Sunday, December 25, 2011
Well, as 2011 draws to a close, we PRT believers have been given a Christmas present! Finally, for the first time in history, a large city with a real traffic problem is actually going to install a meaningful PRT system. ULTra, having proved its technology in its Heathrow Airport system, has partnered with an Indian company to build a 200 vehicle, 100k passenger per day system in Amritsar, India.
I know. I’ve been critical of ULTra in past posts. I have questioned if the system really can be called PRT at all – if coordinated robocars really fit the definition, especially since they do not enjoy the weatherproof speed and efficiency advantages of running on steel rails. I have worried aloud if the inherent performance shortcomings of steerable soft rubber tires on “pavement” would give PRT a bad name. But I have to say, all in all, that I’m pretty damned pleased, and I’ll tell you why.
There is one basic concept, best taught through demonstration that can promote PRT globally. It is the fact that, in an urban setting, ONLY multi-level transportation can be non-stop, and only non-stop travel makes sense in an increasingly resource-strapped world. Since multi-level roadways are too expensive and massive to deploy en masse, the most straight-forward approach is to create a new, lighter infrastructure that can be more affordably elevated above interfering traffic. This lighter infrastructure requires lighter vehicles and payloads as well. The logical way to speed throughput on this smaller infrastructure is intelligent automation - the combination we call Personal Rapid Transit. I had previously worried that a system like ULTra would end up, for cost reasons, having a great deal of track on the ground, which essentially misses the point. It appears that this is not the case.
It also appears that this venture is designed to make a profit for shareholders, with affordable fares, no less. This is obviously a huge deal, especially since every other option ends up being supported with tax dollars. I wish I knew more of the financing details…It sounds almost too good to be true.
We humans are far better at perfecting things than inventing them from scratch, so even if the world comes to believe that the ULTra design is the very definition of PRT, it won’t be long before more capable versions begin to appear. Undoubtedly such work is being done by ULTra itself.
What we will see in Amritsar is not at all what the early PRT pioneers had in mind. There are no grids of one-way track with small, evenly spaced stations. There is no attempt at blanket coverage. There are no loops; these guideways will be bi-directional. The route appears to have a combination of straight runs and a few fairly sharp turns, a combination that will slow fixed speed systems to the speed of the sharpest turn. Unlike the utopian notion of a car free city, many passengers will park their cars and take the system from there. There were the predictable protests over the track, although given the climate; I would wager that those shopkeepers will learn to appreciate every bit of shade afforded by the canopy.
The plan calls for connecting seven destinations: The bus station, the train station, two parking lots, a school (chosen because it was non-private land next to a large commercial complex?) a Bazaar, and a major tourist attraction, the “Golden Temple.” These people need more roads where there is no space for roads, more parking where there is no space for that either. There was little choice as to the routing. What you are handed is you get to work with. Sound like anywhere you know?
The fact remains that we really don’t know how the Amritsar system would compare to the same elevated track populated by ordinary motorized rickshaws, a similarly sized, common form of transportation in that part of the world. This case, however, bears little resemblance to the 1.2 vehicle occupants we are used to. They are reportedly going to pack in up to 6 per vehicle, so any driver would represent reduced capacity. What we do know is that, even though most people’s eyes glaze over when you start talking about a whole new infrastructure, some developers and some people in the Punjab government “got it,” and took a leap of faith. This is a very, very good thing. The more successful it is, the more it will attract competition and innovation.
There are a number of lessons here for PRT designers and would-be PRT vendors. One is to get big local partners. Who can dispute, for example, the (often greedy) symbiosis between real-estate development, politics and infrastructure? ULTra’s Indian partner, Fairwood Consultants, boasts 25 billion in projects under management. That opens a lot of doors.
A related issue is core competency. Ultra has never really tried to break much new ground, mechanically speaking. They use pretty conventional electric vehicles on a track that is nothing special either. They didn’t even opt for advanced batteries, but use simple lead acid ones (like a golf cart) instead. But this is not really a liability. Instead of expending energy working the bugs out of a bunch of new, experimental subsystems, they get to concentrate on creating traffic solutions with what they have. Eventually some company, with deep pockets and great mechanical engineering expertise, will see building a more advanced system as a venture with little downside risk, so long as they themselves are partnered with a company with a proven track record of implementing such systems. ULTra, by this point, will presumably have further cemented its leadership position in that role.
I think they had better not wait too long before they get such a partner however. If their system in Amritsar proves successful and they land subsequent deals, there will be imitators and competitors coming out of the woodwork. My own design explorations have convinced me that there are huge performance improvements to be had across the board, as measured by essentially every important metric. But their success can only make such a partner easier to find. I believe that there is huge amount of positive PR to be gained by any company that takes this plunge. They would be seen as agents of change, as green, and as technological leaders, saviors of the taxpayer, solvers of government debt and on and on… Again, if ULTra can handle the “behind the scenes” grunt work involved in landing deals, planning routes, working with local partners, and generally handling the logistics,(and/or operations) they will become the indispensable (although less glamorous) part of what could become a very big and profitable industry. Wouldn’t it be interesting if a future headline read, “Airbus Industrie Partners with ULTra Global to Create Next Generation Pod-Cars?” Or how about Honda? Or Embraer? Or Bombardier? Or even GM?
So, on this special day, I tip my hat to the folks at ULTra. Well Done. Yes, my friends, we have good tidings! And a Merry Christmas to all of you!
