Patrick Crozier posted a piece on Transport Blog the other day about something called SkyTran, which I hereby throw to the Samizdata comment pack to see what they make of it. It seems like a wonderful idea.
Said Patrick:
Further to my investigations into alternatives to driving, I stumbled across a site promoting SkyTran. SkyTran will be a 100mph, computer-controlled, magnetically-levitated, almost door-to-door, non-polluting, personal transportation system. It will whisk us to our destinations in futuristic, light-weight pods, eliminate congestion at a stroke, cost next to nothing, turn a profit, allow spectacular views and be built along existing rights of way.
Can it be done? I have no idea. But I so, so hope it can. Imagine, an almost perfect transport system, making trains and cars look like the 19th century technologies that they are and consigning both to the rubbish bin of history.
I love it.
Maybe it was just that other blogs were taking the Christmas holiday off and there was nowhere else to go, but I’ve been struck not just by the quantity but also by the quality of the comments samizdata has been attracting recently. I can’t reasonably expect the number of comments that David Carr got for his piece about communism not collapsing the way it should, but a dozen or more good, informed responses to this proposal, maybe referring to what else has been said about this scheme by critics and commentators in America, is not an unreasonable hope. The more lucid of these comments, if there are any, can then be swung back to Transport Blog, together with a link to the rest if them. So let’s show these trainspotters what we can do, eh? A very cursory google search got me to several more commentaries about SkyTran, but they all seemed to be echoing the original sales pitch. Has anyone been minded to shoot the thing down in flames?
I’m not sure I quite love SkyTran. There’s something uniquely satisfying about choosing and owning your own vehicle, which SkyTran doesn’t seem ever to allow. Nevertheless for commuting SkyTran looks most enticing, if it can be made to work.
SkyTran is basically a scheme I myself have gone a good way towards inventing – in a science fiction kind of way – as a result of my decades-long enthusiasm for the idea of road pricing. Road pricing, once it is installed (and I do believe that it will be with us in a big way any decade now), will reward the road operator who manages to fit as many vehicles as he can onto his road, and this he might eventually do by taking control of the vehicles himself. The trouble with both trains and road vehicles now is that the gaps between them are too big. Computerised control of the vehicles by the system itself might make much denser track and road usage possible. Essentially, what you need are traffic jams which move along as convoys, all vehicles starting and stopping at the same time, yet the individual vessels being separable and recombinable into different convoys, by destination. Need I add that you also need the faultless driving – second by second, day after day, year after year – that a humans can’t manage but which a computer might?
But we’re decades away even from a fully rational pricing system for roads, and who knows when computerised vehicle guidance will come on the roads, if ever? This might be a much quicker fix, at any rate for urban transport.
My principle technical confusion about SkyTran is: does the system involve “points”? (As in railway-type points. Funny, I never realised until now what an odd word that is to describe what it describes.) It seems as if it must, in order (a) to allow the SkyTran pods to go from any destination to any other destination, and (b) to enable the pods to detatch themselves from the main line and to insert themselves into the stopping system, like so many London taxis in a cab rank.
Such road pricing as does happen in the near future will definitely help, because it will concentrate minds wonderfully on dreaming up and arguing about possible alternatives. Alternatives like SkyTran.
The gaps between road vehicles (and trains) are an important saftey feature. In a tightly packed system, a fault will trigger an instant pileup, and that pileup will propagate down the line, quickly snarling up (and injuring!) just about everybody on the road.
When was the last time you met a computer (or its programs) that never goofed?
Brian Micklethwait:
We’re decades away even from a fully rational pricing system for roads, and who knows when computerised vehicle guidance will come on the roads, if ever?
Since it’s already possible in any car with a decent computer and telematics system to ‘latch’ on to the car in front and have your vehicle mimic everything it does whilst maintaining a safe distance, or for the car to take control of driving when it considers you to be doing so dangerously, and assorted similar functions, I don’t see why road pricing is a necessary precursor to the development of fully computer-controlled road networks.
Julian Morrison:
When was the last time you met a computer (or its programs) that never goofed?
Of course there’ll be errors and bugs, but how do you think the accident rate will compare with what we experience under the current manual system?
I could write a large book. But I won’t.
1) Consider a local area power failure. Consider hanging in a pod, in the winter, untill the utility company restored power, or untill a snorkel truck could come by and rescue you.
2) Consider an ice storm, such as we recently had. Consider 1/2″ of ice on the maglev bearing surfaces.
