With most traditional transit technologies, there is little consideration about the variations within that technology. A bus is a bus; a streetcar is a streetcar; and a subway is a subway. Sure, there’s variation between suppliers and models, but those differences are negligible compared to the overall technologies themselves.
That’s one of the real competitive advantages traditional transit technologies possess over cable: Understanding them is simple, and that makes them highly attractive to time-constrained planners, policy-makers and politicians.
Cable is not so simple. While the basic concept behind all the modes remains the same (a vehicle propelled by a moving cable), the variations between the modes tend to cause confusion. Beyond the 4 major families of Cable-Propelled Transit (Gondola, Aerial Tram, Funicular, Cable Car), there exists a wide range of cable transit modes, each with its own advantages and disadvantages.
The key to cable is understanding the strengths and weaknesses of each respective mode and then matching the right mode to the right environment. It’s kind of like pairing wine with food: You’ve got to know the subtleties to do it right.
Over the coming months, I’ll describe these modes and give appropriate examples (probably one per week). But to begin with, let’s just get an idea of how many different modes there are:
- Monocable Detachable Gondola (MDG)
- Bicable Detachable Gondola (BDG)
- Funitel
- Pulsed Gondola
- 3S
- Funicular
- Traditional Funicular
- Cincinnati Funicular
- Hybrid Funicular
- Aerial Tram
- Funifor
- Cable Car
- MiniMetro
- Cable Liner
- Cable LIner Shuttle
There are other modes, too, but these are the major ones. Like I said; it’s just not as easy as “a bus is a bus.”
12 Comments
This may be kind of a dumb question, but wouldn’t the system be far more flexible if the cars were ‘moving’ instead of the cable? Every major turn currently requires a fairly large amount of infrastructure, correct? However, if the car was the only thing moving, wouldn’t these turns require simply a bend in the cable?
Andrew,
The only dumb questions are the ones nobody asks . . . You are correct about requiring infrastructure to turn. You could actually have on board engines in vehicles so that they were moving and not the cable. Systems such as these were actually developed in the mid 20th century, but none of them ever really took off.
Basically it’s a question of trade-offs: If you had on-board engines in the vehicles, yes turning stations would be smaller. But vehicles would be heavier which would mean towers would be larger and more expensive. Vehicles would also be more expensive and Operations and Maintenance costs would go through the roof.
The current thinking is to make sure turning stations are integrated with actual stations for boarders and alighters. In this way, the cost of turning becomes marginal.
That’s not to say that self-propelled cars wouldn’t work. It’s to say that based on current thinking (which could always change) systems such as currently exist provide many operational and economic efficiencies.
Thanks for the post Steven. My line of thinking with this was that if gondolas were to be run in-median, that a lot of roadways are not exactly straight. Heck, most hydro ROWs are not even perfectly straight lines. If the alignment chosen for the gondola is not very straight, the cost of building the infrastructure for the turning locations may make it far less economical than if it was a straight line.
Andrew,
You are right about that. But the question is: how extreme is the angle? Most gondola systems can withstand on-tower turns of roughly 2 degrees. As long as the turn was a gradual one, then it doesn’t need to be in a perfectly straight alignment. Sharp turns would, however, require a turning station ideally integrated with a standard station.
Steven,
I have read some of your research project and got to tell you, everything is great, but I would like yo know if you have post some aerial technologies history though, because I have been searching and I dont find anything…Anyway Thanks for your help and once again congratulations.
Andrew,
I can definitely do a history post (or a few) sometime in the future. The history is actually quite interesting and dates back to the BC era. Thanks for your interest and support!
Thanks for the post Steven. My line of thinking with this was that if gondolas were to be run in-median, that a lot of roadways are not exactly straight. Heck, most hydro ROWs are not even perfectly straight lines. If the alignment chosen for the gondola is not very straight, the cost of building the infrastructure for the turning locations may make it far less economical than if it was a straight line.
+1
Gondola systems can navigate turns up to two degrees on tower. Anything beyond that would require an angle station or intermediary station. Even using such stations, the cost is still far more economical than other standard transit technologies.
Hello i was wondering if there is a post here on the engine/ electric motor that propells the cables for aerial lifts? If there arent, is there a link or could you post something regarding the specifications of the motors that are currently being used? Thank you =)
Hi Joshua,
We don’t actually have/post that info for a few reasons:
1. Getting into that kind of minutiae can alienate more generalist readers.
2. It’s going to be highly dependent upon manufacturer, location and system configuration.
3. Possible security concerns.
Nevertheless, feel free to throw the question out in our forums. The forums may be small, but there’s a group of dedicated engineers who hang out there and they might be able to help you out a bit more.