MAGLEV Munich (Muenchen) Germany Project Kaput.

(leak handling...)

Nasadowsk wrote:Let's see, for large vessels, the best practice is nuclear reactor containments, where a 2% leakage rate is about the most they'll accept. Getting THAT requires x-raying EVERY weld, and generally multiple seals and all. Penetrations are fun, too.

There is also the problem of how to build it. It will need to have VERY low horizontal curvature, meaning that it would be difficult to acquire surface-level right-of-way for it. So it would have to either be elevated or underground.

lpetrich wrote:So in a post-petroleum world where aviation has become expensive due to the expense of its fuel, we may have a national airline that specializes in long-distance travel ("Amfly"?).

Nasadowsk wrote:No. Since a) we're a long way off from that. b) there's more and more serious talk of hydrogen powered aircraft (don't laught, there's a safety advantage to it, among other things) and c)aircraft are getting progressively more efficient, and there's a bit of room left to go - relaxed stability, geared turbofans, flying wings, etc etc etc. The current generation coming out of A and B's doors are a heck of a lot better than even 15 years ago.

Hydrogen leaking outward and upward and not downward is a safety advantage, yes, and it's one shared with methane (natural gas). However, liquid hydrogen is very difficult to store -- its density is relatively low and it boils at 20 K under 1 atm pressure. Its critical point is at 33 K and 13 atm, so pressurizing it won't help very much. So neither is very practical for an airplane, where weight is at a premium. So one wants a fuel that is liquid at room temperatures without pressurization, and kerosene is a good one. The main operational drawback of such fuels is the safety one of their leaking downward.

I suspect that in some decades, we may see a thriving synfuels and/or biofuels industry that can produce kerosenelike liquid fuels, but that will require economies of scale that won't exist when such industries get started, so there will likely be a liquid-fuel gap for a while. As to biofuels, it will be necessary to use approaches more efficient than fermenting corn, like cellulose digestion and algae baking, but those are not exactly mature technologies.

And most of all, the public's seen what happened to nationalized passenger rail. Everytime you try to sell Amair, everyone will point to Amtrak.

So I suspect that such a system will be some private airlines propped up by subsidies in the fashion of the Essential Air Services subsidies. But we may not get to that point for a while, if we ever do so at all.

lpetrich wrote:I find it hard to take seriously the idea of a continent-length vacuum tube. There's the serious problem of possible leaks -- how will that be handled? Will the tubes have airlock doors and crossovers every few 10s of mi/km? That would likely be necessary to enable detouring by crossover around a disabled train.

And construction will be a nightmare. Will the entire length of tube be in a tunnel? Or will some of the tube be above ground?

I would assume it would be built underground. That makes it a lot easier to reduce air infiltration. Don't forget that you're thinking of construction in today's terms. In 20 or 30 years, which is the earliest we'll likely to attempt something like this, tunnel boring technology will have greatly advanced. Also, you definitely don't need crossovers/airlocks every few tens of kilometers. With this type of system there is no such thing as needing to go around a disabled train. Even on a continental-length system there will probably only be a few trains at most in a tube thousands of miles long. Just do the math. Let's say we have NYC-LA. The trip might take around an hour. With 15 minute headways in each direction you'll have at most four trains in transit in a tube 2400 miles long. I'm not even sure exactly what would constitute a disabled train. By definition once the train gets up to speed, it'll have enough momentum to reach its destinition due to practically zero drag. The lift system can be designed to be failsafe (not relying on computer correction) and with backup batteries and such since the consequences of failure are too high. So the only thing which could potentially constitute a problem is a train failing to reach cruising speed due to a power interruption of some sort (propulsion power is much higher than levitation power). Due to the headways between trains, the next train will know whether or not the previous train reached cruising speed. If not, it just doesn't launch. I fail to see any scenario where one train would need to go around a disabled train. And if the train in the tube doesn't acquire enough momentum to reach the end of the tube, it will simply be stuck in the tube until power is restored (which is actually the same situation as exists on electric railways).

As to the more typical sort of HSR, it would be hard to justify building the western half of a transcontinental line between the east and west coasts, like from New York City to Los Angeles.

