MDG

10
Jan

2012

Correction: Vail Gondola Most Certainly Not The World’s Fastest Gondola

Last week I discussed the upcoming Vail, Colorado gondola and its promoters’ claims of it being “The World’s Fastest Gondola.” And while I correctly demonstrated how it couldn’t be the fastest gondola, in general, I readily fell for the marketing-speak and accepted without inquiry the idea that at 6 m/s the system could very well be the fastest MDG type gondola in the world.

However, since that post went live I’ve had several individuals inform me that while 6 m/s gondolas aren’t common, they’re not exactly rare either. One ropeway engineer even went out of his way to inform me that he’d build a 6.2 m/s gondola a few years back – though he readily admitted he couldn’t remember where and we’ve been unable to track it down.

To further the embarrassment even more, I stated in that post that the upper limit of an MDG gondola was 5 m/s which is completely and 100% incorrect.

And the evidence that it’s completely and 100% incorrect?

A little website known as The Gondola Project and it’s assertion that the maximum speed of an MDG gondola is 22 km/hr – which coverts into a little bit over 6 m/s. Guess who wrote that post?

Bingo, and I wrote that one about 2 years ago.

So three things to get out of the way here:

Firstly: Please accept my apologies for not taking the time to check my own website to confirm if something a project promotor says is accurate or not. It was hasty and unacceptable.

Secondly:  What’s the deal Vail, Colorado? How are you laying claim to “The World’s Fastest Gondola?”

Thirdly: Very sorry. Again.



Want more? Purchase Cable Car Confidential: The Essential Guide to Cable Cars, Urban Gondolas & Cable Propelled Transit and start learning about the world's fastest growing transportation technologies.

24
Jan

2010

Aerial Technologies, Lesson 2: MDG

Teleférico do Alemão in Rio de Janeiro, Brazil (2011). At 3.5km, with 6 stations, it is one of the world's largest CPT systems. Image by Flickr User minplanpac.

Monocable Detachable Gondolas (MDG) are likely the most common CPT system you’ll encounter as their low cost has made them an attractive addition to public transit systems in the developing world. Systems like the Medellin MetroCable, Telecabine de Constantine and Caracas Metrocable all use MDG technology.

Characterized by a detachable grip which allows for intermediary stations and corner turning, MDG’s utilize a single cable (hence, monocable) for both propulsion and support. This means that the cable that pulls the vehicles is also the cable that supports the vehicle.

MDG Stats:

  • Maximum Speed: 22 km/hr.
  • Maximum Capacity: 3,000 persons per hour per direction.
  • Vehicle Capacity: 4 – 15 persons.
  • Cost: $5 – 20 million (US) / kilometre.

MDG’s suffer from a relatively low capacity (though still comparable to many urban tram routes) and given their single cable are prone to stoppages due to winds in excess of 50 km/hr. MDGs are therefore most useful in calm wind environments with low capacity needs.

As the investment is quite low compared to other technologies, MDGs are excellent “starter” systems for cities intrigued by the technology but question its effectiveness. A short, low-capacity feeder line, for example, would be a fine place for cities to experiment with MDG technology.

The Medellin MetroCable is one of the world's most successful Cable Propelled Transit systems. It utilizes MDG technology.

Proceed to Technologies Module, 3: BDG.

Return to Technologies Module, 1: Introduction

Creative Commons images by Big C Harvey and Felimartinez.



Want more? Purchase Cable Car Confidential: The Essential Guide to Cable Cars, Urban Gondolas & Cable Propelled Transit and start learning about the world's fastest growing transportation technologies.