3S / Tricable Detachable Gondola

Koblenz Rheinseilbahn – Image by Steven Dale

The 3S is a fast, modern gondola technology. The term 3S derives from the phrases drei Seile or drei Seil in German which translate directly to three ropes or three rope in English because cabins run along 3 cables. Two of the cables provide support while the third is for propulsion. Similar to an MDG or BDG, detachable grip cabins run in a continuous loop. The extra cables (as opposed to the MDG or BDG) allow for increased wind stabilization and additional capacity (because more cables can support more weight, aka more riders.)

Major Characteristics:

Grip: Similar to an MDG or BDG gondola, the 3S cabins have detachable grips. This means cabins can detach from the cable when in the station allowing for intermediary stations and turning (at stations).

Cables: The 3S has three cables — two for support and one for propulsion.

Speed: At least 7.5 m/s, which is equal to 27 km/h. Technological advances now allow speeds up to 8.5 m/s. 

Capacity: Cabins are large, holding around 35 passengers each. This amounts to around 6,000-8,000 people per hour per direction. As the technology’s speed capabilities increase, so will the capacities.

Towers: 3S systems are supported by large lattice towers.

Cost: Although cost is very dependent on location, situation, and customization, generally the cost for a 3S is between $10-24 million (US) / km, the highest for all gondola technologies.
Note: Cost estimates given are for informational purposes only. Actual costs can vary dramatically for individual systems.


The Peak 2 Peak in Whistler, Canada was one of the first and most high profile 3S systems ever built. It currently holds the world record for longest unsupported span at 3 km between towers. CC image by Flickr user clickflashphotos

3S and Cities:
3S systems are ideal for cities — they are high speed, high capacity systems that are elevated and therefore have a small footprint.

The interior of the urban concept vehicle.

Built in 2010, the Rheinseilbahn 3S system in Koblenz, Germany was the first to showcase the “urban concept” design, a cabin that is made to look and feel like public transit. Some of the features include bucket seats (not benches), bike racks, video displays, and the kind of bars you hold on to when riding a crowded bus.

This type of customization and design can be adapted to other types of cable transit, but is important as it demonstrates both the viability of cable in cities as well as the interest in catering it to the urban market.


The Gondola Project has profiles on several 3S systems, including:

If you’re looking for the original post on 3S technology, you can find it here.