Some of the Spanish HSR trainsets are not Talgos. The S/103's are Siemens Velaro trainsets, very similar to the German Rail ICE 3's. US passenger rail technology seems to have come to a halt in the 1960's.
C&NW, CA&E, MILW, CGW and IC fan
clarkfork Of course adapting foreign trains to US rail does require some modifications. However, it shouldn't be impossible. In the 1970s Amtrak purchased/leased the French RTL and RTG turbotrains. Those designs were in common use in France. I understand they were precursors to the TGV. I don't think they were considered totally successful; however, the design was considered good enough that some were rebuilt for continued use in the 2000s. I understand that adapting them for US service required a bell and knuckle couplers. For that matter the Talgo trains are a Spanish design. I think that most of the reasons that we can't/don't bring over foreign designs are regiulatory, like impact strength and percentage of domestic components. But those are arbitrary and can, and maybe should, be changed.
Of course adapting foreign trains to US rail does require some modifications. However, it shouldn't be impossible. In the 1970s Amtrak purchased/leased the French RTL and RTG turbotrains. Those designs were in common use in France. I understand they were precursors to the TGV. I don't think they were considered totally successful; however, the design was considered good enough that some were rebuilt for continued use in the 2000s. I understand that adapting them for US service required a bell and knuckle couplers. For that matter the Talgo trains are a Spanish design.
I think that most of the reasons that we can't/don't bring over foreign designs are regiulatory, like impact strength and percentage of domestic components. But those are arbitrary and can, and maybe should, be changed.
Regulatory, indeed. I note that CN (pre-VIA) used American-built turbos and dedicated low-slung coaches for years on its Montreal - Toronto corridor. The trains occasionally had to be pulled out of service for maintenance, but not inordinately so, it seems, as the equipment lived out its normal life before CN got rid of it. While in service, the trains made much better time on that Montreal - Toronto corridor than conventional trains, even though conventional trains could run in excess of 80 mph when conditions warranted (no ICC 79 mph speed limit for engines without cab signalling). The turbos probably offered some of the fastest non-electrified passenger service in N. America in the late Sixties - early Seventies. Yet despite a "home court advantage," they never quite took hold here in the USA. Note that I am not talking about the Rohr turboliners that Amtrak used with --as you said-- rather mixed success on its upstate New York (exx-NYC) routes.
BTW some of Europe's fastest passenger trains right now are fourth-generation Talgos running as HSR between Madrid, Barcelona and other principal cities. They are supposed to average (average!) about 180 mph if I am converting correctly from km.
Yes, regulatory ossification has kept U.S. rail technology back in the fifties, 1956, when Santa Fe debuted bilevel long-distance coaches (a year or two after some Chicago commuter lines put into service gallery-style bilevel coaches.) With the possible exception of the Metroliner, there were no more significant innovations and U.S. rail technology just stopped expanding when Budd stopped making transit equipment. Anything high-tech now is out of non-US-owned companies like Bombardier or Breda. Even the Accela traces back its heritage to a Swedish tilt design ca. 1990.
The RTG were used extensively on non-electrified lines in France in the mid-1970s. In many cases, they were allowed to run at 200kph (124mph); but the only one I rode did mostly 40 mph on a serpentine line around deep valleys between Bordeaux and Lyon. Eventually more lines were electrified and the TGV came along. I have no idea whether their was any dissatisfaction, per se.
