Saturday, February 7, 2009

19> A More "Mature" PRT Track Design

Here is a section of a more mature PRT track design. I envision this with a skin to keep out the elements. Not shown in the picture is the soundproofing, except for the vibration absorbing material shown in purple, which isolates track vibration from the truss structure. The circular holes are for utility conduits. I have not figured out the cost or even the weight yet, but I must say it is dirt-cheap. Greater height and steel gauge enables longer spans. Note that the design does not show a great strength against sideways forces such as very high winds. A horizontally triangulated truss can cap the structure to address this, but it probably should be in removable sections, so as to provide access to the conduits.

In the traditional business model, a big company would keep the details of the track secret or proprietary, even though it could provide lots of local jobs and that could be a selling point. The integration of utility lines and street lighting could also be of interest to local companies, but again, if the PRT company wants to keep complete control, this is less likely to be in the cards.

The design obviously has to be made approvable by structural engineers for anticipated weight and span, but after that any structural steel fab shop can whip the stuff out. Any city has a dozen such firms. Let’s remember that city managers like to “bring home the bacon”. Also, once the track (at least the structural aspect) is free to be outsourced to locals, and city officials can get bids that they believe in, those in charge will be forced to justify the much greater expense of every subsequent road expansion project against the backdrop of this simple, outsourcable alternative. That would seem to be a battle that PRT can win.

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