Historical Significance
The VH 400 cable clamp marked a major milestone in ropeway construction during the 1980s. It was developed by two Swiss companies, Von Roll and Habegger – the initials “VH” stand for Von Roll-Habegger. It was first used in the mid-1980s, for example in 1984 in Schönried, Switzerland, on a chairlift. This clamp was specially designed for detachable systems, such as modern gondolas and chairlifts. In 1987, the VH 400 was even installed in Anzère (Valais), on what was then the fastest chairlift in the world, reaching a speed of 18 km/h (about 11 mph).
The VH 400 was historically important because it helped usher in the era of detachable ropeway technology. Thanks to this clamp, chairs or cabins could be detached from the main haul rope at stations, allowing them to slow down – a major improvement in passenger comfort and safety. Riders no longer had to jump into fast-moving vehicles; instead, they could board and exit at low speeds. At the same time, the ropeway could travel much faster along the route, significantly increasing its transport capacity. The VH 400 was a key factor in the boom of modern high-speed lifts during the 1980s. Even today, the detachable clamp remains at the heart of most modern ropeways and is essential for their performance and safety.
Technical Function
The VH 400 clamp is a large, robust mechanical grip that firmly attaches a cabin or chair to the moving rope. It bears the full weight of the vehicle and its passengers, and must remain absolutely secure even at high speeds and in changing weather. The VH 400 is a detachable clamp, meaning it can be automatically released from the rope in stations and then reattached afterward.
During normal operation, the clamp grips the rope with great force – often more than 600 kg of pressure – to prevent any slippage. When the cabin or chair enters a station, special mechanisms (like rails and rollers) automatically open the clamp in a controlled way. Once released from the haul rope, the vehicle is moved slowly through the station by a low-speed system (usually tires or a conveyor chain), allowing passengers to board and disembark safely, at just 0.5 to 0.8 m/s (roughly 2–3 km/h or 1–2 mph).
Afterward, the clamp is closed again and firmly regrips the rope, so the cabin or chair is once more pulled by the main cable – this time at full line speed (often 15 to 30 km/h, or about 10–20 mph). This process of detaching, slowing, and reattaching happens almost invisibly to passengers and makes for a smooth ride.
In summary, the VH 400 clamp ensures a secure connection between the rope and the vehicle, while allowing it to temporarily detach in stations for safer boarding. It is one of the most crucial components of any modern detachable ropeway system.