Regulations are what they are and hardly without reason in the sense of being arbitrary. We've been over that in previous topics. Most would agree that keeping trains apart is a better course than designing for survivability with the forces involved; but this is predicated on a better and costly signal system than is generally the case in the US.
clarkforkOf course adapting foreign trains to US rail does require some modifications. However, it shouldn't be impossible. In the 1970s Amtrak purchased/leased the French RTL and RTG turbotrains. Those designs were in common use in France. I understand they were precursors to the TGV. I don't think they were considered totally successful; however, the design was considered good enough that some were rebuilt for continued use in the 2000s. I understand that adapting them for US service required a bell and knuckle couplers. For that matter the Talgo trains are a Spanish design. I think that most of the reasons that we can't/don't bring over foreign designs are regiulatory, like impact strength and percentage of domestic components. But those are arbitrary and can, and maybe should, be changed.
henry6 It is not a matter of reinventing the wheel, or others knowing more, but rather adapting a different wheel. As has been stated, North American railroads chose a heaver standard than did European railroads (for instance). Therefore thier trains are lighter which leads to other variables and therefore it is not a matter of just bringing a European model over here, put it on the tracks and let it go, Adapting to our rail system is much more comlex than that. That, at least in general, is how an Alstom VP explained to me why we can't just bring 'em over and run 'em.
It is not a matter of reinventing the wheel, or others knowing more, but rather adapting a different wheel. As has been stated, North American railroads chose a heaver standard than did European railroads (for instance). Therefore thier trains are lighter which leads to other variables and therefore it is not a matter of just bringing a European model over here, put it on the tracks and let it go, Adapting to our rail system is much more comlex than that. That, at least in general, is how an Alstom VP explained to me why we can't just bring 'em over and run 'em.
It is kind of true too that we are talking about a continent that is also a lot larger. Our scales just do not jive that easily. Another thing that has to thrown in is our population densities are nowhere near what they are in Europe or China. If we were to do this it would have to be done from within our own collective reality anyways. Transcontinental HSR? Doubt that'll ever happen, but city pairs? Why not? I can even see an eventual daisy chain of city pairs across a portion of N.A., but again---? The whole thing about dedicated rails could be decades in coming---what with all the steps and hoops one would need to go through...
Any argument carried far enough will end up in Semantics--Hartz's law of rhetoric Emerald. Leemer and Southern The route of the Sceptre Express Barry
I just started my blog site...more stuff to come...
http://modeltrainswithmusic.blogspot.ca/
The current Horizon (GSI?) truck is comparable in overall design to the Hiawatha Nystrom truck even if the latter is better riding in your memories. The difference may be more a function of spring rates and travel. The problem now is that little would be gained without tilt suspension. FWIW, Europe got away from similar trucks for trains running above 100 mph.
I was impressed by the soft ride of the old single-level 400's. They rolled and pitched gently over battered rail joints. It seems that the bolster snubber was removed.
Dear Al:
Nystrom trucks were under REAL Hiawatha cars on the C.M.St.P.&P., also known as The Milwaukee Road. Those cars were built in the 1930s. What you referred to as Milwaukee are the Amtrak trains running between Chicago and Milwaukee now. The REAL Milwaukee Road trains took 75 minutes for the journey. They ordinarily ran at least 100 m.p.h. for part of the trip. All of this occurred before the 1948 signal rules and the unfortunate advent of the FRA--a mere agency subject to whatever Act or Acts of Congress governing it may provide.
natelord Why not see if Nystrom (Milwaukee Rd Hiawatha) bogie trucks could be fitted to Viewliners? The patents have probably expired.
Why not see if Nystrom (Milwaukee Rd Hiawatha) bogie trucks could be fitted to Viewliners? The patents have probably expired.
I was quite surprised the other day to see a Hiawatha zip past the Touhy Ave. (Niles) crossing. Consist was a mixture of Amfleet and the square bodies I associate specifically with the Hiawatha fleet.
Next thing you know, they'll be wanting reservations! AFAIK Hiawathas are the only Amtrak trains that don't require them.
best
al-in-chgo
Pardon me, but to some extent I feel that the technical discussion is a diversion from the intended thread topic. The US needs to improve and expand passenger rail service. Airlines are going broke. Planes are falling*. Automobile manufacturers are going broke. Highways are overcrowded.
Without a philosphical commitment, the economic and political barriers will always be too great. Without a product to sell, market studies are meaningless.
