As I see it, the principle barrier that all PRT companies face is skepticism. Who can blame city planners and transit officials? The would-be companies come to the table with claims that they can build vehicles profitably, can build city infrastructure, including bridge-like track segments, can coordinate street traffic while utilities are being re-routed, negotiate the acquisition of right-of-way where needed, create a control system for these vehicles that is safe, build stations, maintain the fleet, collect tolls, etc.
“Gee that sounds like really fascinating technology,” Transit officials say, “Let me run it up the flagpole, and I’ll get back to you…”
One way to gain the confidence of customers is to have established standards and an independent standards body. After all, you need a license to practice medicine or even do plumbing. Anyone, however, can call himself a PRT provider. Standards creation is made difficult, however, by the fact that there are so many versions of what PRT should look like. I would hope that many of these providers would reconsider the highly proprietary nature their designs. Apple computer may have survived having it’s own standard, but that is certainly the exception rather than the rule.
I cannot champion all designs at once, and so I will concentrate on my own favorite, hanging designs, and more specifically the track, which is the part that needs standardizing most. This is because PRT companies might come and go, and vehicles will wear out, but the track is a very long-term investment. Even removal would be expensive. Cities need a “plan B”. Making a standardized, non-proprietary track that is cheap, simple and as versatile as possible seems like a worthy goal.
Here you see in the foreground the basic track shape I have shown previously. Just scroll down to my June 26th and July 16th posts for reference. I had mentioned in my last post that there could be various types of specialized track, such as low profile or industrial configurations that could extend the usefulness of PRT track. As long as there is some standardization, especially the slot width, there are many potentially useful configurations.
First, note that the track here is simple angle steel. It is shown as discontinuous so that it may be demonstrated that travel can be accomplished on a single side. The light brown hangers are produced from simple steel plate by a CNC flame-cutting machine. In other words, anyone can produce such track for little more than the weight cost of steel. For anyone who wondered, now you can see why my PRT track design has those hollow running surfaces. It is for flexibility in the support and steel thickness choices.
The picture above shows how simple a slower, more limited-range bogie may be. There are two aspects in particular which are not very practical in a PRT bogie that may be used here. One is the rims on the drive wheels (green), which hold the bogie in the track like a traditional railroad car. With high speeds, continuous use and quiet rubber wheels, these flanges would wear out. An alternative, shown here in violet, is guide wheels that are small enough to fit in the slot. In PRT, such wheels would spin over 5000 rpm, and would be too prone to heating and wear. Here I have redundantly included both of these slow speed options in a single bogie, for illustration purposes. Either would be OK for the occasional cross-town trip at reasonable speeds. Also note that there are no upper guide wheels, either for steering (blue) or centering. (violet) This is because this bogie is not designed to withstand the twisting torque of low-slung heavy loads on high-speed turns.
It can be seen that for companies to move goods around a factory, sky-hook style, is quite easy and cheap. It is not necessary to build full PRT track around the warehouse. Such a system could replace forklifts and conveyor systems, adding floor space. Goods could be moved between warehouses or to stores, increasing the usefulness of PRT track, especially at night. What is lacking, of course, is the software, which would be essentially the same as for PRT.
When we ask for taxpayer or investor money to build a network, that network should be very, very useful. Having certain key dimensions and construction details standardized just makes sense for everyone. An easy-to-remember acronym like SMARTS can’t hurt either.