3) Pollution free? This is a NIMBY system. The power has to be produced somewhere. The same number of calories will be required to move X pounds Y miles weather they come from a big power station, or from burning fuel locally.
4) Imagine buying a weeks worth of groceries for a family of 4. Imagine unloading them at the dismount point a mere 1/2 block from your front door.
5) Existing infrastructure must be retained. An 80,000 lb diesel truck full of bulk cargo will not be replaced by 160 pods. Imagine a bulk shipment to a furnature company. Your new sofa will be delivered in a truck.
6) Instalation: Someone with a copy of Photoshop(r), please take some of the pictures on the ‘Photo tour’, and put them a more typical urban background. Use narrow sidewalks and roads typical of an urban environment. Include some colorful grafitti on the pods.
7) Cost: This is new technology. It’s possible to build known technology (roads or rails) pretty close to estimates (<5X over runs). New technology can be expected to be vastly more expensive, and this is the infrastructure costs. Operating costs can be more easily estimated. Light rail (trolley) costs about 1USD / passenger mile. Diesel bus costs about half that. Private auto runs about .35USD/mile last time I looked. These numbers are for Denver, Colorado, and YMMV. Profit? Look up your local cost / passenger mile for a taxi. This will be government operated, so double the cost.
8) This is not to say that it can't be made to work. It's just that I expect that it won't work as advertised, or anywhere near within budget. The energy that is currently self contained in motor vehicles, will be demanded from the public power grid. I don't know how things are in your neck of the woods, but we don't have that much surplus capacity, and trying to add it would bring howls of protest from the very 'Greens' that would demand that SkyTran be implemented.
Public transportation has always been a sore point with me. Rant mode off, I take my soapbox, and steal softly into the night.
I’d be interested in seeing how they plan to switch these cars from one track to another. Monorails are notoriously difficult to design switches for, and I can’t think of any that currently exist with high-speed switches. Something in an urban area will require LOTS of them, and I’ll get switches will provide the bulk of the infrastructure cost.
This will definitly not be as convenient as cars. I can currently get in my truck in my garage, drive to work, and get out in the garage at work without being rained or snowed on. Who wants to walk a couple hundred yars to get to the on/off loading points?
And imagine how nasty the interiors of those cars are going to get. All those teenagers going on dates, riding home drunk, realizing this is their last opportunity alone together before getting back to the parentals. You want to ride in that car afterwards?
I’d bet my sword collection this thing will never be built here or anywhere else. There are no commercial incentives (individual cars are doing fine thankyouverymuch) and while some statist government may look with interest at it as a public relations stunt, vested interests for the road, car, and gasoline industries would make it politically untenable.
in re “points” —
I believe that the word you’re looking for might be “vertices”, the plural of “vertex”. I take this from 3D modeling. As it concerns this concept, it’s the point[s] where line segments meet.
I went and looked over the SkyTran idea, and I was not impressed, for reasons that become apparent with consideration of vertices. In their nature, they cannot be everywhere — for that would be a plane, and not a network of lines — and to be everywhere is a necessary implication if the thing can get me “anywhere”. Here is an example of the principle taken to its extremity of logic: I could look at the 1×1-mile grid, and imagine a requirement — or just the whim — to arrive somewhere less than a mile away from a SkyTran station, without walking under the load of, say, my trip to the electronics or book store.
Can you imagine a SkyTran grid in, perhaps, Montana? (Absurd? Okay, then, try…) …anywhere between New York City and Syracuse?
No, the thing cannot go “everywhere”, and that’s why I’ll own a car until the day I die. Now, it’s quite true that my ’72 Chevelle couldn’t “go everywhere”, either, but it could do one hell of a lot better resolution than vertices a mile apart. Even in metro Atlanta, I could not imagine being constrained to one-mile resolution in my mechanized travel.
And all that is before I even get going on the matter of someone else leaving their chewing gum on the dashboard of a vehicle that they don’t own and don’t care for. It’s late, however, and I think I get the picture.
I say the thing is nonsense.
I can’t add a lot to Bill’s destruction of this notion, which is reminiscent of something dreamed up in a late-night bulldusting session and fancy computer modelling (note how clear the landscape is of actrual buildings, people, mess, other types of vehicles).
But unless my eyes deceive me, the single seat is going to be a bit difficult fo pack the kids in for shopping trips and school drop-offs.
This is a fantasy for lone Dan Dare fans.
