We have a residential building elevator crashed in the pit, it dropped from the 1st floor, it was coming from the 6th floor and should have been stopped in the 1st floor, but it crashed with the absorber,(it was overloading with people)......people inside the car are telling different story, some say it dropped directly from the 6th floor to the pit, others say it stopped in the 1st floor then dropped from the 1st floor to the pit, what are the probabilities for both cases?
It will happen with counter weighted traction elevators that are lightly loaded at the top floor causing the car to drift into the overhead and counter weighted overloaded traction elevators at the bottom floor causing the car to drift into the buffers.
George Gibson has a DVD available from elevator world book store that describes in great detail about the physics and math about this.
The building owner is to blame here because it is their building. As building owners and managers move to the "cheaper is better" paradigm, it causes them to neglect principals that are known and have been known for many years. (Thank you Sir Issac Newton Jr.) It's making a tidy little niche market for under employed attorneys to shake down the building owners and their insurance providers for such ignorance. For some reason the people who overloaded the lift are seen as exempt from the part they played by obviously overloading the elevator.
It is most likely that the lift failed to stop and continued to drift to the pit from the terminal floor. It would most likely have been traveling at rated speed or less when broke traction and struck the buffers. In some extreme cases, it could happen when the load is put on the lift.
Hollister Whitney has a great product that can mitigate such incidents. It's called the rope gripper and prevents unintended movement of the car.
Will the owner put one in after the horse has left the barn? Please keep us posted.
Respectfully Submitted.
What is almost a cetainty, is that it DID NOT "drop" from the 6th floor, in a true freefall, as the public is so very fond of imagining. There is no way for the passengers to know exactly what the elevator did, without having the advantage of visual refrence. When you are "blind" inside a box, the theater of the mind conjures up the most fantastic scenarios, compounded by the fear of the unknown. The pit of one's stomach is not an arbiter of velocity, nor direction of travel. For example, a change in velocity in a given direction, is often reported as a change in direction, when that in fact is not the case. The Star Tours ride at Universal Studios doesn't move more than a few feet, but you'd swear your Tie Fighter was swooping down through chasms hundreds of feet deep in the Death Star. In the same manner, the publics' reporting of elevator motion is notoriously innacurate, especially with those who have a predisposition for being emotional.
In this case, if it had actually fallen without restriction, it would have most likely had structural damage, and serious injurys. (The buffer is not designed to dissipate impact from "terminal" velocity, but rather, closer to contract speed velocity) It is very likely that the lift slowed down for the bottom floor in the normal manner, then after stopping, (upon the normal removal of torque from the motor that was slowing it down), either slipped through the brake, (or broke traction), then slid into the buffer. Of course, there are other possibilities, but no evidence demands no verdict.
As has been said, in any case, the fact of the elevator being overloaded precipitated the event.
The replies given by all these professionals were excellent answers to your question. Sounds like you need a reputable elevator company to send a licensed elevator man to take a look at this thing.
Did anyone seek medical attention? Not sure about residential elevators but if there is an alleged injury on a commercial elevator, it should be locked and tagged for a State Elevator Inspector to inspect before it is moved, worked on, or (in worst case) put back in service. He will try and determine if the negligence was on the part of the people riding (highest probably in this case), the elevator malfunctioning, the building owner and/or the elevator maintenance company - if there is one.