bdg / Bicable Detachable Gondola

Ngong Ping Cable Car - CC Image by Flickr user plynoi

Bicable Detachable Gondolas (BDG) are rarely seen or built anymore. Originally they had superior wind stability and could reach higher speeds than their single cable MDG counterparts, and without the cost or complexity of the 3S systems. Today, with advancements in MDG and 3S technology, BDG systems have become overall redundant –even the wind speed capabilities, as compared to the MDG, are nearly identical.

The BDG still has a slight speed advantage over the MDG but this minimal benefit is generally offset by the addition cost and complexity incurred by the second cable.

Major Characteristics:

Grip: The BDG uses a detachable grip. This means cabins can detach from the cable when in the station allowing for intermediary stations and turning (at stations).

Cables: A BDG has two cables, one which provides support and a second which provides the system’s propulsion.

Speed: Systems can travel at about 7 or 7.5 m/s, which is equal to 25-27 km/h.

Capacity: Generally cabins hold 8 passengers with a maximum of 17 people.

Towers: BDG systems are generally supported by cylindrical towers.

Cost: Although cost is very dependent on location, situation, and customization, generally the cost for an BDG is between $15-25 million (US) / km, slightly higher than an MDG system.


The Singapore Cable Car was first constructed as a BDG system, but when it underwent a complete overhaul in 2009, it was changed to an MDG system. (CC image by Flickr user DerekL)


Several BDG system pages:

This is outdated, but if you’d like to see the original BDG post, click here.