Return to List

Dec 20, 2009

Grip Module, Lesson 2: Detachable Grips

Post by admin

Detachable Grip

It’s important to recognize that the term used to describe a Detachable Grip is detachable not attachable. Detachable grips are attached to a cable with heavy, industrial springs providing the pressure necessary to create the grip’s vice-like hold. Until a constant, targeted, external and specially-designed force is applied to pry open the grip, the grip’s hold is (for all intents and purposes) permanent. The above image should give you a better idea of the mechanism.

So who cares, right? Why would anyone want to detach from the cable?

For a cable transit line to have intermediary stations, vehicles must be able to stop at those stations. But to stop a vehicle means the cable must also stop, which in turn means that every other vehicle attached to the cable must stop as well. This was a problem back in 1872 for an Austrian fellow named Orbach and he solved the matter by patenting and inventing what would be the world’s first detachable grip:

Image from Orbach's original patent.

Detachable grips allow a cable vehicle to stop at a station without stopping the flow of the entire line. Upon approaching a stop, a mechanism located at the station opens the grip and the vehicle is slowed by another mechanism. Passengers get on and off, the vehicle is re-accelerated to line speed, and while departing the grip is re-engaged. This process is incredibly fluid, seamless and is virtually invisible to riders.

Basically, without the detachable grip, intermediary stations and corner-turning would be impossible, at least for aerial supported cable systems. And as urban transit needs many stops and turns many corners, detachable is almost always the way to go.

Proceed to Grip Module, Lesson 3: Attachable Grips

Return to Grip Module, Lesson 1: Introducing Grips

Creative Commons image available here.



You may also like