Discussion on:

New York to London in an hour - by train

check out the Extreme Engineering video about this subject, program entitled "Transatlantic Tunnel"

The company claims that "construction would cost a tenth of high-speed rail and a quarter of freeways", and if you believe that, I have an evacuated bridge to sell you!

Care to explain?

It should seem obvious to even the casual observer. You just have to make a grade and lay some track for a high speed rail (concrete and/or asphalt for a highway). An evacuated transatlantic tunnel costing LESS?!?! C'mon.

It should just be common sense. No issues about pressure, weather, ocean currents, new technology, etc., with a high speed rail or highway.

I'd be nervous riding in a vacuum tunnel across the ocean. One little leak and you're in trouble. The safety standard would be so much higher compared to any issues regarding rail or highways that it would dramatically increase costs. That's not to mention the massive equipment needed to keep the tunnel in an evacuated state.

Even not accounting for the cost of developing the new technology, even if you just compare cost of construction, there's no way you'll ever convince me that such a project could be accomplished for less per mile than laying track or highways, let alone one quarter to one tenth the cost.

These sound like short sighted numbers cooked up by someone with a stake in the project. As I said, common sense would suggest otherwise.

Your assumptions put no value on the cost of the travelers time or on the environmental costs of large heavy trains on large heavy tracks that are exposed to the elements. Or the immense complexity of building ever larger, heavier, slower jets which require ever larger airports burning kerosene in the upper atmosphere and necessitate a hub and spoke topology that virtually insures that smaller markets will bear the largest costs.

The maglev technology has been in use since the 1960s. The control systems to regulate a segmented evacuated tube would not be that difficult to implement.

The Boeing 707-320 went into commercial service in 1959. It cruised at 540 kn/hr, burned 6.4 gal/mi carried 202 people, had a range of 3800 mi and its cost in 2011 dollars was $35.5M.
The Boeing 787-8 went into commercial service (sort of) in 2011. It cruises at 490 kn/hr, burns 4.4 gal/mi carries 280 people, has a range of 7800 mi and its cost in 2011 dollars is $194M.

So after 52 years and $32B in development costs (just on the 787 project not counting the 727, 737, 747, 757 767 and 777 development costs) Boeing has succeeded in building a plane that is 10% slower with 2x the range and carries 80 additional people using 49% of the fuel per person as the 1959 707.

That is pathetic. If you would have proposed that to the engineers that built those 707s back in 1959 they would have laughed you out of the freaking building.

My question to a naysayer like yourself is, ???What is your brilliant alternative plan to move people at 3-4X the speed of present day transportation at ten percent of the cost in the most environmentally safe way????

The solution certainly isn't this. And I'm all for moving people for less cost, but why does it have to be at the 3-4x the speed of present day conveyances? Nowadays we can transmit information at the speed of light. Why should we invest our limited human resources just so the 1 percent can cross the pond in less time?

You are correct transatlantic ET3 (tm) will be expensive, however more than 95% of the ET3 network will operate at 200mph to 600mph design speed, and across land -- not water. Only if ET3 networks are built to the same standard in every country can they eventually be networked together with a global backbone operating at 4k mph. This will only cross less than 100 miles of ocean (between Alaska and Siberia).

An $20k automobile with 5 seats = $4k/seat. HSR (high speed rail) costs $60k/seat. A 747 jet costs $462k/seat. The 6 seat ET3 capsules (not a train) can be mass produced using 1/8th as much material as an automobile, and cost even less on a per seat basis. HSR must be elevated for safety and air-blast issues. Elevated double track must withstand the mass of two 100 ton locomotives passing each other. Elevated double tube ET3 infrastructure must bear the weight of two 1200lb capsules for only a little over a ton of live-load. For this reason ET3 guideway requires 1/35th as much material to build as HSR infrastructure. Tubes are produced using automated equipment for much less labor cost per mile than all the "false work" needed to assemble and unassembled forms for making HSR. Detailed cost comparisons have been done between ET3 and maglev trains, ask for the spreadsheet by sending an e-mail to: et3 (at symbol) et3 (dot) com.

