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Mar 13, 2010
Media & Blogs

The Mark News & Cable Propelled Transit

Post by admin

We interrupt our regularly-scheduled Medellin/Caracas Photo Essay with this shameless bit of self-promotion:

The Mark News recently posted an interview segment on Cable Propelled Transit with myself and Dr. Eric Miller of the University of Toronto Cities Centre. Here it is:

The Mark also posted a related op-ed piece I wrote on the matter. Read the article: Take the Gondola to Work. Big thanks to Terese Saplys and Tony Ferguson for involving me in The Mark. It’s a great news publication. Unlike most other web-news sites, The Mark isn’t just another aggregator, it privileges new and original content. Please take the time to look them up.

The Medellin/Caracas Photo Essay will return tomorrow.

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9 Comments

  • Eric L says:

    Interesting site. I have a lot of questions about it, particular aerial trams/gondolas, as they could be a particularly interesting technology for Seattle with its hills and bodies of water.

    1) So just how much do they cost? Comparing to “light rail or street car” is unhelpful as light rail varies widely in cost depending on ROW type and streetcars are even cheaper (about $30 million/mile, dual track, if I remember correctly).

    2) You say they’re fast — but aerial technologies top out at 24 km/h or 15 mph. If there are stops, the average will be lower. That’s not something I’d consider fast. Our light rail system averages about 30mph. This is fast enough to provide a good alternative to all the places we’re looking at building streetcars, but not for longer routes e.g. crossing Lake Washington, which would be a more interesting use. Are there ways to make them faster, other than the expense of putting them on rails? Have you looked into this technology at all?

    I guess that’s enough questions for now. Hope to hear more!

    • Steven Dale says:

      Eric,

      1) Like any transit technology, aerial cable transit systems vary widely as well. I’ve seen systems installed for $5M per kilometre up to $55M per kilometre. The reason I make the comparison to Light Rail/Streetcar is that to obtain the general level of service in a given location, the cost will almost always be a fraction of the cost, somewhere in the range of 30-60%. I’m familiar with Seattle’s light rail situation, and as I’m aware, that system cost roughly $120M per kilometre. At the absolute highest end of aerial cable transit, you’d be looking at a price roughly half.

      2) Firstly, aerial cable systems top out at around 35 km/hr, not 24. When you say that your light rail systems average about 30mph, I’m not sure if you’re talking about Seattle specifically. The American Public Transit Association 2010 Factbook shows light rail/streetcar to average roughly 24 km/hr across North America, making cable very competitive. You should also factor in lack of delays, reliability and availability as well. These all contribute to an increased level of service.

      As I understand the Seattle situation, much of the system runs underground with long station spacing. In such a configuration, the light rail in Seattle is for all intents and purposes more of a metro line, not a light rail line. I would likely not recommend cable in that specific situation. At the same time, if I’m remembering correctly, the Seattle LRT offers a fairly low capacity, something cable can match.

      My personal desire would be to see a network of aerial cable systems linking the various islands in Puget Sound. Considering Washington State recently considered spending $6 BILLION dollars on replacing their ferry system, new cable technology could be used to ferry both people and their vehicles throughout Puget. This could be done schedule-free at a cost remarkably cheaper than ferries.

      Thanks for the questions!

  • Eric L says:

    1) Okay, so $8 to $88 million/mile, quite competetive with streetcar and cheaper than light rail. I’m assuming we’d be something toward the high end of that for better speeds, routing complications, better availability on windy days.

    2) I got the 24 km/hr number from your site, here, but I’ll take your word for it. So 20 mph is what PRT systems usually claim and with few enough stops or some PRT-like setup with off-line stations, should be quite useful for a lot of circumstances.

    Yes I was referring to Seattle’s light rail specifically. It’s set up to be a regional system. If you run the numbers for the initial segment, it’s a little under 30 mph, but expected travel times for the second phase are a pretty consistent 30. And I wish it were faster.

    Replacing the Bremerton ferry would be an interesting use. That ferry takes 1 hour to go 10 miles. There was once (when there was funding) a passenger-only ferry serving the same route in 30 or 40 minutes. I’d assume the gondola version would take a 15 mile route to have shorter water crossings and to replace as many ferries as possible. But however you route it, you’re going to go through some rural areas that probably won’t want to become full of condos overnight (and that includes places that currently have ferries to Seattle). And there’s going to be a 2 mile span over the Puget Sound somewhere, which I’d assume is fairly expensive. So, great for Bremerton, who knows what Vashon and Southworth will think. A route could also serve West Seattle — there is talk of putting a light rail extension to there on the ballot in the next year or two — but for West Seattle, I don’t know if it’s fast enough. That area is currently served by express buses that take a highway straight downtown. Assuming the gondola can take a diagonal route that goes downtown faster, it’s still likely to be slower than bus or the hypothetical rail line, though it could be more regular.