---------------------
*(Slight digression--severe tropical thunderstorms, likely cause of AF 447 crash, will become more common as climate changes; this is a scientific consensus and my observation from living on Maui over 37 years. Weather was one element of the Buffalo crash, economic stability of airlines another. Christian Science Monitor has an on-line item today about possible terrorism in Air France crash; I doubt it, but for more on that topic see the "Railroads for Civil Defense" thread.)
"Make no little plans; they have no magic to stir men's blood." Daniel Burnham
HarveyK400I understood it took about a second per car, 1-1/2 min for a 90-car train, for brake pipe pressure reduction (signal propagation?) which is the reason for the interest in electronic brake control. Did I get this wrong; or are there separate issues?
The brake valves react rather quickly to the pressure signal, but the brake cylinder gets up to full pressure rather slowly. But, there is not much variablility car to car.
HarveyK400Conversely, are dynamic brakes operationally unreliable? Isn't this similar to a unit being shut down in modeling performance?
Every spring and fall there is a spate of UDEs due to frost in the brake valves for exactly this reason.
DB can quit and the train can still operate through. Think of it as a "nice to have" train handling feature. Whether it's working or not is really a moot point. I suppose a rather sophisitcated train automation system could plan on using DB and if results were not sufficient, go to the air.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
HarveyK400This seems to be a very negative outlook. Why on earth would PTC have to assume "all-loads" when tonnage and car data already is available and accumulated for the train?
The problem is the association of the waybill to the event reporting that tells you this car is on this train. AEI scanners are pretty good at giving an accurate consist, but how do you know that that car in the consist that shows as empty is really empty?
The waybilling system knows about origins and destinations and what's in the car but it doesn't know where the car is. The car reporting system knows where the car is (most of the time) but has no idea where the car is going or what's in it. The association betweent the two is made in the back-office using some heuristic logic - and it doesn't always get it right.
The error rate may be very small, but it can come in bunches. You may get 20 cars out of one industry where erroneous car reporting or logic causes you to associate the previous empty waybill with the current load. So, you think that they are empties when they are actually loads. If they make up half the local train that pulled them from industry, the safe braking curve calculated from this information would not insure the train stopped short of movement authority. Very bad.
Part of the problem is drawing a bright line between the placment, release and pull. The placment and pull information is manually collected by the train crew, faxed to the yard office, and manually entered into the car reporting system. Despite edits in the data systems there are still lots of places for errors and omissions to occur. Even when the data is correct, there are still timing issues that can cause problems. You can get a release from the customer before you even get the placement event into your own system.
Elevating car reporting and waybilling systems to be part of a safety system leaves butterflys in my stomach.
I think the way to do this is to implement ECP braking and get data from each car directly. The "smarts" on each car plus the commications train line could handle more than just braking info. You could get car weight (good enough for a braking algorithm), bearing temperature info, car ride quality info, etc. by adding a few sensors.
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All of this has been very interesting. BUT...why do we really need to invent the wheel? To do so seems to not take advantage of what others already have had to struggle with. Can we not examine the HSR and sub-HSR practices in France, Germany, etc. to see what they are using, their experience, what works, what doesn't, costs, etc.? Or are we too parochial and thin-skinned to admit that other countries may know more than we do about some topics.
RWM
Even if PTC used virtually the same worst-case algorithm as in establishing signal block lengths and allowable speeds, why would it be necessary then to brake before reaching the approach block? This is equivalent to imposing an advance approach block which is not deemed necessary for current, assumed less reliable or compliant, non-PTC operation.
For train handling purposes, PTC might allow one train to drift and reduce speed to save fuel or to time a rolling meet well before the approach block. Keeping a train rolling may save time overall starting and recovering speed after a delay.
A long time ago I read some stuff on rail profile and the cant of the tie plate. This seemed inconclusive with pros and cons; so I hadn't worried about it. What's changed with respect to heavy-haul and high-speed now that was refered to in recent posts? How does it work in mixed traffic for the NEC at 125 and 150; and could it work in the Midwest at 110?
