Trans-Atlantic MagLev

...physic would be. Or more succintly stated it would be the human bodies reaction to extreme acceleration.

Let's say you wanted to get to London from NY in one hour and wanted to get up to 4000mph in that distance...

acceleration=(final velocity-initial velocity) / time

a=(4000mph*5280ft/mile-0mph) / 18000 seconds (half an hour, we might need some time to deccelerate)

a=21120000/1800=1,173 ft/s2

The gravitational pull of earth is 32.2 ft/s2

You would be pulling over 36 Gs for an hour (half during acceleration and half during decceleration).

I hope you enjoy your show in London but I think you may need some medical attention as blood flow to your brain probably stopped about an hour ago.

Your calculation contains a bit of an error. You are missing a conversion.

4000 miles = 4000*5280 ft
But we must convert hours to seconds.
Therefore, 4000mph = 4000*5280/(60*60) = 5867 ft/s
Over the course of 30 minutes, which is 1800 second, we then have an acceleration of, 5867 ft/s / 1800 s = 3.3 ft/s/s

So, in reality, we are looking at 1/10 of the gravitational acceleration.

Otherwise, yeah, 36.6Gs would be a pretty major hole in their theory!

The world seems to be having troubles building infrastructure right now. I don't know how we would be able to convince people to put up the money for this kind of a project. Long term, I don't think it is viable.

In addition, the world is in uproar over "terrorism". I think this would be a primary terrorist target, and much easier to attack than anything within a continent. Can the entire length of the tunnel be monitored for depth charges at all times? What would happen if the tunnel blew during a train ride? What about ocean currents? The surface area of such a tunnel is quite large - the tunnel would be thrown about by ocean currents, no matter how weak they are.

Neat idea, but unfeasible.

This is still highly theoretical technology requiring over $100billion dollars to create just this one line. The fact remains that however possible this is to do mathematically (physically) speaking, monetarily speaking there is no-one to front the bill.

The most important factor to figure in, is that this technology is clean i.e. it does not run on burnable fuels, Great for the environment not so nice on the billionaires wallet. The maglev if created could make for the obsolescence of air travel(in the long term), which requires massive amounts of burnable fuel (a sustainable income for big oil). Through the perpetuation of old transport technology i.e. planes, trains and auto mobiles, societies 'elite' have the means to deepen there pockets at the expense of the rest of us (not to mention at the expense of everyone's future), a trade that big business has proven time and time again it is willing to make e.g. The Electric Car, Or the Bayer AIDS Infected Drug Sale Scandal. There would also be a lack of support via the government and thus the media, (bearing in mind that the three entities have become interchangeable in regards to personnel) meaning that this kind of maglev has almost insurmountable obstacles before entering creation. The technology is there, but Policy and economy will not allow for its creation.

Smaller industries could also lose out thanks to the brilliance of maglev. These trains do not run on the track they are magnetically levitated above the track in a vacuum meaning zero friction. Provided that the technology is sound(which you would hope to be the case before people were propelled at 4000mph under the ocean) the parts could last an exceptional amount of time lowering machine replacement needs. Although you do have to assume that monitoring the tunnel itself for structural integrity (maintaining the vacuum) etcetera would be of extreme importance, lets face it the last thing anyone wants is a 4000mph fireball caused by a sonic boom.

This theoretical maglev seems to belong to a utopian ideology that may or may not be feasible. The sad truth is that this incredible technology is likely to go the way of the electric car, brilliant and potentially destiny defining, but disabled because it is a hindrance to the power, wealth and control of the ruling class.

The only real hope for such a transport system is overwhelming public support to an extent that it cannot be ignored.

//In regards to the terrorist comments, I only have one word 'ZEITGEIST'. Go to google video type in that word and watch the two hour documentary. If this does not help you change your thinking, go to the library get out a book called 'MANUFACTURING CONSENT', and read at least the first chapter. Very good stuff. Trust Me.

wow so cheap! there's NO EXCUSE not to build a worldwide network of these things. it would be just the thing to save our physical economy. after throwing 3 trillion dollars into the black hole, we'd actually have something to show for... something to shore up our physical economy. lets ban speculation and end the $550 trillion in derivatives contracts placed EACH DAY and put that into our physical economy and get 100% employment. let's get something real not just paper money! yeah!

