How Reliable Are Elevators And Escalators
LIFT AND ESCALATOR BREAKDOWN STATISTICS:
Elevators and escalators are very complex machines with a large number of parts and complex electronic components. Despite their complexity, elevators and escalators are reliable pieces of equipment. A well-maintained elevator in commercial or residential environment will typically experience between 0.5 – 2 breakdowns in a year, of which 20% or 0.4 occurrences are mantraps (a person getting stuck inside a lift car). Industrial elevators and service elevators may experience slightly higher breakdown rates between 2-4 per year due to the intensity of usage and heavier loading.
Typical root causes for breakdowns or mantraps are
- badly maintained equipment
- bad equipment design, manufacturing quality and early failure of components
- improper installation
- high intensity of usage
- external causes such as water, fire, vandalism, electrical network failures
If you experience increased number breakdowns or mantraps in your building, it is wise to contact an independent third party such as Elevating Studio to better understand what is causing excessive breakdowns, and to help you to improve the situation.
HOW PROBABLE IS IT TO GET STUCK IN AN ELEVATOR CAR?
An average office elevator makes about 400,000 trips per year. Elevators and escalators in an office building run about 10 hours per day. In offices with 5 working days per week, elevators operate about 260 working days per year, or 2600 hours per year. If you use an elevator 8 times per day in your office and you work 200 days per year, you will take 1600 trips per year. If an installed lift experiences an average of 0.4 mantraps per year, the probability of an entrapment during any single trip is then 0.4/400,000 = 0,01% annually. If you travel 1600 times up and down to your office in a year, your chance of getting trapped in an elevator is thus 0.16%. During a 40 years’ working career, this means roughly a 6% probability of getting into a mantrap in an office elevator. If you happen to live in a high-rise apartment building and use the apartment elevators, your chance of getting trapped may rise to about 12% during 40 years of lift usage.
Although the probability of personally being a trapped in a lift car is very low, most do however know someone who has been in an elevator mantrap.
Anyone who has been trapped in an elevator, will tell you that it is not a pleasant experience.
The elevator car is a small claustrophobic and confined space, where one is cut off from the rest of the world. The sudden unexpected stop or jerk, often associated with a breakdown, makes the experience even more unpleasant – especially when the elevator is traveling in up-direction.
Sudden stop of an elevator car is often caused by the lift system to protect its passengers. There are a lot of safety sensors, limit switches and software functions, to ensure that the passenger will always be safe. In case any of these sensors or switches detect an anomaly in the functioning of the elevator or escalator, the equipment will automatically try to stop the lift car from moving.
In case of a breakdown or mantrap, the elevator company will come to attend to the problem and repair the equipment. In case of a mantrap, the elevator technician will first try to move the elevator to the nearest floor and open the door. Climbing out the lift car is not desirable and must be avoided when possible.
As the average load of an elevator over a day is about 15% of its designed maximum load capacity, chances are that the number of trapped persons inside the elevator is relatively small. There’s a greater chance of being trapped in an empty car than in a fully loaded elevator cabin.