I misspoke in trying to summarize: it is the brake shoe pressure braking ratio that was the product of a (nominal, general use) brake ratio of 60% light weight assuming 70-ton cars [Hay].
I understood it took about a second per car, 1-1/2 min for a 90-car train, for brake pipe pressure reduction (signal propagation?) which is the reason for the interest in electronic brake control. Did I get this wrong; or are there separate issues?
This is understandable sitting in the yard overnight; but what about changes in the weather in route or climbing to higher, colder elevations?
"I don't know if we'll ever get to a point where we're allow to count on the DB for anything other than convenience. It's certainly not a safety device!"
I suppose dynamic braking may not meet an industry definition of a safety device since it poops out at low speed. Even so, it would seem to aid in reducing train speed so partial disabling of train air brakes, for instance from ice build-up, would not be a total catastrophe.
Conversely, are dynamic brakes operationally unreliable? Isn't this similar to a unit being shut down in modeling performance?
"Could a weather forecast give you enough "9s" for your reliability calculation?"
That's a good question. Isn't weather condition more for adjusting for what might be considered worst-case operating conditions? It's not so much a forecast as monitoring real-time weather reporting sites and interpolating data for the railroad ahead of the train.
It just came to mind that the railroads, at least the BNSF, have their own weather department to warn of severe weather and flooding dangers, perhaps more.
"If the PTC system has to assume "all loads", it could really slow things down. This could make a big difference getting trains into passing sidings, etc."
This seems to be a very negative outlook. Why on earth would PTC have to assume "all-loads" when tonnage and car data already is available and accumulated for the train?
"There are attempts to reduce this variablility in train operation and minimize fuel consumption at the same time by providing the engineer with dynamically generated "suggested" train handling and measuring compliance. NS's LEADER program is one of these."
Don said all this much better than I could have.
HarveyK400Braking horsepower would seem to have a wide range of values depending on the ratio of loaded and empty cars. In explanation to other readers, braking force was limited to about 60% of empty car weight to avoid locking the wheels and sliding; but this may have changed more recently time.
Braking HP per wheel would be brake shoe force X coeff of friction (shoe to wheel) X train speed. Brake shoe force is a function of brake pipe pressure and geometry of braking mechanism (cylinder diameter, levers, etc.)
HarveyK400Railroads seem to have gotten away from weighing cars, and the comment on the accuracy of the trainsheet complicates calculating train braking distance. The railroads' care that the load limit is not exceeded; but seemingly have little interest other than for customer car supply to know how much the lading weighs or if it maxes car volume.
Lots of stuff gets weighed, but not always for billing purposes. Many coal loaders weight what they're loading on the fly. RRs have weigh in motion scales to verify weights in some locations. WILDs weigh cars as a secondary function of measuring impacts. Automated hump systems have weigh in motion scales on th hump grade. The problem is if you are going to use car weight as an input, you have to have it almost before you turn a wheel. Most of the time, you don't know it until you are part way through the trip. And, you almost never have anything useful for intermodal boxes.
HarveyK400One thing you didn't mention was the number of cars and the time it takes to set up brakes for the whole train. It seems newer brakes are faster acting, so that is another variable to deal with.
Not much of a variable. Airbrake signal propogation is and has been pretty close to the speed of sound for quite a while now. (something like 80-90% of it, I think) Time for the brake to actually set up on the car isn't much of a variable, either.
HarveyK400 With ambient temperatures near or below freezing, I understand how ice buildup is problematic and may need manual input/override if suspected. The engineer can't really see what's happening behind him, although a passing train might. Another possibility may be to make running brake applications periodically and prior to the distance required for dynamic braking to bring down speed. Never having run a train or read an account of this procedure, I have no idea if this is done. In the same vein, do air brake valves freeze up often from moisture in the line condensing and icing up with falling temperatures?