First of all, this train WILL happen if the free market is allowed to operate. I don't know about you, but I would be the first to put in buy a few shares in the company that builds this, and I don't think I'm alone. As for saving our economy....sorry to disappoint you, but transportation already makes up a rather small percentage of the price of most products, and nothing can "save" a government regulated economy, least of all a train. It will however, drastically reduce the price of, and increase the speed of, transportation.

All the objections people have posted in comments could have been easily solved had they given the thought to it. How will it be funded? (Sell shares in a public company.) How will it withstand ocean currents? (Anchor the tunnel to the ocean floor/) How will it be protected from terrorism? (1. Keep the government out of train operations, to avoid making the train a terrorist target. 2. Employ various security systems, which may include ir proximity detectors, cameras, ocean current monitors, electric field detectors, touch sensors, robotic patrols, security contractors, and huge bounties on the discovery of vandalism and capture of vandals.) Won't other forms of transportation lose out? (Yes they will, just like the manufacturers of steam engines did. As long as the government stays out, these industries will be powerless to stop it.)

I do have one objection though: Traditionally, trains were built with large, interconnected cars (as opposed to many separate cars), because this reduced air resistance, reduced engine costs, and reduced the risk of collision and derailment. The downside is that the entire train must stop at each station. However, this MagLev tran has no air resistance, no onboard engines (it operates by alternating magnetic fields, like the motor in a disc drive), and no chance of derailment. As long as collisions are avoided by the computer control system (which isn't hard), operational costs can be dramatically reduced if two tracks are built, and cars are allowed to run individually, with off-ramps at appropriate locations. Think about it: the majority of energy waste in any transportation system is braking; by allowing through traffic to proceed without stopping, braking is dramatically reduced, resulting in massive energy and cost savings.

1/10g accelleration. Let's think about this factor.
If you seat on a train and feel accelleration of 1/10g for 1/2 hour, will it be comfortable? half of accelleration and next half of decelleration. I think this journey will be very uncomfortable. Otherwise the amount of accelleration will be increased. In this case, is this a realistic project?

In regards to the 1/10g acceleration: That is the horizontal acceleration only. The vertical acceleration will still hold at 1g plus the force to lower you 150-300ft initially and raise you at the end. For you to have a nice ride and to feel comfortable, you WOULD want the horizontal forces to be as close to zero as possible.

Secondly, the train will not be accelerating for half an hour. As i read from some other sources, it will accelerate for 18 mins, remain at that top speed for 18 mins, and then decelerate for 18 mins. Therefore, its acceleration will be
(4000mph)(5280ft/mile)(1hr/3600sec)/1080sec = 5.4 ft/sec2.
this is 17% of the earth's gravitational pull. The total force due to acceleration that you will feel, therefore, is 32.7ft/sec2 (sqrt(32.2^2+5.4^2)) which is 1.02g into your seat.

Not much difference - Enjoy your ride! I hope that it will be smoother than the ones you may feel in your city trains.

Also in other articles i read that it is supposed to reach speeds up to 5000mph but the equations change slightly and the force felt still comes out to be 1.02g. So it still comes out to be a nice ride at those speeds. Enjoy!