There are enough larger towns even out west to make HSR feasible. It's a matter of serving stops spaced no more than 100 miles apart at fairly regular intervals. That would get enough people out of planes/cars to make it work. Thrown into this line of thought is the fact that driving/flying is only going to get much more expensive. All of the liquid fuel alternatives aren't much cheaper than $5 gas. And while electric cars might save the auto for the average person, no such alternative exists for aviation which is the main competitor with HSR. As I see it, we're in the midst of a major shift in our mindset regarding long distance transport. The need to get somewhere as fast as planes fly will likely vanish given the increased electronic connectivity of businesses. That leaves vacation travel as the mainstay for long-distance transportation. Since HSR can double for medium distance commuting, it's feasible to see it filling both that and the long distance role currently filled mostly by aviation. Aviation will probably ultimately be relegated to a niche role where large bodies of water must be crossed, at least until such time as the pieces for the ultra-speed maglev come together. Then it will disappear altogether except for spaceflight/military uses.

Also, you definitely don't need crossovers/airlocks every few tens of kilometers.

Modern safety rules for tunnel require escape means. The standard for new Alpine tunnels is the same as for Eurotunnel. Eurotunnel has an escape tunnel - a third tunnel - linked by passageways every 200 metres (I am not sure about the exact spacing).

The crossovers are essential. Right now the tunnel is working with 5 of its sections because of the fire. This means one single track section and four double track sections. It is always necessary to close off one section for night time maintenance.

And if the train in the tube doesn't acquire enough momentum to reach the end of the tube, it will simply be stuck in the tube until power is restored (which is actually the same situation as exists on electric railways).

That is the sort of thinking that led to the first Eurotunnel fire. The idea was to keep the train moving till it got out so the fire could be tackled outside. But the fire disabled the signalling system and the train stopped. The design of the safety tunnel worked and no-one died.
The psychological effects of being stopped in a tunnel, even when one knows there is an escape tunnel, can be quite severe, even for a few minutes.

We're talking about an evacuated tunnel and a train which carries no flammable fuel. A fire is by definition impossible in the tunnel itself. Even if one started inside the train, which is about the only place it could start, it could quickly be contained. There would be a limited amount of oxygen to feed it. You just don't need the kind of escape systems present in the Eurotunnel, nor would they be feasible. Exactly how would passengers walk from a disabled train to an escape hatch in a tunnel with no air? Even oxygen masks wouldn't suffice. They would need a full pressure suit like the astronauts wear. And IMO carrying road vehicles on trains through the Eurotunnel was/is a huge mistake. On both ends there is plenty of public transportation, and I'm sure renting cars is possible also.

jtr1962 wrote:

lpetrich wrote:I find it hard to take seriously the idea of a continent-length vacuum tube. There's the serious problem of possible leaks -- how will that be handled? Will the tubes have airlock doors and crossovers every few 10s of mi/km? That would likely be necessary to enable detouring by crossover around a disabled train.

And construction will be a nightmare. Will the entire length of tube be in a tunnel? Or will some of the tube be above ground?

I would assume it would be built underground. That makes it a lot easier to reduce air infiltration.

Only to add something much worse: water.

Don't forget that you're thinking of construction in today's terms. In 20 or 30 years, which is the earliest we'll likely to attempt something like this, tunnel boring technology will have greatly advanced. Also, you definitely don't need crossovers/airlocks every few tens of kilometers. With this type of system there is no such thing as needing to go around a disabled train.

Famous last words.

That reminds me of how BART was designed. Its designers expected BART trains to be highly reliable, so they designed the system without sidings and without many crossovers. How wrong they were! The train-control system was as buggy as a hive, and in the early years, BART staff members were sometimes reduced to waving signal flags.

I fail to see any scenario where one train would need to go around a disabled train. And if the train in the tube doesn't acquire enough momentum to reach the end of the tube, it will simply be stuck in the tube until power is restored (which is actually the same situation as exists on electric railways).

Other trains will still need to go around it.

As to the more typical sort of HSR, it would be hard to justify building the western half of a transcontinental line between the east and west coasts, like from New York City to Los Angeles.

There are enough larger towns even out west to make HSR feasible. It's a matter of serving stops spaced no more than 100 miles apart at fairly regular intervals.

I find it hard to take seriously. They'd have to be awfully small towns. I know, because I've followed possible routes. I'd posted on that in an earlier page in this thread.

I'm now looking for a downloadable database of city latitudes and longitudes, so I can test that claim.

lpetrich wrote: Other trains will still need to go around it.