With ambient temperatures near or below freezing, I understand how ice buildup is problematic and may need manual input/override if suspected. The engineer can't really see what's happening behind him, although a passing train might. Another possibility may be to make running brake applications periodically and prior to the distance required for dynamic braking to bring down speed. Never having run a train or read an account of this procedure, I have no idea if this is done.
In the same vein, do air brake valves freeze up often from moisture in the line condensing and icing up with falling temperatures?
The problem of ice in the trainline almost always gets you before you leave the initial terminal. You can't get the application and release and get the front to rear differential (or air flow) back to what it wants to be. I have heard that there are instances when a brake valve will stick from frost, but this tends to cause UDEs rather than a "no brake" condition.
HarveyK400Dynamic brake horsepower seems to be as readily available as locomotive horsepower and varies with speed, notwithstanding the small variations in actual unit performance on a given train. Am I missing something? Who cares what the future may bring?
I don't know if we'll ever get to a point where we're allow to count on the DB for anything other than convenience. It's certainly not a safety device!
HarveyK400Weather - temperatures and winds in the area of the train - might be obtained from the Weather Service. It seems newer locomotives may measure ambient air temperature for more efficient operation.
Weather is sometimes the cause of the variable you're interested in, namely the wheel/rail adhesion during braking. You could put a tribometer on the locomotive, I suppose, and measure it in real time, but you'd still not have what you really need. You need to know what the rail conditions are up ahead where the braking will be taking place. Could a weather forecast give you enough "9s" for your reliability calculation?
HarveyK400It seems facetious for people to claim that a human can come in hot and the computer not for the very reason of assuring safety. Sooner or later the hotshot engineer is going to overrun a block and maybe hurt someone. I am not convinced that PTC would reduce capacity to any measurable degree, even with 50 trains a day.
If the PTC system has to assume "all loads", it could really slow things down. This could make a big difference getting trains into passing sidings, etc.
There are lots of other variables that create variablility (duh!) in operations. That hot shot engr. that you allude to, might get over the road quite a bit faster than Mr. Milquetoast. He might try to keep it right on track speed or a mph or two over as much as possible, brake hard into speed restictions and put it back in 8 as soon as possible. Mr. Milquetoast might be content to cruise along letting speed vary quite a bit below track speed before he reacts. He might just coast into speed restictions, and might take his time getting back into 8 once he thought he was clear and then some.
There are attempts to reduce this variablility in train operation and minimize fuel consumption at the same time by providing the engineer with dynamically generated "suggested" train handling and measuring compliance. NS's LEADER program is one of these.
oltmanndStupid me. I knew this. I just forgot. With PTC the engineer has to keep his train "under" the worst case speed/distance curve. This is exactly how the LSL system works with cab signals, only it has no idea of where the train is on the RR. It assumes worst case signal spacing on the territory and is very aggressive lots of places it doesn't need to be.
Stupid me. I knew this. I just forgot. With PTC the engineer has to keep his train "under" the worst case speed/distance curve. This is exactly how the LSL system works with cab signals, only it has no idea of where the train is on the RR. It assumes worst case signal spacing on the territory and is very aggressive lots of places it doesn't need to be.
Like my brain-fade on 539 engines the other day.
There's lots of means by which PTC can be fine-tuned to reduce the capacity loss that is created by making every braking case the worst braking case, which is the safe and simple course. But the cost of implementation and maintenance of these means, and the cost of the proof to the FRA that safety is not being compromised, become impractical in a hurry. There's a lot of research money being spent now looking at ways to reduce the capacity impact, but there's not a lot of confidence that by 2015 when in theory PTC is all rolled out, that we won't have taken a 10-20% capacity hit.
By comparison, the other day we got into a question about hump yard capacity. After talking around with a lot of people who combined had more than 2,000 years of experience designing, managing, and operating hump yards on somewhere around 20 different Class 1s and terminal roads, we concluded that the same hump-yard that had a capacity of 3,000 cars over the hump in 1960 today had maybe 2,000 cars over the hump a day, and the only significant change we could ascribe this to was safety practices. That's not saying, of course, that we begrudge the safety improvement, only that it's usually impossible to have a free lunch.