...with some interesting challenges as well. For example, how does one construct a deep-underwater structure that can maintain a near-complete vacuum without being crushed? Also, in order to achieve the speeds described without crushing the occupants, the path traveled would have to be almost perfectly straight. Even landscapes that are flat enough for conventional HSR would not be flat enough for this.

Planes already achieve that pressure differential. Underwater, for every 10 meters of depth you are adding one atmosphere to the pressure, the vacuum doesn't make much of a difference. You are right about the path: This contraption would only work in water.

The Transatlantic "vactrain" advocated by Frank Davidson (the founder and long time chair of the English Channel Tunnel project from start till completion), along with expert ocean engineer Ernst Frankel DOES NOT ADVOCATE DEEP WATER TUBES -- they advocate SFT "submerged floating tunnel" technology. They admit the horrific expense.

ET3 by contrast is NOT a train. The tubes are less than 1/3rd the diameter (less than 1/30th the cost) as "vactrain" tubes, and mostly will cross dry land (as most roads and railroads do). When ET3 must cross water, it could use SFT tech, OR more likely will be underground underwater (as the Chunnel is).

Even if the landscape were perfectly "flat" - conforming to the surface of the Earth - it has a radius of curvature of ~4400 miles. This works out to a constant acceleration of about .02G

Any conceivable change in altitude of the tube (short of a vertical transition) would be swamped out.

It's the stopping.

handling breakdowns, multiple capsules on the line...will the capacity be worth the construction?

ET3 is NOT a train, the design philosophy is more like an automobile operating on a freeway; but automated so the vehicle frequency can be much greater. (Just as automated telcom has much more capacity than human switchboard operators of 100 years ago). At 350mph, a single 5' (1.5m) diameter ET3 tube has the passenger capacity of 20 lanes of highway traffic (over 10 capsules per second). This is also 10 times the capacity of a high speed rail line.

Your destination will be known before you leave so they will just slow you down at the halfway point. You wouldn't only touch your top speed for a certain amount of time. Stopping shouldn't be hard.

It seems that passengers with certain health issues could be at risk. How might the technology change the precision of mechanical pumps, nano-drug delivery or effect vascular systems of compromised passengers?

Very interesting to consider the possibilities!

It wouldn't affect those devices because the passenger compartments would have to be pressurized like an airplane. If it lost pressurization, everyone would die from oxygen starvation.

The bigger problem for a system like this would be how expensive, large walled, well anchored, and straight the tunnel would have to be to prevent the passenger compartment from hitting the sides of the tunnel or subjecting the occupants to many times the force of gravity as the train went around curves at thousands of miles an hour.

I think you can solve the 'straight tunnel' problem with magnets. If the train levitates inside the tunnel, it can never hit a bump in the wall.
Concerning bends: just slow down I guess?

This thing would have to have some kind of seals to make the vacuum effective. Wondering how advanced seal technology is for something traveling that fast.

Also agree with another post that the vacuum pump would have to be huge!

There are many proven vacuum sealing and pumping technologies for ET3. Instead of large pumps, many small pumps will be used for cost scale factors, and also safe redundancy and ease of replacement without interrupting operation. Once almost all the air is removed, only some of the pumps operate intermittently to remove any air that leaks in.

If seals aren't available, then dolphins will happily help out. Besides, they are smarter than seals, so I would guess that dolphin technology is much more advanced than seal technology. And they work for fish and occasional applause!

Most (over 95%) of the global ET3 network will operate at 200mph to 600mph speed, and be above ground for much less cost. Underground ET3 is at least 3 times the expense of elevated structure. At higher speed than about 600mph, most ET3 will be underground to achieve the straightness required for passenger comfort. Higher speed ET3 must be actively aligned to automatically compensate for normal earth movements, for these reasons the cost will be much greater, (but the capacity will also increase by approximately the same factor).

It would seem that maintaining the vacuum would consume a lot of energy, and you'd have to do it throughout the entire length of the tube at all times.

how much the cost of electricity would be to run the magnetic rails in the tube as well as the vacuum pump. That is one heck of a carbon foot print for only six passengers.