There is only one possible scenario for a train getting stuck in a tube, namely that it fails to acquire enough velocity to make it to the destination before a power interruption. Since the power is interrupted, you wouldn't be able to launch the next train until the power is restored. And the decision to launch the next train is contigent upon the preceding train reaching maximum speed. If it doesn't reach target velocity, the next train is not launched, period. There exists no scenario where one train is stuck in a tube and the next one needs to go around it. And how would you make crossovers for that anyway? For starters they would need to be traversed at hypersonic speeds. This means a very gradual diverging radius which in turn makes them probably tens of miles long. It's easier to just ensure that a situation of bypassing a stuck train will never exist by keeping headways long enough so that the preceding train is at target velocity before the next train is launched. For a 4000 mph system accelerating at 0.2 g this is accomplished with 15 minute or greater headways. Chances are the system would never get sufficient traffic to need shorter headways (and longer trains could deal with greater traffic anyhow).

As to the more typical sort of HSR, it would be hard to justify building the western half of a transcontinental line between the east and west coasts, like from New York City to Los Angeles.

There are enough larger towns even out west to make HSR feasible. It's a matter of serving stops spaced no more than 100 miles apart at fairly regular intervals.

I find it hard to take seriously. They'd have to be awfully small towns. I know, because I've followed possible routes. I'd posted on that in an earlier page in this thread.

I'm now looking for a downloadable database of city latitudes and longitudes, so I can test that claim.

Ever think that maybe a lot of the smaller towns would grow dramatically in a few years if they had an HSR station? Seeing the current trends of higher energy prices and possibly an economic downturn lasting over a decade I think available public transit is going to play a much greater part in where developers decide to build. Gone are the days of sticking a new housing development in the middle of a cornfield 30 miles away from anything or assuming that the majority will have access to their own private transportation.

jtr1962 wrote:

lpetrich wrote: Other trains will still need to go around it.

There is only one possible scenario for a train getting stuck in a tube, namely that it fails to acquire enough velocity to make it to the destination before a power interruption. Since the power is interrupted, you wouldn't be able to launch the next train until the power is restored. And the decision to launch the next train is contigent upon the preceding train reaching maximum speed. If it doesn't reach target velocity, the next train is not launched, period. There exists no scenario where one train is stuck in a tube and the next one needs to go around it.

And BART would never need sidings. Right. *sarcasm*

More seriously, how are you claiming that this system will work? By the trains coasting from each stop to the next without suffering any significant amount of drag?

Vacuum would get rid of air drag, but there are other sources of drag, like electrical resistance in the parts that get eddy currents from the passing magnetic fields. There is also the possibility of failure of the levitation magnets.

And how would you make crossovers for that anyway? For starters they would need to be traversed at hypersonic speeds. This means a very gradual diverging radius which in turn makes them probably tens of miles long.

The trains will have to slow down to use the crossovers -- and stop and wait for each other to make it through the single-tracked section.

It's easier to just ensure that a situation of bypassing a stuck train will never exist by keeping headways long enough so that the preceding train is at target velocity before the next train is launched. For a 4000 mph system accelerating at 0.2 g this is accomplished with 15 minute or greater headways. Chances are the system would never get sufficient traffic to need shorter headways (and longer trains could deal with greater traffic anyhow).

However, a train which has to slow down or even stop because of failing levitation magnets will risk getting rear-ended by the train behind it.

(the western US being thinly populated...)

Ever think that maybe a lot of the smaller towns would grow dramatically in a few years if they had an HSR station? ..

I don't see how that would work for some town in the western deserts and mountains. There'd have to be something else to make such a place worth moving to, and some suitable infrastructure.

Like a good supply of fresh water.

Something that has long been a contentious issue in the western states.

There is only one possible scenario for a train getting stuck in a tube, namely that it fails to acquire enough velocity to make it to the destination before a power interruption.

Um.. No engineer would ever accept that there "there is only one possible" cause of failure.

Frankly, the idea of an evacuated tube looks more impossible the more one thinks about it. A few hundred metres is the most one would allow.

george matthews wrote:

There is only one possible scenario for a train getting stuck in a tube, namely that it fails to acquire enough velocity to make it to the destination before a power interruption.

Um.. No engineer would ever accept that there "there is only one possible" cause of failure.

Frankly, the idea of an evacuated tube looks more impossible the more one thinks about it. A few hundred meters is the most one would allow.

Also, you have that problem of storms. If a tornado hit the pipe carrying the maglev, it might destroy everything inside of the tube, because of the vacuum inside of the tube.

lpetrich wrote: More seriously, how are you claiming that this system will work? By the trains coasting from each stop to the next without suffering any significant amount of drag?

Vacuum would get rid of air drag, but there are other sources of drag, like electrical resistance in the parts that get eddy currents from the passing magnetic fields. There is also the possibility of failure of the levitation magnets.