Railway Man Initial and final speeds are inputs, yes. The answer on signal spacing is actually that the braking curves are very similar with PTC. Signal braking distances are derived from a similiar algorithm that uses vertical profile, an assumed maximum possible weight per car (e.g., every car is 158 TPOB), a conservative braking horsepower, and initial and final speeds. However, signal spacing is only interested in whether a worst-case train that is given an aspect can adhere to that aspect, and leaves it up to the engineer to determine if he is a worst-case train or a best-case train. Thus signal spacing is almost always much greater than what a train is going to actually do, because no train is ever as bad as the worst case. Thus in most cases trains are crowding much closer than the signal spacing nominally dictates. PTC, however, will undo that crowding. For example,using one of the rule books, an engineer sees a yellow aspect. The rule says "Proceed prepared to stop before any part of train or engine passes next signal. Freight trains exceeding 30 mph must immediately reduce speed to 30 mph." The "stop at next signal part" is not discretionary, but where the braking from 30 mph to stop occurs and how hard of a braking effort that will be is discretionary, as is the "immediately reduce" part. What does that mean? Reduce to 30 the minute you see the signal? Reduce to 30 after the head end reaches the signal? How aggressive shall the braking be? PTC will "see" that signal aspect and make sure the train is at 30 before the head-end reaches the signal, which in many cases means the braking will begin to 30 long before the engineer can visually see the signal, and will follow a worst-case braking scenario to arrive at that target speed. In a non-PTC system, the engineer of a light train with good dynamic braking on a dry day may run right up to that signal at 45 and then drop the speed in a hurry as he passes it. Now think what happens at every permanent speed restriction and station stop. I've spent enough time in the cab to know that one engineer can drop his train onto the entrance of the speed restriction or platform aggressively, and another engineer will dawdle up to it. Or put another way, from the viewpoint of a train dispatcher, different engineers can get identical trains across the same territory with remarkably different running times, and both adhere to the rules.
Initial and final speeds are inputs, yes.
The answer on signal spacing is actually that the braking curves are very similar with PTC. Signal braking distances are derived from a similiar algorithm that uses vertical profile, an assumed maximum possible weight per car (e.g., every car is 158 TPOB), a conservative braking horsepower, and initial and final speeds. However, signal spacing is only interested in whether a worst-case train that is given an aspect can adhere to that aspect, and leaves it up to the engineer to determine if he is a worst-case train or a best-case train. Thus signal spacing is almost always much greater than what a train is going to actually do, because no train is ever as bad as the worst case. Thus in most cases trains are crowding much closer than the signal spacing nominally dictates. PTC, however, will undo that crowding.
For example,using one of the rule books, an engineer sees a yellow aspect. The rule says "Proceed prepared to stop before any part of train or engine passes next signal. Freight trains exceeding 30 mph must immediately reduce speed to 30 mph." The "stop at next signal part" is not discretionary, but where the braking from 30 mph to stop occurs and how hard of a braking effort that will be is discretionary, as is the "immediately reduce" part. What does that mean? Reduce to 30 the minute you see the signal? Reduce to 30 after the head end reaches the signal? How aggressive shall the braking be? PTC will "see" that signal aspect and make sure the train is at 30 before the head-end reaches the signal, which in many cases means the braking will begin to 30 long before the engineer can visually see the signal, and will follow a worst-case braking scenario to arrive at that target speed. In a non-PTC system, the engineer of a light train with good dynamic braking on a dry day may run right up to that signal at 45 and then drop the speed in a hurry as he passes it.