Monday, December 12, 2011
Recently there was a posting in the Transport Innovators site that caught my eye. It was entitled “SkyTran a Sham?” I know… I really should join that group and post my thoughts on that site, and lend a little support to what I consider to be a valuable public resource. But I like to scratch my head and measure my words a bit more than most before I open up my mouth, and I am usually too busy to even consider an issue on a timely basis anyway. So I hoard my musings away, like precious little nuggets, to be used as rainy day subject matter for this blog.
I am not so interested in the charge that was made against SkyTran but rather by whom it was made. It was leveled by the author of this study, which starts out promoting and then later disparaging nearly the exact same concepts as SkyTran. In my opinion both have severe problems. The author threw in the towel. SkyTran still purports to be a practical system.
What is it about maglev that makes smart people so crazy as to think that it is appropriate for PRT? maglev’s major advantage is being frictionless, except for air. This is a very minor consideration at city speeds, and yet they want to shoehorn this high speed technology into the sharp cornered, stop and go world of urban transit. A friction free object wants to glide at a steady speed, in a straight line. Navigating a city requires something wholly different. Both systems are designed to travel in excess of 200 km/h (124 mph), far too fast for short trips. Even though he states that, because of G-force constraints, average system speed can never exceed 100km/h (62 mph) in an urban environment, he never wavers from his 200 km/h maglev design, and the inflated track cost that it entails.
In the case of Swift PRT, the author, after all kinds of analysis and simulations, concludes that the track is too expensive (Duh! It’s full of copper coils!) and that vehicles that fast must be spaced way apart to allow exiting, entering, or even simple turns. (Or, alternatively, they need 600 meter ramps to and from the stations.) He states, “If your intersection or station spacing is meant to be <1km apart, you effectively need two lanes in each direction: a fast lane, and an acceleration/deceleration lane. The net result is you have at least doubled your track costs, and the width of your system.” It seems to me that the problem lies with trying to connect 200 km/h fast lanes to every downtown station! That seems to be what SkyTran is advocating as well. Like I say, there seems to be something about maglev that makes people lose their senses.
The conclusions are what bother me most: While I have no problem with his realization that maglev PRT is not cost effective, he then applies his figures to PRT generally. His assumption is that all PRT track must cost 7m/km, even though his own figures show that one way track without the copper coils and in-track electronics would come in at 2m/km. He then, through mathematical inference, extends this inflated cost to justify only putting one station per 2.7 km, and then uses this spacing to assert that PRT (in general) cannot compete because of the long walks to get to the station. His reliance on formulas over common sense has led to the “crap-in, crap-out” phenomena.
What is curious (and unfortunate) is the illogical leap from discovering that his system is too fast and expensive to the conclusion that the future of transportation is in vehicles that run on asphalt. This argument is made without anything to back it up, save the cost and ubiquity of the road system itself. Was it not the shortcomings of the road system that lead him to explore PRT in the first place? Sure, I think we all agree that traffic problems can be reduced by using networking and AI technologies. But asphalt will always be primarily a two dimensional, stop and go system. Multilevel interchanges simply cost too much and are too big to be ubiquitous. So when he compares the cost of his 130 mph, non-stop system against asphalt, he is comparing apples and oranges. If I had to venture a guess, I would say that the author set up an experiment that he was forced to carry it out with scientific rigor, even though the basis for the experiment (his hypothetical system) was clearly flawed. Having exhausted his time and/or interest, he was in no mood to do it all over with a better system, and so hastily framed his results. These conclusions certainly do not reflect the thoughtfulness shown in the sections where he first discusses the original problem.
That being said, one other interesting result of the study highlights the parking problem, something that is often glossed over in PRT discussions. While it has been admitted that PRT vehicles will have to travel around empty sometimes, the extent to which this will occur has been a subject that has remained somewhat opaque. Obviously, during off-hours, if the system is only operating at half capacity, there are 50% empty vehicles, and they have to be somewhere. Are they traveling around in circles? Clearly these vehicles should be staged somewhere, but I have not seen this reality reflected in the various PRT designs. It occurs to me that this is still one more argument for a fully multi-axis (3D) system. Warehousing numbers of empty vehicles would be much more space-efficient if they don’t require long ramps. As with parking cars, a vehicle with a small turning radius is a plus. In PRT, such a radius might be horizontal or vertical. Compact parking is especially important if an attempt is going to be made to shelter those vehicles from the elements. A PRT design that allows a combination of tight turns and compact track switching in full 3D can clearly minimize the real estate (and roofing) required for such storage. Being able to make multiple track configurations in tight spaces would be particularly advantageous in utilizing whatever real estate might be available, including very small or oddly shaped lots. Such parking can be envisioned more in terms of a lattice or matrix, as compared to lines of cars on long parallel tracks typified by the storage of railroad cars.
I might add that tight turning radii in both vertical and horizontal axes is inherently difficult to achieve in systems that use the track as part of the propulsion. This is because of the required tight spacing between track and bogie. Magnetism loses force with distance, so using magnetism between track and bogie for propulsion will always entail a fairly tight fit. This is my major beef with linear motor propulsion, even non-maglev varieties such as simple LIMs, which don’t require coils in the track.
Anyway, to those of us not under the maglev spell, this study illustrates some of the challenges of PRT design that must be, and, indeed, can be properly addressed. The challenge of G forces, of storing and staging pods, the track cost issues, the station spacing… All of these must be carefully balanced and tweaked if PRT is to succeed without the blunt instrument of generous government subsidies. Any good PRT design must address these issues from the onset, not as afterthoughts. Otherwise it will either fail outright or be relegated to a few niche markets.