block Signalling. The following distance and hence the capacity are more limited by the signalling system and its capacity to indicate allowable speed, than by the braking capacity of the trains. The capacity of the system you described is the theoretical maximum capacity not the practical capacity. Let the following train run just one mph faster and watch what happens in a system using long blocks and limited indications, to line capacity.
Yes the Chinese could build a Rapid Transit system thousands of miles long with trains running on one minute headways at 70 mph with moving hordes of people with moving block signalling, but the equipment cost would dwarf the cost of investing in less equipment operating at higher speeds. The Japanese, Germans, French, etc. understand that Revenue Seat Miles per USD decreases as speed increases, until energy costs due to aerodynamic drag offset equipment costs. Passengers will pay more for speed, how much more depends on their affluence, the Germans more, the Chinese less, the average Chinese doesn’t travel by air much either.
The point I took from the Economist article was not equipment utilization, but serving the needs of a market. Are those needs being met?
Most passengers on the system can not afford the price of a high speed ticket. They ride conventional trains. A ticketing systems in disarray. safety concerns set aside, etc. all for a show project.
China’s rail system is an entity of the state. Is the state doing what best meets the needs of the market, or doing what it thinks makes the state look best?
Beauleiu,
The only point I was trying to make is that Schlim’s assumption that higher speed means more trains per hour is not correct. I used typical american practice to illustrate the point.
I agree that higher speed improves equipment utilization. I also agree that if signal and control system designs other that fixed block are used trains may follow more closely than would otherwise be the case.
Mac
Beaulieu,
The only point I was trying to make was to correct Schlims incorrect assertion that higher speed, in and of itself, allows more trains per unit of time. For simplicity and familiarity I used typical North American railroad practice to illustrate the logic.
Of course higher speed will allow improved equipment untilzation. I also recognize that different traffic control systems would increase capacity as measured in trains per unit of time, but that is not what we were talking about.
Mac
I am not Chinese, have never been to China.
I suspect the Chinese governments move to high speed passenger trains is it’s response to the economic requirements of moving it’s population about the country in a timely fashion with minimum investment.
To my knowledge, China does not have a roadway system rivaling the utility of the US Interstate system. What would be the amount of investment required for China to build a Interstate type system linking together all the significant elements of their economic engine? Staggering! With a growing automotive industry it would be a build it and they will come type affair; and what type of investment would be required to ramp that industry up to have automotive utility rivaling that of North America? Staggering again!
China has taken to high speed rail as the minimum cost option to move their population in support of their economic engine.
Meanwhile, here in the USA, high speed rail is facing yet more headwinds (I like mixed metaphors).
From the Wall Street Journal, 1/10/12
John Timm
A few days ago, the California High Speed Rail Peer Review Group, an expert body mandated by state law, expressed serious doubts about the proposed Los Angeles-San Francisco rail system. It concluded that it “cannot at this time recommend that the legislature approve the appropriation of bond proceeds” because the project “represents an immense financial risk” to the state.
But hell hath no fury like a state agency scorned. The California High-Speed Rail Authority issued a quarrelsome response claiming that the rail system is, well, a bargain! The agency repeated its claim that without high-speed rail, Californians would pay more because the state would have to build equivalent transportation capacity through road and airport expansions costing about $171 billion, or between $53 billion and $73 billion more than the $98 billion to $118 billion estimated cost of a rail line.
The constant refrain that it’s “more expensive not to build the rail line” is specious. But it deserves further explanation because of the light it sheds on tricks used to justify other ill-conceived projects to an unsuspecting public.
Estimating the cost to build additional highway and airport capacity in the absence of the rail line requires estimating how many people would be attracted to the train from cars and planes. But that’s not how they did the math, judging by the methodology the authority published.
Proponents based their estimate on train
Cox and Vranich - what an odd couple!
I don’t think China’s embrace of HSR has anything to do with moving people cost-effectively. One big reason why China is embracing HSR is to free up capacity on their freight railroads to move coal.
However, China’s main objective is to promote itself as the world’s premier economic superpower. For that purpose, HSR is simply an expensive hood ornament that China can afford.