Costings and projections are a bit like tax accounts - they can be presented to suit what the client wants. Before the recent turmoil in credit and finance, a small business ( such as a farm ) could buy the materials for reinforced concrete ( ready mix delivered concrete and steel mesh ) in the UK for about £160 ( $320 then )per cubic metre. A triple tunnel (one each way plus a service / emergency , all 7 metres diameter )would require about 22 cubic metres per metre run. This computes to about$5.3 million per kilometer for the bulk of the materials used. Whilst both the material cost and the manufacturing cost are high per unit length for small projects, these can fall dramatically on large projects, both from the buying power exerted and the opportunities to mechanise and automate many of the processes - especially if there are a large number of identical components. Even if we take the lower figure in the article ( $88 billion )most of the money goes on the manufacture and labour.
The passenger capacity of any transport route is the product of the passenger capacity of the vehicles themselves and the headway between them. Headway can be expressed as either distance, or time. For safety reasons this time gap should be related to the emergency stopping time from full speed. This has the effect that if you limit either the length of the train, or the speed,
you inversely affect the other if you wish to increase capacity. For example if you limit the length of the trains, to get more capacity for the route you have to run at a slower speed. Increasing the speed also increases the headway time which then can only maintain route capacity by lengthening the trains
Suppose we had an operating system running at 2700 kilometres per hour ( 1687 mph and still faster than Concorde )and the horizontal acceleration / deceleraton rate was 1 mtre per second squared, then a headway time of 750 seconds would be the same as that required at either end of the journey, a schedule of one every 12.5 minutes could be maintained.If we further assumed 6000 operational hours per year and a train capacity of 800, then the route would be able to transport just over 23 million per direction per year.
Assuming a capital cost of $100 billion and interest and other capital charges totalling 5% ( not unreasonable nowadays ) then that share of the fare would be $108.70 per head.Similar calculations for the rest of the costs would still make the tickets profitable below $130 per trip.
It would seem to me that the tubes should have a small amount of positive bouyancy , so that the cables attaching them to the sea bed were always under some tension

Lauld's cost analysis is awesome. Instead of arguing about whether it would work or not, he actually sat down and did the math. Kudos! I wanted to add, though, the vehicle headway should actually be the stopping distance of the trailing vehicle minus the stopping distance of the lead vehicle, plus the reaction distance. Even in the worst case scenario, when the wall caves in and the lead vehicle runs into a tube full of water, its stopping distance will probably be close to that of the trailing vehicles, especially if they are equipped with emergency brakes. Furthermore, if all vehicles are allowed to run end-to-end, with appropriate safety couplings, the necessary headway can be reduced to zero, since all stopping distances will be equal and reaction time will be zero.

Thanks for the Kudos Azulprofundo, and you are of course correct about headway as it applies to existing traffic confined to roads ,or railways. It is also true that emergency braking systems could be much fiercer than normal deceleration. As an aside the basic physics precludes high speed rail ( steel wheel on steel rail with no other traction aid ) braking at much better than about an eigth G, whereas automobiles can better 5 eighths G. In a train doing 750 meters per second the driver would need to give some warning to the passengers before applying full braking force. This will obviously affect headway. The illustration at the top of this article is probably incorrect as structural efficiency and fail safe security would favour tubes only a little larger than the enclosed trains with frequent interconnecting airlocks. The train itself would not require a streamlined nose unless it expected to travel in the open air a significant portion of it's operating life. The length of trains will be determined by the air lock system at either end of a tube. I am an enthousiast for this transport system, and foresee it initially being adopted for large volume city to city routes in the 60 kilometer plus range. The reasons are basic - for the capacity, speed,safety, and energy efficiency nothing else can, or could match it. Any vehicle travelling in the atmosphere near sea level going faster than 110 km / hour is using most of it's available power overcoming air resistance.

The comments concerning opposition from well established vested interests are very pertinent, but perhaps the shake up in the financial world might cause enough of them to think that there is little mileage in hankering after a better cabin on an unseaworthy liner. Oil prices may be going up and down like the springs on the bed of a house of ill repute, but the trend is for all fossil fuels to get scarcer. Returning to the "back of an envelope" figures I put in my previous comment, Hartsfield Jackson airport near Atlanta claims the worlds largest passenger numbers at about 90 million in 2007 - goodness knows what it is now. This could easily be surpassed by the scheme weare talking about,by reducing the headway to 10 minutes and operating for 8000 hours per year. The scheme is not likely to come about any time soon, but will be more likely if on land versions between the large cities are up and running. There are two types of people, those who verbalise, and those who visualise.No prizes for guessing which group politicians tend to favour. This means they need to be shown something novel, before they appreciate it's merits.

The idea of a train that will carry passengers across a continent or across an ocean comfortably in about an hour without burning fossil fuel is not new. Robert H. Goddard, father of rocketry in the USA, received patents posthumously in 1949 for work that he had done to develop a supersonic train. Literature and science have been captivated by the idea of superfast, energy efficient transport. Such a train would move at about 5000 miles per hour, carry passengers with slightly over 1g gravity, in a vaccuum tube, encountering no friction, levitated by magnets. The need to update our aging transportation infrastructure coupled with the dire predictions of damage to the environment from dependence on fossil fuel makes reconsidering Goddard’s “vactrain” timely.