No, the magnets have eddy drag when they're not in propulsion mode. This is approximately 0.001 times the weight for most of the maglevs I've heard of. Do the math-at 4000 mph with 0.001 g deceleration from the magnet drag it takes about 50 hours and 100,000 miles to coast to a stop (i.e. the train could go 4 times around the world if such a track existed). Heck, if you're going through a 2400 mile tube from NYC to LA you can coast all the way once you attain around 650 mph. Sheesh, even a TGV in open air at only 300 km/hr takes over 10 miles to coast to a complete stop. That's the really neat thing about these vacuum tube systems. Almost all your power consumption is used to get the train up to speed (and you can recover most of that upon deceleration). The only power lost is the eddy current drag and perhaps a tiny amount to air drag (the tube can never be a complete vacuum).

However, a train which has to slow down or even stop because of failing levitation magnets will risk getting rear-ended by the train behind it.

You don't seem to understand that the levitation system MUST be failsafe, period. It's not as simple as "Oh the magnets are starting to fail, let's slow the train down and stop before they do." No, a levitation failure is something instantaneous and catastrophic. There is no warning, there is no chance to do anything. The train would immediately be destroyed from the friction. You're not going to get 5 or 10 minutes warning to be able to slow the train down. You need redundant systems, perhaps even very powerful permanent magnets. Since levitation failure is something that simply cannot be allowed to happen, and is disastrous if it does, worrying about the contigency of getting trains around a disabled train, is moot. Every design I've ever seen for these types of ultra speed systems DO NOT have or need crossovers. And given reasonable headways, should a train suddenly disentegrate in a tube (a very highly unlikely event or the system would never be allowed to be built in the first place), the following one would be far enough behind it to completely stop. It's already this way on HSR systems. To operate otherwise is sheer folly.

And like I've already said, systems like this are NOT going to be built with today's technology so making up a million reasons why we need crossovers, or why we can't make very long tunnels, or how the several feet thick concrete/metal tube can be destroyed by tornadoes, etc, is pointless. Either we'll have the technology to build it and it'll work well, or it simply won't be built. We didn't attempt to put people in space when all we had were flimsy biplanes. We didn't run trains at 200 mph when all we had were steam locomotives. We didn't built skyscrapers when all we had was masonry. We won't build something like this until we have very reliable levitation systems, much better tunneling technology, perhaps new materials to make the tunnel wall out of, etc. My guess is at best we'll see something like this in 30 years, more likely not until the 22nd century.

The point of bringing this entire topic up? Namely that limited stop maglev in open air is a pointless technology since conventional HSR can go nearly as fast and is far more flexible. That's why this particular maglev project was killed. Maglev only makes sense in an environment which can take full advantage of its unique capabilities. One environment is closely spaced stops needing rapid acceleration but not necessarily top speeds of more that ~300 mph. The other is long distance limited or nonstop running at speeds much higher than HSR or even air can. The former type of system can be built today provided it can be justified economically (i.e. the Shanghai maglev). The latter probably not for at least 30 years, although I'm sure we can make shorter proof-of-concept systems with lengths of a few tens of miles.

David Benton wrote:i doubt wether such a systme is feasible . for goods movemnt maybe , but not for passengers . 4000 mph ???. how long to sotp if necessary ? within reasonable g forces ??? how long to accelrate up to that speed ???

For passenger comfort ~0.2g is about the max. That means 15 minutes and 500 miles to/from maximum speed in normal operation and coast to coast in about 50 minutes. I would imagine an emergency stop could be made in under 100 miles as that would involve deceleration rates no worse than a commercial airliner.

Such a system could certainly move goods and passengers. However, I fail to see the economics of building a system solely to move goods at 4000 mph. There just isn't enough of a market for same day delivery to justify the obvious huge expense a system like this would entail. And the economics of such a system for passenger obviously aren't there today but probably will be in 50 years when tunneling costs go down and fossil fuels are pretty much gone. It'll be as simple as not having any alternative if we want to travel faster than about 250 mph. Then again, perhaps society in 50 years may no longer have a need to travel at jetliner or greater speed, so conventional HSR will suffice.

Getting back to HSR and the lack of enough cities out West, I would think using the line for overnight deliveries also might be enough to make it economically viable. In fact, HSR is much more ideally suited to the overnight freight business compared to air as it goes city center to city center

Let's consider the Gotthard Base Tunnel as a benchmark; it will be a double-track hard-rock tunnel. From the Wikipedia article on it, it will be 57 km / 35 mi long, and will cost around $6.4 billion. That's over $110 million/mi or $180 million/mi, which is in the range of some urban-rail projects. Scaling it to the NYC-LA distance of 2800 mi yields a total cost of $500 billion.