Now think what happens at every permanent speed restriction and station stop. I've spent enough time in the cab to know that one engineer can drop his train onto the entrance of the speed restriction or platform aggressively, and another engineer will dawdle up to it. Or put another way, from the viewpoint of a train dispatcher, different engineers can get identical trains across the same territory with remarkably different running times, and both adhere to the rules.
Braking horsepower would seem to have a wide range of values depending on the ratio of loaded and empty cars. In explanation to other readers, braking force was limited to about 60% of empty car weight to avoid locking the wheels and sliding; but this may have changed more recently time.
Railroads seem to have gotten away from weighing cars, and the comment on the accuracy of the trainsheet complicates calculating train braking distance. The railroads' care that the load limit is not exceeded; but seemingly have little interest other than for customer car supply to know how much the lading weighs or if it maxes car volume.
One thing you didn't mention was the number of cars and the time it takes to set up brakes for the whole train. It seems newer brakes are faster acting, so that is another variable to deal with.
I don't have anything on fade as a component of braking horsepower in what's left of my library, but this would seem to be a curve related to speed, brake force, and ambient temperature. Brake force varies for different types of shoes and the individual adjustment of each car. As a train, one might start with the assumption of an average adjusted for empirical deviations.
Dynamic brake horsepower seems to be as readily available as locomotive horsepower and varies with speed, notwithstanding the small variations in actual unit performance on a given train. Am I missing something? Who cares what the future may bring?
Weather - temperatures and winds in the area of the train - might be obtained from the Weather Service. It seems newer locomotives may measure ambient air temperature for more efficient operation.
Even an experienced engineer would have little more than a fuzzy ideal of how the train will handle, taking into account the same but unquantified variables, and act cautiously. Both engineer and computer can get some idea of braking performance by how long it takes to accelerate the train against the actual tonnage and rolling resistance that allows some recalibration. I understand this is a combined rolling resistance and drag algorithm and not the whole answer.
It seems facetious for people to claim that a human can come in hot and the computer not for the very reason of assuring safety. Sooner or later the hotshot engineer is going to overrun a block and maybe hurt someone. I am not convinced that PTC would reduce capacity to any measurable degree, even with 50 trains a day.
oltmanndThis produces braking curves that are longer than those currently used to set existing signal spacing and speeds? Isn't actual speed also an input?
This produces braking curves that are longer than those currently used to set existing signal spacing and speeds?
Isn't actual speed also an input?
Maglev In the face of a crumbling airline industry, we need more government investment in railroads: Airline event reflects industry slump "Media questions fly at a somber meeting of international carrier executives who are focused on survival. The industry has been rocked by the recession, swine flu outbreak and the Air France crash." By Peter Pae, Los Angeles TimesJune 9, 2009 (excerpts) "Reporting from Kuala Lumpur, Malaysia -- The telltale signs of an industry in crisis were unavoidable at the biggest airline trade group's yearly gathering..." "One of the highlights of the event: a panel on whether aviation could ever be economically sustainable. (The consensus: Maybe, but only after further painful consolidation.)" "'We've never seen anything like this before,' Jong Hee Lee, president of Korean Air Lines Co. and a 40-year veteran of the carrier, said of the travel slump that had hammered the industry. 'Everybody is saying, 'Let's survive.' '" "The association's 226 member airlines, including the largest U.S. carriers -- Delta, American and United -- account for about 93% of the world's international traffic. No event draws as many airline chief executives, estimated at 150 at this year's meeting." "In one of the conference's more depressing moments, the group's CEO announced Monday that the industry would lose $9 billion this year, more than double the forecast made just two months ago.""Revenue is projected to tumble 15% to $448 billion, a drop more than twice as big as the falloff in sales after the Sept. 11, 2001, terrorist attacks." "And airline executives say there's little relief in sight..." full story at: http://www.latimes.com/business/la-fi-airlines9-2009jun09,0,3942501.story
In the face of a crumbling airline industry, we need more government investment in railroads:
Volatility has been a characteristic of the airline business since the get go. It will always be the case. Airlines come and go, but to think that airplanes are going to disappear and people are going to flock to trains is unrealistic.
