WARNING: This is Version 1 of my old archive, so Photos will NOT work and many links will NOT work. But you can find articles by searching on the Titles. There is a lot of information in this archive. Use the SEARCH BAR at the top right. Prior to December 2012; I was a pro-Christian type of Conservative. I was unaware of the mass of Jewish lies in history, especially the lies regarding WW2 and Hitler. So in here you will find pro-Jewish and pro-Israel material. I was definitely WRONG about the Boeremag and Janusz Walus. They were for real.
Original Post Date: 2008-02-03 Time: 00:00:00 Posted By: Jan
[I was curious to know what safety features actually exist in lifts. Given these power failures in South Africa and which are a daily feature of life in Zimbabwe, Nigeria and other black African countries I wondered why I’ve never heard of a lift plunging and people being killed when the power cuts out.
Strangely, there isn’t too much mention of anti-power failure features. It mentions it in passing but with little that is definite.
In the building I work in the lifts seem to descend to the ground floor and open their doors when there is a power outage. I’ve not been able to find anyone who was in a lift at the time when the power cut out to find out what happened.
There is an interesting safety feature that prevents a lift from moving while its doors are open.
I’ve only been stuck in a lift once. That was a few months ago. I was stuck in a lift for an hour in the parking garage where I park. The lifts there are NOTORIOUS! It is in one of many buildings in Johannesburg run by “Kings Parking”. They run most of the parkades in Johannesburg and I will tell you that the experience of our company with them is completely SUCKING!
We’ve complained so many times about their lifts to little effect. The lifts are totally notorious and many of my co-workers have been stuck in them. A few years back one of our workers was in a lift that fell 2 floors before coming to a halt. I was stuck for an hour when the lift stopped between the 7th and 8th floors. The staff were so useless that ringing the emergency alarm was worthless. Nobody tells you anything. I eventually used my cell phone to phone my co-workers in the office to ask them to take action. I even had to phone the black guy who had to drive to come and open the lift so I could get out. I was caught in it at 6pm in the evening and wanted to avoid being stuck there all nightlong.
Just 3 weeks earlier I heard the lift alarm ringing like crazy. I walked up the floors and found an Afrikaans lawyer stuck in the lift between 2 floors. He managed to slip me a note through the doors with his cell phone on. I still went and asked the Kings Park staff what they had done and suggested to them that they should tell this man, who’d been stuck in the lift for 45 minutes, that they were actually DOING SOMETHING!! The lawyer was raving mad and threatened to sue their backsides off the next day. I doubt he’d do it.
Anyhow, the following makes for interesting reading. But I think the lifts in Johannesburg city centre are not quite as safe as those described below. Even so, nobody has died yet – that we know of. Jan]
Elevator Safety Features
Today’s elevator systems incorporate a wide variety of features designed to help reduce the chances of accidents and give passengers a quick, dependable ride.
There are two basic types of elevator systems, “Traction” and “Hydraulic.” Because they differ in the way they operate, some of their safety systems differ as well.
Traction Elevators
Most elevators which travel six or more floors are “traction” design. Traction elevators are suspended by strong steel cables propelled by a hoisting machine. Counterweights help balance the load and make it easier for the machine to move the elevator. The steel cables are very strong, and can safely hold several times the weight of the elevator and its full load of passengers.
The safety brake, together with a speed-sensing governor, acts to stop an elevator if it should overspeed in the down direction. If an elevator overspeeds, the governor makes the safety grasp the rails on which the car travels, bringing the elevator to a safe emergency stop.
The door system on a modern elevator also includes several safety devices. Sensors detect passengers or objects in the door opening, preventing the continued closing of the doors. Older systems use mechanical “safety edges” which cause the doors to stop or retract when they make contact with a person or object. More modern systems use a large number of invisible light rays to detect people or objects in the doorway and reverse or stop the doors without having to make physical contact.
Door operators contain devices which limit the amount of closing force. Newer systems are better able to keep the closing force consistent even under unusual conditions such as the “stack effect” which can cause heavy air movement in elevator shafts.
Interlocks on the hoistway doors help assure that the elevator cannot leave a landing unless the doors are fully closed and secured. Should the doors be forced open, the interlock circuit will be broken, causing the elevator to immediately stop.
Various switches in the elevator shaft detect the presence of the car at certain stages of its journey. They initiate slowdowns and stops at the proper points, and help prevent overtravel in the up or down direction.
To discourage the very dangerous practice of passengers trying to open the door of a stalled elevator, door restraints can allow normal operation of the door when the car is near the floor level, but will restrict forcible movement of the door when the car is away from the floor.
The emergency evacuation hatch on most elevators is designed to be opened only from the outside, by trained emergency personnel. This too is intended to help prevent any passenger from gaining access to the dangerous elevator shaftway.
Buffers, located in the “pit” below the car, serve to cushion any unplanned travel below the lowest landing.
In the elevator cab you’ll find several items to help increase safety. An emergency alarm switch will sound an alarm when activated by a passenger. In most elevators, an emergency telephone or intercom can serve as a link to assistance if the car should stall. And, in the event of a power failure, emergency lighting maintains illumination for hours. In some systems, emergency power is available to permit movement of the elevator and evacuation of the passengers.
In many elevator systems, a special fire emergency system has been installed. It may be manually activated, or may respond to smoke sensors in the building. Exact operation varies by local codes, but generally such systems return the elevator to the main floor, open the doors to allow passengers to exit, and make the elevators available to emergency personnel.
Hydraulic Elevators
Hydraulic elevators are propelled by a jack mounted below the elevator. A pump moves hydraulic oil into the jack, causing it to raise the elevator. For the down trip, valves control the oil’s to return to the system’s storage tank, safely lowering the elevator car.
Because of their bottom-supported design, hydraulic elevators do not utilize the type of safety brake found on traction elevators. However, for installations with older jack designs, Schindler has developed the LifeJacket(174)® safety brake that can be added to existing elevators, offering an increased factor of safety in the remote chance of corrosion causing the rupture of the underground jack casing or piping.
Other systems on hydraulic elevators are essentially identical to those on traction systems, and have similar safety features.