And though such a tunnel will not suffer from surface hazards, it will be at risk from earthquakes. In particular, a NYC-LA line will cross the San Andreas Fault, and likely some other active faults.


I've succeeded in finding some suitable databases over at the Census Bureau, and I've put together the appropriate data for the US Metropolitan Statistical Areas and Micropolitan Statistical Areas.

There are some quirks in their official definitions, like Orange County being included in Los Angeles's MSA, but the Inland Empire being in a separate one. But overall, the MSA's seem reasonable.

I created some KML files with the cities as placemarks, using different population thresholds, and some patterns are apparent in the forest of Google Earth pushpins.

The eastern US is thick with MSA's, while they are much more scattered over the western US, with the biggest western concentration being along the west coast. This holds even for very populous MSA's; the two most populous ones are NYC and LA.

The dividing line is Minnesota-Texas, as I'd found earlier. It isn't very clear from Google's satellite imagery, but it's reasonably clear in the imagery of its competitors: Yahoo, Microsoft, and MapQuest -- green on the east, yellow on the west. I've also found a nice diagram of US-county population densities over at Wikipedia; the east-west divide is very apparent there also.

Interesting map. It looks like multiple HSR lines running both east-west and north-south would be feasible in the eartern half of the country. In the west, something running north-south along the coast, connecting major population centers, would work. There appears to be a possibility for one east-west line (Kansas City-Denver-Salt Lake City-San Francisco) which might be feasible if enough priority freight could be moved along with passengers. With stops spaced on average 400 miles, and 225 mph running speeds, this line could offer ~200 mph average speeds. Other than that, it looks like the possibilities for east-west lines in the western half of the country don't exist. Anyway, I wasn't so much thinking of building a NYC-LA HSR line but rather hoping that enough corridor HSR lines could be built to makes such a trip possible on HSR, and to me that looks realistic. Perhaps take two or three corridor HSR lines from NYC-Kansas City, then catch the Kansas City to San Francisco line, and finally the west coast line to LA or wherever else your destination might be. Not the most direct route, but a total trip time of under 15-20 hours with tight connections seems quite realistic. Interestingly, to me it also looks like the USA might be served fairly well in the future with a single ultra-speed maglev line running roughly in the middle of the country (NYC or Washington-Kansa City-LA), perhaps with some trains stopping in Kansas City. The HSR lines in the rest of the country would funnel passengers to these maglev stations. Thinking of the longest possible trip (say Miami-Seattle), you would take HSR from Miami to the maglev in, say, Washington. That's about 6 hours. The maglev ride would take perhaps an hour, give or take. And then you take HSR from LA to Seattle. That's perhaps five hours. With connections the trip might take 14 hours or so. Further down the road, a single trunk maglev line on both coasts might be economically justified, perhaps getting such a trip down to under 4 hours.

Yes, these ultra speed maglev lines will be costly, but we don't need a whole lot of them to serve most of the population well. The two coast lines and single cross country line would be about 5000 miles total give or take. At the prices you quoted, that might be around $1 trillion. A comprehensive national HSR system would probably be about the same. $2 trillion spread over ten or more years isn't a huge expense for something which will largely get us off oil for domestic travel. And it's for something a lot more useful than other things we'll probably spend a trillion dollars on, such as the bailout or the Iraq war. No, I'm not getting sticker shock at all. In fact, if it were up to me, I'd start serious R&D with the goal of actually starting to build the maglev lines in 2025 or so. And I'd start building the HSR lines right away.

jtr1962, I invite you to review various high-speed-rail proposals.

The Federal Railroad Administration's HSR page - Lower-48 US
The Midwest Regional Rail Initiative - Radiating outward from Chicago
The Ohio Hub - 3C's line, and lines to Pittsburgh and Buffalo
The Rocky Mountain Rail Authority - North-south Colorado line going through Denver
The California High-Speed-Rail Authority
The Amtrak Cascades - Eugene-Portland-Seattle-VancouverBC
Some Canada HSR advocates - Windsor-Toronto-Ottawa-Montreal-QuebecCity and Edmonton-Calgary

Notice a pattern: a crisscrossing of HSR lines in eastern North America except for the Appalachian Mountains, and a scattering of lines to the west: Colorado, California, Oregon-Washington, and Alberta. That fits in well with the pattern of population density and city density, with the exception of the dearth of Appalachian HSR proposals. And that is due to the difficulty of building high-speed-capable lines in mountainous terrain.