As our last post introduced, elevator systems are carefully designed to include numerous failsafe mechanisms to protect passengers in the event that one or more of the individual components fail.
The braking systems on elevator cars are dramatically different from the ones that we find on motor vehicles. Instead of activating only when a user pushes a pedal, the brakes remain active until the car’s electronic system gives the go ahead to start moving. In other words, elevator brakes are the opposite-they are on by default.
Cars are also equipped with secondary safety brakes. Linked to electronic systems, these brakes can determine if a car is accelerating at unsafe levels, possibly indicating a freefall or engine overload. When this happens, the brakes activate by jamming into the tracks inside the shaft-this does not stop the car immediately but slowly decelerates it at a safe rate.
Despite all of these systems, elevator accidents still occur. For example, in 2011, a rapidly accelerating elevator killed a passenger. The ensuring investigation revealed that mechanical negligence was to blame for the fatal incident. In fact, negligence is to blame for almost every elevator accident, meaning that victims are usually entitled to compensation in premises liability claims.
Source: Washington Post, “Elevator plunges are rare because brakes and cables provide fail-safe protections,” Brian Palmer, June 10, 2013