Tree with dragon's blood. Dragon tree - a mysterious plant of the tropics
Everything shook with such force that it seemed like the ceiling was falling...
As a child, I was terribly afraid of elevators. Because didn't know what to do when it started to fall. We lived in a private house, so elevators were a novelty. I visited the 6-story elevators several times, but the 12-story elevator was already beyond the bounds. When the lights went out and he stopped, my state is difficult to describe. “That’s it,” I thought.
What to do when the elevator is rapidly falling down with you? When landing, should you jump, bend your legs, or lie on the floor?
According to statistics, it is safe to use an elevator if you comply with all safety requirements, including avoiding any attempts to get out of the cabin.
The main victims are mechanics during elevator repairs and people who fall accidentally, intentionally, or get caught in the elevator doors.
Today, for the safety of people, all kinds of devices are installed in elevators.
Hydraulic lifts
The lift moves as a result of the operation of a fluid-controlled piston. As a rule, the mechanism does not have security configuration functions. Elevators that are custom built and have additional brakes can be customized.
Their mechanisms practically do not fail, but a fall can lead to a real disaster. By the way, buildings are equipped with hydraulic elevators maximum height on 6 floors. But even a fall from 20-30 m at a final speed of about 75 km/h is life-threatening.
Freight and passenger elevators
These mechanisms include steel cables, pulleys, counterweights and speed controllers. In case of very quick descent In the cabin, the control valve immediately reacts to activate the guide rail braking mechanism.
The shafts of such elevators are equipped with switches to fix any increase speed limit safe movement and stopping it on the desired floor or if necessary. In addition, each cable individually can independently hold the cabin with passengers.
In films created by Hollywood directors, the passenger jumps before the cabin hits the ground to reduce the acceleration of his body.
Even with instant reactions and Olympic medals as a high jumper, maximum reduction the fall speed will be 3-5 km/h. Most likely, after a jump, a person will collide his head with the ceiling of the cabin, and then, due to an unsuccessful landing, receive serious injuries.
Another technique that is not very effective is to bend your knees, as if you were landing with a parachute. In fact, the main impact will be on the legs and knees, which can lead to bone fractures.
According to research results, in order to maximize the chances of remaining intact in a falling cabin, you need to lie with your back on the floor and cover your face with your hands from flying debris.
Then the impact load is distributed throughout the human body, and the parallel directed spine with large bones and the impact minimize the risk of their fracture. He stays high probability serious rib injury.
Disadvantages of this method:
1. When colliding with the ground at a speed of 75 km/h, serious bruises of soft tissues, especially the brain, are inevitable.
2. Exists big risk splitting the cabin from a strong impact, from which the floor will split into numerous sharp fragments.
An example is Betty Lou Oliver, who in 1945 was in an elevator falling from the 80th floor inside the famous 103-story Empire State Building. The girl survived. If the woman had taken our advice, she would have been fatally struck by the sharp edges of the cabin debris. The salvation was the cable wound on the floor of the elevator shaft, which softened the fall. But if she took the “lying” position, she most likely could have died. This case is one of the Guinness records.
3. A person finds himself in weightlessness for some moments due to the relativity of free acceleration downward inside the shaft and cabin. In a weightless state, it is not easy for a passenger, especially an untrained one, to lie down on the floor and somehow maintain this position.
However, taking into account all of the above, those who can take the “lying on their back” position have a greater chance of survival and significantly reduce the risk of injury.
I think and want to hope that you will not become participants in similar cases when you need to apply such advice. Anyway, we repeat again - lie on your back and cover your face with your hands.
How to survive a falling elevator? April 18th, 2016
I’m reading today about another tragedy, an elevator in Penza fell with a woman and a child. Recently an elevator with a child in it fell in Moscow, then with a famous presenter, then somewhere else. Over the past six months, the elevator has fallen four or five times (from what I heard in the media). It will soon become scary for you to ride in elevators.
I don't understand how this can be. After all, a long time ago the most reliable MECHANICAL elevator brake was invented. In addition to various electronic brakes, limiters and automation, all elevators are said to have a mechanical and simplest system.
Here's how it works...
The Otis catcher was a flat spring mounted on the roof of the elevator. The tension of the cable bent the spring, and the elevator calmly rose or fell. If the cable broke, the spring straightened and rested its ends against the guides, blocking the elevator.
