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Dec 12, 2009
Analysis

Why Cable Propelled Transit Was Chosen In Oakland

Post by admin


Source: Bay Area Rapid Transit

Source: Bay Area Rapid Transit

As I mentioned yesterday, the Bay Area Rapid Transit (BART) agency announced on Thursday that the Oakland Airport Connector would be a Cable Propelled Transit system. This was a major breakthrough by a cable technology as it competed head-to-head with two other self-propelled transit technologies and won.

One of the reasons cited by BART for awarding the contract to the Parsons/Flatiron group was that their bid came in $60 million dollars less than the initial estimate of $552 million. That’s 10.8% below estimates for anyone whose counting. Considering most transit projects are completed significantly over budget, that’s impressive, assuming of course they can stay on budget.

Cost, however, was likely not the only motivating factor. Increasingly, transit agencies are noticing cable for what it is: A simple, cheap and effective method of transit compared to other more traditional technologies. Consider a recent report by the American Society of Civil Engineers in their publication, Automated People Movers, 2009 (you can find a limited preview of it at Google Books).

In it, the authors investigated people mover systems by method of propulsion. What did they find? Lots:

“It is observed that technologies that use external propulsion, for instance by means of
cables, currently offer the best efficiency indicators when compared to other technological solutions for propulsion and power transmission.” Page 245

“The interest for a technology also marked by the use of an off-vehicle propeller system strengthens the potential of simple but smart technologies, hopefully cheaper than that dominated by the market until nowadays.” Page 248

“Three (of the five most efficient systems studied ) are cable-propelled from Doppelmayr, one not specified and one is the (untested) pneumatic Aeromovel. The systems with lower efficiency scores… are based on self-propelled vehicles.” Page 252

“From the seven least efficient systems, under this analysis, six of them are based on rubber-tired self-propelled vehicles and one is not specified.” Page 254

“Technologies based on alternative propulsion methods, for instance by means of cables or pneumatics, represent a strong potential to become benchmarks.” Page 255

Things are changing. Maybe we should pay attention.

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8 Comments

  • Nate says:

    I have to wonder why a suspended gondola wasn’t chosen for this project? The cost per mile would be significantly less expensive transiting this built-up area. The biggest hurdle that I imagine would be getting the cable low enough to cross under the approaches to the north field runways, but that seems like an entirely workable problem to overcome through the use of a minor grade separation (not entirely dissimilar to VTA light rail transitioning past the runway approaches at Moffet Federal Air Station in Mountain View).

    • Steven Dale says:

      Nate,

      I’ve wondered that myself. I think the answer is that the bid was originally for an APM system, which a gondola would not qualify as. The bid actually had two self-propelled APM bidders and two cable-propelled bidders. I’m also not so sure a gondola system would have kept costs significantly lower. From what I know, the APM system itself only comprised a third of the project costs. The rest is to be spent on stations, professional services and contingencies.

  • Nate says:

    Interesting points, and I’d like to know more about the cost breakdowns. Oakland should look at this as an opportunity to market itself, and an unusual and “fun” conveyance could convince some travelers to opt for Oakland over SFO. Looking at the Google Earth topography between BART and the airport, a gondola could offer a peek over the high walls of the Coliseum, beautiful scenery over the MLK Bay waters on the north side of the airport, and a very visual and active and vibrant appearance to the cars below where it crosses the freeway. A gondola could more easily/cheaply connect with a rental car center, which would get even more buses off the road while increasing ridership. Wait times could be counted in seconds with gondola cars are leaving continuously. I’m sure there’s some detractor to gondola technology I’m missing, but I can see a whole lot of benefits to a system such as this.

    • Steven Dale says:

      Nate,

      Its somewhat a moot point. From what Ive heard the decision to go with a cable liner is set and BART has actually found a way to move ahead with the project despite recent legal difficulties and funding challenges.

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