Frank Davidson wrote about his hopes for this project in "An Express of the (Near) Future in Air&Space, Dec.1995/Jan.1996. In 2009 he is organizing a group to move this project forward with the hope of developing a model to demonstrate the possibility using a vacuum tube and magnetic levitation to propel an accelerating object to the speed of sound, maintain that rate for some period and decelerate to a stop successfully. Such a model would demonstrate success of the transit mode as well as the materials required.

I am continuously perplexed why there is not more research and development going into realising some form of vactrain. As Barbara Thorton wrote, the possibilities from this transport means have been recognised since the time of that great American scientist and engineer Robert Goddard. If the federal assistance that both the aerospace and automotive industries now seem to require was linked to them becoming involved to develop and produce the components and systems of a vactrain network, a win win situation might arrise. The countries who do so are likely to be the world leaders well into the future.

Apart from the financial constraints involved, I'm surprised nobody has brought up the electrical needs of such a train. Acceleration to 4,000 mph is no cheap feat, and without sufficiently low resistance power feeds or wildly inefficient running costs, seems like you'd be set on undersea power generation of a kind that is hardly 'only held back by the costs'.

Anyhow, if we're really going to tackle this, I say we increase speed up to 18,000 mph or so and do proper orbital velocity. Around the world in 80 minutes, as Jules Verne once wrote.

atariteenagepre raises a valid point about the electrical supply and probably identifies the main limiting factor. Even at 100% efficiency (unlikely ) of the magnetic field drive , to accelerate a 500 tonne train to 4000mph with an average acceleration of 1 mmetre per second squared requires an average electrical load of 250 megawatts.But the energy requirement goes up with the square of the speed, so going from 3999 mph to 4000mph takes a lot more energy than going from say 99 mph to 100mph (over 40 times in fact).This means that the acceleration rate will be limited as the speed increases by the power available and the efficiency of the drive. In magnetic materials magnetic fields take some time to rise to their peak and more again to dissapate and some energy is lost in the process. It seems likely that linear induction motors will have a practicable speed limit beyond which it is not worth going. I have to wonder why one would want to try to travel inside a tube at about orbital velocity. The acceration distance to get to that speed would be most, if not all of the way round the earth unless the passengers were willing to endure high g loads for many minutes ( at an average 1 metre per second squared it would take 20,000 miles ) . And then you would face decellerating just as hard and for just as long to stop at your destination.
Vactrains still have a future, but speeds in the 1 to 3 thousand mph range look more practicable. If you must get to the other side of the world as fast as possible, sub orbital space planes look to be the best bet.

lauld fermer- Don't you think the kinetic energy of the train could be converted to potential energy in let's say kinetic batteries during the decellerating phase at the end of the ride. Then those kinetic batteries could be used to accelerate the train going in the opposite direction thereby conserving a lot of the average electric load of 250 megawatts initially used?

HI grandmastertubet, I'm not sure what you mean by kinetic batteries unless that is a general term for flywheels and the like. Certainly it would be prudent to use the electrical energy produced in braking one train to help accelerate the other. In both cases the energy transfer will not be 100%. The problem with averages is that they don't always reflect what the peak load is and it is the peak load that the equipment has to be designed and built to handle. Kinetic energy stores ( if they are flywheels )have limits on how fast they can store or deliver energy depending on the characteristics of the electric motor / generator used. Being heavy they would need to be fixed track side installations with all that implies for delivery to and from the trains ( transmission losses ) If the acceleration rates are to be comfortable to the passengers the 250 megawatt demand will not be required until the train is already going quite fast ( I haven@t taken the time to work out approximately when that might be but it would certainly be some distance from the start )Assuming friction losses are effectively zero, then very high speed can be acheived with a modest power supply, but reaching that speed takes longer both in time and distance, and the decelleration time and distance has to match,unless more power can be dissapated on that phase of the journey.

Would it be possible to keep the train always moving? It could be like those theme park river rafting rides where you step onto a moving loading dock to board the raft. Since it would be at high speeds in a vacuum it may take a little ingenuity to create a feasible method. Perhaps there could be a container that smoothly loads and unloads passengers into and out of the train.