Like the Segway, its success will be brutally limited by its lack of usefulness to the large majority of the population.
In addition to the problems raised in the comments, there’s another big one. SkyTran wants to move the pods at 100 mph in an urban environment. Just build the SkyTran system on the sidewalks? Imagine this though: you’re walking down the street and 20 feet over head pods are whizzing past at 100 mph. The noise of these things will be tremendous. Sure, the pods will be aerodynamic to minimize drag, but moving them along at 100 mph still means displacing a lot of air. With a convoy of pods at 100 mph, any SkyTran route will sound like a constant hurricane and the turbulence from the airflow will affect people walking at gound level. (Quite aside from the psychological effect of pods roaring past at 100 mph just over your head…)
The SkyTran site is really big on stressing the low cost of building the system, but they don’t seem to have any detailed projections on the running costs.
SkyTran is never going to replace the car, for obvious reasons already cited. It might achieve finer granularity than current modes of public transport, but I don’t see it ever becoming as ubiquitous as its inventors claim. At best, it’s going to be an addition to current public transport systems, with SkyTran pods running in subway tunnels rather than overhead. It’s a fun concept to toy with, but I’m afraid reality does intrude.
Another thing I wanted to add about the airflow: it affects the spacing of the pods as well. At 100 mph the wake of the pods will be high turbulent (hence all the noise too). So any following pods must be either very close to the first one in order to get into its slipstream, or there’s going to have to be considerable separation in order to allow the turbulent air to subside. Otherwise you’re flying straight into churned-up air, which in a light-weight pods anchored overhead by maglev is going to be very bumpy.
Oho!
[it will]…eliminate congestion at a stroke, cost next to nothing, turn a profit, allow spectacular views and be built along existing rights of way…
And I am Marie of Romania. And Perry is Henry VIII.
I know it’s the silly season but puhlease…
Make it work in small-scale (a shopping mall for a year would be ideal), THEN come begging for construction funds.
If we’re doing Sci-Fi transport, maybe you’d like a look at the Moller Skycar (a domestic-use VTOL car) or the even more outlandish Solotrek XFV (Exo-skelton Flying Vehicle). Hard to believe that the latter could ever be stable, let alone viable. Nonetheless, the world is a better place for people trying, and I hope my skepticism is proved wrong.
“SkyTran is non-stop, 100 mph personal transit…”
Non-stop? Wouldn’t it make boarding and alighting easier if it stopped? That could also make ADA compliance iffy.
Ideas along this line have been proposed before:
http://faculty.washington.edu/~jbs/itrans/PRT/
And tested once:
http://www.arc.wvu.edu/transportation/PRT.html
But perhaps West Virginia is not the ideal place to introduce an idea into the public’s consciousness.
P.S. Didn’t anyone see Minority Report? That looked much more fun anyway.
I know this comment is very late in the day but I’ve been wanting to respond to some of the criticisms for a long time.
Some are fairly easy to deal with:
Ice storms. Not very common in all sorts of parts of the world and I am not sure their impact on SkyTran (or something similar) would be any worse than their impact on cars.
Shopping. It can’t do this. But neither can planes or trains and they’re viable. It doesn’t have to do everything.
Chewing gum etc. Actually, seeing as all this is computer-controlled and the operator is going to know who has been using his pods, I would have thought it would be fairly straightforward to track down the perpertrators.
Pollution. Personally, I would far prefer to have the pollution a long way from the city centre even if it’s the same amount.
Cost. Well, I suppose roads and rails weren’t known technology either at one time. Sure, the estimates will be wonky. It might kill the idea stone dead but there’s only one way to find out for sure.
Power capacity. Sure, there’s a problem in all sorts of places but, as I understand it, that’s largely due to state regulation. That can be changed.
Convenience. Sure, it’s nowhere near as convenient as the car so long as the road is clear and you don’t mind driving. But in many central districts the road is anything but clear and driving becomes a pain.
Some aren’t so easily dealt with. The point about aerodynamics, noise and capacity raises all sorts of questions. As does the one about what happens in an accident. This point is, of course, absolutely essential. If it can’t be made acceptably safe then it’s doomed.
For my money, its best chance of success would be as a direct replacement for an existing passenger railway line. That way it’s only dealing with the one right of way, it would be doing something rather similar to what it is trying to replace and the stations would be similar distance apart. The fact that no private railway has been sold on the idea suggests that it may not be that feasible.
I watch big brother