Elevator brake: yesterday and today Yesterday: in the normal position the spring is tensioned (1), if the cables break, it becomes a spacer and brakes the elevator (2). Today: in the normal position, the catcher cable is rigidly connected to the cabin (3); when it falls, the cable is blocked and pulls out the wedge-shaped shoe of the catcher (4)
The safety of passengers in a typical modern lift is ensured by approximately 30 electronic and 5 mechanical devices. The most important are automatic catchers. They are still mechanical, although they are designed slightly differently than Otis's original invention. Modern catchers are controlled by a separate cable and a speed limiter pulley. When the vertical speed of the elevator is exceeded, the centrifugal speed limiter stops the pulley and, accordingly, the cable rigidly connected to the cabin also stops. With further movement (including falling) of the elevator, the stopped speed limiter cable “pulls out” the wedge-shaped shoes of the safety device installed on the cabin, braking the elevator to a complete stop. This is somewhat similar to the principle of operation of car seat belts.
Controlling the catchers using a separate cable makes it possible not only to stop the elevator in the event of a break in the traction ropes, but also if the engine control system fails due to, for example, overload.
In addition, on the cabin itself there are catchers - similar to clothespins iron devices, which, if necessary, sharply clamp the cable, stopping the movement of the cabin. So even if all three cables break at once, the elevator will not fall, but will simply stop in the shaft.
Here's how you can "fix" the maintenance or assembly of an elevator so that it collapses down and nothing happens. defense mechanisms wouldn't it work? I also understand the tragedies when, due to the fault of electronics, the cabin starts moving at the wrong time or the doors open when there is no cabin. But in all the cases I listed at the beginning of the post, the cabin simply fell in the elevator shaft. How?
Everything should have been like this:
But the brakes worked properly!
Let's say you find yourself in a free-falling elevator car.
What to do?
According to the creators of Hollywood blockbusters, the most correct thing in such cases is to jump up just before hitting the ground to reduce the speed of your body.
But even if you have a fantastic reaction and won an Olympic medal in high jump, the maximum that can be achieved with this technique is that the speed of your fall will decrease by 3-5 km/h. Most likely, the person who jumps will hit his head on the ceiling of the cabin, and then, landing unsuccessfully, will be seriously injured.
Others suggest standing with bent knees, which must take on the main force of the impact - this is exactly what parachutists do when landing.
Theoretically, once the elevator car reaches the ground, your legs will automatically bend and your body movement will slow down somewhat. However, on high speeds This technique is unlikely to be effective.
Experiments show that with this approach, your knees and legs will take the brunt of the impact, which can lead to broken bones.
What to do?
The researchers concluded that to maximize your chances of surviving an elevator free fall, you should lie on your back on the floor of the car and protect your face from falling debris with your hands.
In this case, the impact force will be more or less distributed throughout the body, and the spine and large bones will be located parallel to the direction of impact, which means they are unlikely to break. The ribs are still at significant risk to be reckoned with.
However, even in this situation, the following problems arise:
1. The main impact will be taken from the cabin floor soft fabrics, in particular, the brain. Imagine colliding with a car at 70 km/h and you'll understand the bruises you'll have to deal with.
2. There is a high probability that if you fall, the elevator car will split, and the floor on which you are lying will turn into a pile of sharp fragments.
One can recall, for example, Betty Lou Oliver, who survived the fall of an elevator in the Empire State Building in 1945. This achievement, by the way, is noted in the Guinness Book of Records. If she had followed our advice, the sharp fragments from the broken elevator car would probably have pierced her right through. She owes her life to the coils of cable at the base of the elevator shaft, which softened her fall. If she had laid down on the floor, she would almost certainly have died.
3. It should be taken into account that you are in free fall not only relative to the elevator shaft, but also relative to the falling cabin itself, i.e. you are in a state of weightlessness for a matter of seconds.
In such a state, it is very difficult to manage to lie down on the floor and somehow stay on it, especially for an untrained person.
But even taking into account the above factors, it is argued that those who still manage to lie on their backs will have the best chances of survival. Also the probability of getting dangerous injuries will decrease greatly.
By the way, I read the forum of specialists in launching and setting up elevators -