Investment in passenger rail makes sense for relatively high density, short corridors where expanding highways and airways is cost prohibitive. Thus, a significant per cent of commercial passengers take the train from Philadelphia to New York. The percentage of commercial passengers taking the train from Charlotte to New York is very low.
Railway Man HarveyK400 My understanding was that PTC computed specific train handling from data on cars and lading and monitored performance such as for acceleration and brake response for calibration, taking into account speed, grades, curves, weather, distance to stop or speed restriction, and safety factor. Weren't these and perhaps other factors used to create algorithms for performance? Inputs are: Horizontal and vertical profile (absolute value) Permanent and temporary speed limits (absolute value) Tonnage of train (absolute value, or at least what the trainsheet claims; there's considerable discussion on how this will be made more accurate -- I expect a whole lot more AEI readers to be installed) Braking horsepower of train (estimated value) Algorithms remain under study at TTCI and at the Class 1s. RWM
HarveyK400 My understanding was that PTC computed specific train handling from data on cars and lading and monitored performance such as for acceleration and brake response for calibration, taking into account speed, grades, curves, weather, distance to stop or speed restriction, and safety factor. Weren't these and perhaps other factors used to create algorithms for performance?
My understanding was that PTC computed specific train handling from data on cars and lading and monitored performance such as for acceleration and brake response for calibration, taking into account speed, grades, curves, weather, distance to stop or speed restriction, and safety factor. Weren't these and perhaps other factors used to create algorithms for performance?
Inputs are:
Algorithms remain under study at TTCI and at the Class 1s.
Paul Milenkovic Don, you lost me there. I don't know the players without a program and don't know who the "lets try this" folk are.
Don, you lost me there. I don't know the players without a program and don't know who the "lets try this" folk are.
The dogmatic "always" or "never' folk are those who grab a position and then hold on tight. They include the frt RR that says "never" to any additional passenger service on their routes and advocates who start with the position that HSR must be 180 mph dedicated ROW,etc. etc, and then work backward to the arguements for.
The "lets try this" folk are those who start with a goal or problem statement and then try to find common ground or mutual benefit for the stakeholders. A good example would be the NCRR program. NC wanted faster and more frequent service in their state. NS and NC worked together to improve the NCRR, replacing high maintenance equilaterals with #20s so that the passenger trains don't have to slow down when the switch is lined normal, adding some sections of double track and installing CTC and upgrading track on a more lightly used portion of the RR. NC gets improved passenger service. NS gets a more fluid (there's that word, again), easier to operate and maintain railroad. Of course, in this case, NC had some leverage - they own the RR!
Or, let's say there is some route where 110 mph service is desired and it has several curves that need reallignment. Rather than just saying "no" to the whole deal, the frt RR sees that the reallignment could benefit them since they could reduce superelevation and all the trouble of maintaining it. So, they offer up some $$ comensurate with the benefit they'll get (plus a fair return) to help move things along.
Or, they look to see if there is some political quid pro quo for being flexible in their approach toward these things.
Paul Milenkovic I don't know where the 110 MPH comes from and whether it was pulled from the air, but it has become a kind of shibboleth in the advocacy community
110 is as fast as you can run with conventional equipment on conventional track without having to jump through all kinds of hoops. The only place I know where this is currently being done outside the NEC is CP-169 (west of Schenectady) to Poughkeepsie NY where CSX (and Conrail before them) maintain Class VI track for NY and Amtrak (at their incremental expense).
From the Conrail days....http://www.railpictures.net/viewphoto.php?id=8020
Phoebe Vet I don't know about anyone else, but I have no intention of ever flying again as long as the airport resembles an East German border crossing in the '60s.
I don't know about anyone else, but I have no intention of ever flying again as long as the airport resembles an East German border crossing in the '60s.
Al - in - Stockton
Dave
Lackawanna Route of the Phoebe Snow
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