    The use I was thinking of (and a much less ambitious place to start) is an alternative to the First Hill streetcar currently being planned — it would be so much easier and faster to go straight up the hill and over the freeway, which wouldn’t be too challenging with a gondola. The challenging part would be navigating the urban environment, building stations, and convincing people they want these hanging over the street and in front of their apartment windows.

    So wait, you say cables could move cars over the water too? Has that sort of thing been done before?

    • Steven Dale says:

      Eric,

      1) The thing about the absolute high end of the cost spectrum is this: I’ve included the Portland Aerial Tram in those estimates. That system, suffered from extreme cost-overruns (like 300%) uses a fairly outdated technology. Were you to remove the PAT from the equation, you’d see numbers in the range of $5 million – $40 million per kilometre.

      2) Regarding max speed: I’ve yet to speak about Funitels, 3S and Aerial Tram systems in great detail. Those technologies have max speeds around 35 km/hr. Forgive me, The Gondola Project’s only been up and running for four months now and I haven’t had a chance to deal with everything yet.

      You’re totally right about the urban environment being the challenging part. You DO NOT want to dangle these things in front of people’s windows or over their backyards. Every city’s unique and never having been to Seattle, I don’t know the what a proper configuration/alignment would look like.

      As for moving cars over water with cable . . . Cable right now is an an adolescent phase where a whole bunch of different things have been done with it. You have to visualize mash-ups and remixes of what’s previously been done. It’s just variations on a theme. So take the Vinpearl Island system then slam it into the Volskwagen Funitel and what you realize is you design a system capable of ferrying cars and people throughout Seattle’s Puget Sound.

      I’d encourage you to use your imagination with cable. That’s one of the sheer beauties of the technology. You can practically do anything you can imagine.

  • Eric L says:

    Very cool. That said it will be a little more challenging to build here, the sound is too deep to put towers in the middle of it. Any of the major ferry crossings would require spans comparable to the Peak2Peak span or longer. And if you were moving cars, I’d imagine you would want to limit the number of cars suspended on that span at any one time, which would limit the capacity of the system.

    Fitting in with the urban environment is a problem with any elevated transit, and to be useful it will need to go on some high density residential, not particularly wide streets. That said, much of West Seattle was recently excited about building a monorail on said streets before that ran into financial issues, so it may be possible to convince people they want this to be a part of their neighborhood.

    • Steven Dale says:

      I think the way a Sound cable ferry system would work is to have a central platform in the centre of the Sound (say like a very small oil platform). This platform would work as a distributor hub bringing people from the various islands to a central point and allowing them to transfer to whatever outbound direction they like. In this way you’d avoid the super long spans required of something like the Peak 2 Peak.

      Again, it would be a super-ambitious project. Pie in the sky? Quite possible. But how “realistic” is a plan to spend $6 Billion on new ferries? I think other options should be explored. By spending just $1 million of the proposed $6 Billion (0.02% of the total proposed project) to explore whether or not this is feasible could conceivably save additional billions. North American governments have to start acknowledging that we don’t have hoards of cash to spend. We need new alternatives.

      As for capacity, you have to consider how many cars per hour a ferry can currently carry. What is the PPHPD? Ferries are slow and unreliable with constantly changing schedules. Cable could avoid that.

  • Eric L says:

    A central hub would make no sense for the Seattle area crossings. It might make sense for the San Juan islands, though you’d probably just want the hub to be on one of the islands rather than on a floating platform. I don’t really know the relative costs of the ferry system for the various regions. I’m really not sure what the platform gets you — you still need a support near it, in the middle of the sound, where such things aren’t built. I think a two mile span is unavoidable here, and that may not make the idea infeasible.

    For capacity, the largest Seattle ferry carries 3,000 people during rush hour, once an hour, only 200 with cars. For the San Juan Islands, the boats can hold 140 cars, run once every 2 hours, and probably don’t carry that many walk-ons. But if you replaced these with a faster, more frequent system, demand would go up considerably. At least in Seattle I think we should stick to passenger-only because otherwise we’ll be widening a lot of roads to handle the traffic.

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